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Dissertations / Theses on the topic 'Enzymes; Breast cancer'
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1
Gunnarsson, Cecilia. "Steroid converting enzymes in breast cancer /." Linköping : Univ, 2005. http://www.bibl.liu.se/liupubl/disp/disp2005/med908s.pdf.
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RICH, WENDY LEA. "Interrelationships Of The Estrogen-Producing Enzymes Network In Breast Cancer." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1230581012.
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Palmebäck, Wegman Pia. "Studies of tamoxifen resistance in breast cancer." Doctoral thesis, Linköpings universitet, Cellbiologi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8943.
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Oestrogen is one of the most important hormonal regulators and is known to play a key role in the development and growth of breast cancer. The majority of tumours have a hormone dependent growth, and this is indicated by the presence of oestrogen receptors (ERs). About two thirds of breast cancers occur after the menopause when the ovaries have ceased to produce oestrogen and despite the low levels of circulating oestrogen’s the tumour concentrations of oestrone, oestradiol and their sulfates have been shown to be significant. Patients with hormone dependent tumours are candidates for treatment with the anti-oestrogen tamoxifen, which acts by competing with oestrogen for binding to the ER thereby, diminish the transcription of oestrogen regulated genes. The drug is mainly metabolised by cytochrome P450 enzymes in the liver and to a lesser extent locally in the breast, where upon several produced metabolites have higher affinity for the ER than the mother substance. Patients treated with tamoxifen have in general a prolonged disease-free survival. Even if most patients respond well to tamoxifen about 30-50 % either fail to respond or become resistant by incompletely understood mechanisms. Therefore, the aim of this thesis was to investigate possible mechanisms responsible for tamoxifen resistance. In paper I and II we studied genetic variants of enzymes participating in the metabolism of tamoxifen and assessed whether these variants correlated to breast cancer prognosis and/or to the benefit of tamoxifen. The results indicate an influence of CYP2D6, CYP3A5, and SULT1A1 genotypes in tamoxifen response. Further, tamoxifen has shown to compete with oestrogen for the binding to ER. In paper III we measured the expression levels of enzymes involved in the local synthesis of oestrogens in order to see if they correlated to clinical outcome. The protein expression of stromal aromatase was shown to have a prognostic significance, especially in ER-positive patients. Finally, tamoxifen and its ER-active metabolites have shown to induce both cell cycle arrest and apoptosis and one central mediator in these processes is the tumour suppressor protein p53. The proapoptotic activity of p53 is dependent on a proline rich domain containing a common Pro-to-Arg polymorphism. In paper IV we examined the value of this genetic variant as a predictive marker for anti-cancer therapy and found that patients carrying the Pro-allele might be good responders of tamoxifen therapy. The present thesis further indicates the complexity of the mechanisms underlying tamoxifen resistance. In summary, genetic variants of metabolic enzymes, genetic variants in p53, as well as expression levels of enzymes involved in local oestrogen synthesis, may have influence on breast cancer prognosis and may be useful markers in the prediction of tamoxifen response.
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Sandri, Maria Ines. "Studies of the expression and regulation of topoisomerase II." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364213.
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Xintaropoulou, Chrysi. "Targeting aerobic glycolysis in breast and ovarian cancer." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29525.
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Cancer cells, unlike normal tissue, frequently rely on glycolysis for the production of energy and the metabolic intermediates required for their growth regardless of cellular oxygenation levels. This metabolic reconfiguration, termed the Warburg effect, provides a potential strategy to preferentially target tumours from a therapeutic perspective. The present study sought to investigate the glycolytic phenotype of breast and ovarian cancer, and assess the possibility of exploiting several glycolytic targets therapeutically. Initially the growth dependency of breast and ovarian cancer cells on the availability of glucose was established. An array of 10 compounds reported to inhibit key enzymes of the glycolytic pathway were investigated and compared against an extended panel of breast and ovarian cancer cell line models. All inhibitors investigated, targeted against multiple points of the pathway, were shown to block the glycolytic pathway as demonstrated by glucose accumulation in the culture media combined with decreased lactate secretion, and attenuated breast and ovarian cancer cell proliferation in a concentration dependent manner. Furthermore their mechanism of action was investigated by flow cytometric analysis and their antiproliferative effect was associated with induction of apoptosis and G0/G1 cell cycle arrest. The glycolytic inhibitors were further assessed in combination strategies with established chemotherapeutic and targeted agents and several synergistic interactions, characterised by low combination index values, were revealed. Among them, 3PO (a novel PFKFB3 inhibitor) enhanced the effect of cisplatin in both platinum sensitive and platinum resistant ovarian cancer cells suggesting a strategy for treatment of platinum resistant disease. Furthermore robust synergy was identified between IOM-1190 (a novel GLUT1 inhibitor) and metformin, an antidiabetic inhibitor of oxidative phosphorylation, resulting in strong inhibition of breast cancer cell growth. This combination is proposed for the treatment of highly aggressive triple negative breast tumours. An additional objective of this research was to investigate the effect of the oxygen level on sensitivity to glycolysis inhibition. Breast cancer cells were found to be more sensitive to glycolysis inhibition in high oxygen conditions. This enhanced resistance at low oxygen levels was associated with upregulation of the targeted glycolytic enzymes as demonstrated at both the mRNA (by gene expression microarray profiling, Illumina BeadArrays) and protein level (by Western blotting). Manipulation of LDHA (Lactate Dehydrogenase A) by siRNA knockdown provided further evidence that downregulation of this target was sufficient to significantly suppress breast cancer cell proliferation. Finally, the expression of selected glycolytic targets was examined in a clinical tissue microarray set of a large cohort of ovarian tumours using quantitative immunofluorescence technology, AQUA. The role of the glycolytic phenotype in ovarian cancer was suggested and interesting associations between the glycolytic profile and clear cell and endometrioid ovarian cancers revealed. Increased PKM2 (Pyruvate kinase isozyme M2) and LDHA expression were demonstrated in clear cell tumours and also low expression of these enzymes was significantly correlated with improved survival of endometrioid ovarian cancer patients. Taken together the findings of this study support the glycolytic pathway as a legitimate target for further investigation in breast and ovarian cancer treatment.
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Segersten, Ulrika. "Vitamin D Hydroxylating Enzymes and Analogues in Parathyroid Tumors and Breast Cancer." Doctoral thesis, Uppsala University, Department of Surgical Sciences, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6008.
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In hyperparathyroidism (HPT) raised serum concentrations of ionized calcium is caused by increased secretion of parathyroid hormone (PTH) by parathyroid tumors. Active vitamin D, 1α,25-dihydroxyvitamin D3, is known to suppress PTH secretion and to reduce proliferation of parathyroid tumor cells.
The aim of this thesis was to examine expression of vitamin D hydroxylating enzymes, regulating the activation and inactivation of vitamin D and to study effects of vitamin D analogues, in parathyroid tumors and breast cancer.
The vitamin D activating enzyme, CYP27B1/25-hydroxyvitamin D3 1α-hydroxylase (1α-hydroxylase) and the vitamin D inactivating enzyme CYP24A1/25-hydroxyvitamin D3 24-hydroxylase (24-hydroxylase) were expressed in parathyroid tumors and breast cancer.
The parathyroid tumors had raised expression levels of 1α-hydroxylase and reduced levels of 24-hydroxylase in comparison to normal parathyroid glands, indicating ability for endogenous activation of vitamin D. The expression of 1α-hydroxylase may be of therapeutic advantage for local activation of non-1α-hydroxylated vitamin D analogues in tumor cells, thereby reducing unwanted hypercalcemic effects.
Three of five selected low calcemic vitamin D analogues had as efficient PTH suppressing effect, in bovine parathyroid cells, as three vitamin D analogues used clinically for treatment of secondary HPT.
The non-1α-hydroxylated vitamin D analogue EB1285 showed antiproliferative and PTH suppressive effects as well as transcriptional activity in parathyroid and breast tumor cells, respectively.
Ketoconazole, an inhibitor of vitamin D hydroxylating enzymes, suppressed PTH secretion and potentiated the effect of vitamin D analogues. Combined treatment with vitamin D analogues and specific 24-hydroxylase inhibitors may be important for future therapy.
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Kopsida, Maria. "Targeting histone deacetylase (HDACs) enzymes with novel bisnaphthalimidopropyl derivatives (BNIPs) as alternative breast cancer therapies." Thesis, Robert Gordon University, 2018. http://hdl.handle.net/10059/3120.
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Breast cancer is the most commonly occurring cancer in women, with incidence rates approaching 1.38 million cases per year worldwide. Over the last few decades, there have been numerous attempts to develop, synthesise and advance into the clinic novel and selective breast cancer therapies. Research work has shown that bisnaphthalimidopropyl diaminodicyclohexylmethane (BNIPDaCHM) exerts potent in vitro anti-cancer activities and strong DNA binding properties. The aim of this thesis was to synthetise novel bisnaphthalimidopropyl derivatives (BNIPs) and investigate their subsequent modes of action within two human metastatic breast cancer cell lines, MDA-MB-231 and SKBR-3. A series of novel BNIPs, bisnaphthalimidopropyl-piperidylpropane (BNIPPiProp), bisnaphthalimidopropyl- ethylenedipiperidine (BNIPPiEth) and (trans(trans))-4,4’-methylenebis-cyclohexylamine (trans,trans-BNIPDaCHM) were synthesised, characterised and studied in comparison to BNIPDaCHM for their DNA binding and anti-cancer activities against MDA-MB-231 and SKBR-3 cells. Thermal denaturation studies have shown that BNIPs can intercalate and stabilize the double helix of Calf Thymus, each BNIP can competitively displace EtBr from DNA in a dose dependent manner and by UV binding studies, high affinity was found for the three novel BNIPs. After 24 hours treatment, all novel BNIPs, exhibited strong cytotoxicity with IC50 values ranging from 1.4 μM to 3.3 μM in MDA-MB-231 cells and 0.2 - 0.7 μM in SKBR-3 cells, confirming the importance of bisnaphthalimidopropyl functionality. BNIPs were also found to increase intracellular ROS levels after 8 hours treatment and induce a significant increase in DNA strand breaks compared to endogenous levels, after 24 hour treatment in both cell lines. After cell synchronisation, cell cycle distribution was studied, revealing that trans,trans-BNIPDaCHM induces sub-G1 cell population arrest in MDA-MB-231 and SKBR-3 cells, after 24 hours treatment. In addition, BNIPs induced apoptotic phosphatidylserine exposure, after 0.5 hours treatment, inhibited Caspase-3 activity and increased autophagy, after 24 hour treatment in MDA-MB-231 and SKBR-3 cells. Moreover, BNIPs inhibited histone deacetylases (HDAC) activity after 24 hours treatment in MDA-MB-231 and SKBR-3 cells and BNIPDaCHM was identified as a potential SIRT2 inhibitor, in SKBR-3 cells. According to Proteome Profiler Arrays, BNIPDaCHM and BNIPPiEth altered the expression of cell stress-related proteins in a cell dependent manner and bioinformatic analysis revealed two novel, putative pathways for BNIP-induced oxidative stress-mediated cell death in MDA-MB-231 and SKBR-3 cells. The above findings indicate that BNIPs represent promising candidates for future breast cancer studies and cancer treatment.
8
Karihtala, P. (Peeter). "Oxidative damage and counteracting mechanisms in breast carcinoma." Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514279530.
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Breast cancer is the leading cause of death from cancer among Finnish women, but the ultimate causation of carcinogenesis still remains unclear. Reactive oxygen species (ROS) is a collective term for several types of reactive oxygen metabolites that are continuously generated in human cells mainly as by-products of aerobic respiration. ROS, including nitric oxide and its derivatives, play highly important roles in cell physiology. If ROS production exceeds the capacity of detoxification systems, principally antioxidant enzymes, oxidative stress is said to occur. This state is known to contribute to all stages of carcinogenesis.
To explore the widely unstudied role of ROS and cell redox state modulating enzymes in breast carcinomas, the extent of ROS-derived macromolecule damage and the expression of the vast majority of known antioxidant enzymes were assessed in a large series of breast carcinomas, and the results were compared to the patients' clinicopathological parameters. The results were also compared to angiogenesis, DNA repair enzymes, cell proliferation, NF-κB, p53 expression, and survival. Immunohistochemistry was the main method applied, but western blotting and immunoelectron microscopy were also used.
There is extensive oxidative damage in breast carcinomas, which seems to associate with tumor development. Oxidative macromolecule damage is notable even in stage I tumors. Cell redox state regulating enzymes, such as peroxiredoxin V, thioredoxin, thioredoxin reductase, and glutamate-cysteine ligase, associate with more aggressive phenotypes of tumors, including larger primary tumors, growth of metastases, increased cell proliferation, and poor differentiation. This indirectly suggests that cell redox state modulating enzymes may be inductive of tumor promotion in an oxidated environment. The results of this thesis support the importance of ROS in all stages of carcinogenesis. These observations are largely in line with the previous studies on different carcinomas, but there seem to be certain carcinoma type specific differences in the expression of these enzymes. Since the expression of given cell redox state modulating enzymes distinctly associates with clinicopathological parameters, these enzymes may be useful as prognostic indicators and facilitate the choice of appropriate treatment in the future.
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Abdullah, Ammara. "Inhibitors of cytochrome P450 enzymes CYP17 and 17β-HSD3 : their role in the treatment of hormone-dependent prostate and breast cancer." Thesis, Kingston University, 2012. http://eprints.kingston.ac.uk/25093/.
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Androgens play an important part in the initiation and progression of hormone-dependent prostate and breast cancer. These types of cancers can be treated by androgen ablation therapy. However, androgen ablation is associated with short (2-3 years) remission of the disease. Therefore therapies that inhibit the systemic biosynthesis of androgens, by targeting the P450 enzymes (CYP17 and 17-[beta]HSD type 3) which catalyse androgen biosynthesis, may represent a rational approach in the treatment of androgen-dependent cancer. Inhibitors of the enzyme CYP17: ketoconazole and liarozole, have been shown to decrease tumour cell adhesion to the endothelium and expression of adhesion molecules. The adhesion of cancer cells to the endothelium is an important preliminary event that underlies cancer matastasis. Within the this study, the development of assays for the enzymes; CYP17 and 17[beta]-HSD3 and the evaluation of a series of compounds which were designed to inhibit these enzymes have been considered. The preliminary screening of the compounds showed good inhibition of 17[alpha]=OHase and 17, 20 lyase components of the CYP17 enzyme in comparison to the reference drug, ketoconazole (KTZ). The IC[sub]50 of compounds 31, 34, 38, 41, 48 and 51 and KTZ was calculated as 14.40 [Mu]M, 5.82 [Mu]M, 0.18 [Mu]M, 1.35[Mu]M, 1.21[Mu]M, 0.50[Mu]M and 5.65[Mu]M respectively. However, only a few of the compounds designed to inhibit 17[beta]-HSD3 showed ap potent inhibitory activity. Compound 132 showed the highest percentage inhibition (40.51 [plus or minus] 0.14%) of 17[beta]- HSD3 activity when compared to the reference drugs, 7-hydroxy flavone (12.90 [plus or minus] 0.31%) and biacalein (13.66 [plus or minus] 0.31%). CYP17 inhibitors did not have any cytoxic effect on human cancerous and non-cancerous cell lines. The adhesion of DU145, PC3 and MCF7 to a non-stimulated HUVEC monolayers was decreased from 100 [plus or minus] 0.01% cell adhesion to 60.93 [plus or minus] 3.95%, 65.79 [plus or minus] 9.39% and 65.12 [plus or minus] 4.04% by compounds 38. 48 and 51 respectively in the absence of tumour necrosis factor alpha (THF-[alpha]). Similarly, compounds 38, 48 and 51 showed the highest anti-adhesion effect of DU145 on stimulated HUVEC monolayers (69.85 [plus or minus] 2.51%) cells respectively. Flow cytometry and immunostaining of intracellular adhesion molecules showed that CYP17 inhibitors did not have any effect on the expression of ICAM-1. In conclusion, the synthesised compounds were found to be good indicators of the CYP17 enzyme with no cytoxic and better anti-adhesion effects when compared to KTZ. Thus, these compounds can be further investigated as a therapeutic strategy against hormone-dependent prostate and breast cancer.
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Lam, Maria Shuk Mun. "Genetic polymorphisms in AH receptor and cytochrome P450 drug-metabolizing enzymes in relation to estradiol metabolism and breast cancer susceptibility." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0021/MQ54164.pdf.
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Sova, H. (Henri). "Oxidative stress in breast and gynaecological carcinogenesis." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526204062.
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Abstract Cancer is the leading cause of death worldwide. Despite the significant research effort, underlying mechanisms of carcinogenic processes are still poorly understood. In recent decades, a group of extremely reactive oxygen metabolites, reactive oxygen species (ROS), have been linked closely to carcinogenesis. Levels of ROS are constantly controlled by antioxidants to ensure stable redox balance in our cells. An aberrant cellular redox balance is thought to be connected to carcinogenesis by inflicting damage to cellular macromolecules and disturbing normal cellular signalling. In this work, the role of ROS in carcinogenesis was studied by observing the ROS-derived DNA damage marker 8-hydroxydeoxyguanosine (8-OHdG) in breast cancer and endometriosis-associated ovarian cancer. This marker was also measured in connection with endometriosis and PCOS to study the early stages of the carcinogenic process. In addition, peroxiredoxin antioxidant enzymes were studied in endometriosis-associated ovarian cancer to explore their impact on the carcinogenic process and relationship with ROS-derived DNA damage. There seems to be a decreasing trend in the expression of 8-OHdG in the development of breast cancer and endometriosis-associated ovarian cancer. In breast cancer, low levels of 8-OHdG in serum and in tumour tissue were found to be associated with more aggressive disease. In endometriosis-associated ovarian cancer, 8-OHdG and Prx II expressions in tissue decreased with malignant transformation from benign endometriosis tissue to ovarian cancer. Patients with PCOS were found to have lower levels of 8-OHdG in serum compared with healthy controls and metformin treatment further decreased 8-OHdG levels in obese patients. These results, together with observations is previous studies indicate that in breast cancer and endometriosis-associated ovarian cancer, a high level of ROS-derived DNA damage could be significant factor in the initiation stage of carcinogenesis, whereas in later stages carcinomas benefit from lower ROS levels that support tumour growth and survival via cellular signalling. In endometriosis, there seem to be high amounts of ROS-derived DNA damage, which could explain the increased ovarian cancer risk, while in PCOS, aberrant ROS levels could contribute to the pathogenesis of the disease itself and also to possible cancer incidence by inducing abnormal cellular signallingTiivistelmä Syöpä on nykyisin maailman yleisin kuolinsyy. Vaikka syöpätutkimukseen kohdistetaan maailmanlaajuisesti huomattavia resursseja, syövän kehittymisen perimmäinen syy on edelleen heikosti tunnettu. Yhä kasvavan todistusaineiston perusteella happiradikaalien epäillään liittyvän läheisesti syövän kehittymiseen. Nämä erittäin reaktiiviset hapen aineenvaihduntatuotteet ovat välttämättömiä solujemme normaalille toiminnalle, mutta liian suurina määrinä ne voivat vaurioittaa solun rakenteita ja häiritä solun normaalia viestintää. Solut sisältävät useita antioksidantteja, joiden tärkeimpänä tehtävänä on kontrolloida happiradikaalien määrää ja näin ylläpitää solun hapetus-pelkistys -tasapaino. Tässä väitöskirjatutkimuksessa tutkittiin happiradikaalien yhteyttä syövän kehittymiseen tarkastelemalla niiden aiheuttaman DNA-vaurion merkkiainetta, 8-hydroksideoksiguanosiinia (8-OHdG), rintasyövässä ja endometrioosiin liittyvässä munasarjasyövässä sekä peroksiredoksiiniperheen antioksidanttientsyymejä endometrioosiin liittyvässä munasarjasyövässä. 8-OHdG:n avulla selvitettiin myös munasarjojen monirakkulaoireyhtymän (PCOS) ja endometrioosin yhteyttä syövän kehittymiseen. Lisäksi tutkittiin metformiinin vaikutusta happiradikaalien aiheuttamaan DNA-vaurioon. Väitöskirjatutkimuksen tulosten perusteella 8-OHdG:n määrä vähentyy rintasyövän edetessä ja endometrioosiin liittyvän munasarjasyövän kehittyessä. Matalat 8-OHdG -tasot syöpäkudoksessa ja verinäytteissä ovat yhteydessä aggressiivisempaan taudinkuvaan rintasyövässä. Endometrioosiin liittyvässä munasarjasyövässä kudoksen ilmentämä 8-OHdG ja Prx II vähentyi asteittain siirryttäessä hyvänlaatuisesta endometrioosista munasarjasyöpään. Munasarjojen monirakkulaoireyhtymässä potilaiden verinäytteiden 8-OHdG -tasot olivat merkittävästi matalammat terveisiin verrokkeihin verrattuna. Korkeilla happiradikaalipitoisuuksilla ja niistä aiheutuvalla DNA-vauriolla on väitöskirjatutkimuksen tulosten perusteella tärkeä rooli syövän syntyvaiheessa, kun taas syövän myöhemmissä kehitysvaiheissa matalat happiradikaalipitoisuudet tukevat syövän kasvua ja selviytymistä soluviestinnän avulla. Endometrioosipotilaiden kohonnut munasarjasyöpäriski vaikuttaisi olevan seurausta runsaasta happiradikaalien aiheuttamasta DNA-vauriosta endometrioosikudoksessa. Munasarjojen monirakkulaoireyhtymässä poikkeavien happiradikaalitasojen aiheuttama puutteellinen soluviestintä liittyy mahdollisesti taudin patogeneesiin ja syöpäriskiin
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Feleni, Usisipho. "Quantum dots-amplified electrochemical cytochrome P450 phenotype sensor for tamoxifen, a breast cancer drug." University of the Western Cape, 2017. http://hdl.handle.net/11394/5505.
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Philosophiae Doctor - PhDBreast cancer is regarded as the most common cancer in South Africa and its rate of occurrence is increasing. About one in every 31 South African women are at the risk of developing breast cancer and early diagnosis and treatment guarantee 90% survival rate. Tamoxifen is the drugs of choice for the treatment of all stages of breast cancer. The drug binds with estrogen receptor (ER) to minimize the transcription of estrogen dependent genes. However, nearly 50% of ER-positive breast cancer patients either become resistant or fail to respond to tamoxifen resulting in a serious clinical challenge in breast cancer management. The Grand Health Challenges of South Africa includes the development of cost effective diagnostic systems suitable for early detection of diseases and drug resistivity for timely invention and better patient management.
2020-08-31
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Han, Hui. "Substrate inhibition of 17 beta-hydroxysteroid dehydrogenase type 1 in living cells and regulation among the steroid-converting enzymes in breast cancers." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/32545.
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Cette étude a permis de démontrer les fonctions et les mécanismes de la 17bêtahydroxystéroïde déshydrogénase de type 1 (17β-HSD1) et de la stéroïde sulfatase (STS) au niveau du cancer du sein, y compris la cinétique moléculaire et cellulaire, la liaison du ligand étudiée par la titration de fluorescence, la régulation des stéroïdes et la régulation mutuelle entre les enzymes stéroïdiennes et les cellules cancéreuses du sein. 1), L’inhibition de la 17β-HSD1 par son substrat a été démontrée par la cinétique enzymatique au niveau cellulaire pour la première fois, soutenant ainsi la fonction biologique de l’inhibition produite par le substrat. 2), En tant qu’inhibiteur, la dihydrotestostérone (DHT) n’a pas affecté la concentration du substrat estrone (E1) à laquelle l’activité enzymatique a commencé à diminuer, mais certaines augmentations de vitesse ont été observées, suggérant une diminution significative de l’inhibition par le substrat. 3), Les résultats de la modulation de l’ARNm ont démontré que la transcription du gène codant la 17β-HSD7 diminuait en réponse à l’inhibition de la 17β-HSD1 ou au knockdown dans les cellules du cancer du sein par la modification estradiol (E2). 4), L’expression de la STS est stimulée par E2 de manière à générer une rétroaction positive, ce qui favorise la biosynthèse de E2 dans les cellules de cancer du sein. 5), L’inhibition conjointe de la STS et de la 17β-HSD7 pourrait bloquer leurs activités enzymatiques, diminuant ainsi la formation de E2, mais rétablissant la formation de DHT, réduisant de façon synergique la prolifération cellulaire et induisant l’arrêt du cycle cellulaire en G0 / G1. 6), Les 17β-HSD7 et STS synthétisent E2 et sont toutes deux régulées par E2. Ainsi, elles forment un groupe fonctionnel d’enzymes mutuellement positivement corrélées, l’inhibition de l’une peut réduire l’expression d’une autre, amplifiant ainsi potentiellement les traitements inhibiteurs. 7), Le recepteur estrogenique α ERα a été non seulement régulés à la baisse par E2, mais également réduits par la DHT grâce à l’activation des récepteurs aux androgènes (AR). En conclusion, la 17β-HSD1 et la 17β-HSD7 jouent des rôles essentiels dans la conversion et la régulation des hormones sexuelles, et l’inhibition conjointe de la STS et de la 17β-HSD7 constitue une nouvelle stratégie pour le traitement hormonal des cancers du sein sensibles aux estrogènes.Human 17beta-hydroxysteroid dehydrogenase type 1 (17β-HSD1), 17betahydroxysteroid dehydrogenase type 7 (17β-HSD7) and steroid sulfatase (STS) play a crucial role in regulating estrogen synthesis for breast cancer (BC). However, mutual regulation of enzymes and the interaction of these steroids (estrogens, androgens and their precursor dehydroepiandrosterone (DHEA)) are not clear. This study demonstrated the functions and mechanisms including kinetics at molecular level and in cells, ligand binding using fluorescence titration, regulation of steroids and mutual regulation between steroid enzymes in BC cells: 1) Substrate inhibition of 17β-HSD1 was shown for the first time by enzyme kinetics at the cell level, supporting the biological function of substrate inhibition. 2) As an inhibitor, dihydrotestosterone (DHT) did not affect the estrone (E1) substrate concentration at which the enzyme activity started to decrease, but some increases in velocity were observed, suggesting a corresponding decrease in substrate inhibition 3) The mRNA modulation results demonstrated that 17β-HSD7 transcription decreased in response to 17β-HSD1 inhibition or knockdown in BC cells due to estradiol (E2) concentration decrease. 4) The expression of STS is stimulated by E2 in a positive-feedback manner which finally promotes E2 biosynthesis within BC cells. 5) The joint inhibition of STS and 17β-HSD7 could block the activities of these enzymes, thus decreasing E2 formation but restoring DHT formation, to synergistically reduce cell proliferation and induce G0/G1 cell cycle arrest. 6) 17β-HSD7 and STS can synthesize E2 and are all regulated by E2. Thus, they form a functional group of enzymes mutually positively correlated, inhibition of one can reduce the expression of the other, thereby potentially amplifying the inhibitory effects. 7) Estrogen Receptor α (ERα) is not only down-regulated by E2, but also reduced by DHT though androgen receptor (AR) activation. In conclusion, 17β-HSD1 and 17β-HSD7 play essential roles in sex-hormone conversion and regulation, and the joint inhibition of STS and 17β-HSD7 constitutes a novel strategy for hormonal treatment of estrogen-receptor positive BC
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Silvestrov, Pavel. "Computational Investigation of DNA Repair Enzymes: Determination and Characterization of Cancer Biomarkers and Structural Features." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157566/.
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Genomic integrity is important for living cells' correct functioning and propagation. Deoxyribonucleic acid as a molecule is a subject to chemical reactions with agents that can come from environment as well as from internal metabolism processes. These reactions can induce damage to DNA and thus compromise the genetic information, and result in disease and death of an organism. To mitigate the damage to DNA, cells have evolved to have multiple DNA repair pathways. Presented here is a computational study of DNA repair genes. The structure of the Homo sapiens direct DNA repair gene ALKBH1 is predicted utilizing homology modeling methods and using AlkB and DBL proteins as templates. Analysis of the obtained structure and molecular dynamics simulations give insights into potentially functionally important residues of the protein. In particular, zinc finger domains are predicted, and lysines that could perform catalytic activities are investigated. Subsequent mutagenesis experiments revealed the effect of the residues predicted to form zinc fingers on activity of ALKBH1. Structure and dynamics of AlkD, a Bascillus cereus base excision DNA repair protein is also studied. This protein has been shown to bind DNA with large alkyl adducts and perform excision catalysis without base flipping which is characteristic to other enzymes in the same family. MD simulations of AlkD revealed that B helix, which interacts with DNA, has higher fluctuations when AlkD is not bound to DNA, and thus could have a role in binding and recognition of DNA. For the purpose of finding biomarkers and to further our understanding of a mode of action of DNA repair genes, statistical methods were applied to identify mutations that are linked to cancer phenotypes. Analysis was based on case-control studies of patients with cancers of prostate, breast, pancreas, lung as well as chronic lymphocytic leukemia from NCBI dbGAP database. Those mutations that result in missense mutations were further investigated. In particular, extensive MD simulations and experimental investigations were performed on the mutation in the ALKBH7 gene that was found to be linked to prostate cancer.
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Egleton, James Edward. "Small molecule colorimetric and fluorescent probes for specific protein detection." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:0a1a1c80-8055-491a-920a-3e17f7919e93.
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This thesis describes the design, synthesis, analysis, mechanistic evaluation and optimisation of small molecule probes for the specific detection of proteins, focusing on the target protein human arylamine N-acetyltransferase type 1 (HUMAN(NAT1)) and its murine homologue, mouse arylamine N-acetyltransferase type 2 (MOUSE(NAT2)). The HUMAN(NAT1) gene is reported to be one of the most highly overexpressed genes in estrogen-receptor-positive (ER+) breast tumours, leading to its potential use as both a novel diagnostic biomarker and a novel therapeutic target for this disease. Chapter 1 reviews the literature on optical methods for the specific detection of a protein target, exploring strategies both based on biosensors and on chemical probes, before introducing the arylamine N-acetyltransferases as a family of enzymes. In Chapter 2, a family of naphthoquinone inhibitors of HUMAN(NAT1) are introduced, which undergo a colour change from red to blue upon binding specifically to the enzyme. The mechanism of this colour change, a proton transfer-mediated process, is discussed via the synthesis, pharmacological and colorimetric evaluation of close analogues of the hit compound lacking a key acidic sulfonamide-NH proton. During these studies, it was found that direct O-methylation of a sulfonamide is possible under certain conditions; such a reaction has not previously been reported. Furthermore, upon heating in polar solvents the O-methylated sulfonamide was observed to undergo rearrangement, and the mechanism of this process is investigated via NMR and kinetic studies. In Chapter 3, the design, synthesis and evaluation of HUMAN(NAT1) inhibitors with improved pharmacological and colorimetric profiles over the initial hit are described. From this optimisation, structure-activity relationships and an in silico model of interactions between the inhibitors and enzyme are evaluated. Testing of these compounds in cellular environments, however, exposes some limitations of this approach, notably the lack of sensitivity of the probes when dosed at low concentrations in cellular samples. In order to overcome this limitation, in Chapter 4 fluorescent analogues of the hit compound are designed and synthesised. Initial compounds developed in this series possess promising properties, but each compound generated suffers from either a low fluorescent intensity, lack of a pH-dependent switch in fluorescence or a low fluorescence excitation wavelength, which overlaps with those of tryptophan or tyrosine residues in proteins. Insights into the mechanism of molecular fluorescence and application of some simple quantum mechanical principles, however, lead to the design of a species which possesses all the required properties. The fluorescent emission intensity of this probe correlates linearly with [MOUSE(NAT2)] in E. coli cell extracts, and can quantify as little as 0.64% MOUSE(NAT2) in the samples; furthermore, the probe is capable of unambiguously detecting HUMAN(NAT1) within a cell extract from the ER+ breast cancer cell line ZR-75-1; future work on this probe may therefore enable its clinical use in improved early diagnosis of breast tumours. This study also represents, to the best of our knowledge, the first ever example of a small molecule, non-covalent probe capable of quantifying the concentration of a target protein in cellular extracts. In Chapter 5, the series of naphthoquinone probes is further optimised in order to study the roles of HUMAN(NAT1) in a cellular environment. Firstly, structure-activity relationships are utilised to design inhibitors with improved physical properties such as aqueous solubility and cell membrane permeability, in order to test the effect of HUMAN(NAT1) inhibitors in tumour cell models, which could have implications for the future use of a HUMAN(NAT1) inhibitor as a therapeutic agent in oncology. Secondly, the effect of the cofactor folic acid on the function and activity of HUMAN(NAT1) is explored. Finally, in Chapter 6, the conclusions of this study are outlined and a hypothesis as to how the concepts developed in this thesis might be applied to alternative, more ubiquitous biological targets is discussed, paving the way for future investigations.
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Yang, Xiaoqing. "Dissection of α6β4 Integrin-Dependent Signaling and Breast Carcinoma Invasion: A Dissertation." eScholarship@UMMS, 2011. https://escholarship.umassmed.edu/gsbs_diss/563.
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Breast cancer is one of the most prevalent cancers in the world. Each year, over 400,000 women die from breast cancer world wide and metastasis is the main cause of their mortality. Tumor cell invasion into the adjacent tissue is the first step in the multistep process of cancer metastasis and it involves multiple protein changes. The α6β4 integrin, a transmembrane heterodimeric laminin receptor is associated with poor prognosis in many tumor types, including breast cancer. Src family kinase (SFK) activity is elevated in many cancers and this activity also correlates with invasive tumor behavior. The α6β4 integrin can stimulate SFK activation and promote cancer invasion, however the mechanism by which it does so is not known. In the current study, I provide novel mechanistic insight into how the α6β4 integrin selectively activates the Src family kinase member Fyn in response to receptor engagement. Specifically, the tyrosine phosphatase SHP2 is recruited to α6β4 and its catalytic activity is stimulated through a specific interaction of its N-terminal SH2 domain with pY1494 in the β4 subunit. Importantly, both catalytic and non-catalytic functions of SHP2 are required for Fyn activation by α6β4. Fyn is recruited to the α6β4/SHP2 complex through an interaction with phospho-Y580 in the C-terminus of SHP2. In addition to activating Fyn, this interaction with Y580-SHP2 localizes Fyn to sites of receptor engagement, which is required for α6β4-dependent invasion. Moreover, the selective activation of Fyn, but not Src, requires the palmitoylation modification of Fyn on its N-terminus. Of clinical relevance, phospho-Y580-SHP2 and phospho-Y418-SFK could be used as potential biomarkers of invasive breast cancer because their expression are elevated in high-grade breast tumors.
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Quinn, Anne L. "Aromatase expression and enzyme activity in breast cancer /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487943610782795.
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Vuorela, M. (Mikko). "Role of the RNF8, UBC13, MMS2 and RAD51C DNA damage response genes and rare copy number variants in hereditary predisposition to breast cancer." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526203096.
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Abstract Mutations in the currently known breast cancer susceptibility genes account for only 25–30% of all familial cases. Novel susceptibility genes can be identified by several methods, including candidate gene re-sequencing and genome-wide microarrays. We have applied microarrays for the detection of a new genomic variation class, copy number variants (CNVs), which potentially could disrupt genes in multiple pathways related to breast cancer susceptibility. The aim of the current study was to evaluate the role of the RNF8, UBC13, MMS2 and RAD51C DNA damage response genes in breast cancer susceptibility as well as to study if rare CNVs are associated with the predisposition to this disease. The analysis of 123 familial breast cancer cases revealed altogether nine different changes in the RNF8 and UBC13 candidate genes. However, none of the observed alterations were considered pathogenic. No alterations were observed in MMS2. The obtained results suggest that breast cancer predisposing alterations in RNF8, UBC13 and MMS2 are rare, or even absent. The RAD51C mutation screening of 147 familial breast cancer cases and 232 unselected ovarian cancer cases revealed two deleterious mutations: c.-13_14del27 was observed in a breast cancer case with familial history of ovarian cancer and c.774delT in an ovarian cancer case. Both mutations were absent in the control cohort. The results of the study support the hypothesis that rare variants of RAD51C predispose predominantly to ovarian cancer. A genome-wide scan of CNVs was performed for 103 familial breast cancer cases and 128 controls. The biological networks of the genes disrupted by CNVs were different between the two groups. In familial breast cancer cases, the observed mutations disrupted genes, which were significantly overrepresented in cellular functions related to maintenance of genomic integrity (P=0.0211). Biological network analysis showed that the disrupted genes were closely related to estrogen signaling and TP53-centered tumor suppressor network, and this result was confirmed by the analysis of an independent young breast cancer cohort of 75 cases. These results suggest that rare CNVs represent an alternative source of genetic variation contributing to hereditary risk for breast cancerTiivistelmä Tunnetut rintasyöpäalttiusgeenien mutaatiot selittävät vain 25–30 prosenttia kaikista perinnöllisistä rintasyöpätapauksista. Uusia alttiusgeenejä voidaan tunnistaa useilla eri menetelmillä, kuten kandidaattigeenien mutaatiokartoituksella ja genomin-laajuisilla mikrosirutekniikoilla. Tässä tutkimuksessa sovelsimme mikrosirutekniikkaa uuden geneettisen variaatioluokan, kopiolukuvariaation (CNV), tutkimiseen. CNV:t voivat vaurioittaa lukuisia rintasyöpäalttiuteen liittyviä biokemiallisia reittejä. Tämän tutkimuksen tarkoitus oli arvioida RNF8-, UBC13-, MMS2- ja RAD51C -DNA- vauriovastegeenien sekä harvinaisten CNV:iden yhteyttä rintasyöpä-alttiuteen. 123 familiaalisen rintasyöpätapauksen analyysissä löytyi yhteensä yhdeksän muutosta RNF8- ja UBC13-geeneistä, joista yksikään ei osoittautunut patogeeniseksi. MMS2-geenissä ei havaittu muutoksia. Tulosten perusteella rintasyövälle altistavat muutokset RNF8-, UBC13- ja MMS2- geeneissä ovat joko erittäin harvinaisia tai niitä ei esiinny lainkaan. RAD51C-geenin mutaatiokartoitus 147 familiaalisesta rintasyöpätapauksesta sekä 232 valikoimattomasta munasarjasyöpätapauksesta paljasti kaksi haitallista mutaatiota. c.-13_14del27 havaittiin rintasyöpäpotilaalla, jonka suvussa esiintyi munasarjasyöpää, ja c.774delT todettiin munasarjasyöpäpotilaalta. Kumpaakaan mutaatiota ei havaittu verrokkiaineistossa. Tulokset vahvistavat hypoteesia RAD51C-geenin harvinaisten varianttien yhteydestä pääasiassa munasarjasyöpäriskiin. CNV:iden genomin-laajuinen skannaaminen suoritettiin 103 familiaaliselle rintasyöpätapaukselle ja 128 verrokille. CNV:iden häiritsemien geenien muodostamat biologiset verkostot olivat erilaiset näiden kahden ryhmän välillä. Familiaalisilla rintasyöpätapauksilla havaitut CNV:t vaikuttivat geeneihin, jotka olivat voimakkaasti korostuneita genomin eheyttä ylläpitävissä tehtävissä (P=0.0211). Biologisten verkostojen analyysi paljasti, että CNV:iden vahingoittamat geenit liittyivät läheisesti estrogeenisignalointiin sekä TP53-tuumorisupressoriverkostoon, ja tämä tulos vahvistettiin analysoimalla riippumatonta nuorista rintasyöpäpotilaista koostuvaa kohorttia (N=75). Tutkimuksen tulosten mukaan harvinaiset CNV:t ovat vaihtoehtoinen geneettisen variaation lähde perinnölliseen rintasyöpäalttiuteen
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Dillenburg, Crisle Vignol. "Incidência das mutações 185delAG e 5382insC no gene BRCA1 em mulheres judias Ashkenazi de Porto Alegre." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/13534.
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Base Teórica: O câncer de mama é provavelmente o mais temido pelas mulheres devido a sua alta freqüência e, sobretudo, pelos seus efeitos psicológicos que afetam a percepção da sexualidade e a própria imagem pessoal. Ele é relativamente raro antes dos 35 anos de idade, mas acima desta faixa etária sua incidência cresce rápida e progressivamente. Estudos indicam que fatores genéticos e ambientais são responsáveis pela incidência do câncer de mama, sendo que a hereditariedade provavelmente tenha participação restrita no desenvolvimento deste tipo de tumor. Os principais genes associados ao desenvolvimento do câncer de mama, BRCA1 e BRCA2, são responsáveis por cerca de 80% desses casos, conferindo um risco de 71 a 85% de chance de desenvolver a neoplasia em alguma fase da vida. Mutações nesses genes, classificados como supressores tumorais, demonstram que a perda de suas funções não pára o ciclo celular, não permite a ação do sistema de reparo, e não estimula a apoptose (morte celular programada), culminando em replicação anormal e câncer. A observação epidemiológica de que mulheres judias de origem Ashkenazi parecem ser mais vulneráveis ao câncer de mama está sendo explicada através de estudos moleculares dos genes BRCA1 e BRCA2, onde encontramos a prevalência de três mutações específicas: 185delAG e 5382insC, no gene BRCA1 e 6174delT, no gene BRCA2. Métodos: Utilizou-se um banco de DNA pré-existente, extraído de 209 mulheres da comunidade judaica Ashkenazi da cidade de Porto Alegre. A amplificação do DNA foi realizada por PCR, através da técnica PSM (PCR Mediated site-direct) seguida de digestão dos produtos de PCR com enzimas de restrição. Os objetivos foram verificar se as freqüências das mutações 185delAG e 5382insC, no gene BRCA1 são significativas nesta população e compará-las com demais freqüências encontradas. Resultados: Foram encontradas três pacientes com a mutação 185delAG e duas pacientes com a mutação 5382insC, com as freqüências de 1,435% (95% IC: 0,366; 3,856) e 0,957% (95% IC: 0,161; 3,125), respectivamente.Introduction: Breast cancer is probably the worst diagnosed cancer for women due to its high frequency and furthermore by its psychological problems that affect the perception of sexuality and the self image. It is relatively rare before 35 years of age, but beyond this age its incidence increases rapidly and progressively. Studies show that genetic and environmental factors are responsible for breast cancer incidence, but heredity may play a restrict role in the development of this kind of tumor. The main genes associated to the development of breast cancer, BRCA1 and BRCA2, are responsible for almost 80% of these cases, reaching a chance between 71 and 85% of developing the disease at any life stage. Mutations in these genes, classified as tumor suppressors, do not allow the repair mechanisms of DNA to perform its action and do not stimulate apoptosis, culminating in abnormal replication and cancer. The epidemiological observation in which Ashkenazi Jewish women seems to be more vulnerable to breast cancer is explained through molecular studies of BRCA1 and BRCA2 genes, where three specific mutations have been found (185delAG and 5382insC, in the BRCA1 gene and 6174delT, in the BRCA2 gene). Methods: A pre-existent bank of DNA extracted from 209 women of the Ashkenazi Jewish community of Porto Alegre city has been used. The DNA amplification was performed through PCR, using the PSM (PCR Mediated Site-Direct) technique followed by the digestion of PCR products with restriction enzymes. The objectives of this study was to identify the frequencies of mutations 185delAG and 5382insC at the BRCA1 gene and verify if they are significantly different in this population when compared to frequencies found in other studies. Results: We found three patients with 185delAG mutation and two patients with 5382insC mutation, with frequencies of 1.435% (95% CI: 0,366; 3,856) and 0,957% (95% IC: 0,161; 3,125), respectively.
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Abdul, Ahmad Bustamam H. J. "The devlopment and use of a high performance immunoassay system and a lectin - elisa assay for the c-erbB2 oncoprotein." Thesis, University of Newcastle Upon Tyne, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387528.
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Rylander, Rudqvist Tove. "Extrahepatic cytochrome P450s : relation to cancer susceptibility /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-601-4/.
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Singh, Sukriti. "The evaluation of enzyme inhibitors as potential anti-tumour agents in the treatment of breast cancer." Thesis, University of the West of Scotland, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.739952.
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Blount, Kathryn. "Cancer systems biology : is the devil in the glycolytic detail?" Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/cancer-systems-biology-is-the-devil-in-the-glycolytic-detail(e0ad0c6b-76ec-4bba-8dd3-b583910f46f4).html.
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An approach to investigating cancer that has recently seen resurgence of interest is the “Warburg effect”. Otto Warburg originally described the altered metabolism of cancer cells and identified that they exhibit an increase in glucose uptake and lactate production. This up-regulation of glycolytic flux and glucose transport is now associated with 90% of cancers. In order to improve the overall understanding of the “Warburg effect” two forms of systems biology have been implemented - comparative in vitro analysis of kinetic activities and dynamic modelling. In this analysis, human breast cancer cell lines MCF-7, MDA-MB-231 and T47D and a non transformed breast cell line MCF-10A were used to identify key similarities and differences in kinetic activities across the glycolytic pathway. Additionally, activities of key glycolytic enzymes hexokinase, pyruvate kinase and lactate dehydrogenase were compared under hypoxic conditions to further understand regulation of cancer cells. The most prominent feature that arose from comparing the kinetic activities of the three malignant and one non-malignant cell line is that each cell line has its own specific set of activities for glycolysis. This indicates that there are differences in regulation across the glycolytic pathway for each of these cell lines. This is of specific interest in the search for therapeutic targets. Further, we determined that despite the prominence of oncogenic HIF signalling activities of hexokinase, pyruvate kinase and lactate dehydrogenase were further modulated by growth under hypoxic conditions. Despite the lack of obvious distinct kinetic differences between the non-cancerous and cancerous cells lines some discernible differences are apparent when modelled in silico.
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Rodgers, Eleanor Hazel. "Effect of manipulation of enzyme activities on the cytotoxicity of mitoxantrone in MCF7 human breast cancer cells." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248507.
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Rood, Michael K. "Enzyme-activated growth: development of a nuclear receptor based genetic selection system for engineering biocatalysts." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53072.
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Beyond their physiological roles, nuclear receptors have been exploited for their ability to act as intracellular sensors of small molecules. Accordingly, yeast two- and three-hybrid systems have been developed, exploiting them to control reporter gene expression. These systems may be used to identify nuclear receptor ligand interaction, or for protein engineering applications, particularly of the nuclear receptor ligand binding domain. In this work, the use of estrogen receptors as sensors for enzyme catalysis is explored, where expression of a reporter gene is induced in the presence of the product from an enzymatic reaction. This system, which we have called enzyme-activated growth, has applications for the engineering of biocatalysts. Biocatalytic routes are currently being explored in industrial applications since they often have financial and environmental benefits over traditional heterogeneous catalysis. Enzyme-activated growth is designed to serve as a system to select for engineered enzymes capable of catalyzing the desired reaction. For this work, a new yeast two-hybrid strain has been developed and characterized to allow for detection of both agonist and antagonist compounds. To increase the sensitivity of this assay, a variant of the estrogen receptor was created through random mutation, which responded to ligand concentrations an order of magnitude lower than the wild type receptor. The five mutations identified in the best variant were previously unknown in the literature and the roles of each of these are investigated, as is the mechanism by which they alter ligand sensitivity. As a proof-of-principle, the enzymatic production of genistein, an estrogenic metabolite from plants, using the enzyme isoflavone synthase, as well as the production of estrogen from testosterone, is explored. Synthesis of genistein from the starting material naringenin in vivo was detected in the yeast two-hybrid strain; however, attempts at pairing this with estrogen receptor activation and cell growth were met with limited success. Lastly, targeting the estrogen receptor with a series of novel anti-cancer therapeutics is explored. These compounds were designed to both bind and (in)activate the estrogen receptor while inhibiting histone deacetylase activity. The (anti-)estrogenic properties were analyzed as well as their potency as histone deacetylase inhibitors. These properties were compared to their anti-proliferative effects against various cancerous and healthy cell lines to determine their potential as selective anti-cancer therapeutics.
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Lombardi, Olivia. "Investigating the role of mRNA capping enzyme in C-MYC function." Thesis, University of Dundee, 2017. https://discovery.dundee.ac.uk/en/studentTheses/4816aeec-c481-4494-9a07-56e74a83c08e.
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C-MYC is a transcription factor and a potent driver of many human cancers. In addition to regulating transcription, C-MYC promotes formation of the mRNA cap which is important for transcript maturation and translation. However, the mechanistic details of C-MYC-dependent mRNA capping are not fully understood. Since anti-cancer strategies to directly target the C-MYC protein have had limited success, enzymatic co-factors or effectors of C-MYC present attractive alternatives for therapeutic intervention of C-MYC-driven cancers. mRNA capping enzyme (CE) initiates mRNA cap formation by catalysing the linkage of inverted guanosine via a triphosphate bridge to the first transcribed nucleotide. The involvement of CE in C-MYC-dependent mRNA capping and C-MYC function has not yet been explored. Therefore, I sought to determine whether C-MYC regulates CE, and whether CE is required for C-MYC function. I found that C-MYC promotes CE recruitment to RNA polymerase II (RNA pol II) transcription complexes and to regions proximal to transcription start sites on chromatin. Consistently, C-MYC increases RNA pol II-associated CE activity. Interestingly, cells driven by C-MYC are highly dependent on CE for C-MYC-induced target gene expression and cell transformation, but only when C-MYC is overexpressed; C-MYC-independent cells or cells retaining normal control of C-MYC expression are insensitive to CE inhibition. C-MYC expression is also dependent on CE. Taken together, I present a bidirectional regulatory relationship between C-MYC and CE which is potentially therapeutically relevant. Studies here strongly suggest that inhibiting CE is an attractive strategy to selectively target cancer cells which have acquired deregulated C-MYC.
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Kumar, Amit. "Synthesis and biochemical evaluation of novel enzyme inhibitors as potential anti-tumour agents in the treatment of breast cancer." Thesis, University of the West of Scotland, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.739948.
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Rueda, Lidiane Camila 1982. "Avaliação de polimorfismos nos genes CYP1A1, CYP2D6 e CYP19 em uma amostra de pacientes com cancer de mama esporadico." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310493.
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Orientador: Carmen Silvia Bertuzzo, Luis Alberto MagnaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: O câncer de mama (CM) é uma doença heterogênea e complexa, compreendendo múltiplas formas de apresentação clínica e morfológica, com diferentes graus de agressividade tumoral e potencial metastático. Acredita-se que 90% a 95% de todos os CM sejam esporádicos e decorram de mutações somáticas que se verificam durante a vida e que 5% a 10% sejam hereditários em virtude de uma mutação germinativa ao nascimento, que confere a estes indivíduos suscetibilidade ao CM. Entre os polimorfismos mais conhecidos de metabolização de drogas, estão os do sistema do citocromo P450. Os genes CYP1A1, CYP2D6 e CYP19 estão sendo estudados e em algumas populações mostraram uma associação positiva com a maior suscetibilidade ao CM. Este trabalho teve como objetivo investigar a presença dos polimorfismos T6235C (m1) e A4889G (m2) no gene CYP1A1, a presença dos polimorfismos A2637del (*3) e G1934A (*4) no gene CYP2D6 e a presença de alterações [TTTAn] no gene CYP19, por meio de um estudo de associação com uma amostra de 170 indivíduos, sendo 45 pacientes portadores de Adenocarcinoma e 120 controles normais. Foram utilizadas as técnicas extração de DNA, PCR e digestão enzimática. Não foi demonstrada, no presente estudo, associação entre os polimorfismos estudados e CM esporádico: (?2(2) = 1,12; p= 0,57) para o polimorfismo m1, (?2(2) = 0,83; p= 0,65) para o polimorfismo m2 do gene CYP1A1; (?2(2) = 0,15; p = 0,69) para o polimorfismo *3, (?2(2) = 2,41; p = 0,30) para o polimorfismo *4 do gene CYP2D6 e para as repetições em tandem [TTTA]n do gene CYP19. Os resultados sugerem que os polimorfismos gênicos estudados não estariam associados ao CM na amostra de indivíduos da região metropolitana de Campinas. Palavras-chave: CYP1A1, CYP2D6, CYP19, câncer de mama esporádico.
Abstract: Breast cancer (BC) is a complex disease, with heterogeneous clinical and morphologic presentation, that has with different degrees of tumoral aggressiveness and metastatic potential. It is known that 90% to 95% of all the BC are sporadical and happens because of somatic mutations that occurs during life and that 5% to 10% are hereditary because of germinate mutation due to births, which makes these individuals susceptibly to the BC. Among the best known polymorphism of metabolism of drugs, are the system cytochrome P450. The genes CYP1A1, CYP2D6 and CYP19 are being studied and in some populations because they had shown a positive association with the biggest susceptibility to the BC. This work had as objective to investigate the presence of polymorphisms T6235C (m1) and A4889G (m2) in gene CYP1A1, polymorphisms A2637del (*3) and G1934A (*4) in gene CYP2D6 and the presence of alterations [TTTAn] in gene CYP19, through a study of association with a sample of 170 individuals: 45 carrying patients of adenocarcinoma and 120 normal controls. The techniques had been used extraction of DNA, PCR and enzymatic digestion. It was not demonstrated, in this study the association between the polymorphisms studied and sporadic BC (?2(2) = 1,12; p= 0,57) for the polymorphism m1, (?2(2) = 0,83; p= 0,65) for the polymorphism m2 of gene CYP1A1; (?2(2) = 0,15; p= 0,69) for polymorphism *3, (?2(2) = 2,41; p= 0,30) for polymorphism *4 of gene CYP2D6 and for gene CYP19. The results suggest that the genic polymorphisms studied would not be associated with the BC in the sample of individuals in the metropolitan area of Campinas. key words: CYP1A1, CYP2D6, CYP19, sporadic breast cancer.
Mestrado
Mestre em Farmacologia
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Liu, Jie-Yu. "Development of a Competitive Enzyme-Linked Immunosorbent Assay (ELISA) for Zeranol Detection and the Gene Regulation by Zeranol in Breast Cancer." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313426678.
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Costa, Renato Nascimento da. "Avaliação da implementação da pesquisa de anticorpos irregulares com hemácias tratadas com enzima nos exames pré-transfusionais de pacientes com neoplasia maligna de mama do Instituto Nacional do Câncer." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17155/tde-08062017-100958/.
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A aloimunização contra antígenos eritrocitários decorre normalmente de gestações ou transfusões prévias e torna-se um problema mais frequente entre pacientes submetidos à transfusão, até mesmo entre pacientes transfundidos de forma esporádica, como nos casos de pacientes com câncer de mama. A detecção de anticorpos irregulares deve ser realizada com técnica sensível, capaz de detectar os anticorpos de maior relevância clínica. A falha na detecção de um aloanticorpo pode levar a reação transfusional hemolítica aguda ou tardia de intensidade variável que podem agravar ainda mais a condição clínica do receptor. Atualmente no Hospital do Câncer III, a detecção de anticorpo irregular é realizada na técnica em gel-teste na fase de antiglobulina humana. O presente trabalho teve como objetivos avaliar o impacto da implantação da técnica enzimática na pesquisa de anticorpos irregulares (P.A.I) na rotina pré-transfusional em associação à técnica utilizada na rotina, e estudar o perfil de aloimunização em portadores do câncer de mama atendidos nesse serviço. Entre junho de 2015 e maio de 2016, 429 amostras de sangue de pacientes com câncer de mama coletadas para testes pré-transfusionais foram submetidas à P.A.I pelas metodologias em Liss\\AGH e Nacl\\Enzima. Quando a P.A.I resultava positiva, a identificação do anticorpo era realizada utilizando a técnica correspondente. A frequência de aloimunização encontrada pela técnica de Liss/AGH foi de 1,86% (8/429), enquanto a técnica enzimática revelou uma taxa de aloimunização de 7,6% (32/421) e com associação dos resultados de ambas técnicas obtivemos 9,32% (40/429). . Assim como na literatura, os anticorpos dos sistemas Rh foram os mais frequentes. A rotina institucional apresentou o Anti-D como predominante em 5 amostras (41,6%), seguido por 2 Anti-E (16,6%), 2 Anti-C (16,6%), 1 Anti-Lea (8,4%) , 1 Anti-Jka (8,4%) e 1 Anti-S (8,40). Enquanto que em enzima, o Anti-E foi o mais predominante em 13 amostras (35%), seguido por 9 (24%) autoanticorpos públicos quentes, 7 Anti-Lea (19%), 4 Anti-D (11%), 1 Anti-C (2,75%), 1 Anti-Cw (2,75%), 1 Anti-K (2,75%) e 1 Anti- Dia (2,75%). Para comparar proporções do perfil de aloimunização desses pacientes, foram utilizados os testes Qui-quadrado e Teste G, com valores de p<0,10 considerados significantes. Foram observadas diferenças significantes entre aloimunizados e não aloimunizados quanto à cor da pele, classificação RhD, histórico transfusional e tempo de incidência de aloanticorpo. Observamos que a aloimunização não está correlacionada ao número de transfusões de concentrados de hemácias na Instituição e sim pelo histórico transfusional. Antecedentes transfusionais foram identificados em 27,5% dos aloimunizados e 14% dos não aloimunizados (p) = 0.0398. O predomínio de RhD 7 positivo foi verificado tanto nos aloimunizados quanto nos grupos dos não aloimunizados com percentuais de 75% e 90%, respectivamente (p) = 0.0147. De acordo com a estimativa do tempo para geração de aloanticorpos, todas as aloimunizadas (100%) apresentaram resultado considerado longo, sendo superior a 72 horas. Dentre as não aloimunizadas o mesmo tempo apresentouse em 41 (82%) das pacientes (p) = 0.0583, demonstrando que a técnica enzimática pode ser utilizada com o intuito de se detectar aloanticorpos em reduzido intervalo de tempo pós-exposição a antígenos eritrocitários. Diante desses fatos, propomos a aplicação da fenotipagem eritrocitária para os antígenos dos sistemas Kell e Rh, para os indivíduos portadores do câncer de mama. Também propomos a ampliação deste projeto na rotina pré- transfusional sobre os demais grupos de pacientes oncológicos tratados pelo INCA. Tal medida certamente contribuirá para reduzir o risco de transfusões fenótipo imcompatíveis que poderiam acarretar reações transfusionais hemolíticas ou transfusões ineficazes.The alloimmunization from erythrocyte antigens usually happens from previous pregnancies or transfusions and becomes a frequent problem among patients undergoing transfusion, even among those transfused sporadically, as in the cases of patients with breast cancer. The detection of irregular antibodies should be performed with sensitive technique capable of detecting the most clinically relevant antibodies. The failure of detecting an alloantibody can provoke acute or delayed hemolytic transfusion reaction of varying intensity that can further worsen the clinical condition of the recipient. Currently in the Cancer Hospital III, irregular antibody detection is performed in the gel-test technique at the stage of human antiglobulin. This study aimed to evaluate the impact of enzymatic technique implementation in irregular antibody screening (PAI) in the pre-transfusion routine in association with the technique used in routine, and study the alloimmunization profile in patients with breast cancer treated in this service. Between June 2015 and May 2016 XXX blood samples (serum? Plasma?) Of patients with breast cancer collected for pre-transfusion tests were submitted to the P.A.I methodologies Liss \\ AGH and NaCl \\ enzyme. When P.A.I resulted positive, identification of the antibody was carried out using the corresponding technique. The frequency of alloimmunization found by the technique Liss / AGH was 1.86% (8/429), whereas the enzymatic technique revealed an alloimmunization rate of 7.6% (32/421) and association of the results of both techniques was 9.32% (40/429). As found in literature, the antibodies of the Rh systems were the most frequent. The institutional routine presented anti-D as prevalent in 5 samples (41.6%), followed by anti-E 2 (16.6%) 2 Anti-C (16.6%) 1 Anti-Lea (8, 4%), anti-Jka 1 (8.4%) and anti-S 1 (8.40). While in enzyme technique, Anti-E was the most predominant in 13 samples (35%), followed by 9 (24%) hot public autoantibodies 7 Anti-Lea (19%) 4 Anti-D (11%), 1 Anti-C (2.75%), Anti-Cw 1 (2.75%) 1 Anti-K (2.75%) and Anti Day 1 (2.75%). To compare alloimmunization profile proportions of these patients, the Chi-square test and test G were used, with p <0.10 considered significant. Significant differences were observed between alloimmunized and not alloimmunized as ethnicity, RhD classification, transfusional historic and time of incidence of alloantibodies. We note that alloimmunization is not correlated to the number of red cell concentrate transfusions in the institution but by transfusional historic. Past transfusions have been identified in 27.5% of alloimmunized and 14% of non-alloimmunized (p) = 0.0398 patients. The prevalence of RhD positive was observed in both groups alloimmunized and non-alloimmunized with 75% and 90%, respectively (p) = 0.0147. According to the estimated time for the generation of alloantibodies, all isoimmunized (100%) had 9 results considered long, and more than 72 hours. Among the non-alloimmunized, 41 (82%) patients (p) = 0.0583 presented the same time, indicating that the enzymatic technique can be used in order to detect alloantibodies in a reduced post-exposure interval to erythrocyte antigens. Given these facts, we propose the application of phenotyping erythrocyte to the antigens of the Kell and Rh systems, for all individuals of breast cancer. We also propose the extension of this project in the pre-transfusion routine on other groups of cancer patients treated by INCA. This measure will certainly help to reduce the risk of transfusion incompatible phenotype that could cause hemolytic transfusion reactions or ineffective transfusions.
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Gauche, Caroline. "L’héparane sulfate 3-O-sulfotransférase 3A (3-OST3A) : une enzyme de maturation des glycosaminoglycanes en tant que nouveau régulateur tumoral dans le cancer du sein." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0187/document.
Full textAbstract:
Les protéoglycanes à héparane-sulfates (HSPGs) sont des macromolécules ubiquitaires situées à la surface des cellules et au sein des matrices extracellulaires jouant un rôle clé dans le contrôle des interactions cellules-matrice et du micro-environnement tumoral. Leur biosynthèse est assurée par une machinerie enzymatique complexe impliquant des glycosyltransférases et sulfotransférases, lesquelles ajoutent des motifs sulfatés en différentes positions des résidus de la chaîne glucidique. Ces modifications confèrent aux HSPGs la capacité d’interagir avec de nombreux ligands comme les facteurs de croissance et leurs récepteurs permettant de réguler divers processus physiopathologiques tels que la prolifération et la survie cellulaires, l’angiogenèse et le développement tumoral. J’ai focalisé mon étude sur une famille de sulfotransférases, les 3-O-sulfotransférases (3-OSTs) responsables d’une modification rare et terminale des chaînes de HS et en particulier sur l’isoforme 3A (3-OST3A) dont le rôle dans le développement tumoral a été précédemment mis en évidence par notre équipe. L’objectif de ce travail de thèse est d’explorer le rôle de la 3-OST3A dans la régulation du développement du cancer du sein. Ces travaux mettent en évidence que le gène 3-OST3A est régulé épigénétiquement dans un panel de lignées cellulaires cancéreuses mammaires. Les tests cellulaires de prolifération et d’apoptose montrent que la 3-OST3A exerce une action oncogénique ou suppresseur de tumeur dépendante de la signature moléculaire des cellules cancéreuses mammaires. Au niveau clinique, un fort taux d’expression de la 3-OST3A dans les tumeurs est corrélé négativement avec la survie des patientes atteintes d’un cancer du sein de sous-type HER2+. Ces travaux sont les premiers à mettre en évidence un rôle fonctionnel de la 3-OST3A en tant que régulateur du comportement tumoral des cellules cancéreuses mammaires et permettent de l’envisager comme marqueur pronostique de l’évolution du sous-type de tumeur mammaire HER2. La poursuite de cette étude a pour objectif de comprendre les mécanismes qui expliquent les conséquences délétères de la forte expression de la 3-OST3A sur l’agressivité du cancer du sein HER2+. Mes résultats suggèrent que la 3-OST3A induirait l’activation du récepteur HER2 par une voie dépendante de la formation du complexe ternaire HS 3-O-sulfatés/FGF-7/FGFR2IIIb dans les cellules SKBR3, un modèle de cellules cancéreuses mammaires surexprimant le récepteur HER2 responsable du caractère agressif du cancer du sein HER2+Heparan sulfate proteoglycans (HSPG) are ubiquitous macromolecules located at the cell plasma membrane and in extracellular matrices playing a key role in the control of cell-matrix interactions and in the tumor micro-environment. Their biosynthesis is performed by a complex enzymatic machinery involving glycosyltransferases and sulfotransferases, the latter adding a sulfate group at different residue positions of the polysaccharide chain. These modifications provide to the HSPG the ability to interact with many ligands such as growth factors and their receptors, and to regulate multiple pathophysiological processes such as cell proliferation and survival, angiogenesis and tumor development. I focused on a sulfotransferase family, the heparan sulfate 3-O-sulfotransferases (HS3STs) responsible for a rare, terminal modification of HS chains. Specifically, we investigated the HS3ST3A isoform whose role in tumor development has been previously demonstrated by our team. Here I explored the role of HS3ST3A in breast cancer. My studies demonstrate that HS3ST3A gene is epigenetically regulated in a panel of breast cancer cell lines. Cell proliferation and apoptosis assays in cellulo showed that HS3ST3A exerts an oncogenic or tumor suppressor effect in a cell-dependent context. A clinical study performed in a cohort of breast cancer patients showed that a high expression level of HS3ST3A in tumors is associated with reduced relapse-free survival in HER2+ patients. For the first time, we report a functional role of HS3ST3A as a tumor regulator of breast cancer cells behavior and this study allows considering it as a prognostic marker of the HER2 breast cancer evolution. The last part of my work attempted to understand the mechanisms that explain the deleterious consequences of the high expression level of HS3ST3A on the aggressiveness of HER2+ breast cancer. In this regard, my results suggested that the HS3ST3A may induce HER2 receptor activation following the formation of the ternary complex HS 3-O-sulphated/FGF-7/FGFR2IIIb in SKBR3 (HER2+) cells
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Pineda, Moncusí Marta. "Epidemiological study of aromatase inhibitors in women diagnosed with breast cancer: evaluation and management of secondary effects." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/672258.
Full textAbstract:
Aromatase inhibitors (AI) are one of the main therapies to treat estrogen-receptor positive breast cancer. AI use is associated with several side effects that affects patient’s quality of life and reduces treatment adherence. Hence, it is necessary to make further efforts in elucidating and diminishing the AI-related side effects.
In this line, this thesis provided new and additional evidence for this purpose. Starting by the importance of assessing vitamin D levels during AI treatment, especially to those who underwent to chemotherapy. We also studied the bone health evolution at the end and one-year after AI cessation, and the impact of oral bisphosphonates (BP). Moreover, we analyzed the arthralgia (VAS score) and health-related quality of life in osteoporosis (ECOS-16 score) progression during the AI treatment until one- year post-treatment. Then, fracture incidence and risk during AI therapy compared to tamoxifen (TAM) was analyzed, as well as the protective effect of BP. Finally, we studied the cardiovascular and thromboembolic risk, and overall survival benefit of AI compared to TAM.
Our research leads us to state that bone health and circulant vitamin D levels monitoring, plus calcium and vitamin D supplementation is key for the clinical management of AI patients. BP treatment is proved to diminish bone loss and fracture risk, but cannot reverse risk levels towards patients at low fracture risk. Furthermore, prior TAM treatment enhances the odds to withdraw during the first year, increases bone loss during
AI treatment, and restricts the recovery in lumbar spine location at one-year post-treatment. On the other hand, since there are no differences in cardiovascular and thromboembolic risk between AI and TAM users, but AI users have lower all-cause mortality, AI should be the preferable choice.
In summary, it is mandatory to clinical monitoring AI patients, especially those who were previously treated with TAM, including fracture risk and related risk factors assessments. These would reduce early cessation of treatment and improve patients’ quality of life.
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Ghanem, Ali [Verfasser], and Stefan [Akademischer Betreuer] Wölfl. "On the Regulation and Multiple Functions of the Key Gluconeogenic Enzyme Fbp1 in Rapidly Proliferating Cells: Insights from Yeast and Breast Cancer Cells / Ali Ghanem ; Betreuer: Stefan Wölfl." Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177149605/34.
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Miettinen, M. (Minna). "17β-hydroxysteroid dehydrogenase types 1 and 2:expression and activities in various tissues and cell lines and effect of the type 1 enzyme on estrogen-dependent growth of breast cancer cells." Doctoral thesis, University of Oulu, 1999. http://urn.fi/urn:isbn:9514254163.
Full textAbstract:
Abstract
17β-Hydroxysteroid dehydrogenases (17HSDs) catalyze
the reactions between 17-hydroxy and 17-keto steroids. In the present
study, the enzyme activities and tissue distribution of 17HSD type
1, type 2 and type 4 were characterized. Furthermore, the role of
17HSD type 1 in estrogen-dependent growth was studied in MCF-7 breast
cancer cells which were stably transfected with type 1 cDNA.
Endogenous oxidative 17HSD activity found in COS-m6 monkey
kidney cells was first compared with that of human placental 17HSD.
Cultured COS-m6 cells exclusively possessed oxidative 17HSD activity,
converting estradiol (E2) to less active estrone (E1). When placental
17HSD was transfected into these cells, highly reductive activity
appeared. The 17HSD enzyme in COS-m6 cells also catalyzed the conversion
of testosterone to androstenedione, whereas the placental enzyme
was estrogen-specific. These results further proved the existence
of different 17HSD isoenzymes.
The enzymatic properties and cell- and tissue-specific expression
of 17HSD type 1, type 2 and oxidative type 4 were further characterized.
The data confirmed that in cultured cells the direction of 17HSD
activity is determined by the expression of different isoenzymes
and not by the intracellular environment. In addition, the 17HSD
type 1 gene expresses two mRNA signals, 1.3 kb and 2.3 kb in size.
The expression of 1.3 kb mRNA, but not 2.3 kb mRNA was related to
enzyme concentration in all the cell types studied. The type 1 enzyme
was expressed in the placenta, ovary and in some breast cancer specimens
and in the cell lines originated from these tissues. 17HSD type
2 was more widely expressed in both steroidogenic and in target
tissues of steroid action. 17HSD type 4 was expressed in almost
all cell lines and in all tissues studied, but no correlation with
17HSD activity was detected. These results suggest that 17HSD type
1 is involved in E2 production in females and 17HSD type 2 is responsible
for inactivation of sex steroids. However, the oxidation of 17β-hydroxysteroids
seems not to be the primary activity of 17HSD type 4.
The mRNAs for 17HSD type 1, type 2 and type 4 were found to
be expressed in human mammary epithelial cells. In breast tissue
samples both 17HSD type 1 and type 2 were detected by in
situ hybridization. Despite the presence of 17HSD type
1 mRNA in human mammary epithelial cells, only oxidative 17HSD activity
was detected. The reason for the lack of reductive activity is not
yet known.
Finally, MCF-7 breast cancer cells were stably transfected
with 17HSD type 1 cDNA in order to study the effect of 17HSD type
1 on estrogen-dependent growth. In wild type MCF-7 cells, very low 17HSD
activity was detected and E1 did not have any effect on cell growth.
In the cells expressing 17HSD type 1, E1 was rapidly converted to
E2. Hence in these cells E1 had a similar growth-promoting effect
as E2 as a result of the action of 17HSD type 1. The presence of
17HSD type 1 in breast cancer cells may thus be an important factor
regulating estrogen exposure and the estrogen-responsive growth
of breast cancer tissue.
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Thinnes, Cyrille Christophe. "Chemical and biological studies on human oxygenases." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:455f2e65-f294-461b-b44f-cd53796b14a0.
Full textAbstract:
As depicted in Chapter I, 2-oxoglutarate- (2OG) dependent oxygenases are ubiquitous in living systems and display a wide range of cellular functions, spanning metabolism, transcription, and translation. Although functionally diverse, the 2OG oxygenases share a high degree of structural similarities between their catalytic sites. From a medicinal chemistry point of view, the combination of biological diversity and structural similarity presents a rather challenging task for the development of selective small molecules for functional studies in vivo. The non-selective metal chelator 8-hydroxyquinoline (8HQ) was used as a template for the generation of tool compound I for the KDM4 subfamily of histone demethylases via application of the Betti reaction. Structural analogue II was used as the corresponding negative control (Figure A). These compounds were characterised in vitro against a range of 2OG oxygenases and subsequently used for studies in cells. I displays selectivity for KDM4 and increases the level of the H3K9me3 histone mark in cells. It has an effect on the post-translational modification pattern of histone H3, but not other histones, and reduces the viability of lung cancer cells, but not normal lung cells, derived from the same patient. I also stabilises hypoxia-inducable factor HIF in cells via a mechanism which seems to be independent from prolyl hydroxylase inhibition. This work is described in Chapters II and III. The chemical biology research in epigenetics is complemented by qualitative analysis conducted in the social sciences at Said Business School. With a global view on how innovation occurs and may actively be fostered, Chapter IV focuses on the potential of epigenetics in drug discovery and how this process may actively be promoted within the framework of open innovation. Areas of focus include considerations of incremental and disruptive technology; how to claim, demarcate, and control the market; how knowledge brokering occurs; and insights about process, management, organisation, and culture of open innovation. In contrast to the open-skies approach adopted for the development of a tool compound in Chapters II and III, a focused-library approach was taken for the generation of a tool compound for the OGFOD1 ribosomal prolyl hydroxylase. The development of a suitable in vitro activity assay for OGFOD1 in Chapter V enabled the development of lead compound III in Chapter VI. III is selective for OGFOD1 against the structurally closely related prolyl hydroxylase PHD2.
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Fortgens, Philip Hendrik. "Proteinases and extracellular matrix degradation in breast cancer." Thesis, 1996. http://hdl.handle.net/10413/9728.
Full textAbstract:
A variety of proteases have been shown to promote the progression of cancer by virtue of their ability to degrade extracellular proteinaceous barriers, such as
basement membrane and interstitial stroma. At the outset of this study available
evidence strongly implicated cathepsin D in breast cancer metastasis. It was
envisaged that an antibody inhibitory to the activity of this enzyme might retard
invasion, and restrain a tumour from spreading. To this end anti-peptide
antibodies were generated against a peptide sequence derived from the substrate
capturing "flap" of the enzyme. Inhibition of enzyme activity by these antibodies
could not be demonstrated, probably due to the lack of a suitably sensitive
enzyme assay. However, the rationale of this study and the expertise gained from
it could be applied, in the future, to enzymes that have since been found to be
more relevant to tumour invasion.
A feature of many transformed cells is an anomalous lysosomal enzyme
trafficking system, and concomitant hyper-secretion of some enzymes. The
distribution of low pH compartments and lysosomal enzyme-containing
compartments was investigated in human breast epithelial cells, and their c-Ha-ras-
transformed counterparts. Immunofluorescence and immunoelectron
microscopy showed that these compartments have a more peripheral cellular
distribution with respect to normal cells, and cathepsins B and D were cell
surface-associated.
Studies were undertaken to reveal the extracellular matrix degrading ability of c-Ha-
ras-transformed cells. Transformed cells exhibited increased degradation of
fluorescein-labelled extracellular matrix in serum free medium, and increased motility, and degradation and disruption of extracellular matrix in serum-containing
medium. In vitro invasion through artificial basement membrane by
transformed cells was investigated using scanning electron microscopy, and was
further used to preliminarily identify the proteases involved in invasion by
specific inhibition. By this means, greatest inhibition of in vitro invasion was
obtained using a specific metalloproteinase inhibitor. Overexpression by
transformed cells of a metalloproteinase was detected by gelatin zymography.
Together these results suggest that the increased invasive capacity of ras-transformed
breast epithelial cells may be largely due to increased
metalloproteinase activity.Thesis (Ph.D.)-University of Natal, Pietermaritzburg , 1996.
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Chen, Yueh-Ling, and 陳玥伶. "Study of metabolic enzyme polymorphisms for breast cancer in Taiwan." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/10147586078810613322.
Full textAbstract:
碩士高雄醫學大學
醫學檢驗生物技術學研究所
97
Objectives: Damage to breast epithelium by reactive oxygen species is important in the initiation and promotion of cells to neoplastic growth. Therefore, this study investigated the genomic polymorphisms of metabolic enzymes, including detoxification and oxidative stress-related enzymes, associated with the risk of breast cancer. Materials and Methods: 5ml of EDTA blood was taken from 260 patients admitted to breast cancer surgery from Kaohsiung Medical University Hospital and 224 controls. Genomic polymorphisms of detoxification enzymes, including CYP2E1, GSTM1, and oxidative stress related-enzymes, including manganese superoxide dismutase (MnSOD) , glutathione peroxidase1 (GPx1), myeloperoxidase (MPO）, and catalase 【CAT -15A>T, and CAT -262C>T】were analyzed. Results: ①Compared with the subjects with the CYP2E1 -1053C>T CC genotype, those with the CYP2E1 -1053C>T TT genotype have a decreased risk of breast cancer (OR=0.26, p<0.05). In addition, those with the MnSOD 1183T>C C carrier rather than those with the MnSOD 1183T>C wild-type were predisposed to having a decreased risk of breast cancer, regardless of their allele, genotype (CC) and phenotype frequencies.（OR=0.41, 0.57 and 0.58 respectively, p<0.005） Furthermore, those with the GPx1 Pro198Leu T carrier rather than those with the GPx1 Pro198Leu wild-type were predisposed to having a decreased risk of breast cancer, regardless of their allele, genotype (CT) and phenotype frequencies. (OR=0.17, 0.15 and 0.19 respectively, p<0.001).② Those with the combimed genotypes for the CYP2E1 -1053C>T CC and MnSOD 1183T>C C carrier, and the combimed genotypes for the CYP2E1 -1053C>T T carrier and MnSOD 1183T>C C carrier rather than those with the CYP2E1 -1053C>T CC and MnSOD 1183T>C TT genotypes were predisposed to having a decreased risk of breast cancer (OR=0.60 and 0.46 respectively, p<0.05 ); those with the combimed genotypes for the CYP2E1 -1053C>T CC and GPx1 Pro198Leu T carrier, and the combimed genotypes for the CYP2E1 -1053C>T T carrier and GPx1Pro198Leu T carrier rather than those with the CYP2E1 -1053C>T CC and GPx1Pro198Leu CC genotypes were predisposed to having a decreased risk of breast cancer (OR=0.12 and 0.18 respectively, p<0.001 ). ③ Those with the combimed genotypes for the MnSOD 1183T>C C carrier and GSTM1 null-type rather than those with the MnSOD 1183T>C TT and GSTM1 wild-type genotypes were predisposed to having a decreased risk of breast cancer (OR=0.54, p<0.05); those with the combimed genotypes for the MnSOD 1183T>C C carrier and CAT -15A>T AA, and the combimed genotypes for the MnSOD 1183T>C C carrier and CAT -15A>T T carrier rather than those with the MnSOD 1183T>C TT and CAT -15A>T AA genotypes were predisposed to having a decreased risk of breast cancer (OR=0.56 and 0.55 respectively, p<0.05); those with the combimed genotypes for the MnSOD 1183T>C C carrier and CAT -262C>T CC rather than those with the MnSOD 1183T>C TT and CAT -262C>T CC genotypes were predisposed to having a decreased risk of breast cancer (OR=0.56, p<0.001); those with the combimed genotypes for the MnSOD 1183T>C C carrier and MPO -463G>A GG and the combimed genotypes for the MnSOD 1183T>C C carrier and MPO -463G>A A carrier genotypes rather than those with the MnSOD 1183 T>C TT and MPO -463G>A GG genotypes were predisposed to having a decreased risk of breast cancer (OR=0.49 and 0.43 respectively, p<0.001). ④ Those with the the combimed genotypes for the MnSOD 1183T>C TT and GPx1Pro198Leu T carrier and the combimed genotypes for the MnSOD 1183T>C C carrier and GPx1 Pro198Leu T carrier genotypes rather than those with the MnSOD 1183T>C TT and GPx1Pro198Leu CC genotypes were predisposed to having a decreased risk of breast cancer. (OR=0.22 and 0.07 respectively, p<0.001) Conclusion: We suggested that the subjects with the CYP2E1-1053 T carrier、MnSOD 1183 C carrier, GPx1 T carrier have a decreased risk for breast cancer.
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Liu, Qun. "Enzyme microencapsulation and its application for overcoming multidrug resistance in breast cancer treatment." 2008. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=742620&T=F.
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Peng, Kai-Lin, and 彭凱琳. "Characterization of the role and regulation of DNA demethylation enzyme TET1 in breast cancer." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/59587949991813690348.
Full textAbstract:
博士國立陽明大學
生化暨分子生物研究所
104
Aberrant DNA methylation is a leading cause of cancer formation. DNA methyltransferases contribute to oncogenesis partly through methylation and inactivation of tumor suppressor genes. Whether DNA demethylation counteracts this oncogenic effect has been a burning issue in cancer epigenetics. In 2009/2010, the ten-eleven translocation gene family protein 1-3 (TET1-3) were identified as DNA demethylation enzymes to convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) through iterative oxidation reactions. Subsequently, 5fC and 5caC can be excised by thymine DNA glycosylase (TDG) and replaced with intact cytosines through base excision repair mechanism. We discovered the first mechanism by which TET1 suppresses tumor invasion/metastasis. We found that TET1 inhibited DNA methylation of tissue inhibitors of metalloproteinases (TIMP2 and TIMP3) to potentiate TIMP2 and TIMP3 expressions, further leading to invasion suppression (Best 5 Article of Cell Reports 2012). How TETs are regulated and maintained in normal cells is poorly understood. In Chapter II, we showed that only TET1 was positively regulated by p53, an important tumor suppressor. Using luciferase reporter and promoter deletion assay, we identified -500 bp to the transcription start site (TSS) as the minimal TET1 promoter for TET1 expression in normal cells. The DNA affinity protein assay (DAPA) revealed that p53 could be pulled down by this minimal TET1 promoter region. Chromatin immunoprecipitation (ChIP) further demonstrated that p53 bound to the minimal TET1 promoter in cells. TET1 expression decreased when p53 was knocked down. Consistently, ectopically expressed p53 activated TET1 expression and promoter activity. Furthermore, the expression and function, ex, 5hmC level, of TET1 were activated when normal cells were treated with DNA damage inducers to activate p53. Consistently, p53-null cells could not activate TET1 upon DNA damage, indicating that both TET1 expression and 5hmC increase in a p53-dependent manner. In summary, our findings indicate that p53 positively regulates and maintains TET1 expression and function. In Chapter III of the study, we analyzed how TET1 expression is downregulated in breast cancer tissues. We used different histone modification antibodies in ChIP assay to illustrate that H3K9me2/3, hallmarks for transcriptional repression, were enriched in TET1 promoter in breast cancer tissues. By analyzing The Cancer Genome Atlas (TCGA) database, we showed that KMT1D/GLP was up-regulated in the majority of breast cancer tissues and inversely correlated with TET1 expression. In addition, depletion of KMT1D/GLP increased the expressions of TET1 and TET2 but not TET3. ChIP assays further showed that the endogenous KMT1D/GLP bound to TET1 promoter region. These results indicate that KMT1D/GLP may contribute to transcriptional silencing of TET1 expression in cancer cells via histone H3K9 methylation. Taken together, in this thesis work, we uncovered the mechanistic role of TET1 in cancer suppression and illustrated the regulation of TET1 in normal or breast cancer tissues. These results not only greatly advance our knowledge of DNA demethylation enzymes under physiological condition and in cancer but also provide an opportunity to develop a potential anti-cancer strategy by targeting TET1 expression. We believe that the study will exert a great impact on the cancer epigenetic field.
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WANG, ZHENG-KANG, and 王正康. "Purification and characterization of Cytosolic NADP^^-dependent malic enzyme from human breast cancer cell line." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/13036798029459661515.
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Wu, Jing-Ni, and 吳晶霓. "Using DDH as a target enzyme for screening Taiwan native plants with anti- breast cancer activity." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/67273711836789686618.
Full textAbstract:
碩士國立中興大學
生命科學院碩士在職專班
99
Nowadays, the existing treatments, including surgical removal, radiation therapy, chemotherapy, long-acting hormone therapy or even the emergence of the recent target therapy did not overcome the difficulties of the treatment. The major problem is the spontaneous resistance of cancer cells to the available drug. In order to improve the effectiveness of chemotherapy, our study screened 88 plant extracts in order to find out cancer-specific cytotoxicity of species unique to Taiwan. High expression of DDH was confirmed in many kinds of cancer, and was also correlated to carcinogenesis as well as increasing drug-resistant. Thus, we detected DDH levels in five breast cancer cell lines. The result showed differential expression of DDH. We further performed 2-D analysis of BT-20, which revealed the highest amount of DDH, and of MCF-7. It showed that BT-20 expressed AKR1C1 and C3, whereas MCF-7 displayed only C1. Using WST-1 assay, we found 10 extracts on BT-20 and 11 extracts on MCF-7 exhibited inhibitory effects on cell growth. We evaluated changes of protein levels of DDH and ATA3A, which is recently uncovered to relate to drug resistance associated with cancers. Only BC (#37) had inhibitory effects both on two proteins in two cells. Detection of PARP found that although two cells have different sensitivities to BC, it can be observed in the case of PARP has been cut, and with the amount of full-length PARP reducing in a dose-dependent manner. Observation of Rad23A (responsible for ubiquitinated proteins identification) distribution found that use of BC resulted in cells accumulating autophagic vacuoles, and Rad23A gathered in the vicinity of vacuoles. Taken together, BC reduced the DDH level hence the application of BC with existing drugs may be able to raise the sensitivity of cancer cells to drugs. Besides, BC may perform its effects through the induction of apoptosis and/or autophagy. Therefore our results showed BC to be with great potential in anti-breast cancer drug development.
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LU, YA YU, and 呂亞諭. "Functional Roles of Mitochondrial NAD(P)+-Dependent-Malic Enzyme (ME2) Lung and Breast Cancer Cell Line." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/52524676675814439583.
Full textAbstract:
碩士國立中興大學
生命科學系所
101
Malic enzyme (Malic Enzyme; ME) has three isoforms, which mitochondrial malic enzyme (Mitochondrial NAD (P) +-dependent malic enzyme; ME2) acting on the rapid proliferation of tissue, intestinal mucosa, spleen, thymus and tumor cells; ME2 catalytic substrates malate (Malate) generate pyruvate (Pyruvate), accompanied produce NADH. NADH in the mitochondrial membrane electron transport chain via oxidative phosphorylation to produce ATP provides direct role in cellular energy, the process will have a chance to produce O2-, via Superoxide Dismutase (SOD) catalyzes the formation of H2O2. Finally, to assist the formation of metal ions OH-, on the cell undergoes oxidation damage, thus activating downstream proteins, the occurrence of procedural plans death (Apoptosis). ME2 catalytic reaction accompanied by NADH generated energy metabolism as a major source of ATP molecules, while in the fight against ROS damage may also play a very important role in helping to generate and promote NADPH Glutathione (GSH) maintained at reduced state, effectively reduce the ROS injury. In the anticancer mechanism, in addition to promote apoptosis in cancer cells, but also inhibit the proliferation of channels, I also conducted research there for mitochondrial malic enzyme (Malic enzyme 2, ME2) mechanism for cell proliferation mitochondrial malic enzyme activity is correlated mitochondrial malic enzyme is a cell in another to obtain energy pathways, many tumor cells can use glutamine (glutamine) to replace glucose as a major energy source, malic enzyme ie the catalytic glutamate metabolism, called "Glutaminolysis". Metabolic process, α-ketoglutarate converted to malate system by the Krebs cycle (citric acid cycle) in enzyme catalysis. Normal intracellular malic acid in the Krebs cycle by malate dehydrogenase (malate dehydrogenase) catalysis of oxaloacetate; But in Glutaminolysis process, malic acid from malic enzyme catalyzed the formation of pyruvic acid (pyruvate). In the citric acid cycle malic acid (Malate) will be converted into the catalysis by ME2 pyruvate and NADH accompanied by the generation of carbon dioxide, the cells get energy and to promote cell proliferation. In addition, the majority of cancer cells generated from the epidermis, so epidermal growth factor EGF in cancer compared to other growth factors most universal and most research potential, but also found that ATP can induce increased activity of EGFR, suggesting that EGF and ME2 has the possibility of mutual influence. Then explore the ME2 in H1299 lung cancer cells (non-small cell lung cancer) than in normal lung cells whether overexpression, and overexpression of whether ME2 AKT/PI3K signaling pathway can be activated with the ERK / MAPK signaling pathway to induce cell proliferation; even after can be contacted by Repamycin (mTOR inhibitor) to investigate the activation of EGF and ME2 path, further research H1299 lung cancer cell proliferation inhibition ways.
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Tsai, Wen-Chen, and 蔡汶真. "NAD(P)+-Dependent-Malic Enzyme Suppresses Senescence and Senescence-Inflammatory Response in Human Breast Cancer Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/57062774735410743132.
Full textAbstract:
碩士國立中興大學
生命科學系所
102
Malic enzyme (Malic Enzyme；ME) has three isoform, which mitochondrial malic enzyme 2 (Mitochondrial NAD(P)+-dependent Malic Enzyme；ME2) affected on the rapid proliferation of tissue, intestinal mucosa, spleen, thymus and tumor cells. ME2 catalytic substrates malate generate pyrevate, accompanied produce NADPH. NADPH in the mitochondrial membrane electron transport chain via oxidative phosphorylation to produce ATP provides direct role in cellular energy. In addition, ME2 also via glutamine metabolic pathway, the extra produce NADPH. The p53 is a tumor suppressor protein, most of the cells to be able to decide. In this study, downregulation of ME2 increased cellular ROS levels leading to DNA damage. Then, it enhanced the p53 activation, activation of downstream proteins to induce cell maintenance of senescence. Conversely, ME2 expression also suppressed the p53 levels. The p53-mediated senescence was reduced. However, cell accelerated proliferation and metabolism. We knew the senescence, perceived as a cancer barrier. In addition, we found that is paradoxically associated with chronic inflammation, which promote tumorigenesis. Suppress or promote tumorigenesis from p53 functional normal or not. The absence of p53 in cells, the cells would lose its growth control capacity and invasiveness. In this study, we silenced of p53 by shRNA in normal p53 cancer cells. We supposed cancer cell still through a Senescence-associated pathway inducing a Senescence-associated inflammatory response (SIR), which is still inflammation state in the cell. Therefore, we investigated the mechanisms of Senescence-associated inflammatory in human breast cancer cells. We contributed to the future use of anti-inflammatory agents and Malic enzyme inhibitors inhibit tumor formation.
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Chou, Yu-Ching, and 周雨青. "Molecular Epidemiological Studies on Genetic Polymorphisms of Xenobiotic Metabolizing Enzymes and Susceptibility to Lung and Breast Cancers." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/79010826805922346256.
Full textAbstract:
碩士國防醫學院
公共衛生學研究所
89
Objective: Individual genetic susceptibility is an important factor in the carcinogenic process. This study was to assess the role of xenobiotic metabolizing enzymes including cytochrome 1A1(CYP1A1), CYP2E1, glutathione S-transferase M1(GSTM1), GSTT1, and GSTP1 in the risk of lung cancer in Taiwan. Methods: A nested case-control study was conducted within a population-based cohort study of major cancers in seven townships in Taiwan, which was initiated in 1991. A total of 64 incident lung cancer cases was identified by linkage of the study cohort with the national cancer registry system during the period between 1992 and 1998. Four individuals who were cancer-free at the time of diagnosis of lung cancer cases were matched to each case on age(±2 years), sex, residential areas, and date of blood collection(±3 months), resulting in a total of 256 control subjects for this study. Information on cigarette smoking habit was collected from each participant by questionnaire interview at baseline recruitment. Genetic polymorphisms of xenobiotic metabolizing enzymes studied were determined by polymerase chain reaction-restriction fragment length polymorphism methods. There were 40 cases and 160 controls who had adequate specimens for this study. Results: As compared with individuals with CYP1A1 m1/m1 genotype, the odds ratio of lung cancer for those who had m1/m2 or m2/m2 genotypes was 0.3(95% CI=0.2-0.7). In addition, among individuals with CYP1A1 genotype of m1/m1 , subjects who had a cumulative cigarette consumption of at least 24 pack-years or more were associated with a significantly increased risk of lung cancer when compared with non-smokers (odds ratio[OR]=12.3, 95% CI=1.6-93.1). Individuals who had CYP2E1 genotypes of c1/c2 or c2/c2 had 1.6 times higher risk of lung cancer than those who had c1/c1 genotype. In addition, smokers who had CYP2E1 genotypes of c1/c2 or c2/c2 were associated with a significantly increased risk of lung cancer when compared with non-smokers who had c1/c1 genotype(OR=4.1, 95% CI=1.2-13.3). With respect to GSTs, the ORs of lung cancer associated with null genotypes of GSTM1 and GSTT1 were 1.3(95% CI=0.6-2.7) and 1.8(95% CI=0.8-4.0), respectively. Furthermore, among individuals who had null genotypes of GSTM1 and GSTT1, subjects who had a cumulative cigarette consumption of at least 24 pack-years or more were associated with a significantly increased risk of lung cancer when compared with non-smokers, the ORs were 4.7(95% CI=1.2-18.2) in the stratum of GSTM1 null genotype and 5.2(95% CI=1.3-20.2), in the stratum of GSTT1 null genotype. With respect to GSTP1 genotypes, the OR of lung cancer associated with genotypes of Ile/Val or Val/Val was 1.1(95% CI=0.5-2.5). In addition, among subjects with Ile/Val or Val/Val genotypes, individuals with a cumulative cigarette consumption of at least 24 pack-years or more were associated with a significantly increased risk of lung cancer when compared with non-smokers, the OR was 6.3(95% CI=0.9-43.7)。 Conclusions: Genetic polymorphisms of xenobiotic metabolizing enzymes including CYP1A1, CYP2E1, GSTM1, GSTT1, and GSTP1 were associated with an increase in the risk of lung cancer in a Chinese population in Taiwan. In addition, gene-gene interaction and gene-environment interaction may play important roles in the pathogenesis of lung cancer.
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Chu, Wei-jer, and 朱維哲. "Investigation of the Associations of Genetic Polymorphisms in Estrogen Metabolism Enzyme catechol-o-methyl transferase (COMT) with the Risk of Developing Breast Cancer." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/58682795314163657340.
Full textAbstract:
碩士國立中興大學
環境工程學系所
103
The objectives of this research were to investigate. the associations of the genetic polymorphisms in estrogen metabolism and the background of risk factors in breast cancer in Taiwanese women. Results from analysis of single nucleotide polymorphisms indicated that COMT Val158Met and E2-2,3-Q-4-S-Alb were negatively correlated with the healthy in age > 50 of Taiwanese women.whereas,COMT Val158Met were not correlate with quinone-derived protein adducts background level of the healthy age <50 Taiwanese women;COMTVal158Met、E2-2,3-Q-4-S-Alb and E2-3,4-Q-4-S-Alb were not correlate with BMI> 27 of healthy Taiwanese women; COMT Val158Met were not correlate with quinone-derived protein adducts background level of the healthy BMI<27 Taiwanese women. The frequency of variant allels of estrogen metaboism gene COMT Val158Met were estimated to be 25% for healthy women (n=142). Another the frequency of variant allels of estrogen metaboism gene COMT Val158Met were estimated to be 27.7% for breast cancer patient (n=146). The finding suggest that variant allels of COMT Val158Met do not associate with the risk of developing breast cancer in Taiwanese women.
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HUANG, SHI-MING, and 黃世明. "Cloning and expression of both pigeon liver and human breast cancer cell line cytosolic NADP﹢-dependent malic enzyme cDNAs and their nutritional and hormonal regulation." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/94356519629317914123.
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"Aryl hydrocarbon receptor-mediated transcription and CYP1 class gene expression: could it be a possible mode of action of traditional chinese medicine in the management of breast carcinoma?" 2009. http://library.cuhk.edu.hk/record=b5896926.
Full textAbstract:
Cheung, Tsz Yan.Thesis (M.Phil.)--Chinese University of Hong Kong, 2009.
Includes bibliographical references (leaves 97-116).
Abstracts in English and Chinese.
Thesis/Assessment Committee Members --- p.ii
Declaration for Plagiarism and Copyright --- p.iii
Abstract --- p.iv
摘要 --- p.vi
Acknowledgements --- p.viii
Table of Contents --- p.ix
List of Abbreviations --- p.xii
List of Figures --- p.xv
List of Tables --- p.xvi
Chapter CHAPTER TWO: --- Introduction
Chapter 1.1 --- Background Information
Chapter 1.1.1 --- Breast Cancer --- p.1
Chapter 1.1.2 --- General Statistics of Breast Cancer Worldwide and in Hong Kong --- p.1
Chapter 1.1.3 --- Risk Factors for Breast Cancer --- p.2
Chapter 1.1.4 --- Breast Cancer Treatment and Side Effects --- p.2
Chapter 1.1.5 --- Types of Breast Cancer --- p.3
Chapter 1.2 --- Estrogen and Estrogen Receptor
Chapter 1.2.1 --- Estrogen --- p.4
Chapter 1.2.2 --- Estrogen Receptor --- p.5
Chapter 1.2.3 --- Estrogen Receptor mediated Gene Transcription --- p.5
Chapter 1.2.4 --- Estrogen Receptor Alpha and Estrogen Receptor Beta --- p.6
Chapter 1.2.5 --- Estrogen Receptor Positive Breast Cancer and Treatment --- p.7
Chapter 1.3 --- Estrogen metabolism and Cytochrome P450 family 1 (CYP1) members
Chapter 1.3.1 --- Estrogen Metabolism in Human --- p.9
Chapter 1.3.2 --- CYP1A1 and CYP1B1 --- p.9
Chapter 1.3.3 --- Estrogen Metabolism in Breast --- p.10
Chapter 1.3.4 --- Carcinogenesis of Estrogens and Estrogen Metabolites --- p.13
Chapter 1.3.5 --- The Importance of CYP1B1 in Carcinogenesis --- p.15
Chapter 1.4 --- Aryl Hydrocarbon Receptor
Chapter 1.4.1 --- General Information of Aryl Hydrocarbon Receptor --- p.16
Chapter 1.4.2 --- Signaling/Regulation Pathways of Aryl Hydrocarbon Receptor --- p.17
Chapter 1.4.3 --- Crosstalk with Estrogen Receptor --- p.17
Chapter 1.5 --- Introduction of Herba Scutellaria Barbata and its active ingredient Pheophorbide a --- p.19
Chapter 1.6 --- Hyposthesis and Objectives --- p.21
Chapter CHAPTER TWO: --- Direct Cytotoxic/Cytostatic Effect of Pheophorbide a
Chapter 2.1 --- Backgrounds --- p.22
Chapter 2.2 --- Materials
Chapter 2.2.1 --- Chemicals --- p.24
Chapter 2.2.2 --- Cell Lines --- p.26
Chapter 2.2.3 --- "Cell Culture Mediums, Buffers and Consumables"
Chapter 2.2.3.1 --- Roswell Park Memorial Institute Tissue Culture Medium1640 (RPMI1640) --- p.26
Chapter 2.2.3.2 --- RPMI 1640 (Phenol Red-free) --- p.26
Chapter 2.2.3.3 --- Serum supplement - Fetal Bovine Serum (FBS) --- p.27
Chapter 2.2.3.4 --- Serum supplement - Charcoal/Dextran Stripped FBS --- p.27
Chapter 2.2.3.5 --- Antibiotics - Penicillin-Streptomycin (P/S) --- p.27
Chapter 2.2.3.6 --- Trypsin (0.25%) with EDTA --- p.27
Chapter 2.2.3.7 --- Trypsin (2.5%) (Phenol Red-free) with EDTA --- p.28
Chapter 2.2.3.8 --- Dulbeccóةs Phosphate-Buffered Saline (D-PBS) --- p.28
Chapter 2.2.3.9 --- Tissue Culture Flasks and Multi-well Plate --- p.28
Chapter 2.2.3.10 --- Trypan Blue Solution --- p.29
Chapter 2.2.4 --- Reagents for Direct Cytotoxity Test
Chapter 2.2.4.1 --- MTT Assay --- p.29
Chapter 2.2.4.2 --- Tritiated Thymidine Incorporation Assay --- p.29
Chapter 2.3 --- Methods
Chapter 2.3.1 --- Cell Culture --- p.30
Chapter 2.3.2 --- Direct Cytotoxicity/Cytostatic Test
Chapter 2.3.2.1 --- MTT Assay --- p.31
Chapter 2.3.2.2 --- Tritiated Thymidine Incorporation Assay --- p.32
Chapter 2.3.3 --- Statistical Analysis --- p.32
Chapter 2.4 --- Results
Chapter 2.4.1 --- The Cytotoxic Effect of Pheophorbide a --- p.34
Chapter 2.4.2 --- The Combine Effect of Pheophorbide a with 17-β Estradiol and Tamoxifen Citrate --- p.34
Chapter 2.5 --- Discussions --- p.48
Chapter CHAPTER THREE: --- Mechanistic Study of Pheophorbide a
Chapter 3.1 --- Backgrounds --- p.53
Chapter 3.2 --- Materials
Chapter 3.2.1 --- Real time PCR
Chapter 3.2.1.1 --- General Chemicals and Equipments --- p.54
Chapter 3.2.1.2 --- RNA isolation --- p.55
Chapter 3.2.1.3 --- Reverse Transcription --- p.55
Chapter 3.2.1.4 --- Real Time PCR --- p.56
Chapter 3.2.2 --- Western Blotting
Chapter 3.2.2.1 --- Microsome Isolation --- p.58
Chapter 3.2.2.2 --- Measurement of Protein Concentration --- p.58
Chapter 3.2.2.3 --- Western Blotting --- p.58
Chapter 3.2.3 --- Estrogen Metabolism Assay
Chapter 3.2.3.1 --- Chemicals --- p.59
Chapter 3.2.3.2 --- Estrogen Metabolites Extraction --- p.60
Chapter 3.2.3.3 --- Liquid Chromatography/Mass Spectrometry --- p.60
Chapter 3.3 --- Methods
Chapter 3.3.1 --- Real time PCR
Chapter 3.3.1.1 --- Cell Culture --- p.61
Chapter 3.3.1.2 --- RNA Isolation and Reverse Transcription --- p.61
Chapter 3.3.1.3 --- Real Time PCR --- p.62
Chapter 3.3.2 --- Western Blotting
Chapter 3.3.2.1 --- Cell Culture --- p.63
Chapter 3.3.2.2 --- Microsome Isolation --- p.63
Chapter 3.3.2.3 --- Measurement of Protein Concentration --- p.64
Chapter 3.3.2.4 --- Western Blotting --- p.64
Chapter 3.3.3 --- Estrogen Metabolism Assay
Chapter 3.3.3.1 --- Preparation of Calibration Standard --- p.65
Chapter 3.3.3.2 --- Cell Culture --- p.66
Chapter 3.3.3.3 --- Estrogen Metabolites Extraction --- p.66
Chapter 3.3.3.4 --- Liquid Chromatography/Mass Spectrometry --- p.67
Chapter 3.3.4 --- Statistical Analysis --- p.68
Chapter 3.4 --- Results --- p.69
Chapter 3.5 --- Discussions --- p.80
Chapter CHAPTER FOUR: --- Overall Conclusion and Future Directions
Chapter 4.1 --- Significance of the Study --- p.87
Chapter 4.2 --- Overall Conclusion --- p.87
Chapter 4.3 --- Limitation and Difficulties of the Study --- p.89
Chapter 4.4 --- Future Directions --- p.89
Appendices
"Appendix I The Melting Curve of real time PCR for β-actin, CYP1A1 and CYP1B1" --- p.92
Appendix II The Calibration Curve of BSA for Protein Concentration Measurement --- p.93
Appendix III The Representative Peak of Estradiol Metabolite Standards with corresponding Retention Time --- p.94
Appendix IV The Calibration Curve of Different Estrogen Metabolites for LC/MS --- p.95
Appendix V The Accuracy and Precision of Quality Control of Estradiol Metabolites --- p.96
Bibliography --- p.97
48
Huang, Ting-Chieh, and 黃庭杰. "Targeting Human Mitochondrial NAD(P)+-Dependent-Malic Enzyme (ME2) , Sirtuin 1 (SIRT1) and Cyclooxygenase-2 (COX-2) in Lung and Breast Cancer Cells : A Novel Chemotherapeutic Approach Depending on p53 Expression Status." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/15313558750116910911.
Full textAbstract:
碩士國立中興大學
生命科學系所
103
There are three isoforms in malic enzymes (MEs) family which include ME1, ME2 and ME3. Mitochondrial NAD(P)+-dependent malic enzyme (ME2) is particularly expressed in tumor mitochondria and rather than normal cells . ME2 catalyzes substrate malate to generate pyruvate and accompanies with the production of NAD(P)H. In addition, ME2 participates in tumor cell metabolism pathway, glutaminolysis, which utilizes glutamine to replenish and substitute for glucose as energy source. A reciprocal negative feedback loop between tumor suppressor p53 and ME2 involves the p53-dependent cellular senescence and ME2-mediated metabolic rewiring. These observations suggest that ME2 is involved in tumor development. In addition, SIRT1 is a histone deacetylase (HDAC). Histone deacetylation may downregulate gene transcription and protein expression. SIRT1 is also found to acetylate the non-histone protein. The tumor suppressor p53 is the first discovered deacetylated non-histone protein by SIRT1. p53 is downregulated by SIRT1 deacetylation and then inactivated. Deacetylation of p53 by SIRT1 declined p53 activity and inhibited p53-dependent apoptosis, suggesting that SIRT1 activation may promote tumor survival and progression. Moreover, significant senescence-inflammatory response (SIR) may occur in cancer patients especially after chemotherapy. SIR might switch cancer development from inhibition to promotion and p53 highlighted a critical role in inhibiting SIR and tumor progression. However, p53 mutant is a frequently event in tumors. Nonsteroidal anti-inflammatory drugs (NSAIDs) might prohibit SIR and the development of cancer. Cyclooxygenase-2 (COX-2) overexpression is found in many malignancies. Besides, multiple pro-carcinogenic roles for COX-2 has been completed from promoting tumors proliferation to chemotherapy resistance. Herein, the ME2 and SIRT1 inhibitors will be combined with chemotherapeutic agent VP16 and COX-2 inhibitor which are a prominent chemotherapeutic policy depending on p53 expression condition. Expectantly, the strategy will enhance the susceptibility of cancer drug in tumor chemotherapy.