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1
Sun, Haipeng. "Regulation of Cyclooxygenase Gene Expression by Glucocorticoids in Cardiomyocytes." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/194896.
Full textAbstract:
Glucocorticoids (GCs) are endogenous steroid hormones that regulate a number of critical physiological processes. Psychological stress increases the level of GCs in the circulating system. The biological effect of elevated GCs on the heart is not well understood. We found that GCs induced Cyclooxygenase-1 (COX-1) and COX-2 gene expression in cardiomyocytes. COX-1 or COX-2 encodes the rate-limiting enzyme in the biosynthesis of prostanoids, which modulate crucial physiological and pathophysiological responses. The present studies aim to elucidate the signaling transduction pathway and the mechanism underlying GC induced COX expression.Our data demonstrate that GCs activate COX-1 gene expression through transcriptional regulation. COX-1 gene promoter studies support a role of Sp binding site in CT induced COX-1 gene expression. The nuclear protein binding to this site appears to be Sp3 transcription factor. Co-immunoprecipitation assays indicated a physical interaction between GR and Sp3 protein. Silencing of Sp3 transcription factor with small interfering RNA suppressed CT-induced COX-1 promoter activation. These data suggest that the activated GR interacts with Sp3 transcription factor that binds to COX-1 promoter to up-regulate COX-1 gene expression in cardiomyocytes.We also found that administration of GC in adult mice increased the level of COX-2 in the ventricles. With isolated neonatal cardiomyocytes, corticosterone (CT) induces the transcription of COX-2 gene. This response appears to be cardiomyocyte cell type specific and GC receptor (GR)-dependent. CT causes activation of p38 MAPK and subsequently CREB phosphorylation that mediates COX-2 gene expression. Mifepristone, a GR antagonist, failed to inhibit p38 and CREB activation and p38 inhibition failed to prevent activation of GR. These data suggest that two parallel signaling pathways, GR and p38 MAPK, act in concert to regulate the expression of COX-2 gene in cardiomyocytes.In addition to the investigation of mechanism and signaling transduction pathway, I have explored pharmacological agents that modulate COX expression. LY294002, a commonly used PI3K inhibitor, inhibited COX-2 gene expression via a PI3K-independent mechanism. Whereas GSK-3 inhibitors, such as lithium chloride, upregulated COX-2 gene expression, but suppressed GC-induced COX-1 expression. These data have paved the foundation for pharmacological manipulation of COX-1 and COX-2 gene expression in the heart.
2
Tarantino, E. "THE ROLE OF CYCLOOXYGENASE-1 (COX-1) AND CYCLOOXYGENASE-2 (COX-2) IN A VENOUS THROMBOSIS MOUSE MODEL." Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/353697.
Full textAbstract:
Background: Deep vein thrombosis (DVT) is a serious national health problem, and pulmonary thromboembolism (PE) represents the life-threatening most common complication. Venous thromboembolism (VTE), including both these conditions, is traditionally treated with anticoagulant drugs. In particular, vitamin K antagonists and heparins are usually used in the reduction of thrombus development and in secondary prevention. However, the use of these drugs has several limitations: wide variability dose/response relationship between patients and in the same patient, multiple interactions with other drugs/foods, variability of daily doses, need of periodic withdrawals of blood during therapy, problems of overdosing. Then, the discovery of new drugs for VTE needs.
The cyclooxygenase isoenzymes, COX-1 and COX-2, catalyse the formation of prostaglandins and, thromboxane from arachidonic acid, and play a critical role in thrombosis. Recent meta-analysis suggests that low-dose aspirin (ASA) reduces the rate of VTE recurrence. In contrast, the clinical use of COX-2 inhibitors seems associated with increased risk of venous thrombosis. However, the role of COX-1 and COX-2 in venous thrombosis remain unclear.
Aim: We investigated the impact of COX-1 and COX-2 enzymes in venous thrombosis in order to identify the molecular mechanisms responsible for this effect and develop new therapeutic strategies to prevent venous thrombosis. In particular, we focused on the impact of inhibition of COX-pathway on leukocyte activation, important regulators of formation and propagation of venous thrombus.
Methods and Results: Using in vivo and in vitro approaches, we provide evidence that:
a) thromboxane, produced by platelets, triggers activation of leukocytes, with consequent development and propagation of venous thrombus induced by inferior vena cava ligation. In particular, we showed that ASA, by inhibiting irreversibly platelet COX-1, prevents platelet thromboxane production resulting in decreased venous thrombosis.
b) COX-2 deletion induces platelet hyper-activity and hyper-coagulation state, associated with a reduced fibrinolysis and formation of bigger thrombi. In this scenario, the high levels of tissue factor observed in leukocytes of COX-2KO mouse may explain the positive association observed between administration of COX-2 inhibitors and VTE. Thanking advantage of an accurate, and clinically relevant, technique such as ultrasonography, we are setting a method helpful to monitor thrombus growing and to better understand the pathophysiology of venous thromboembolism.
Conclusion: In conclusion, data obtained show that the inhibition of COX-1 and COX-2 in a venous thrombosis mouse model could lead to opposite effect on the thrombus development, stabilization and resolution. In particular, COX-1 inhibition is responsible of an impairment development and growth of venous thrombus, with a mechanism most likely dependent of TXA2/TP pathway. In contrast, COX-2 inhibition caused an increased in thrombus development, growing accompanied with reduction in the thrombus resolution. All data obtained support evidences that both COX-1 and COX-2 play a key role in DVT, opening the way to novel therapeutic approaches.
3
Hunter, John Cameron. "Multiple Recoding Mechanisms Produce Cyclooxygenase and Cyclooxygenase-Related Proteins from Frameshift-Containing COX-3/COX-1b Transcripts in Rat and Human." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/6149.
Full textAbstract:
To increase diversity of enzymes and proteins, cells mix and match exonic and intronic regions retained in mature mRNAs by alternative splicing. An estimated 94% of all multi-exon genes express one or more alternatively spliced transcripts generating proteins with similar or modified functions. Cyclooxygenase is a signaling enzyme that catalyzes the rate-limiting step in the synthesis of diverse bioactive lipids termed prostaglandins. Prostaglandins are involved in myriad physiological and pathopysiological processes including vasoregulation, stomach mucosal maintenance, parturition, pain, fever, inflammation, neoplasia and angiogenesis and are inhibited by aspirin-like drugs known as NSAIDs. In 2002 an alternatively spliced, intron-1 retaining variant of COX-1 was cloned from canine brain tissue. This new variant, termed COX-3 or COX-1b, is an enzymatically active prostaglandin synthase expressed at relatively high levels in a tissue and cell type dependant manner in all species examined. In humans and most rodent species intron-1 is 94 and 98 nucleotides long respectively. Retention of the intron in these species introduces a frameshift and is predicted to result in translation of a very small 8-16kD protein with little similarity to either 72kD COX-1 or COX-2, calling into question the role of this variant. In this dissertation, I present my results from cloning and ectopically expressing a complete and accurate COX-3 cDNA from both rat and human. I confirmed that COX-3 mRNA encodes multiple large molecular weight cyclooxygenase-like proteins in the same reading frame as COX-1. Translation of these proteins relies on several recoding mechanisms including cap-independent translation initiation, alternative start site selection, and ribosomal frameshifting. Using siRNA and Western blotting I have identified some of these proteins in tissues and cells. Two COX-3 encoded proteins are active prostaglandin synthase enzymes with activities similar to COX-1 and represent novel targets of NSAIDs. Other COX-3 proteins have unknown function, but their size and cellular location suggest potential roles as diverse as cytosolic enzymes and nuclear factors.
4
Chen, Suzi Su-Hsin, and suzi chen@med monash edu au. "Cyclooxygenase Expression in Human Diabetes." RMIT University. Medical Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080206.121439.
Full textAbstract:
Cyclooxygenase (COX) is the rate limiting enzyme that catalyses the production of prostanoids, which are crucial to vascular homeostasis. Evidence suggests that endothelial dysfunction and inflammation play a role in vascular complications in aging and diabetes. Previous animal studies by our laboratory at RMIT University reported enhanced COX expression with aging in rat aortas, platelets and monocytes. Potentially, alteration in COX expression may result in an imbalanced prostanoid production favoring the synthesis of vasoconstrictors and hence increase the risk of cardiovascular events in the aging population. The regulation of altered COX expression in aging, however, is not clear. It has been suggested that histone hyperacetylation may be an important mechanism that regulates COX levels during the aging process as increased histone acetylation has been shown to occur with aging. Thus, we hypothesized that COX expression is modulated by histone hyperacetylati on. This was investigated by measuring COX expression in histone hyperacetylated cultured endothelial cells. In the case of diabetes, studies have reported that the development of diabetes and its complications is associated with persistent inflammatory activity, evident with increased inflammatory markers in the circulation. COX-mediated pathways may be involved in this inflammatory process in diabetes. Furthermore, the formation of advanced glycation end products (AGEs) is accelerated in diabetes. AGEs can bind to receptors for AGEs (RAGE), which has also been suggested to play a role in inflammation in diabetes. We hypothesized that COX- and RAGE-mediated pathways contribute to increased inflammation in diabetes and potentiate the development of diabetic vascular complications. This was investigated by measuring changes in COX-mediated pathways in both rat and human diabetic models. The current thesis reports: 1) in cultured endothelial cells, histone hyperacetylation was associated with increased COX expression; 2) an overall increase in inflammation was observed in diabetes involving COX- and RAGE-mediated pathways. This was supported by increased platelet COX-1 and monocyte COX-2 levels in Zucker rats, increased monocyte COX-2 in human Type 1 diabetes and elevated plasma TXB2 and PGE2 levels in both human Type 1 and Type 2 diabetic subjects. Up-regulation of RAGE expression was further found in platelets and monocytes in both human diabetes types. When treated with NSAIDs, plasma prostanoid levels, COX and RAGE expression were reduced significantly in both platelets and monocytes in human diabetic subjects. 3) It is unclear how COX and RAGE expression was regulated, but histone modifications may be one of the mechanisms. Data from cultured cells indicated that increased COX expression was associated with increased histone acetylation levels induced by TSA. Concurrent increases in histone acetylation and COX-2 levels were also observed in human Type 1 diabetes, but similar findings were not observed in human Type 2 diabetes. In addition, we failed to find an age-dependent increase in monocyte histone H4 acetylation in human Type 2 diabetes despite an age-dependent increase in monocyte COX-2 expression. Thus, whether histone hyperacetylation modulates COX expression and in what conditions require further investigation.
5
Kellogg, Aaron. "Effect of Cyclooxygenase (COX)-2 Activation on Diabetic Neuropathy." University of Toledo Health Science Campus / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=mco1211909697.
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6
Bühler, Nico Martin. "Selektive COX-2 Inhibitoren und Nierenschädigung bei salzsensitiver Hypertonie /." [S.l.] : [s.n.], 2009. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000297941.
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7
Kim, Janet Heejung. "Cyclooxygenase-2 Expression in Post-Mastectomy Chest Wall Relapse." Yale University, 2006. http://ymtdl.med.yale.edu/theses/available/etd-06282006-104942/.
Full textAbstract:
The purpose of this study was to assess the prognostic significance and clinical correlations of cyclooxgenase-2 expression (COX) in a cohort of patients treated with radiation (RT) for post-mastectomy chest wall relapse (PMCWR). Between 1975 and 1999, 113 patients were treated for isolated PMCWR. All patients were treated with biopsy and/or excision of the CWR followed by RT. Median follow-up was 10 years. All clinical data including demographics, pathology, staging, receptor status, HER-2/neu status, and adjuvant therapy were entered into a computerized database. Paraffin-embedded CWR specimens were retrieved from 42 patients, of which 38 were evaluated, created into a tissue microarray, stained by immunohistochemical methods for COX, and graded 0-3+. A score of 2-3+ was considered positive. Overall survival from original diagnosis for the entire cohort was 44% at 10 years. Survival rate after chest wall recurrence was 28% at 10 years. The distant metastasis-free survival rate after CWR was 40% at 10 years. Local-regional control of disease was achieved in 79% at 10 years after CWR. COX was considered positive in 13 of 38 cases. COX was inversely correlated with ER (p= .045) and PR (p = .028), and positively correlated with HER-2/neu (p =.003). COX was also associated with a shorter time to PMCWR. The distant metastasis-free rate for COX negative patients was 70% at 10 years, compared with 31% at 10 years for COX-2 positive patients (p = 0.029). COX positive had a poorer local-regional progression-free rate of 19% at 10 years, compared with 81% at 10 years for COX negative (p = 0.003). Outcome following RT for PMCWR is relatively poor. Positive COX correlated with other markers of poor outcome including a shorter time to local relapse, negative ER/PR and positive Her-2/neu status. Positive COX correlated with higher distant metastasis and lower local-regional control of disease. If confirmed with larger studies, these data have implications with respect to the concurrent use of COX-2 inhibitors and radiation for PMCWR.
8
Vijitruth, Rattanavijit. "ROLES OF CYCLOOXYGENASE-2 IN MICROGLIAL ACTIVATION AND DOPAMINERGIC CELL DEATH." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_diss/237.
Full textAbstract:
Accumulating evidence suggests that inflammation plays an important role in the progression ofParkinson's disease (PD). Among many inflammatory factors found in the PD brain, cyclooxygenase(COX), especially the inducible isoform, COX-2, is believed to be the critical enzyme in theinflammatory response. Induction of COX-2 is also found in an experimental model of PD producedby administration of 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). To investigate whetherinhibition of COX-2 by valdecoxib or deficiency in COX-2 could prevent dopaminergic neuronaltoxicity and locomotor activity impairment, we injected MPTP into valdecoxib-treated C57BL/6N miceand COX-2 deficient mice, respectively. Both automated total distance and vertical activitymeasurements of the open-field test were significantly reduced in the vehicle-treated mice at two weekspost-MPTP injection. In contrast, valdecoxib treatment significantly attenuated these deficits.Similarly, COX-2 deficiency attenuated MPTP-induced loss of coordination on a rotarod assay.Valdecoxib or deficiency of COX-2 reduced microglial activation while preventing loss of tyrosinehydroxylase (TH)-positive neurons in the substantia nigra pars compacta (SNpc). The total number ofactivated microglia in the SNpc had a strong positive correlation with the level of COX-2 anddopaminergic neurodegeneration. The results of this study indicate that reducing the activity of COX-2can mitigate the progressive loss of dopaminergic neurons as well as the motor deficits caused byMPTP neurotoxicity, possibly by suppressing the activation of microglia in the SNpc.
9
Mukherjee, Kamalika. "ROLE OF CYCLOOXYGENASE-2 IN ABDOMINAL AORTIC ANEURYSMS IN MICE." UKnowledge, 2012. http://uknowledge.uky.edu/pharmacy_etds/29.
Full textAbstract:
Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease with no available pharmacological treatment. AAA formation reduces the structural integrity of the vessel and increases the susceptibility to rupture. The inflammatory response within human aneurysmal tissue is characterized by increased expression of cyclooxygenase-2 (COX-2). Similarly, in a mouse model of the disease induced by chronic Angiotensin II (AngII) infusion, we have shown that COX-2 expression in the abdominal aortic smooth muscle layer increases early in the development of the disease. Furthermore, genetic or pharmacological inactivation of COX-2 prior to disease initiation reduces AAA incidence.
The current study utilized nonhyperlipidemic mice to determine the effectiveness of COX-2 inhibition initiated after AAA formation. COX-2 inhibitor treatment was initiated 5 days after beginning the AngII infusion, a time-point where significant aneurysmal pathology is observed. COX-2 inhibition with celecoxib significantly reduced the incidence as well as severity of AAAs as compared to the control group. Celecoxib treatment also protected the mice from aortic rupture and death. AAA development is characterized by degradation of the aortic smooth muscle layer with loss of the contractile phenotype. We found that the effectiveness of celecoxib was associated with significantly increased mRNA expression of alpha-actin, SM22alpha and desmin, all of which are markers of a differentiated smooth muscle cell phenotype. Celecoxib treatment also decreased mRNA expression of a marker of dedifferentiated smooth muscle (hyaluronic acid synthase 2). We also examined the role of altered expression of COX-2 in the increased susceptibility of the abdominal segment to AAA formation. We found a prolonged and greater induction of COX-2 in the abdominal aortic smooth muscle layer in contrast to a transient induction of COX-2 in the other regions of the aorta throughout disease progression. Overall, these findings suggest that COX-2 plays an important role in AAA development in mice, and COX-2 inhibition with celecoxib attenuates progression of aneurysm development by maintaining a differentiated phenotype in abdominal aortic smooth muscle cells.
10
Kim, Youngsoo. "Molecular characterization of cyclooxygenase-2 (COX-2) expression in murine skin carcinoma cells /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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11
Huang, Hai. "The role of cyclooxygenase gene in liver inflammation using COX-1 knockout mice /." View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36396539.
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12
Strillacci, Antonio <1979>. "RNA Interference and cyclooxygenase-2 (COX-2) regulation in colon cancer cells." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/680/1/Tesi_Strillacci_Antonio.pdf.
Full textAbstract:
Despite new methods and combined strategies, conventional cancer chemotherapy still lacks
specificity and induces drug resistance. Gene therapy can offer the potential to obtain the success in
the clinical treatment of cancer and this can be achieved by replacing mutated tumour suppressor
genes, inhibiting gene transcription, introducing new genes encoding for therapeutic products, or
specifically silencing any given target gene. Concerning gene silencing, attention has recently
shifted onto the RNA interference (RNAi) phenomenon. Gene silencing mediated by RNAi
machinery is based on short RNA molecules, small interfering RNAs (siRNAs) and microRNAs
(miRNAs), that are fully o partially homologous to the mRNA of the genes being silenced,
respectively. On one hand, synthetic siRNAs appear as an important research tool to understand the
function of a gene and the prospect of using siRNAs as potent and specific inhibitors of any target
gene provides a new therapeutical approach for many untreatable diseases, particularly cancer. On
the other hand, the discovery of the gene regulatory pathways mediated by miRNAs, offered to the
research community new important perspectives for the comprehension of the physiological and,
above all, the pathological mechanisms underlying the gene regulation. Indeed, changes in miRNAs
expression have been identified in several types of neoplasia and it has also been proposed that the
overexpression of genes in cancer cells may be due to the disruption of a control network in which
relevant miRNA are implicated. For these reasons, I focused my research on a possible link
between RNAi and the enzyme cyclooxygenase-2 (COX-2) in the field of colorectal cancer (CRC),
since it has been established that the transition adenoma-adenocarcinoma and the progression of
CRC depend on aberrant constitutive expression of COX-2 gene. In fact, overexpressed COX-2 is
involved in the block of apoptosis, the stimulation of tumor-angiogenesis and promotes cell
invasion, tumour growth and metastatization.
On the basis of data reported in the literature, the first aim of my research was to develop an
innovative and effective tool, based on the RNAi mechanism, able to silence strongly and
specifically COX-2 expression in human colorectal cancer cell lines. In this study, I firstly show
that an siRNA sequence directed against COX-2 mRNA (siCOX-2), potently downregulated COX-2
gene expression in human umbilical vein endothelial cells (HUVEC) and inhibited PMA-induced
angiogenesis in vitro in a specific, non-toxic manner. Moreover, I found that the insertion of a
specific cassette carrying anti-COX-2 shRNA sequence (shCOX-2, the precursor of siCOX-2
previously tested) into a viral vector (pSUPER.retro) greatly increased silencing potency in a colon
cancer cell line (HT-29) without activating any interferon response. Phenotypically, COX-2
deficient HT-29 cells showed a significant impairment of their in vitro malignant behaviour. Thus,
results reported here indicate an easy-to-use, powerful and high selective virus-based method to
knockdown COX-2 gene in a stable and long-lasting manner, in colon cancer cells. Furthermore,
they open up the possibility of an in vivo application of this anti-COX-2 retroviral vector, as
therapeutic agent for human cancers overexpressing COX-2.
In order to improve the tumour selectivity, pSUPER.retro vector was modified for the shCOX-2
expression cassette. The aim was to obtain a strong, specific transcription of shCOX-2 followed by
COX-2 silencing mediated by siCOX-2 only in cancer cells. For this reason, H1 promoter in basic
pSUPER.retro vector [pS(H1)] was substituted with the human Cox-2 promoter [pS(COX2)] and
with a promoter containing repeated copies of the TCF binding element (TBE) [pS(TBE)]. These
promoters were choosen because they are partculary activated in colon cancer cells. COX-2 was
effectively silenced in HT-29 and HCA-7 colon cancer cells by using enhanced pS(COX2) and
pS(TBE) vectors. In particular, an higher siCOX-2 production followed by a stronger inhibition of
Cox-2 gene were achieved by using pS(TBE) vector, that represents not only the most effective, but
also the most specific system to downregulate COX-2 in colon cancer cells.
Because of the many limits that a retroviral therapy could have in a possible in vivo treatment of
CRC, the next goal was to render the enhanced RNAi-mediate COX-2 silencing more suitable for
this kind of application. Xiang and et al. (2006) demonstrated that it is possible to induce RNAi in
mammalian cells after infection with engineered E. Coli strains expressing Inv and HlyA genes,
which encode for two bacterial factors needed for successful transfer of shRNA in mammalian
cells. This system, called “trans-kingdom” RNAi (tkRNAi) could represent an optimal approach for
the treatment of colorectal cancer, since E. Coli in normally resident in human intestinal flora and
could easily vehicled to the tumor tissue. For this reason, I tested the improved COX-2 silencing
mediated by pS(COX2) and pS(TBE) vectors by using tkRNAi system. Results obtained in HT-29
and HCA-7 cell lines were in high agreement with data previously collected after the transfection of
pS(COX2) and pS(TBE) vectors in the same cell lines. These findings suggest that tkRNAi system
for COX-2 silencing, in particular mediated by pS(TBE) vector, could represent a promising tool
for the treatment of colorectal cancer.
Flanking the studies addressed to the setting-up of a RNAi-mediated therapeutical strategy, I
proposed to get ahead with the comprehension of new molecular basis of human colorectal cancer.
In particular, it is known that components of the miRNA/RNAi pathway may be altered during the
progressive development of colorectal cancer (CRC), and it has been already demonstrated that
some miRNAs work as tumor suppressors or oncomiRs in colon cancer. Thus, my hypothesis was
that overexpressed COX-2 protein in colon cancer could be the result of decreased levels of one or
more tumor suppressor miRNAs.
In this thesis, I clearly show an inverse correlation between COX-2 expression and the human miR-
101(1) levels in colon cancer cell lines, tissues and metastases. I also demonstrate that the in vitro
modulating of miR-101(1) expression in colon cancer cell lines leads to significant variations in
COX-2 expression, and this phenomenon is based on a direct interaction between miR-101(1) and
COX-2 mRNA. Moreover, I started to investigate miR-101(1) regulation in the hypoxic
environment since adaptation to hypoxia is critical for tumor cell growth and survival and it is
known that COX-2 can be induced directly by hypoxia-inducible factor 1 (HIF-1). Surprisingly, I
observed that COX-2 overexpression induced by hypoxia is always coupled to a significant
decrease of miR-101(1) levels in colon cancer cell lines, suggesting that miR-101(1) regulation
could be involved in the adaption of cancer cells to the hypoxic environment that strongly
characterize CRC tissues.
13
Strillacci, Antonio <1979>. "RNA Interference and cyclooxygenase-2 (COX-2) regulation in colon cancer cells." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/680/.
Full textAbstract:
Despite new methods and combined strategies, conventional cancer chemotherapy still lacks
specificity and induces drug resistance. Gene therapy can offer the potential to obtain the success in
the clinical treatment of cancer and this can be achieved by replacing mutated tumour suppressor
genes, inhibiting gene transcription, introducing new genes encoding for therapeutic products, or
specifically silencing any given target gene. Concerning gene silencing, attention has recently
shifted onto the RNA interference (RNAi) phenomenon. Gene silencing mediated by RNAi
machinery is based on short RNA molecules, small interfering RNAs (siRNAs) and microRNAs
(miRNAs), that are fully o partially homologous to the mRNA of the genes being silenced,
respectively. On one hand, synthetic siRNAs appear as an important research tool to understand the
function of a gene and the prospect of using siRNAs as potent and specific inhibitors of any target
gene provides a new therapeutical approach for many untreatable diseases, particularly cancer. On
the other hand, the discovery of the gene regulatory pathways mediated by miRNAs, offered to the
research community new important perspectives for the comprehension of the physiological and,
above all, the pathological mechanisms underlying the gene regulation. Indeed, changes in miRNAs
expression have been identified in several types of neoplasia and it has also been proposed that the
overexpression of genes in cancer cells may be due to the disruption of a control network in which
relevant miRNA are implicated. For these reasons, I focused my research on a possible link
between RNAi and the enzyme cyclooxygenase-2 (COX-2) in the field of colorectal cancer (CRC),
since it has been established that the transition adenoma-adenocarcinoma and the progression of
CRC depend on aberrant constitutive expression of COX-2 gene. In fact, overexpressed COX-2 is
involved in the block of apoptosis, the stimulation of tumor-angiogenesis and promotes cell
invasion, tumour growth and metastatization.
On the basis of data reported in the literature, the first aim of my research was to develop an
innovative and effective tool, based on the RNAi mechanism, able to silence strongly and
specifically COX-2 expression in human colorectal cancer cell lines. In this study, I firstly show
that an siRNA sequence directed against COX-2 mRNA (siCOX-2), potently downregulated COX-2
gene expression in human umbilical vein endothelial cells (HUVEC) and inhibited PMA-induced
angiogenesis in vitro in a specific, non-toxic manner. Moreover, I found that the insertion of a
specific cassette carrying anti-COX-2 shRNA sequence (shCOX-2, the precursor of siCOX-2
previously tested) into a viral vector (pSUPER.retro) greatly increased silencing potency in a colon
cancer cell line (HT-29) without activating any interferon response. Phenotypically, COX-2
deficient HT-29 cells showed a significant impairment of their in vitro malignant behaviour. Thus,
results reported here indicate an easy-to-use, powerful and high selective virus-based method to
knockdown COX-2 gene in a stable and long-lasting manner, in colon cancer cells. Furthermore,
they open up the possibility of an in vivo application of this anti-COX-2 retroviral vector, as
therapeutic agent for human cancers overexpressing COX-2.
In order to improve the tumour selectivity, pSUPER.retro vector was modified for the shCOX-2
expression cassette. The aim was to obtain a strong, specific transcription of shCOX-2 followed by
COX-2 silencing mediated by siCOX-2 only in cancer cells. For this reason, H1 promoter in basic
pSUPER.retro vector [pS(H1)] was substituted with the human Cox-2 promoter [pS(COX2)] and
with a promoter containing repeated copies of the TCF binding element (TBE) [pS(TBE)]. These
promoters were choosen because they are partculary activated in colon cancer cells. COX-2 was
effectively silenced in HT-29 and HCA-7 colon cancer cells by using enhanced pS(COX2) and
pS(TBE) vectors. In particular, an higher siCOX-2 production followed by a stronger inhibition of
Cox-2 gene were achieved by using pS(TBE) vector, that represents not only the most effective, but
also the most specific system to downregulate COX-2 in colon cancer cells.
Because of the many limits that a retroviral therapy could have in a possible in vivo treatment of
CRC, the next goal was to render the enhanced RNAi-mediate COX-2 silencing more suitable for
this kind of application. Xiang and et al. (2006) demonstrated that it is possible to induce RNAi in
mammalian cells after infection with engineered E. Coli strains expressing Inv and HlyA genes,
which encode for two bacterial factors needed for successful transfer of shRNA in mammalian
cells. This system, called “trans-kingdom” RNAi (tkRNAi) could represent an optimal approach for
the treatment of colorectal cancer, since E. Coli in normally resident in human intestinal flora and
could easily vehicled to the tumor tissue. For this reason, I tested the improved COX-2 silencing
mediated by pS(COX2) and pS(TBE) vectors by using tkRNAi system. Results obtained in HT-29
and HCA-7 cell lines were in high agreement with data previously collected after the transfection of
pS(COX2) and pS(TBE) vectors in the same cell lines. These findings suggest that tkRNAi system
for COX-2 silencing, in particular mediated by pS(TBE) vector, could represent a promising tool
for the treatment of colorectal cancer.
Flanking the studies addressed to the setting-up of a RNAi-mediated therapeutical strategy, I
proposed to get ahead with the comprehension of new molecular basis of human colorectal cancer.
In particular, it is known that components of the miRNA/RNAi pathway may be altered during the
progressive development of colorectal cancer (CRC), and it has been already demonstrated that
some miRNAs work as tumor suppressors or oncomiRs in colon cancer. Thus, my hypothesis was
that overexpressed COX-2 protein in colon cancer could be the result of decreased levels of one or
more tumor suppressor miRNAs.
In this thesis, I clearly show an inverse correlation between COX-2 expression and the human miR-
101(1) levels in colon cancer cell lines, tissues and metastases. I also demonstrate that the in vitro
modulating of miR-101(1) expression in colon cancer cell lines leads to significant variations in
COX-2 expression, and this phenomenon is based on a direct interaction between miR-101(1) and
COX-2 mRNA. Moreover, I started to investigate miR-101(1) regulation in the hypoxic
environment since adaptation to hypoxia is critical for tumor cell growth and survival and it is
known that COX-2 can be induced directly by hypoxia-inducible factor 1 (HIF-1). Surprisingly, I
observed that COX-2 overexpression induced by hypoxia is always coupled to a significant
decrease of miR-101(1) levels in colon cancer cell lines, suggesting that miR-101(1) regulation
could be involved in the adaption of cancer cells to the hypoxic environment that strongly
characterize CRC tissues.
14
Huang, Hai, and 黃海. "The role of cyclooxygenase gene in liver inflammation using COX-1 knockout mice." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B45010699.
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15
Hurst, Emma Allan. "Identification and characterisation of the role of cyclooxygenase-2 (COX-2) in cancer stem cell biology : a comparative study." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28852.
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Cancer is a stem cell disease and populations of cancer stem cells (CSCs) are evident in many cancer types. CSCs exhibit similarities to normal embryonic and adult stem cells: they are able to self-renew and have the potential to give rise to a diverse array of differentiated progeny. CSCs are responsible for driving tumourigenesis and metastasis, and are inherently resistant to chemotherapy and radiotherapy. This cell population is enriched after treatment and, as a result of their tumourigenic capability, can re-populate tumour growth resulting in patient relapse, often with increased chemotherapeutic resistance. Increasing evidence supports that only by targeting this population of cells will a cure for cancer be possible. Hence, it is essential to identify pathways within CSC populations that can be targeted therapeutically. Cyclooxygenase-2 (COX-2) is an enzyme associated with inflammation and disease, and is upregulated in many cancers types. The COX-2 / prostaglandin E2 (PGE2) signalling pathway is associated with increased tumour growth, metastasis, immune evasion and overall worse patient prognosis. Recent evidence has identified that COX-2 is further upregulated in CSC populations isolated from cancer cell lines. Previously, we have shown that inhibition of COX-2 reduces CSC sphere-forming ability, a characteristic of stem cell self-renewal, suggesting a role for COX-2 in maintaining CSC populations. This work was carried out in both human and canine osteosarcoma cell lines with similar results. Cancer in dogs is a major health concern among an aging pet population. Many cancer types exhibit similarities between these species, suggesting that naturally occurring canine cancer may be a potential model for the human disease. The aim of this PhD project was to investigate the role of COX-2 in CSCs in a comparative cancer study. CSCs that express stem cell markers have been isolated from a panel of canine and human cancer cell lines including, mammary carcinoma and transitional cell carcinoma of the urinary bladder. CSCs over-express COX-2 compared to non-CSCs, therefore to determine the role of COX-2 in CSC biology the selective COX-2 inhibitor mavacoxib, a non-steroidal anti-inflammatory drug currently licenced for treating osteoarthritis in dogs, was utilised. Our results demonstrate that inhibiting COX-2 has a multifaceted impact on CSC biology, including reducing self-renewal capacity, clonogenicity, proliferation, migration, invasion and in vivo tumourigenicity. To confirm that mavacoxib is mediating these CSC-specific effects via inhibition of COX-2 rather than through unknown off-target effects, we generated canine specific-small interfering RNA to specifically reduce gene expression of COX-2. Our results confirm that mavacoxib exerts its anti-tumour effects via inhibition of COX-2. This project has highlighted a plethora of CSC-specific COX-2 effects, and to gain further insight we compared the global gene expression profiles of CSCs compared to non- CSCs isolated from a canine bladder carcinoma cell line. This data revealed that both mavacoxib and COX-2 specific siRNA target similar pathways within the two cell populations, confirming that mavacoxib exerts its effects in a COX-2 dependent manner. Interestingly, mavacoxib reduced the expression of a number of stemness related genes in the CSC population, including NOTCH and Wnt, suggesting that mavacoxib can inhibit CSC related pathways. Our overall results are comparable between canine and human cancer cell lines supporting the concept of naturally occurring tumours in dogs as models for the human disease. In conclusion, COX-2 plays an important role not only in maintaining CSC populations but also in their function, and targeting COX-2 in CSCs may provide therapeutic benefit.
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Fürstenberg, Antje. "Einfluß des Cyclooxygenase-2-Inhibitors NS-398 auf Proliferation und Apoptose von Ovarialkarzinomzellinien." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2005. http://dx.doi.org/10.18452/15175.
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Mehrere Studien haben gezeigt, daß die Cyclooxygenase-2 (COX-2) eine bedeutende Rolle sowohl bei Entstehung als auch Progression maligner Tumoren spielt. COX-2-Inhibitoren werden bereits in klinischen Studien zur Krebstherapie getestet. COX-2 ist die induzierbare Isoform der Cyclooxygenase - dem Schlüsselenzym der Synthese von Prostaglandinen und anderen Eicosanoiden. Im Tier- und Zellkulturmodell konnten COX-Hemmer anti-Tumor-Effekte hervorrufen. Es ist jedoch unklar, ob diese Effekte durch Hemmung des COX-Enzyms oder durch COX-unabhängige Mechanismen vermittelt werden. Wir untersuchten daher die Auswirkung der COX-Inhibition zum einen durch den selektiven COX-2-Hemmer NS-398 sowie zum anderen durch COX-Isoform-spezifische RNA-Interferenz (RNAi) in zwei humanen Ovarialkarzinomzellinien (OVCAR-3 und SKOV-3). OVCAR-3 zeigte eine konstitutive COX-1-Expression und eine durch IL-1beta induzierbare COX-2-Expression. SKOV-3 war COX-1- und COX-2-negativ. IL-1beta führte bei OVCAR-3 zu einer vermehrten Produktion von Prostaglandin E2 (PGE2), die durch eine gegen die COX-2 gerichtete siRNA gehemmt werden konnte, wohingegen COX-1-siRNA keinen Effekt hatte. Das deutet darauf hin, daß die COX-2 die Hauptquelle von PGE2 in OVCAR-3 ist. 1mikroM NS-398 waren ausreichend, um die PGE2-Produktion und somit auch die COX-2 in OVCAR-3 zu inhibieren. Höhere Konzentrationen NS-398 (>10mikroM) hatten einen antiproliferativen Effekt. Auch in der COX-2-negativen Zellinie SKOV-3 trat diese Wachstumshemmung auf; sie war nicht durch exogene Zufuhr von PGE2 (10mikroM) reversibel. Durchflußzytometrische Zellzyklusanalyse ergab, daß der Wachstumshemmung in beiden Zellinien ein G0/G1-Zellzyklusarrest zugrunde liegt. Dagegen führten weder COX-1- noch COX-2-Ausschaltung durch RNAi zu ähnlichen Auswirkungen auf Proliferation bzw. Zellzyklus. Diese Ergebnisse zeigen, dass ein COX-2-unabhängiger Mechanismus für den durch NS-398 induzierten G0/G1-Arrest verantwortlich ist.Several studies have provided evidence that the enzyme Cyclooxygenase-2 (COX-2) plays an important role in tumor development and progression. COX-2-inhibitors are already evaluated in clinical trials as cancer therapeutics. COX-2 is the inducible isoform of cyclooxygenase - the rate-limiting enzyme in the synthesis of prostaglandins and other eicosanoids. COX-inhibitors cause antitumor effects in animal models and in cell culture experiments. However, it is not clear, whether these effects are due to inhibition of the COX-enzyme or mediated via a COX-independent mechanism. We therefore investigated the effects of COX inhibition by the selective COX-2-inhibitor NS-398, as well as by COX-isoform specific RNA interference (RNAi) in the human ovarian carcinoma cell lines OVCAR-3 and SKOV-3. OVCAR-3 cells showed a constitutive expression of COX-1, and an inducible COX-2 expression. COX-2 was induced through stimulation with Interleukin-1beta, leading to production of high levels of Prostaglandin E2 (PGE2). SKOV-3 cells were negative for both COX isoforms. Selective COX-2-suppression by RNAi reduced PGE2 production in OVCAR-3, whereas COX-1-siRNA had no effect on PGE2 synthesis. Thus, COX-2 is the main source of PGE2 in OVCAR-3 cells. In these cells, 1microM NS-398 was sufficient to completely inhibit PGE2-synthesis - and thus the activity of the COX-2 enzyme. Increasing amounts of NS-398 (>10microM) had an antiproliferative effect. This growth inhibition was also observed in the COX-negative cell line SKOV-3, it could not be reverted by exogenous addition of PGE2 (10microM). Flowcytometric analysis of the cell cycle revealed that this growth inhibition was based on a G0/G1-cell-cycle-arrest. In contrast, suppression of COX-1 or COX-2 by RNAi had no effect on proliferation or cell cycle progression. These results suggest that a COX-independent mechanism is responsible for the G0/G1-arrest induced by NS-398.
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Wang, Xingya. "The distinct role of cyclooxygenase-2 in prostate and bladder carcinogenesis." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1180488733.
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Fredericks, Ernst. "Molecular signaling in colorectal carcinogenesis : the roles and relationships of beta-catenin, PPARgamma and COX-2." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1021014.
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Colorectal cancer (CRC) is a common disease with significant morbidity and mortality. In spite of significant advances in understanding the molecular signaling in this disorder, unanswered questions remain. Cyclooxygenase-2 (COX-2) and β-catenin have established roles in colorectal carcinogenesis, with both being upregulated early in the disease course. The role of peroxisome proliferator-activated receptor γ (PPARγ) is less clear, but has been shown to be downregulated in colon cancer models. Butyrate, a short chain fatty acid, produced by colon microbiota and transported into the colonocyte by transporter proteins, appears to be important in early carcinogenesis. The butyrate concentration is reduced in CRC and so are its transporters. Interleukin-17 (IL-17) plays a role in colitis-associated colorectal cancer (CAC), but its function in sporadic CRC is less clear. Similarly, Protein kinase C (PKC) has proven involvement in many solid tumours, including CRC, but its exact mechanistic role is still speculative. AIM: To investigate the role and possible signaling pathways of the major role players, β-catenin, COX-2 and PPARγ in early CRC. Further, to elucidate the mechanistic pathways of butyrate and its transporters, IL-17 and PKC in CRC. METHOD: Informed consent was obtained for all patients. Patients were recruited in various disease categories, including normal, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and CRC. Colon biopsy specimens were obtained during colonoscopy and used for immunohistochemistry (IHC) and gene expression analysis of the above genes by quantitative polymerase chain reaction (qPCR). RESULTS: β-catenin mRNA and protein expression was increased in CRC and the IBD groups compared to the normal group, while it was reduced in the IBS groups. COX-2 mRNA expression showed a steady increase from normal, through IBS, IBD and CRC groups to a statistically significant degree. The COX-2 protein expression, however, did not match the mRNA expression with increased COX-2 protein expression in normal and IBS groups and reduced expression in IBD and CRC groups. PPARγ mRNA expression was unchanged in IBD and CRC groups, but significantly increased in the IBS group compared to normal. Butyrate transporter, SLC16A1 mRNA was significantly reduced in CRC, but also in the IBS groups, which was unexpected. In the IBD group, SLC16A1 mRNA was unchanged in Crohn’s disease (CD) but significantly reduced in ulcerative colitis (UC). Similarly, SLC5A8 mRNA expression was significantly reduced in the CRC as well as the IBS groups. In the IBD groups, SLC5A8 was unchanged in UC but significantly increased in CD. IL-17 mRNA expression was significantly reduced in CRC and IBS groups, but unchanged in the IBD groups. PKCε mRNA was significantly increased in CRC as expected. In the IBD groups, PKCε mRNA was unchanged in CD but significantly increased in UC. In the IBS groups, PKCε mRNA in constipation –IBS (C-IBS) was significantly reduced, but unchanged in diarrhoea – IBS (D-IBS). CONCLUSIONS: β-catenin mRNA and protein expression was increased in CRC and the CRC promoting IBD groups. COX-2 protein expression was incongruent with the COX-2 mRNA expression and this may reflect homeostatic control mechanisms. High COX-2 mRNA expression in CRC and CRC promoting IBD groups may be a secondary phenomenon reflecting the inflammatory milieu, rather than a true carcinogenesis-related event. PPARγ does not appear to play a central role in early colon carcinogenesis, in spite of available literature suggesting otherwise. Butyrate transporters showed inconsistent results and for now no firm conclusions can be drawn from this. IL-17 may play a role in CAC as confirmed in this and other studies, but its role in sporadic CRC is tenuous and requires further investigation. Likewise for PKCε, upregulation is associated with increased tumourigenecity as shown in this study, however, the mechanistic pathway(s) involved is still speculative and requires further study.
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Abdalla, Salem Ishtiwi. "Cyclooxygenase-2 (cox-2) expression in Barrett's oesphageal epithelium : relationship to inflammation and cancer." Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418127.
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Gagnaire, Aurelie. "Rôle de la voie COX-2 au cours de l'infection par Brucella." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4054.
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Brucella est une bactérie intracellulaire facultative à Gram négatif responsable d’une zoonose, la brucellose. Pour persister dans l’organisme, Brucella agit comme un pathogène furtif en modulant la réponse immunitaire de l’hôte. La cyclooxygénase 2 (COX-2) est l’enzyme responsable de la synthèse des prostanoïdes, des médiateurs lipidiques dérivés de l’acide arachidonique (AA) présentant des propriétés immunorégulatrices. Cette thèse est centrée sur l’étude de cette voie métabolique au cours de l’infection par Brucella in vitro dans des cellules dendritiques (DC) humaines et murines ainsi qu’in vivo chez la souris en comparant différentes routes d’infection. Nous avons mis en évidence la capacité de l’infection à stimuler in vitro la production d’AA ainsi que l’expression de Ptgs2. In vivo, la comparaison des différentes routes d’inoculation a montré que l’infection intradermale induit une signature génique inflammatoire caractérisée par l’expression de Ptgs2 et d’Ifng. L’utilisation de NS-398, un inhibiteur spécifique de COX-2 stimule la clairance bactérienne dans les ganglions cervicaux (CLN) drainant le site d’infection. Ces résultats ouvrent ainsi la voie à de nouvelles stratégies thérapeutiques dans le traitement de la brucellose. La seconde partie de la thèse traite de l’implication des infections bactériennes dans l’initiation des processus oncogéniques. Nous y présentons une revue répertoriant l’ensemble des mécanismes pouvant contribuer à l’initiation oncogénique ainsi qu’un projet que nous développons au laboratoire portant sur l’initiation d’un lymphome folliculaire à la suite d’une stimulation antigénique chronique suite à l’infection par B. abortusBrucella is a facultative intracellular Gram-negative bacterium, responsible for a zoonosis called brucellosis. To persist into the host, Brucella acts as a stealthy pathogen by modulating the host immune response. The cyclooxygenase 2 (COX-2) is the enzyme responsible for the synthesis of prostanoids, a family of lipid mediators derived from the arachidonic acid (AA) and presenting immunomodulatory properties. Here, we have studied the impact of this pathway during Brucella infection in vitro in human and murine dendritic cells (DCs) as well as in vivo by comparing different infection routes. We have highlighted the ability of the infection to stimulate the AA synthesis and Ptgs2 expression. In vivo, by comparing different inoculation routes we showed that intradermal infection induces a specific inflammatory gene signature characterized by an important expression of Ptgs2 and Ifng. The use of NS-398, a specific inhibitor of COX-2 stimulates the bacterial clearance in the cervical lymph nodes (CLN) draining the site of infection. These results might open the way to new therapeutic strategies in the treatment of brucellosis. In a second part of the thesis, we discuss the involvement of bacterial infections in initiating oncogenic processes. Here, we present a review listing all the mechanisms that contribute to the oncogenic initiation and a project that we are developing in the laboratory dealing with the initiation of follicular lymphoma following chronic antigenic stimulation during B. abortus infection
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Marques, Daniela Cristina Sobreiro. "Avaliação da expressão da Cox-2 em tumores mamários de cadela." Master's thesis, Universidade de Lisboa. Faculdade de Medicina Veterinária, 2013. http://hdl.handle.net/10400.5/6222.
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Dissertação de Mestrado Integrado em Medicina VeterináriaA ciclooxigenase-2 (COX-2) é uma proteína que se encontra envolvida na oncogénese e na inflamação, tendo sido demonstrada a sua sobrexpressão em diversas neoplasias humanas e animais. Nos tumores mamários esta enzima está associada a indicadores de pior prognóstico, tanto na mulher como na cadela. Adicionalmente, a utilização de fármacos inibidores da COX-2 demonstrou uma diminuição da incidência e da capacidade metastática em mulheres portadoras de cancro da mama. Também nos tumores mamários de cadela existe a evidência de que a utilização destes fármacos tem efeitos benéficos na melhoria da qualidade de vida e no aumento do tempo de sobrevivência. O objetivo principal deste estudo foi avaliar a expressão da COX-2 em neoplasias mamárias caninas e a sua associação com diversos parâmetros clinico-patológicos, de forma a investigar a importância desta proteína como um futuro alvo terapêutico. A expressão da COX-2 foi avaliada em 21 amostras de tumores por imunohistoquímica (IHQ), utilizando dois anticorpos anti-COX-2. Como controlo positivo foi utilizado útero de cadela com piómetra. A percentagem de células positivas nos tumores analisados foi classificada semiquantitativamente do seguinte modo: 0 - <10%; 1 - 10-25%; 2 - 26-50%; 3 – 51-75%; 4 – 76- 100%. A classificação da intensidade de marcação foi distribuída por quatro categorias: 1 - discreta (+); 2 - moderada (++); 3 - intensa (+++); 4 - muito intensa (++++). Tendo em conta estes dois parâmetros, foi atribuída uma pontuação a cada neoplasia resultante da soma dos dois valores analisados. A IHQ realizada com o clone 33 revelou que a grande maioria dos tumores da amostra (85,7%) demonstraram ter menos de 10% de células positivas e intensidade de marcação 3 (+++), resultando numa pontuação final de 3. Ainda com este clone foram classificados dois tumores com pontuação 5 (1 – 10-25%; 4 - ++++) e um com 6 (2 – 26-50%; 4 - ++++). O padrão de marcação observado foi de tipo citoplasmático difuso e perinuclear. Relativamente ao clone SP21, 95,2% das neoplasias demonstraram positividade de nível 4 (76-100%) e intensidade entre 3 (+++) e 4 (++++), resultando na atribuição de pontuações de 7 e 8, respectivamente. Com este clone foi observado tanto um padrão de marcação membranar como um padrão citoplasmático difuso e perinuclear. Este último foi comum aos dois anticorpos e observado nos mesmos tumores, correspondendo a neoplasias menos diferenciadas. No presente estudo, a expressão da COX-2 revelou associação estatisticamente significativa com o tamanho e grau de diferenciação dos tumores. Será necessário mais investigação nesta área de modo a estabelecer quais os anticorpos, protocolos e respectivos padrões de marcação que se correlacionam inequivocamente com níveis elevados da expressão da COX-2, para que inibidores desta proteína possam ser testados como terapia.
ABSTRACT - Evaluation the expression of COX-2 in canine mammary tumours - Cyclooxygenase-2 (COX-2) is a protein involved in oncogenesis and inflammation and its overexpression has been demonstrated in several human and animal neoplasias. In mammary tumours this enzyme is associated with indicators of poor prognosis, in both human and canine species. Additionally, the use of drugs inhibitors of COX-2 showed reduction in incidence and metastatic capability in women with breast cancer. Also in canine mammary tumours, there is evidence that the use of these drugs have beneficial effects in improving the quality of life and increasing survival time. The main purpose of this study was to evaluate COX-2 expression in canine mammary neoplasias and its association with clinicopathological parameters, in order to investigate the importance of this protein as a future therapeutic target. The expression of COX-2 was evaluated in 21 tumour samples by immunohistochemistry (IHQ), using two anti-COX-2 antibodies. Canine uterus with pyometra was used as positive control. The percentage of cellular positivity in each tumour was classified semi-quantitatively as follows: 0 - <10%; 1 - 10%-25%; 2 - 26-50%; 3 – 51-75%; 4 – 76-100%. The grading of intensity of the labelling was distributed by four categories: 1 - discrete (+); 2 - moderate (++); 3 - intense (+++); 4 - very intense (++++). Given these two parameters a score was assigned to each tumour, resulting from the sum of the two values. IHQ with clone 33 revealed that the majority of tumour samples (85,7%), had less than 10% of positive cells, and a labelling intensity of 3 (+++), resulting in a final score of 3. Also with this clone two tumours were classified as 5 (1 – 10-25%; 4 - ++++), and one as 6 (2 - 26- 50%; 4 - ++++). The labelling observed was diffuse cytoplasmic and perinuclear. With clone SP21, 95,2% of the neoplasias revealed positivity in 76-100% of the cells, and intensity between 3 (+++) and 4 (++++), resulting in final scores of 7 and 8. With this clone both cell membrane as diffuse cytoplasmic and perinuclear labelling were observed. This last pattern was common in the same tumours with both antibodies, corresponding to poorly differentiated neoplasias. In the present study, COX-2 expression revealed a statistically significant association with tumour size and grading. More investigation in this field is required, in order to definitively establish a protocol and labelling pattern that unequivocally correlate with the levels of COX-2 expression, so that COX-2 inhibitors can be tested for therapeutic benefits.
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Gu, Baoying. "Selective increase of neuronal cyclooxygenase-2 (COX-2) expression in vulnerable brain regions of rats with experimental Wernicke's encephalopathy : effects of nimesulide." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112627.
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Wernicke's encephalopathy is a neuropsychiatric disorder resulting from thiamine deficiency (TD) and is characterized by neuronal loss, astrocytic proliferation and microglial activation. Cyclooxygenases (COX) are enzymes which catalyze the first step in the synthesis of prostanoids. COX-1 is expressed constitutively and COX-2 is the inducible isoform. Groups of TD rats and pair-fed controls were killed at presymptomatic and symptomatic stages of encephalopathy. Cresyl violet and NeuN staining showed decreased numbers of neuronal cells in vulnerable regions (medial thalamus and inferior colliculus) but not in a spared region (frontal cortex). Numbers of GFAP-positive and OX-42-positive cells were increased at symptomatic stage of encephalopathy. Expression of COX-2 mRNA and neuronal COX-2 immunoreactivity were selectively increased in vulnerable regions of TD rats at symptomatic stages of encephalopathy. Nimesulide, a highly selective COX-2 inhibitor, lowered PGE2 levels and precipitated the progression of encephalopathy suggesting that COX-2 in this model is conferring neuroprotection.
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Lee, Jonathan J. "Studies on the Roles of Translationally Recoded Proteins from Cyclooxygenase-1 and Nucleobindin Genes in Autophagy." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/6538.
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Advances in next-generation sequencing and ribosomal profiling methods highlight that the proteome is likely orders of magnitude larger than previously thought. This expansion potentially occurs through translational recoding, a process that results in the expression of multiple variations of a protein from a single messenger RNA. Our laboratory demonstrated that cyclooxygenase-3/1b (COX-3/1b), a frameshifted, intron-1-retaining, alternative splice variant from the COX-1 gene, is multiply recoded, which results in the translation of at least seven different COX-3 proteins. Two of the recoded COX-3 proteins that we identified are active prostaglandin synthases and are inhibited by non-steroidal anti-inflammatory drugs (NSAIDs). Here we show that the other non-prostaglandin-generating recoded COX-3 proteins perform new roles in innate immunity, a process in which COX are known to generally function. Our analyses determined that these recoded COX-3 proteins bind at or near the amino-terminal region of ATG9a, a critical regulator of both canonical (i.e. digestive autophagy associated with mTORc inhibition and nutrient deprivation) and non-canonical (i.e. xenophagy involved in the innate immune response to invading organisms) autophagy. We further show that this process requires mTORc signaling activity, which opposes the digestive pathway. As a final confirmation of the biological relevance of these recoded COX-3 proteins and their central role in xenophagy, we demonstrate that expression of these COX-3 proteins in an encephalomyocarditis virus infection model system differentially affects infectious virion production. These COX-3 proteins also associate with recoded cytosolic nucleobindin around large, innate immune-related, large LC3-II positive structures (LLPSs). Through mutagenizing catalytic residues of recoded COX-3 proteins and drug assays, we determine LLPS formation is dependent on oxylipin generation.
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Kommareddy, Madhavi. "Upregulation of COX-2 protein expression in porcine macula densa with L-NAME treatment." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/6073.
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Thesis (M.S.)--University of Missouri-Columbia, 2008.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Includes bibliographical references.
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Laube, Markus. "Synthese von Cyclooxygenase-2-Inhibitoren als Grundlage für die funktionelle Charakterisierung der COX-2-Expression mittels PET." Doctoral thesis, Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A28510.
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Eine erhöhte COX-2-Expression wird bei Krankheiten wie rheumatoider Arthritis aber auch Parkinson, Alzheimer und Krebs beobachtet. Die nichtinvasive Visualisierung und Quantifizierung der COX 2-Expression in vivo mittels Positronen-Emissions-Tomographie (PET) könnte wertvolle Beiträge zur Diagnose dieser Krankheiten liefern. Zur Nutzung der PET-Technik werden geeignete COX-2-adressierende Radiotracer benötigt, deren Entwicklung auch die Identifizierung neuer, der Radiomarkierung zugänglicher COX-2-Inhibitoren als Leitstrukturen voraussetzt.
Ziel dieser Arbeit war die Synthese von selektiven, der Radiomarkierung zugänglichen COX 2-Inhibitoren und deren In-vitro-Evaluierung, um Verbindungen zu identifizieren, die für eine weitere Entwicklung zu COX-2-adressierenden Radiotracern geeignet sind. Im Rahmen dieser Arbeit wurden ausgehend von literaturbekannten COX-2-Inhibitoren zwei grundlegende Strategien verfolgt: die Derivatisierung an der Peripherie sowie der Austausch von Strukturelementen im Grundgerüst der COX-2-selektiven Inhibitoren.
In dieser Arbeit wird zum einen die Synthese der Zielverbindungen (Diphenyl-substituierte Indol-, Pyrazolo[1,5-b]pyridazin-, 1,2-Dihydropyrrolo[3,2,1-hi]indol- und Pyrrolo[3,2,1-hi]indol-Derivate sowie 2-Carbaboranyl-substituierte Indol-Derivate) und deren strukturanalytische Charakterisierung vorgestellt. Es konnte die McMurry-Cyclisierung als neuer Zugang für die Synthese von Carbaboranyl-substituierten Verbindungen und 1,2-Dihydropyrrolo[3,2,1-hi]indol-Derivaten sowie die Dehydrogenierung mittels DDQ als neue Variante zur Synthese von Pyrrolo[3,2,1-hi]indol-Derivaten etabliert werden. Durch Röntgeneinkristallstrukturanalyse wurde die Molekülstruktur von sechs Zwischenverbindungen und neun Zielverbindungen aufgeklärt.
Zum anderen erfolgte die Charakterisierung der Verbindungen in vitro, wobei die COX-inhibitorischen Eigenschaften mit einem Fluoreszenz-basierten, einem Enzymimmunoassay (EIA)-basierten und einem [14C]Arachidonsäure-basierten COX-Assay bestimmt und zudem viele Verbindungen hinsichtlich ihrer Redoxeigenschaften untersucht wurden. Im Besonderen die hergestellten Indol-Derivate besitzen antioxidative Eigenschaften, die bei der Untersuchung der COX inhibitorischen Eigenschaften beachtet werden müssen.
Die Derivatisierung an der Peripherie der bekannten Inhibitoren führte zur Identifizierung von zwei Aminosulfonyl-substituierten Indol-Derivaten und einem Fluorethoxy-substituierten Pyrazolo[1,5 b]pyridazin-Derivat, die grundsätzlich geeignete Kandidaten für eine weitere Entwicklung zum Radiotracer darstellen. Das Fluorethoxy-substituierte Pyrazolo[1,5 b]pyridazin-Derivat wurde im Rahmen dieser Arbeit mit Fluor-18 markiert und die initiale Charakterisierung des Radiotracers in vitro durchgeführt. Der Austausch von Strukturelementen im Grundgerüst der literaturbekannten COX-2-Inhibitoren mit voluminöseren Gruppen führte zum einen bei Austausch eines Phenylrings gegen einen Carbaboranyl-Cluster zum Verlust der COX-inhibitorischen Eigenschaften, was eine weitere Entwicklung dieser Verbindungen zum Radiotracer ausschließt. Zum anderen wurde ausgehend von 2,3-Diphenyl-1H-indol-Derivaten die bicyclische auf eine tricyclische Kernstruktur vergrößert. Dies lieferte hoch affine und selektive COX-2-Inhibitoren. Unter den hergestellten Verbindungen wurden ein 1,2-Dihydropyrrolo[3,2,1-hi]indol- und drei Pyrrolo[3,2,1-hi]indol-Derivate als vielversprechende Kandidaten für die weitere Entwicklung zum Radiotracer identifiziert.
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Mehar, Ayaz. "Inhibitors of cyclooxygenase-2 (COX-2) and prostate cancer : effects on apoptosis and role in tumour inhibition." Thesis, University of Surrey, 2005. http://epubs.surrey.ac.uk/843556/.
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In comparison to other cancers, advanced prostate cancer is resistant to chemotherapy. There is a need to understand the mechanisms which are responsible for this resistance and find better treatments for this disease or methods to increase the efficacy of current treatments. Cancer cells often evade apoptosis. Cyclooxygenase-2 (COX-2) is an enzyme reported to be elevated in prostate cancer, and has oncogenic properties, including apoptosis attenuation. Because of this, COX-2 inhibition could be beneficial for both prevention and treatment of cancer. This study showed that COX-2 protein was not detected in LNCaP, PC-3 or DU145 cells. To assess the effect COX-2 has on the apoptotic sensitivity of prostate cancer cells, we transfected two cell lines (stable transfection in LNCaP, transient in PC-3) with the human COX-2 gene or empty control vector. We measured the effect on cell viability of COX-2 after treatment with a diverse set of agents e.g. etoposide, carboplatin, Fas, TRAIL, celecoxib and sulindac, using the MTT assay. We observed COX-2 dependent resistance to carboplatin, etoposide and celecoxib in LNCaP but not PC-3. Carboplatin mediated reduction in cell viability was due to an S phase block and induction of apoptosis. COX-2 transfection in LNCaP cells attenuated both the cell cycle block and apoptosis. There was reduced p53 and p27KIP1 induction following carboplatin treatment in LNCaP-COX-2, compared to LNCaP-Neo. COX-2 transfection caused elevated cellular- levels of anti-apoptotic proteins Bcl-2, BC1-XL and survivin. Summary Celecoxib could not reverse the resistance seen in LNCaP-COX-2 to carboplatin, and PGE2 could not increase the resistance in LNCaP-Neo cells, suggesting that COX-2 mediates an apoptotic resistance which is COX-2 enzymatic activity independent. Other mechanisms were sought to reverse the carboplatin resistance. PI3K inhibitors wortmannin and LY294002 partially reversed the LNCaP-COX-2 resistance. These data suggests that COX-2 acts on the PI3K signalling pathway to mediate resistance in LNCaP. This was confirmed by Western blot findings of elevated levels of in P-Aktser473 LNCaP-COX-2 compared with LNCaP-Neo. Celecoxib decreased levels of P-Aktser473 inn a manner similai- to PI3K inhibitors, indicating that the PI3K inhibitors and celecoxib act in different ways on PI3K signalling. Because complete reversal of resistance does not occur with PI3K inhibition, COX-2 must be acting on other pathways also. However, unlike the PI3K inhibitors, celecoxib could not reverse resistance to carboplatin. Wortmannin and LY294002 decreased levels of Bcl-2, BC1-XL, survivin and, surprisingly, COX-2 protein. In contrast, celecoxib had little effect on Bcl-2 and increased COX-2 levels. Cyclin B1 levels were higher in LNCaP-COX-2 than LNCaP-Neo. Gene microarray analysis confirmed the up-regulation of survivin in LNCaP-COX-2 and also showed elevation of cyclin I and fatty acid synthase and down-regulation of glutathione-S-transferase in LNCaP-COX-2. In conclusion, stable COX-2 transfection causes a selective resistance to cytotoxic agents which is mediated via activation of the PI3K pathway and attenuation of p53 induction in LNCaP. COX-2 also causes the up-regulation of a number of anti- apoptotic factors and PI3K inhibition results in down-regulation of these proteins.
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Laube, Markus. "Synthese von Cyclooxygenase-2-Inhibitoren als Grundlage für die funktionelle Charakterisierung der COX-2-Expression mittels PET." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-160091.
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Eine erhöhte COX-2-Expression wird bei Krankheiten wie rheumatoider Arthritis aber auch Parkinson, Alzheimer und Krebs beobachtet. Die nichtinvasive Visualisierung und Quantifizierung der COX 2-Expression in vivo mittels Positronen-Emissions-Tomographie (PET) könnte wertvolle Beiträge zur Diagnose dieser Krankheiten liefern. Zur Nutzung der PET-Technik werden geeignete COX-2-adressierende Radiotracer benötigt, deren Entwicklung auch die Identifizierung neuer, der Radiomarkierung zugänglicher COX-2-Inhibitoren als Leitstrukturen voraussetzt.
Ziel dieser Arbeit war die Synthese von selektiven, der Radiomarkierung zugänglichen COX 2-Inhibitoren und deren In-vitro-Evaluierung, um Verbindungen zu identifizieren, die für eine weitere Entwicklung zu COX-2-adressierenden Radiotracern geeignet sind. Im Rahmen dieser Arbeit wurden ausgehend von literaturbekannten COX-2-Inhibitoren zwei grundlegende Strategien verfolgt: die Derivatisierung an der Peripherie sowie der Austausch von Strukturelementen im Grundgerüst der COX-2-selektiven Inhibitoren.
In dieser Arbeit wird zum einen die Synthese der Zielverbindungen (Diphenyl-substituierte Indol-, Pyrazolo[1,5-b]pyridazin-, 1,2-Dihydropyrrolo[3,2,1-hi]indol- und Pyrrolo[3,2,1-hi]indol-Derivate sowie 2-Carbaboranyl-substituierte Indol-Derivate) und deren strukturanalytische Charakterisierung vorgestellt. Es konnte die McMurry-Cyclisierung als neuer Zugang für die Synthese von Carbaboranyl-substituierten Verbindungen und 1,2-Dihydropyrrolo[3,2,1-hi]indol-Derivaten sowie die Dehydrogenierung mittels DDQ als neue Variante zur Synthese von Pyrrolo[3,2,1-hi]indol-Derivaten etabliert werden. Durch Röntgeneinkristallstrukturanalyse wurde die Molekülstruktur von sechs Zwischenverbindungen und neun Zielverbindungen aufgeklärt.
Zum anderen erfolgte die Charakterisierung der Verbindungen in vitro, wobei die COX-inhibitorischen Eigenschaften mit einem Fluoreszenz-basierten, einem Enzymimmunoassay (EIA)-basierten und einem [14C]Arachidonsäure-basierten COX-Assay bestimmt und zudem viele Verbindungen hinsichtlich ihrer Redoxeigenschaften untersucht wurden. Im Besonderen die hergestellten Indol-Derivate besitzen antioxidative Eigenschaften, die bei der Untersuchung der COX inhibitorischen Eigenschaften beachtet werden müssen.
Die Derivatisierung an der Peripherie der bekannten Inhibitoren führte zur Identifizierung von zwei Aminosulfonyl-substituierten Indol-Derivaten und einem Fluorethoxy-substituierten Pyrazolo[1,5 b]pyridazin-Derivat, die grundsätzlich geeignete Kandidaten für eine weitere Entwicklung zum Radiotracer darstellen. Das Fluorethoxy-substituierte Pyrazolo[1,5 b]pyridazin-Derivat wurde im Rahmen dieser Arbeit mit Fluor-18 markiert und die initiale Charakterisierung des Radiotracers in vitro durchgeführt. Der Austausch von Strukturelementen im Grundgerüst der literaturbekannten COX-2-Inhibitoren mit voluminöseren Gruppen führte zum einen bei Austausch eines Phenylrings gegen einen Carbaboranyl-Cluster zum Verlust der COX-inhibitorischen Eigenschaften, was eine weitere Entwicklung dieser Verbindungen zum Radiotracer ausschließt. Zum anderen wurde ausgehend von 2,3-Diphenyl-1H-indol-Derivaten die bicyclische auf eine tricyclische Kernstruktur vergrößert. Dies lieferte hoch affine und selektive COX-2-Inhibitoren. Unter den hergestellten Verbindungen wurden ein 1,2-Dihydropyrrolo[3,2,1-hi]indol- und drei Pyrrolo[3,2,1-hi]indol-Derivate als vielversprechende Kandidaten für die weitere Entwicklung zum Radiotracer identifiziert.
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Scheer, Martin-Jürgen [Verfasser]. "Die Rolle der Cyclooxygenase-2-(COX-2)-Expression auf Prognose und Therapie oraler Plattenepithelkarzinome / Martin-Jürgen Scheer." Köln : Deutsche Zentralbibliothek für Medizin, 2011. http://d-nb.info/1017871841/34.
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Sheridan, Jared. "Partnership between the aryl hydrocarbon receptor (AHR) and RELB regulates cigarette smoke-induced cyclooxygenase-2 (COX-2) expression." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123307.
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Chronic obstructive pulmonary disease (COPD) is an inflammatory disease of the lungs caused by cigarette smoke exposure; COPD is also now the third leading cause of death worldwide. Controlling lung inflammation is a priority in COPD patients, but currently-available medications offer little relief. Thus, new therapeutic targets represent a major unmet need. Previously, the aryl hydrocarbon receptor (AHR) has been shown to suppress cigarette smoke-induced inflammation. The AHR is a ligand-activated transcription factor, and well-established for its response to xenobiotic ligands. AHR-mediated suppression of smoke-induced inflammation requires the NF-κβ family member RELB. To date, nothing is known about the expression of AHR or RELB in subjects with COPD. Therefore, we investigated the expression of the AHR and RELB in human lung fibroblasts derived from Control (Non-smoker), Smoker and COPD subjects, as well as the mechanism through which they repress the production of the inflammatory protein cycloxygenase-2 (COX-2) in response to cigarette smoke extract (CSE). There was reduced AHR expression in COPD subjects, which was associated with increased expression of COX-2 protein (but not mRNA) in quiescent COPD fibroblasts. Inhibition of AHR activity in lung fibroblasts by the pharmacological AHR antagonist CH-223191 increased COX-2 protein induction by CSE. Mechanistically, this increase in COX-2 protein corresponded with increased cytoplasmic shuttling of the RNA binding protein HUR which is known to prolong the half-life of RNA transcripts - including COX-2. HUR was observed to be cytoplasmically-localized in lung tissue from COPD subjects, but not Control, suggesting altered regulation of HUR in COPD subjects. Another protein associated with the suppressive function of the AHR- RElB, was reduced in both Smoker and COPD lung fibroblasts, suggesting cigarette smoke may contribute to the reduced expression. siRNA-knockdown of RELB increased the production of Cox-2 mRNA in response to CSE or IL-1β, supporting that RELB contributes to the suppression of Cox-2. We hypothesized this may be due to miR-146a, an anti-inflammatory microRNA (miRNA) which targets Cox-2 mRNA for degradation. miR-146a basal expression was not significantly different between the subject groups. However, only Control fibroblasts increased miR-146a expression in response to CSE. siRNA knockdown of RELB abrogated the expression of miR-146a in response to IL-1β, but not CSE, suggesting RELB repression of Cox-2 mRNA does not involve miR-146a, but that RELB may regulate miR-146a under certain stimuli. Collectively, these data support the regulatory role of AHR and RELB in cigarette smoke-induced inflammation, and thus represent promising new cellular targets with the potential for controlling inflammation characteristic of COPD.La maladie pulmonaire obstructive chronique (MPOC) est une maladie inflammatoire chronique des poumons causée par l'exposition à la fumée de cigarette, maintenant au troisième rang des causes de mortalité mondiaux. Le contrôle de l'inflammation pulmonaire est hautement prioritaire pour les patients atteints de MPOC, mais les médicaments actuellement disponibles ne réduisent guère cette inflammation. Les nouvelles cibles thérapeutiques restent donc un important besoin non satisfait. La RAH est bien établi comme une réponse à des ligands xénobiotiques toxiques. La suppression par l'entremise de RAH de l'inflammation causée par la fumée de cigarette nécessite un membre de la famille NFκβ. Jusqu'à date, rien n'est connu de l'expression de RAH ou RELB parmi les patients atteints de MPOC. Par conséquent nous avons examiné ci-dessus la relation entre l'expression de RAH et RELB dans les fibroblastes de poumon humains dérivés des sujets témoins (non-fumeurs), fumeurs, et sujets atteints de MPOC, ainsi que le mécanisme par lequel ils répriment la production de la protéine inflammatoire cyclo-oxygénase 2 (COX-2) en réponse à l'extrait de la fumée de cigarette (EFC). L'expression des protéines RAH a été réduite parmi les fibroblastes des sujets atteints de MPOC, qui était aussi associée avec une expression accrue de la protéine COX-2 (mais pas ARNm) parmi les fibroblastes quiescents. L'inhibition de l'activité de RAH dans les fibroblastes pulmonaires par l'antagoniste pharmacologique CH-223191 a augmenté l'induction de COX-2 par EFC. Mécaniquement, cette augmentation de la protéine COX-2 a correspondu avec un accroissement du transport cytoplasmique de la protéine de liaison d'ARN HUR, qui est connu pour prolonger la demi-vie des transcrits d'ARN, y compris COX-2. Il a été observé que HUR est cytoplasmiquement localisé dans le tissu pulmonaire des sujets atteints de MPOC, mais non pas les témoins, suggérant une régulation altérée de HUR parmi les sujets atteints de MPOC. Une autre protéine associée avec cette fonction de suppression de la RAH=RElB a été réduite parmi les fibroblastes pulmonaires des sujets-fumeurs et sujets atteints de COP, suggérant que la fumée de cigarette puisse contribuer à cette expression réduite. pARNi (ou siRNA) anéantissement de RELB accroissait la production de COX-2 ARNm en réponse à CSE ou IL-1, appuyant l'observation que RELB contribue à la suppression de COX-2. Nous avons formulé l'hypothèse que cela pourrait être du à miR-146a, un micro-ARN (miARN) qui cible COX-2 mRNA pour dégradation. L'expression basale de miR-146a ne fut pas significativement différente parmi les divers groupes de sujets. Pourtant seulement les fibroblastes des sujets témoins ont accru l'expression de miR-146 en réponse à l'EFC. pARNi (ou siRNA) anéantissement de RELB a abrogé l'expression de miR-146 en réponse à IL-1β, mais pas l'EFC, suggérant que la répression par RELB de COX-2 ARNm n'entraîne pas miR-146a, mais que RELB pourrait réglementer miR-146a soumis à certains stimuli. Collectivement, ces données étayent le rôle régulateur de RAH et RELB dans l'inflammation induite par la fumée de cigarette, et donc représentent de nouvelles cibles cellulaires prometteuses, pleines de potentiel de contrôler l'inflammation caractéristique de MPOC.
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Garrelfs, Nicklas [Verfasser], Jessica [Akademischer Betreuer] Günzle, and Astrid [Akademischer Betreuer] Weyerbrock. "Die Hemmung der Cyclooxygenase (COX) durch Acetylsalicylsäure (ASS) verstärkt die Antitumorwirkung von JS-K bei Glioblastomen in vitro." Freiburg : Universität, 2021. http://d-nb.info/1229835245/34.
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Serra, Kátia Piton 1979. "Expressão da COX-2 em carcinomas de mama intraductais e invasores e sua relação com a expressão de HER-2, p53 e receptores de estrógeno e progesterona." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/312150.
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Orientadores: Sophie Françoise Mauricette Derchain, Luis Otávio Zanatta SarianDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Introdução: evidências laboratoriais sugerem que a enzima ciclooxigenase-2 (COX-2), é um dos principais componentes da cascata inflamatória. A enzima é responsável pela conversão do ácido araquidônico em prostaglandinas e tromboxanos. Estudos sugerem que a expressão da COX-2 correlaciona-se diretamente com o potencial maligno dos tumores de mama, e essa relação é em parte explicada pelo papel desempenhado pela COX-2 no reforço da neoangiogênese e processos de imortalização celular. Pouco se sabe, no entanto, sobre a relação da expressão da COX-2 com outros marcadores prognósticos e preditivos de tumores de mama como HER-2, p53, e receptores de hormônios (estrogênio [RE] e progesterona [RP]). Objetivos: avaliar a relação entre a expressão da COX-2 e da p53, receptores de hormônios e HER-2 nas frações in situ e invasivo de carcinomas ductais da mama. Sujeitos e métodos: foram incluídas amostras de 87 mulheres com carcinoma invasivo da mama, que tivessem áreas de carcinoma intraductal associadas. A expressão da COX-2, p53 e receptores hormonais foi avaliada por imuno-histoquímica (IHQ), a expressão de HER-2 foi avaliada por IHQ e hibridização fluorescente in situ (FISH). Nas análises estatísticas, os níveis de confiança foram ajustados para 5% (p=0,05). Na análise univariada, qui-quadrados foram calculados para comparar a expressão dos marcadores tumorais nos componentes in situ e invasivo. Coeficiente de correlação intraclasse (ICC) e qui-quadrado foram calculados para avaliar a tabulação cruzada da expressão da COX-2 nos componentes intraductal e invasor. Qui-quadrados foram utilizados para comparar as proporções de tumores in situ e invasivos que expressaram cada um dos marcadores tumorais de acordo com a expressão da COX-2. Todas as tabulações foram novamente testadas de forma multivariada, utilizando modelos de regressão logística para avaliar especificamente a expressão dos marcadores nos componentes intraductal versus invasivos e nos grupos formados pela expresão da COX-2. Resultados: a COX-2 estava expressa em 44 (61%) dos componentes in situ e em 49 (58%) dos componentes invasivos; 44% dos casos expressaram COX-2 em ambos os componentes. Dos componentes invasivos com expressão da COX-2, 17% foram negativos para a enzima no componente intraductal. Em contrapartida, nos tumores que expressaram COX-2 no componente in situ, 17% apresentaram resultados negativos para a enzima em seu componente invasivo (ICC 0,29, p=0,02). Não houve diferença estatística na expressão da COX-2 ao comparar os componentes intraductal e invasivo dos tumores (p=0,80). A expressão da p53 foi maior no componente intraductal (52%), comparada ao invasor (33%) (p<0,01). O HER-2 estava superexpresso em 21% na fração in situ e 28% no componente invasivo (p=0,49); 69% dos componentes intraductais foram positivos para RE. Aproximadamente a mesma proporção (75%) dos tumores invasivos foram também positivos para RE (p=0,36). Houve um desequilíbrio marginal na expressão de RP, com maior prevalência deste na forma in situ (59% versus 46% no componente invasivo, p=0,08). No componente intraductal, houve uma diferença estatisticamente limítrofe da expressão da p53 em tumores que também expressaram COX-2 (66% versus 44% em amostras negativas para COX-2 p=0,07). No entanto, a proporção de tumores que expressaram HER-2 (p=0,73), RE (p=0,25) e RP (p=0,57) não diferiu em tumores que expressaram ou não a COX-2. Houve uma proporção ligeiramente maior (84% versus 67%) das amostras RE positivas no grupo de tumores invasivos que expressaram COX-2 (p=0,07). Em contrapartida, a expressão de RP não foi relacionada com a da COX-2 (p=0,22) na avaliação multivariada. Conclusões: a expressão da COX-2 foi semelhante nas frações intraductal e invasora das neoplasias de mama. A expressão da p53 foi marginalmente superior nas frações in situ que expressavam COX-2. Na fração invasora, houve maior proporção de tumores expressando receptores de estrógeno entre os que expressaram COX-2
Abstract: Introduction: laboratorial evidence implicates the cyclooxygenase-2 (COX-2) enzyme as one of the major components of the inflammatory cascade. The enzyme is responsible for the conversion of aracdonic acid in prostaglandins and tromboxanes. Previous research suggests that COX-2 expression correlates directly with the malignant potential of breast tumors, and this relation is, at least in part explained by the role played by COX-2 in the enhancement of the neoangiogenesis and cell immortalization processes. Little is known, however, about the relation of COX-2 expression with other well-stablished breast tumor prognostic and predictive markers, e.g. HER-2, p53, and hormone (estrogen [ER] and progesterone [PR]) receptors. Objectives: to assess the relationship between the expression of COX-2 and that of p53, hormone receptors (estrogen (ER) and progesterone (PR)) and HER-2 in the in situ and invasive regions of ductal carcinomas of the breast. Subjects and methods: samples from 87 women with invasive carcinoma of the breast with areas of in situ carcinoma were included. The expressions of COX-2, p53 and hormone receptors were assessed with immunohistochemistry (IHC); the expression of HER-2 was assessed with IHC and Fluorescent in situ Hybridization (FISH). In statistical analyses, confidence levels were set to 5% (p 0.05). In univariate analysis, chi-squares were calculated to confront the expression of the tumor markers in the in situ and invasive components. The intraclass correlation coefficient (ICC) and chi-squares were calculated to assess the cross-tabulation of COX-2 expression in the in situ versus invasive components. Then, chi-squares were also used to compare the proportions of tumors expressing (individually for the in situ and invasive components) each of the tumor markers in the groups formed according to the COX-2 expression. All tabulations were then retested in a multivariate fashion, using logistic regression models fit specifically for the comparison of marker expression in the in situ versus the invasive components, and in the COX-2-positive and negative groups. Results: COX-2 was expressed in 44 (61%) of the in situ components and in 49 (58%) of the invasive components; 44% of the cases expressed COX-2 in both components. Of the tumors whose invasive components expressed COX-2, 17% were negative for the enzyme in the in situ component. By contrast, of the tumors that expressed COX-2 in the in situ component, 17% were negative for the enzyme in their invasive component (ICC 0.29; p=0.02). There was no statistical difference in COX-2 expression comparing the in situ and invasive components of the breast tumors (p 0.80). The p53 expression was higher in the in situ component (52%), contrasted to that in the invasive (33%) region of the tumors (p<0.01). HER-2 was expressed in 21% in the in situ component and 28% in the invasive component (p=0.49). Sixty-nine percent of the in situ components tested positive for ER, and approximately the same proportion (75%) of the invasive components were positive for ER (p=0.36). There was a marginal imbalance in PR expression, favoring the in situ component (59% versus 46% in the invasive component; p=0.08). In the in situ component, there was a statistically borderline increase in p53 expression in tumors that also expressed COX-2 (66% versus 44% in COX-2 negative specimens p=0.07). However, the proportions of tumors that expressed HER-2 (p=0.73), ER (p=0.25) and PR (p=0.57) did not differ in tumors that expressed or not COX-2 protein. There was a marginally increased proportion (83% versus 66%) of ER-positive specimens in the group of invasive tumors that expressed COX-2 (p=0.07). By contrast, PR expression was not related to that of COX-2 (p=0.22) in the multivariate assessment. Conclusions: the expression of COX-2 was similar in the in situ and invasive regions of the breast neoplasms. The expression of p53 was marginally higher in the in situ regions that were positive for COX-2. In the COX-2-positive invasive regions, there were a higher proportion of ER-positive tumors
Mestrado
Oncologia Ginecológica e Mamária
Mestre em Ciências da Saúde
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Yeoh, Ann Suk Jing. "Nuclear factor kB (NFkB) and cyclooxygenase-2 (Cox-2) expression in the irradiated colorectum is association with subsequent histopathologic changes /." Title page and abstract only, 2004. http://web4.library.adelaide.edu.au/theses/09MSB/09msby46.pdf.
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Lin, Ho-Pi. "Celecoxib its non-COX-2 targets and its anti-cancer effects /." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124114562.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xix, 94 p.; also includes graphics (some col.). Includes bibliographical references (p. 87-94). Available online via OhioLINK's ETD Center
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Sawdy, Robert John. "The role of the type-2 isoform of the cyclooxygenase enzyme (COX-2) in human parturition : potential benefits of selective COX-2 inhibitors in the management of preterm labour." Thesis, Imperial College London, 2003. http://hdl.handle.net/10044/1/11444.
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László, Csaba F. "Translation regulation of UV-light-induced transcription factor NF-kappa-B and oncogene COX-2." View abstract, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3353542.
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Öztürk, Özlem Altuntaş İrfan. "Yaşlı ratlarda selektif ve non selektif cox inhibitörlerinin NMDA reseptör subunitlerine etkisi /." Isparta: SDÜ Tıp Fakültesi, 2006. http://tez.sdu.edu.tr/Tezler/TT00268.pdf.
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Godinho, Camila Capel. "Análise metabolômica da bioatividade em vias COX e LOX-dependentes de plantas da subtribo Lychnophorinae." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/60/60138/tde-03102016-143050/.
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Muitas substâncias das espécies de Lychnophorinae (Asteraceae) são relatadas como inibidoras da síntese de mediadores da cascata do processo inflamatório. Nesse processo, duas enzimas são essenciais e atuam no metabolismo do ácido araquidônico, formado em processos inflamatórios: ciclooxigenase (COX) e lipoxigenase (LOX). A análise de impressões digitais metabólicas é um método capaz de fornecer informações sobre o objeto de estudo através da utilização de ferramentas estatísticas, além de possibilitar a correlação desses dados com outros utilizando métodos in silico. O objetivo deste estudo foi analisar 26 espécies da subtribo Lychnophorinae quanto à atividade inibitória in vitro das vias COX- e LOX-dependentes e identificar as substâncias responsáveis por essa atividade através de análises in silico de correlação entre bioatividade e impressão digital metabólica. As impressões digitais metabólicas dos extratos hidrometanólicos das espécies de Lychnophorinae foram obtidas utilizando UHPLC-UV-(DAD)-MS (OrbitrapTM). Os ensaios de triagem de inibição das vias COX-1 e 5-LOX-dependentes revelaram que 20 espécies possuem atividade inibitória dupla para ambas as vias com valores de IC50 menores que 100 ?g.mL-1. Dentre essas, 11 espécies apresentaram valores de IC50 menores que 40 ?g.mL-1, e cinco apresentaram valores de IC50 menores que 10 ?g.mL-1. Utilizando-se as impressões digitais metabólicas e os resultados de inibição enzimática foram realizadas análises estatísticas multivariadas supervisionadas e não supervisionadas (PCA, PLS e OPLS) visando à identificação de substâncias discriminantes (ativas). Através das análises de correlação, obtiveram-se as prováveis substâncias que detém o potencial inibitório. As cinco substâncias com maior potencial discriminante foram identificadas por técnicas de desreplicação e são: a lactona sesquiterpênica (4,5-diidro-15-desoxigoyazensolido), dois flavonóides glicosilados (3-O-(acetil-hexosídeo)-quercetina e 7-O-(cumaroil-hexosídeo)-apigenina), e um hidroxinerolidol. Assim, este estudo revelou o ótimo potencial inibidor das enzimas COX-1 e 5-LOX dos extratos hidrometanólicos das espécies de Lychnophorinae. Além disso, indicou as substâncias mais discriminantes responsáveis por essa atividade, sendo as substâncias acima mencionadas as propostas como as principais responsáveis pela atividade inibidora das enzimas COX e LOXSeveral compounds from Lychnophorinae species (Asteraceae) are reported as inhibitors of cascade mediators that elicits the inflammatory process. During this process, two enzymes are essential in the metabolism of the arachidonic acid: cyclooxygenase (COX) and lipoxygenase (LOX). The analysis of metabolic fingerprinting is a method that provides information about the object of study by using statistical tools, and enables the correlation of these data with others using in silico methods. This work therefore aimed to analyze 26 species of the Lychnophorinae subtribe for in vitro inhibition of COX-1 and 5-LOX and (to) identify the bioactive compounds responsible for this activity by in silico correlation analysis between bioactivity and metabolic fingerprint. The metabolomic analysis was carried out using UHPLC-DAD-ESI-Orbitrap and a metabolic fingerprint for each extract was obtained. The in vitro inhibition screening assays of COX-1 and 5-LOX revealed that 20 extracts presented dual inhibitory activity on both enzymes with IC50 values lower than 100 ?g.mL-1. Among them, 11 species showed IC50 values lower than 40 ?g.mL-1 and five lower than 10 ?g.mL-1. In order to identify discriminant substances (active), supervised and non-supervised multivariate statistical analysis (PCA, PLS e OPLS) were performed using the metabolic fingerprints and the results of enzyme inhibition. Through correlation analysis, it was possible to locate the substances most likely to be responsible for the pharmacological activity in both enzymes simultaneously; among them, five were chosen as the most likely. The substances were identified by dereplication as: a sesquiterpene lactone (4,5-dihydro-15-desoxygoyazensolide), two flavonoids (3-O-(acetil-hexoside)-quercetin and 7-O-(cumaroil-hexoside)-apigenine), and a hidroxynerolidol. In summary, in this work it was possible to reveal crude extracts with outstanding inhibitory potential of both, COX-1 and 5-LOX, enzymes as well as to propose the most probable compounds responsible for this action, and the compounds mentioned above were proposed as the main responsible for the inhibitory activity.
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Mouawad, Charbel. "Effets pleiotropiques des statines : un rôle anti-inflammatoire impliquant la HO-1 et antifibrogénique impliquant la COX-2." Paris 7, 2009. http://www.theses.fr/2009PA077156.
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Les statines sont des inhibiteurs compétitifs de la HMG-CoA réductase, enzyme essentielle dans la voie du mévalonate aboutissant à la biosynthèse du cholestérol. Elles possèdent des propriétés anti-inflammatoires, antiprolifératives, anti-oxydantes et anti-thrombotiques leur conférant un puissant effet protecteur. Les hème-oxygénases sont les enzymes responsables du catabolisme de Thème pour libérer la Fe²⁺, la bilirubine et le monoxyde de carbone. Les deux derniers produits sont responsables des propriétés protectrices. Une large variété de stimuli est capable d'induire l'expression de la hème-oxygénase-1, l'isoforme inductible, y compris les endotoxines, les métaux lourds, les donneurs de l'oxyde nitrique et les statines. Cette régulation se fait essentiellement au niveau transcriptionelle. Les cyclo-oxygénases et les prostaglandines E synthases sont responsables de la libération de la PGE2 à partir de l'acide arachidonique. Les isoformes inductibles de ces deux enzymes sont la cyclo-oxygénase-2 et la prostaglandine E synthase microsomale-1. Elles sont impliquées dans multiples processus physiologiques et pathophysiologiques dans l'organisme. Le but de ce travail est d'étudier les effets bénéfiques des statines en explorant la régulation de la hème-oxygénase-1 et de la prostaglandine E₂. Dans un premier temps, nous avons montré que les statines induisent l'expression de la HO-1 dans les macrophages murins (lignées et primaires). Cette induction, temps et dose dépendante, implique une signalisation via l'oxyde nitrique dans les RAW 264. 7 et J774A. 1 (lignées) mais non dans les macrophages murins péritonéaux élicités de deux souches différentes de souris. Nous avons également montré que le C/EBPβ et PAP-1 sont parmi les facteurs de transcription activés lors de cette régulation. Les statines sont anti-inflammatoires et réduisent la libération de l'IL-6 et du TNFα induite par le LPS dans les macrophages péritonéaux isolés de souris C57BL/6. L'effet observé sur le TNFa impliquerait la HO-1. Pour explorer davantage la régulation transcriptionnelle du gène de la HO-1 par les statines, nous avons utilisés les fibroblastes murins NIH3T3 et montré que les statines activent le C/EBPβ et δ ainsi que les USF-1 et 2. L'effet des statines est contrôlé par la région 0. 149Kb proximale du promoteur de la HO-1. D'autre part, nous avons montré que les statines induisent l'expression de la cyclo-oxygénase-2 et de la prostaglandine E synthase microsomale-1 dans les myofibroblastes hépatiques humaines. L'induction est dépendante de la voie du mévalonate et particulièrement de la géranylgéranylation des Rhô A/C. Dans ce système, les statines sont capables d'induire la libération de la prostaglandine E2 ainsi que de l'AMP cyclique. Finalement, nos travaux suggèrent que les effets antiprolifératifs observés pour les statines impliqueraient la COX-2Statins are competitive inhibitors of the HMG-CoA reductase, the rate limiting enzyme in the mevalonate pathway leading to cholesterol biosynthesis. First described as lipid lowering agents, these molecules also play an anti-inflammatory, anti-oxidant and anti-thrombotic role. Heme-oxygenase-1 is the inducible form of heme-oxygenase, responsible for the degradation of heme into Fe²⁺ and the mainly protective bilirubin and carbon monox4de. A wide variety of stimuli is able to induce transcriptional régulation of heme-oxygenase-1 including heavy metals, nitric oxide donors and statins. Cyclo-oxygenase-2 and microsomal prostaglandin E synthase-1 are inducible enzymes responsible of the formation of the active metabolite prostaglandin E₂ from arachidonic acid. Our aim is to explore the beneficial effects of statins by studying the regulation of heme-oxygenase-1 and cyclo-oxygenase-2/ microsomal prostaglandin E synthase-1 in different cellular models. First we show that statins upregulate heme-oxygenase-1 protein expression in both cell line and primary murine macrophages. This upregulation is partially mediated by nitric oxide in RAW 264. 7 and J774A. 1. In RAW 264. 7, we describe a role of C/EBPβ and AP-1 in the statins response. In primary macrophages elicited form C57BL/6 mice, statins are anti-inflammatory. To further explore the transcriptional regulation of heme-oxygenase-1 by statins, we used a murine embryonic flbroblast cell line, NIH 3T3 and demonstrate an activation of the C/EBPβ and δ and USF-1 and 2 transcription factors by statins. Transfection experiments with different HO-1 promoter constructs show that the statins effect is mediated by thé 0. 149 Kb proximal promoter region. We also show that statins induce cyclo-oxygenase-2 and microsomal prostaglandin E synthase-1 protein expression and the release of prostaglandin E₂ and cyclic AMP in human hepatic myofibroblasts. The cyclo-oxygenase-2 induction is dependent on the mevalonate pathway and the geranylgeranylation of Rho A/C small G protein and could play a role in the anti-proliferative effect of statins observed in these cells
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Almeida, Paulo Roberto Carvalho de. "ImunoexpressÃo de ciclooxigenase-2 (COX-2) e caderina-e no cÃncer gÃstrico: contribuiÃÃo ao estudo da progressÃo tumoral-linfonodal." Universidade Federal do CearÃ, 2007. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1222.
Full textAbstract:
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorCOX-2 e Caderina-E participam de forma fundamental na manutenÃÃo do estado fisiolÃgico da mucosa gÃstrica e tÃm papel essencial na reaÃÃo inflamatÃria e reparo, e no cÃncer. O objetivo deste trabalho à avaliar a expressÃo das duas proteÃnas no carcinoma gÃstrico e metÃstases linfonodais e suas possÃveis participaÃÃes na progressÃo tumoral. Foram utilizados 97 casos de gastrectomias por carcinoma gÃstrico, 36 dos quais com linfonodos disponÃveis, dos arquivos do Hospital do CÃncer do CearÃ. Os casos foram classificados nos tipos intestinal (40 casos), difuso (34), mistos (16) e nÃo-classificados (7 casos) de acordo com a classificaÃÃo de Lauren (1965). Utilizou-se tÃcnica de tissue microarray associada à imunohistoquÃmica com anticorpo monoclonal anti-COX-2 e anti-Caderina-E e sistema de detecÃÃo universal estreptavidina-biotina-peroxidase. A expressÃo de COX-2 foi avaliada de acordo com os seguintes escores: Intensidade (I): 0=negativa; 1=discreta; 2= moderada; 3= acentuada; ExtensÃo (E) de cÃlulas coradas: 1= 0 a 25%; 2= >25 a 50%; 3= >50 a 75%; 4= >75 a 100%. Escore final: I x E, sendo considerados escores < 6 como COX-2 de baixa expressÃo e escores ≥6 de alta expressÃo. Classificou-se a expressÃo de Caderina-E nos escores: 0=negativo; 1=citoplasmÃtica; 2=citoplasmÃtica + membranar; 3= membranar-normal (Jawhari et al., 1997a). Foram comparadas expressÃo normal e anormal e membranar e nÃo membranar em cada histotipo de carcinoma, na sede primÃria e linfonodos. ExpressÃo positiva para COX-2 e anormal de Caderina-E predominaram nos diversos histotipos de carcinoma gÃstrico primÃrio, principalmente difusos e mistos. Observou-se maior expressÃo de COX-2 nas metÃstases linfonodais, em relaÃÃo Ãs lesÃes primÃrias, sobretudo nos carcinomas difusos. Carcinomas intestinais estavam associados à expressÃo membranar de Caderina-E enquanto tumores difusos se relacionaram com ausÃncia de expressÃo membranar, o que mostra a importÃncia da Caderina-E na diferenciaÃÃo do cÃncer gÃstrico. Carcinomas gÃstricos apresentam dois padrÃes de imunomarcaÃÃo citoplasmÃtica: granular (paranuclear), associado à expressÃo citoplasmÃtica exclusiva, que prevalece no componente difuso dos tumores mistos, e homogÃneo, em todo o citoplasma, correlacionado com expressÃo citoplasmÃtica-membranar, predominante nos outros histotipos. Carcinomas difusos apresentam expressÃo membranar de Caderina-E, que se expressa com maior freqÃÃncia nas metÃstases linfonodais do que nas lesÃes primÃrias e està presente em grupos celulares infiltrantes e cÃlulas isoladas, nas duas sedes anatÃmicas. Os dados sugerem que o carcinoma misto representa histotipo distinto de carcinoma gÃstrico, baseado nos aspectos peculiares da expressÃo citoplasmÃtica de Caderina-E aqui mostrados e em outros achados da literatura. NÃo houve associaÃÃo estatisticamente significativa entre expressÃo de COX-2 e de Caderina-E e demais parÃmetros clÃnico-patolÃgicos nesta amostra. Os dados aqui observados sugerem que COX-2 e Caderina-E sÃo importantes proteÃnas relacionadas com a progressÃo tumoral-linfonodal no cÃncer gÃstrico
Both COX-2 and E-Cadherin play important roles in physiological and pathological processes in the stomach, such as control of acid secretion, inflammation and cancer. The aim of this study was to analyze the relationship between COX-2 and E-Cadherin immunoexpression in human gastric adenocarcinomas and respective lymph node metastases and their possible action in tumoral progression. Tissue microarrays were prepared from paraffin embedded samples of 97 primary gastric cancers, included 36 with respective nodal metastases. Cases were classified according to Laurenâs classification as intestinal (n=40), diffuse (n=34), mixed (n=16) and undetermined (n=7). Immunoexpression of COX-2 was evaluated regarding intensity (0-absent; 1-mild; 2-moderate; 3-strong) and extension (0-negative or rare cells; 1-<25%; 2-25-50%; 3-50-75%; 4->75% immunoreactive neoplastic cells). A combined score was calculated (intensity x extension): 0-12. A cut-off of 6 was considered to classify COX-2 expression as low (<6) or high (≥6). E-Cadherin expression was evaluated according to the system proposed by Jawhari et al. (Gastroenterology, 1997) as abnormal patterns of expression: 0-no expression; 1-cytoplasmic expression; 2-heterogeneous expression, both membranous and cytoplasmic) and normal membranous pattern (3). Membranous (scores 2 and 3) and Non-membranous (scores 0 and 1) were too compared. Overall, COX-2 positive and abnormal E-Cadherin expression predominate in all types of primary gastric carcinomas. COX-2 expression was higher in lymph node metastases than in primary tumors, with a significant difference for diffuse carcinoma. A positive relationship was observed between E-Cadherin membranous expression and intestinal tumors, and absence of membranous expression and diffuse ones, which indicates the importance of E-Cadherin to gastric cancer differentiation. Granular (paranuclear) cytoplasmic immunostaining pattern was basically associated with cytoplasmic E-Cadherin expression while homogeneous pattern is frequently seen in cytoplasmic-membranous expression. Diffuse carcinomas show membranar expression more frequently in lymph nodes metastases than in gastric primary tumors in both isolated and grouped cells. The data suggest that mixed carcinoma is a distinct hystotype, based on its peculiar cytoplasmic expression of E-Cadherin shown here and other features of literature. There was no significant association linking COX-2 and E-Cadherin expression to other clinicopathological parameters. The data show that COX-2 and E-Cadherin are important proteins related to tumoral progression in gastric cancer
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Tomitão, Michele Tatiana Pereira. "Análise de polimorfismos do gene ciclooxigenase-2 (COX-2) no câncer colorretal." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/5/5168/tde-20042016-142620/.
Full textAbstract:
A População brasileira apresenta elevada diversidade genética devido à multietnicidade, que têm implicações clínicas/genéticas importantes. O estudo de genes polimórficos pode auxiliar na detecção de pessoas com maior risco de desenvolver câncer, caracterização de evolução diferenciada, resposta distinta ao tratamento quimioterápico ou radioterápico e prognóstico. A ciclooxigenase-2 (COX-2) é induzida em resposta ao fator de crescimento e citocinas, sendo expressa nas doenças inflamatórias, lesões pré-malignas e tumores colorretais. Este trabalho teve como objetivos avaliar a influência dos polimorfismos 1195A > G e 8473T > C do gene COX-2 como fatores de risco para o desenvolvimento de câncer colorretal e investigar o impacto dos polimorfismos na progressão e sobrevida de pacientes submetidos ao tratamento cirúrgico por câncer colorretal. Avaliaram-se SNPs (polimorfismos de nucleotídeo único) em 230 pacientes submetidos à ressecção cirúrgica no Hospital das Clínicas (SP), seguidos por 5 anos e 196 controles, operados por doença benigna na mesma instituição, pareados quanto ao sexo e idade, sem histórico individual ou familial de câncer. Isolou-se o DNA dos leucócitos utilizando-se do kit de extração e purificação PureLink DNA Minikit, seguido de amplificação pela reação em cadeia da polimerase (PCR). Utilizou-se a análise do PCR em Tempo Real para determinar os genoótipos os polimorfismos através dos ensaios TaqMan ® SNP Genotyping Assay. Os resultados encontrados foram associados aos dados epidemiológicos e clinicopatológicos dos pacientes. Determinaram-se as frequências genotípicas, alélicas e estimaram-se as frequências de haplótipos dos polimorfismos do COX-2 -1195A > G e 8473T > C. As populações estão em equilíbrio de Hardy-Weinberg, a exceção do grupo controle para o polimorfismo 8473T > C (p=0,02). As frequências foram similares nos grupos caso e controle para genótipos e haplótipos, portanto, não há associação entre esses polimorfismos e risco de CCR. Em relação às variáveis epidemiológicas e anatomopatológicas do grupo caso, demonstraram-se associação das mesmas com alguns perfis genotípicos. Encontrou-se frequência elevada do genótipo polimórfico -1195GG na população oriental, grupo constituído em sua maioria por japoneses, e dos genótipos 8473TC e CC em afrodescendentes (p < 0,05). Neste grupo, o genótipo -1195GG é ausente. Foi encontrada. Encontrou-se associação entre invasão angiolinfática e genótipo polimórfico 8473 CC (p < 0,05). Na análise de sobrevida, houve associação, no modelo codominante e dominante, do genótipo COX-2 -1195GG com menor sobrevida global (AAxGG: RR = 2,78; IC95% = 1,13-6,84; p < 0,020 e AA/AG x GG: RR = 2,59; IC95% = 1,07-6,27; p < 0,04), utilizando o modelo de regressão múltipla, ajustado para as variáveis de confusão. Assim, pode-se concluir que as variantes -1195A > G e 8473T > C não participam da suscetibilidade genética ao CCR na população brasileira. O polimorfismo -1195A > G, associado à menor sobrevida, pode atuar como marcador prognóstico nestes pacientesBrazilian population displays very high levels of genomic diversity due to the multi-ethnicity, which have important clinical/genomic implications. Polymorphic genes\' study may aid in the detection of people at higher risk of developing cancer, characterization of differentiated outcome, distinctive response to chemotherapy or radiotherapy and prognosis. Cyclooxygenase-2 (COX-2) is induced in response to growth factor and cytokines, and it is expressed in inflammatory diseases, precancerous lesions and colorectal tumors. This study aimed to evaluate the influence of COX-2 -1195A> G and 8473T> C gene polymorphisms as a risk factor for developing colorectal cancer and to investigate the impact of polymorphisms on progression and survival in patients who have undergone surgical treatment for colorectal cancer. We evaluated SNPs (Single nucleotide Polymorphism) of 230 colorectal cancer resected patients admitted at the Hospital das Clinicas (SP), followed by 5 years, and 196 controls, operated for benign disease at the same institution, matched for age and sex, and no individual or familial history of cancer. DNA was isolated from leukocyte using PureLink (TM) Genomic DNA Mini Kit, followed by amplification by polymerase chain reaction (PCR). Real-time analysis was used for genotyping of polymorphisms, through the TaqMan ® SNP Genotyping Assay. The results of the polymorphisms were associated to epidemiological, clinicopathological and immunohistochemical features of the patients. Were determined genotype and allelic frequencies, and were estimated the haplotype frequencies of COX-2 -1195A > G and 8473T > C polymorphisms. The populations are in Hardy-Weinberg equilibrium, except for the control group to the 8473T > C polymorphism (p = 0,02). The frequencies were similar in case and control groups for genotypes and haplotypes, therefore, there is no association between these polymorphisms and risk of CCR. Regarding the epidemiological and pathological variables in the case group, we demonstrate their association with some genotypic profiles. A high frequency of the polymorphic genotype -1195GG was found in an Asiatic population, group composed in its majority by Japaneses, and 8473TC and CC genotypes in African descent (p < 0,05). In this group, the 1195GG genotype is absent. Association was found between angiolymphatic invasion and polymorphic genotype 8473 CC (p < 0,05). In survival analysis, there was an association, in co-dominant and dominant model, of the COX-2 genotype -1195GG with decreased overall survival (AAxGG: RR = 2,78, 95% CI 1,13-6,84; p < 0,020 and AA / AG x GG: RR = 2,59, 95% CI 1,07-6,27; p < 0,04), using the multiple regression model, adjusted for confounding variables. Therefore, -1195A variants > G and 8473T > C does not appear participate in genetic susceptibility to CCR in the Brazilian population, but the polymorphism -1195A > G, associated with decreased survival, may act as a prognostic marker in these patients
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Valkealahti, M. (Maarit). "The effects of bisphosphonates and COX-2 inhibitors on the bone remodelling unit." Doctoral thesis, University of Oulu, 2008. http://urn.fi/urn:isbn:9789514288548.
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Abstract Bone remodelling occurs in humans throughout life, therefore bone is continuously renewed to better respond to changes in weightbearing circumstances. Bone remodelling is extremely vulnerable during fracture healing and integration of prostheses into the surrounding bone. Bone remodelling is a complex system in which many growth factors, cytokines and enzymes, which are essential for the differentiation of osteoblasts and osteoclasts, are involved. Some widely used drugs can affect this sensitive system of remodellation in unexpected manner. Painkillers such as cyclooxygenase (COX) inhibitors have been demonstrated in animal studies to interfere with fracture healing and a few retrospective clinical studies confirm these observations. Bisphosphonates (BP), main target of which is the bone resorbing osteoclast, have been suggested to be the drug of choice to improve periprosthetic bone density and thus prevent aseptic loosening of implants. The exact mechanism of action of clodronate (CLO), a non-amino-BP, which was selected for the study, has not been clarified thus far. In order to gain a deeper understanding of the role of the COX enzyme in the differentiation of osteoblasts we studied human mesenchymal stem cell (hMSC) cultures in the presence of different COX-inhibitors; indomethacine, parecoxib and NS398, a specific COX-2 inhibitor. We used the liposome encapsulated CLO metabolite (AppCCl2p) to study in detail the mechanism of BP induced apoptosis in osteoclast. The effects of different BPs CLO, pamidronate (PAM) and zoledronic acid (ZOL), on the differentiation of osteoblasts and osteoclasts were tested in vitro. The optimal concentration for in situ CLO rinsing in clinical study was found. Finally, the effects of in situ and per oral CLO on the periimplant bone density and integration of prostheses were studied in vivo. All tested COX-inhibitors significantly inhibited osteoblast differentiation from hMSCs and stimulated the differentiation of adipocytes. It was also demonstrated that AppCCl2p inhibits mitochondrial function by a mechanism that involves competitive inhibition of ADP/ATP translocase. In the comparison of BPs, ZOL seemed to posses the properties of both non-amino- and amino-BPs and it thus belongs to a new class of BPs. Peroral and in situ CLO seemed to have different mechanisms of action. Peroral CLO delayed the integration of prosthesis to the bone and increased peri-implant osteolysis while is situ CLO accelerated integration. In conclusion, we can alter normal bone remodellation during fracture healing and prosthesis integration. On the other hand, we can also improve the circumstances for the integration of implant to the surrounding bone by in situ BP rinsing, thus creating a better environment for bone ingrowthTiivistelmä Läpi elämän luustossa tapahtuu uudelleenmuotoutumista, remodelaatiota, jonka seurauksena luu pystyy paremmin vastaamaan muuttuneisiin kuormitusolosuhteisiin. Remodelaatioprosessi on hyvin haavoittuvainen murtuman luutumisen aikana sekä proteesin kiinnittyessä ympäröivään luuhun. Luun remodelaatioon osallistuvat kasvutekijät, sytokiinit ja entsyymit, jotka puolestaan ovat välttämättömiä osteoblastien ja osteoklastien erilaistumiselle. Monet lääkeaineet voivat yllättävällä tavalla vahingoittaa tätä herkkää remodelaatiosysteemiä. Kipulääkkeet, kuten syklo-oksygenaasi (COX) estäjät, voivat häiritä murtuman luutumista aikaisempien eläintöiden ja muutamien retrospektiivisten potilastutkimusten mukaan. Lisäksi bisfosfonaatit, joiden päävaikutuskohde on luuta hajoittava osteoklasti, voisivat olla lupaavia lääkkeitä myös parantamaan proteesia ympäröivän luun laatua ja siten estämään aseptista implantin irtoamista. Tutkimuksen yhtenä tarkoituksena oli selvittää klodronaatin, ensimmäisen polven typpi-ryhmää sisältämättömän bisfosfonaatin tarkka vaikutusmekanismi. Viljelemällä ihmisen luuytimen kantasoluja indometasiinia, parekoksibia tai spesifistä COX-2 estäjää NS 398:a, sisältävässä kasvatusliuoksessa selvitettiin COX-entsyymin merkitys osteoblastien erilaistumiselle. Liposomien sisälle pakattua klodronaatin metaboliittia (AppCCl2p) käytettiin tutkittaessa millä vaikutusmekanismilla klodronaatti aiheuttaa osteoklastien apoptoosin. Bisfosfonaattien; klodronaatin, pamidronaatin ja tsoledronaatin vaikutusta osteoklastien ja osteoblastien erilaistumiseen tutkittiin soluviljelmämallissa ja määritettiin kliinisessä potilastyössä paikallisesti käytettävän klodronaattiliuoksen pitoisuus. Lopuksi potilastyössä selvitettiin paikallisen klodronaattihuuhtelun ja suun kautta annostellun klodronaatin vaikutus proteesia ympäröivän luun tiheyteen ja proteesin kiinnittymiseen ympäristöönsä. Tutkimukseen valitut COX-estäjät vähensivät ihmisen kantasolujen erilaistumista osteoblasteiksi ja lisäsivät erilaistumista rasvasoluiksi. Lisäksi todettiin, että AppCCl2p estää mitokondrioissa tapahtuvaa hengitystä estämällä ADP/ATP-vaihtajan toiminnan, saaden aikaan solukuoleman. Vertailtaessa bisfosfonaatteja, tsoledronaatilla vaikutti olevan sekä ensimmäisen, että kolmannen polven (sisältää typpi-ryhmän) bispfosfonaattien vaikutuksia, joten tsoledronaatti kuuluu aivan uuteen bisfosfonaattiryhmään. Potilastutkimuksessa suun kautta ja paikallisesti reisiluun ytimeen annostellulla klodronaatilla oli täysin erilainen vaikutus. Suun kautta syötynä klodronaatti hidasti proteesin kiinnittymistä ja aiheutti osteolyysiä. Sen sijaan paikallinen klodronaatti nopeutti merkittävästi proteesin kiinnittymistä ympäröivään luuhun. Näiden tutkimustulosten perusteella voidaan olettaa, että COX-estäjät, samoin kuin peroraalinen bisfosfonaatti, voivat tahattomasti häiritä luun remodelaatiota
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An, Ying. "Cell-Type Specific Actions of Inflammatory Mediators in the CNS." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1460544960.
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Davies, Richard. "Effect of selective COX-2 inhibitors on hepatic progenitor cells and the pathologies of experimental hepatocarcinogenesis." University of Western Australia. School of Medicine and Pharmacology, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0190.
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[Truncated abstract] Hepatocellular carcinoma (HCC) is the major malignancy complicating chronic liver disease. New therapies for the prevention of HCC are required due to the limited success and high tumour recurrence rates of existing treatments. Emerging evidence suggests that HCC arise from the transformation of adult liver progenitor cells (LPCs), which have the capacity to differentiate into hepatocytes and biliary cells during liver regeneration. LPC activation precedes neoplasia in experimental hepatocarcinogenesis. LPCs share antigenic epitopes with HCCs, including α-fetoprotein (AFP) and M2- pyruvate kinase (M2PK). In animal models of hepatocarcinogenesis, attenuation of the LPC response reduces the incidence of HCC following prolonged liver injury via a tumour necrosis factor (TNF) dependent mechanism. As TNF is a pro-inflammatory cytokine, these data suggest that anti-inflammatory agents may be effective in inhibiting LPC activation and hepatocarcinogenesis. Cyclo-oxygenase-2 (COX-2) is an inducible enzyme that mediates the production of many prostaglandins during inflammation and carcinogenesis. Recent investigations show that the administration of selective COX-2 inhibitors (SC2Is) may reduce the incidence of a variety of tumours including breast, colon and skin. The broad aim of this thesis was to conduct a series of detailed studies on the effects of a SC2I on LPC activation and the hepatic pathologies associated with hepatocarcinogenesis in order to test the hypothesis that S2CIs may be a beneficial therapy that can reduce liver injury and pre-neoplastic changes in the choline-deficient, ethionine supplemented (CDE) murine model of hepatocarcinogenesis. Administration of a SC2I (SC-236) significantly inhibited a variety of hepatic cell populations that expand during the first month of the CDE mouse model of hepatocarcinogenesis (a choline deficient, ethionine supplemented diet). Numbers of M2PK-positive LPCs (which are more hepatocytic in morphology and are also COX-2 positive) and inflammatory cells were all significantly reduced by SC-236. In contrast, numbers of A6-positive LPCs (which are more biliary cell-like in morphology and do not express COX-2) were unchanged. ... In summary, these data suggest that COX-2 inhibitors such as SC-236 inhibit LPC activation and a variety of pre-neoplastic liver pathologies as a result of COX-2 dependent and independent mechanisms that may be mediated through inhibition of Akt phosphorylation and induction of apoptosis. Moreover, SC2Is may be useful as preventative treatment strategies for HCC in patients with chronic liver disease.
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Pinheiro, Anderson 1981. "Receptores de estrógeno e progesterona, Ki67, Bcl-2 E Cox-2 em pólipos endometriais de mulheres na pré e pós-menopausa e associação com a obesidade, : Estrogen and progesterone receptors, Ki67, Bcl-2 and Cox-2 markers in benign endometrial polyps in pre and postmenopausal women and their association with obesity." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310480.
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Orientador: Lúcia Helena Simões da Costa PaivaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Introdução: A prevalência de obesidade tem aumentado em todo o mundo e hoje já representa um problema de saúde pública. Na população feminina, seu aumento ocorre principalmente nos anos próximos da transição para menopausa. O aumento de peso representa um risco para diversas comorbidades, dentre elas um importante fator de risco para patologia endometrial. A etiologia e a patogênese dos pólipos não estão completamente esclarecidas. Estuda-se se o desenvolvimento dos pólipos endometriais está diretamente relacionado à presença de receptores hormonais, além de estar relacionado a mecanismos envolvidos à proliferação e à apoptose celular. Objetivos: Avaliar a imunoexpressão dos receptores de estrógeno (RE), progesterona (RP), Cox-2, Ki67 e Bcl-2 em pólipos endometriais benignos na pré e pós-menopausa e associação com a obesidade. Materiais e métodos: Dentre 1050 mulheres submetidas à histeroscopia cirúrgica no Hospital da Mulher Prof. Dr. Aristodemo Pinotti - CAISM/UNICAMP, de janeiro de 1998 a dezembro de 2008, 800 foram casos de polipectomia endometrial confirmados com exame anatomopatológico. Deste total, foram excluídas as usuárias de Tamoxifeno, as que faziam uso de terapia hormonal e os casos de pólipos malignos ou pré-malignos. Obteve-se uma amostra de 515 pólipos endometriais benignos em mulheres na pré e pós-menopausa. Foram avaliadas as expressões de RE, RP, Bcl-2, Ki67 e Cox-2, através de imuno-histoquímica, segundo a porcentagem de células coradas, intensidade da coloração e escore final. Os escores finais de RE, RP, Bcl-2, Cox-2 variam de 0 a 8 e o de Ki67 de 0 a 3. A mediana dos escores finais de RE, RP, Bcl-2, Cox-2 e Ki67 no epitélio glandular e no estroma dos pólipos foi comparada entre mulheres obesas e não obesas na pré e pós-menopausa, utilizando os testes qui-quadrado, exato de Fisher ou não paramétrico de Mann-Whitney. Resultados: A mediana do escore final de receptores hormonais mostrou maior expressão de RP no estroma e no epitélio glandular das mulheres obesas na pós-menopausa, sem diferença em relação à expressão dos RE. Em mulheres na pré-menopausa não houve diferença na expressão de RE e RP entre obesas e não obesas. Nos pólipos endometriais de mulheres pós-menopausadas houve maior expressão de Cox-2 e Bcl-2 no epitélio glandular das mulheres obesas do que em relação às mulheres não obesas. Não houve diferenças em relação ao estroma endometrial. Na pré-menopausa, houve maior expressão de Bcl-2 apenas no epitélio glandular das mulheres obesas. Não houve diferenças na expressão de Ki67 entre obesas e não obesas tanto na pós-menopausa quanto na pré-menopausa. Conclusões: Os pólipos de mulheres obesas apresentam, na pós-menopausa, maior expressão de RP glandular e estromal, Cox-2 glandular e Bcl-2 glandular, sem diferenças na expressão de Ki67. Estes dados sugerem que sua etiopatogênese dos pólipos em obesas parece estar mais relacionada aos receptores de progesterona, à inibição da apoptose e aos mecanismos relacionados à inflamação celular
Abstract: Introduction: The prevalence of obesity has increased worldwide and represents a public health problem nowadays. The female population, considerably presents its increase in the coming years of the transition to menopause. Weight gaining represents a risk for various comorbidities, but among them all, it is an important risk factor for the endometrial pathology. The polyps etiology and pathogenesis have not been completely clarified so far. It has been studied whether the endometrial polyps development is directly related to the presence of hormone receptors, besides being associated with mechanisms involved in the proliferation and cellular apoptosis.Objectives: To evaluate the immunoexpression of estrogen and progesterone receptors, Ki67, Bcl-2 and Cox-2 in benign endometrial polyps in pre and postmenopausal women and their association with obesity. Methods: It was observed that among 1050 women who underwent hysteroscopic surgery at the "Prof. Dr. José Aristodemo Pinotti" Women's Hospital-CAISM-UNICAMP from January 1998 to December 2008, 800 were confirmed with endometrial polyp anatomopathological diagnosis. Of this total amount, it was excluded tamoxifen users, those who used hormone therapy and cases of malignant or pre-malignant polyps. It was obtained a sample of 515 benign endometrial polyps in women before and after menopause. It was also assessed the expression of ER, PR, Bcl-2, COX-2 and Ki67 through immunohistochemistry according to stained cells percentage, staining intensity, and the final score. The ER, PR, Bcl-2, Cox-2 final score ranges from 0 to 8 and the Ki67 from 0 to 3). The ER, PR, Bcl-2, Cox-2 and Ki67 median final scores in the glandular epithelium and stroma of the polyps were compared among obese and nonobese women, in pre and postmenopausal condition, using the Chi-square Fisher's exact test or nonparametric Mann-Whitney test. Results: The hormonal receptors median final score has showed an increased expression of progesterone receptors in the stroma and glandular epithelium of postmenopausal obese women but there was no difference in expression of ER estrogen receptors. In premenopausal women, there was no difference in expression of ER and PR among obese and nonobese women. The endometrial polyps in postmenopausal women have showed a higher expression of Cox-2 and Bcl-2 in glandular epithelium in obese women rather than in nonobese women. There were no differences in the endometrial stroma. In premenopausal women, there was a higher expression of Bcl-2 only in the obese women glandular epithelium. There were no differences in Ki67 expression among obese and nonobese both postmenopausal and premenopausal women. Conclusions: Obese women polyps, in postmenopausal condition, have increased expression of glandular and stromal PR, Cox-2 and Bcl-2 glandular. However, there are no differences in the Ki67 expression . These data suggest that its etiopathogenesis in obese women polyps, seem to be related to progesterone receptors, apoptosis inhibition and also to mechanisms associated with cellular inflammation
Mestrado
Fisiopatologia Ginecológica
Mestre em Ciências da Saúde
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Hoxha, M. "THE POTENTIAL THERAPEUTIC ROLE OF MONTELUKAST AND NEW HYBRID AGENTS, TXA2 ANTAGONIST-COX-2 INHIBITORS IN CARDIOVASCULAR EVENTS." Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/347148.
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The main target of my PhD research project was to explore new alternatives to reduce the cardiovascular (CV) risk targeting the arachidonic acid metabolites. Hence, I have been part of two different projects, one studying multitarget compounds with balanced COXIB and TP receptor antagonist properties, and the other evaluating the potential role of a leukotriene (LT) antagonist drug such as montelukast in improving the CV outcome.
In reference to the first project, new multitarget compounds were synthesized at the University of Turin, by substituting the carboxylic function of Lumiracoxib. This strategy led to several new compounds, of which we have analyzed the platelet aggregation, total inositol phosphate production, COX-1 and COX-2 inhibitory activity. Out of all the studied compounds compound 18, the terazole derivative as well as compound 20 were the most active, with a decent balanced activity as COXIB and TP antagonist . Whereas, compound 32, displaying a functional group of terutroban did not accomplish our expectation to be a more potent TP antagonist with respect to compounds 7,18,20. Our main goal is to obtain new molecules with higher TP antagonist properties but at the same time retaining the COXIB activity. It is important to highlight that the therapeutic effect of these new compounds depend on the balance of two pharmacological profiles. The results we obtained demostrate that it is possible to have new chemical entities with higher TP antagonist potencies, and better balanced COX-2 selectivity. This approach will provide further benefits for patients with chronic pain taking a COXIB, and in patients with higher CV risk, like diabetics and hopefully can lead to a new generation of safer non steroidal antiinflammatory drugs.
The second project of my PhD was focused on a LT antagonist drug such as montelukast, which is a pharmacological alternative for patients suffering asthma, allergic rhinites and urticaria. We performed a retrospective study including patients exposed or not to montelukast for a total of eight hundred asthmatic patients to assess the potential role of montelukast in primary and secondary prevention of major CV events as ischemic stroke (IS) or myocardial infarction (MI). Each of the two subjects sample was further classified in patients with or without MI or IS based on their diagnosis according to the International Classification of Diseases (ICD). The myocardial infarction event rate was almost 6 fold higher in asthmatic patients not taking montelukast and 9 fold higher for ischemic stroke events. Drug used in these patients were also monitored in order to exclude potential confounders of the results. Overall, our results suggest a reduction of CV events by montelukast, including both MI and IS eventhough the study should be expanded to a larger number of subjects. Given their association with the inflammatory onset and amplification, LTs synthesis inhibitors or LT receptor antagonists such as montelukast could be consider as potential approach for CV diseases.
The results obtained during this three years of PhD cycle have shown that new innovative strategies targeting arachidonic acid metabolites can be implied to improve the CV outcome. There is still an unmet need for an anti-inflammatory treatment to reduce the CV risk, and these strategies can lead to new pharmacological approaches.
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Elliott, Christopher S. "The Chemoprevention of Lung Cancer Using Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1041537546.
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Laube, Markus [Verfasser], Torsten Akademischer Betreuer] Kniess, Jens [Akademischer Betreuer] [Pietzsch, Jörg Akademischer Betreuer] Steinbach, and Thomas [Akademischer Betreuer] [Henle. "Synthese von Cyclooxygenase-2-Inhibitoren als Grundlage für die funktionelle Charakterisierung der COX-2-Expression mittels PET / Markus Laube. Gutachter: Jörg Steinbach ; Thomas Henle. Betreuer: Torsten Kniess ; Jens Pietzsch ; Jörg Steinbach." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://d-nb.info/1069093106/34.
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Laube, Markus Verfasser], Torsten [Akademischer Betreuer] Kniess, Jens [Akademischer Betreuer] [Pietzsch, Jörg Akademischer Betreuer] Steinbach, and Thomas [Akademischer Betreuer] [Henle. "Synthese von Cyclooxygenase-2-Inhibitoren als Grundlage für die funktionelle Charakterisierung der COX-2-Expression mittels PET / Markus Laube. Gutachter: Jörg Steinbach ; Thomas Henle. Betreuer: Torsten Kniess ; Jens Pietzsch ; Jörg Steinbach." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://d-nb.info/1069093106/34.
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Ronkainen, H. L. (Hanna-Leena). "Novel prognostic biomarkers for renal cell carcinoma." Doctoral thesis, Oulun yliopisto, 2012. http://urn.fi/urn:isbn:9789514297731.
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Abstract Background and aims: Stage and grade are the most widely used prognostic parameters for renal cell carcinoma (RCC). The clinical course of this disease is not, however, always predictable by traditional prognostic factors. In the era of new molecular targeted therapies a more accurate prognostication of RCC patient survival is important for the individualization of treatment and follow-up of patients. Despite exhaustive research there are still no prognostic biomarkers for RCC in clinical practice. In order to find novel prognostic tissue markers for RCC, we examined the expression of 14 biomarkers involved in carcinogenesis and clarified their prognostic significance in RCC. Material and methods: Out of 189 consecutive patients who underwent surgery for kidney cancer at Oulu University Hospital in the 1990s, 152 patients with histologically verified RCC were included in this study. The stage distribution was 70 (46%), 12 (8%), 51 (34%) and 19 (12%) patients with stages I-IV, respectively. The majority of the tumours (83 tumours, 55%) were nuclear grade II and 5 (3%), 40 (27%) and 22 (15%) of the tumours were grades I, III and IV, respectively. Clinical and follow-up data were obtained from patient records, the Finnish Cancer Registry and on demand from the Population Register Centre of Finland. The biomarkers studied included markers of the oxidative and neuroendocrine systems as well as proteins related to cell adhesion and migration, invasion, metastasis, inflammation and immune responses. The expression of various biomarkers was characterized via immunohistochemical tests of archival tumour material. The staining intensity was compared to clinicopathological parameters and patient RCC-specific survival. Results: The 5-year RCC-specific survival was 77%. The expression of Toll-like receptor 9 (TLR9) was an independent marker of favourable RCC-specific survival whereas cytoplasmic myosin VI expression was found to be an independent prognostic factor of poor RCC-specific survival. Cell culture experiments showed how cyclooxygenase-2 (COX-2) expression is regulated by HuR in RCC. HuR and COX-2 immunoexpression were also related to decreased RCC-specific survival. Immunostaining of Keap1 was associated with advanced RCC and a marker of a poorer RCC-specific prognosis. The expression of different neuroendocrine markers was evaluated but we could not establish any prognostic value for them. Conclusions: In particular, TLR9, HuR and myosin VI can be regarded as promising novel prognostic biomarkers in RCC. Stage, however, is the most important single prognostic factor for RCCTiivistelmä Munuaissyöpä on vuosikymmenten ajan jatkuvasti yleistynyt. Vaikka se diagnosoidaan nykyisin useimmiten sattumalöydöksenä vatsan alueen kuvantamistutkimuksissa ja hoitomenetelmät ovat viime vuosikymmenten aikana kehittyneet, munuaissyöpäkuolleisuus ei ole laskenut. Munuaissyövän ennusteen määrittäminen voi olla haasteellista. Perinteiset ennustetekijät, levinneisyys ja erilaistumisaste, eivät riitä selittämään kaikkien potilaiden taudinkulkua, eikä munuaissyövälle vielä ole kliinisessä käytössä ennusteellista merkkiainetta. Munuaissyöpähoitojen kehittyessä taudinkulun ennustaminen on yhä tärkeämpää, jotta potilaiden hoito ja seuranta voidaan yksilöidä. Tämän väitöskirjatyön tarkoituksena oli etsiä uusia ennusteellisia kudosmerkkiaineita munuaissyöpäkasvaimille. Väitöskirjatutkimus perustuu 1990-luvulla Oulun yliopistollisessa sairaalassa leikatun 152 munuaissyöpäpotilaan aineistoon. Lähes puolet aineiston kasvaimista edusti levinneisyysluokkaa I, ja yli puolet munuaissyöpäkasvaimista oli hyvin erilaistuneita (tumagradus I ja II). Tutkimuspotilaista kerättiin kattavat seurantatiedot. Leikkauksessa poistettujen munuaissyöpäkasvainten arkistomateriaalista tutkittiin eri merkkiaineiden ilmenemistä. Tutkitut merkkiaineet käsittivät oksidatiivisen ja neuroendokriinisen järjestelmän merkkiaineita sekä valkuaisaineita, jotka liittyvät keskeisiin syövän ominaisuuksiin, kuten solujen välisiin liitoksiin ja solujen liikkumiseen sekä etäpesäkkeiden syntymiseen. Lisäksi tutkittiin merkkiaineita, jotka liittyvät tulehdusreaktioihin ja immuunipuolustukseen. Väitöskirjatutkimus paljasti useita uusia kudosmerkkiaineita, joiden ilmeneminen munuaissyöpäkasvaimessa on yhteydessä potilaan ennusteeseen. Näistä merkittävimpiä ovat myosiini VI, joka liittyy syöpäkasvainten metastasointiin, sekä immuunipuolustuksessa vaikuttava Tollin kaltainen reseptori 9 (Toll-like receptor 9, TLR9). Molemmat merkkiaineet osoittautuivat itsenäisiksi ennustetekijöiksi munuaissyövässä. Muita ennusteeseen vaikuttavia merkkiaineita ovat tutkimuksen mukaan oksidatiivista stressiä aistiva Keap1 sekä immunologisiin reaktioihin liittyvä syklo-oksigenaasi 2 (COX-2) ja sen ilmenemistä säätelevä HuR
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Liu, Tongzheng. "Regulation of Inflammtory Activation in Endothelial Cells by PIN1." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1242756227.
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