Dissertations / Theses on the topic 'Tyrosine Kinase Inhibitors Targeting'
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Aljohani, Hashim M. "Targeting Tyrosine Kinase Drug Resistance Mechanisms and Metastatic Pathways in Brain Tumors." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1595846160285645.
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Padi, Sathish K. R., Libia A. Luevano, Ningfei An, Ritu Pandey, Neha Singh, Jin H. Song, Jon C. Aster, Xue-Zhong Yu, Shikhar Mehrotra, and Andrew S. Kraft. "Targeting the PIM protein kinases for the treatment of a T-cell acute lymphoblastic leukemia subset." IMPACT JOURNALS LLC, 2017. http://hdl.handle.net/10150/624055.
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New approaches are needed for the treatment of patients with T-cell acute lymphoblastic leukemia (T-ALL) who fail to achieve remission with chemotherapy. Analysis of the effects of pan-PIM protein kinase inhibitors on human T-ALL cell lines demonstrated that the sensitive cell lines expressed higher PIM1 protein kinase levels, whereas T-ALL cell lines with NOTCH mutations tended to have lower levels of PIM1 kinase and were insensitive to these inhibitors. NOTCH-mutant cells selected for resistance to gamma secretase inhibitors developed elevated PIM1 kinase levels and increased sensitivity to PIM inhibitors. Gene profiling using a publically available T-ALL dataset demonstrated overexpression of PIM1 in the majority of early T-cell precursor (ETP)-ALLs and a small subset of non-ETP ALL. While the PIM inhibitors blocked growth, they also stimulated ERK and STAT5 phosphorylation, demonstrating that activation of additional signaling pathways occurs with PIM inhibitor treatment. To block these pathways, Ponatinib, a broadly active tyrosine kinase inhibitor (TKI) used to treat chronic myelogenous leukemia, was added to this PIM-inhibitor regimen. The combination of Ponatinib with a PIM inhibitor resulted in synergistic T-ALL growth inhibition and marked apoptotic cell death. Treatment of mice engrafted with human T-ALL with these two agents significantly decreased the tumor burden and improved the survival of treated mice. This dual therapy has the potential to be developed as a novel approach to treat T-ALL with high PIM expression.
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Zielger, David Women's & Children's Health Faculty of Medicine UNSW. "Targeting anti-apoptotic mechanisms in malignant gliomas." Awarded by:University of New South Wales. Women's & Children's Health, 2009. http://handle.unsw.edu.au/1959.4/43713.
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Novel strategies for the treatment of malignant gliomas are urgently needed. They are characterised by an inherent resistance to both chemo- and radiotherapeutics resulting in unrelenting tumour progression. While the exact mechanisms of treatment resistance remain undefined, it is now recognized that multiple components within the apoptotic pathway are heavily dysregulated in glioma cells and that the over-expression of anti-apoptotic proteins in patient samples correlates with inferior patient survival. The Inhibitor of Apoptosis Proteins (lAPs) represent the final molecular blockade preventing cellular apoptosis and have been identified as a potential rational therapeutic target in gliomas. The work described herein was focused on the development of novel therapeutic strategies that target the lAPs in malignant gliomas, that are readily translatable to the clinic, and that have the potential to improve patient outcomes. The first series of studies examined the hypothesis that targeting the lAPs in conjunction with other conventional and targeted therapies would overcome treatment resistance, and enhance anti-tumour activity. The novel, small molecule, lAP inhibitor LBW242 was shown to successfully target the lAPs in glioma cells and inhibit their ability to bind to and inactivate caspases. However when tested as a single agent in vitro, no stand alone anti-glioma activity of LBW242 was demonstrated. A screen of the activity of LBW242 in combination other pro-apoptotic compounds led to the discovery that lAP inhibition applied in combination with receptor tyrosine kinase (RTK) inhibition led to enhanced caspase activation and induction of apoptosis with a subsequent synergistic anti-glioma effect. The most profound effect was demonstrated with the specific combination of PDGFR and lAP inhibition both in vitro and in vivo as well as in primary patient derived glioma tumourspheres. While multiple RTKs have previously been validated as rational therapeutic targets, the clinical failure of RTK inhibitors in glioma patients has to date remained unexplained. The results in this thesis provide a novel explanation for the resistance of glioma cells to these targeted therapies, and more importantly offer a clinically tractable strategy of overcoming that resistance and improving patient outcomes. The second series of studies investigated the mechanism of synergy between lAP and RTK inhibition. The results showed that PDGFR inhibition does not stimulate apoptosis in glioma cells by previously described pathways. A screen of the entire apoptotic pathway revealed that treatment with imatinib modulates the expression of the anti-apoptotic protein NOL3/ARC. The results showed that imatinib treatment leads to down-regulation of NOL3 and that this effect is critical to the synergy between lAP and PDGFR inhibition. Further analysis suggested a critical role for NOL3 in gliomagenesis and treatment resistance NOL3 was found to be highly expressed in malignant gliomas and with expression levels that are inversely correlated with patient outcomes. A role for NOL3 has not previously been described in malignant gliomas. Finally, a series of studies were undertaken that tested the use of LBW242 in combination with the standard-of-care therapies of irradiation and temozolomide. In vitro assays demonstrated that LBW242 enhanced the pro-apoptotic activity of radiotherapy, and clonogenic assays showed that the combination therapy led to a synergistic anti-glioma effect in multiple glioma cell lines. Athymic mice bearing established human malignant glioma tumour xenografts treated with LBW242 plus radiation and temozolomide demonstrated a profound and synergistic suppression of tumour growth. Neurosphere assays revealed that the combination of radiation and LBW242 led to a pro-apoptotic effect in highly resistant glioma stem cells with a corresponding inhibition of tumour growth. The results indicate a potentially powerful strategy to enhance the therapeutic activity of standard-of-care therapies in glioma patients. Collectively, the findings of the studies in this thesis contribute to a better understanding of the mechanisms of treatment resistance in malignant gliomas, and demonstrate that the pro-apoptotic and anti-glioma effects of radiotherapy, chemotherapy and specific targeted therapies can be enhanced by the addition of a novel, small molecule lAP inhibitor. These results are readily translatable to clinical trial, and offer the potential for improved treatment outcomes for glioma patients.
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Mukhtar, Lenah. "Targeting the Mevalonate Pathway Enhances the Efficacy of Epidermal Growth Factor Receptor – Tyrosine Kinase Inhibitors in Head and Neck Squamous Cell Carcinoma." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/40391.
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Epidermal growth factor receptor (EGFR) is highly expressed in head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC) and is a key regulator of tumor cell growth and survival. Erlotinib, also known as tarceva, (a first-generation) and afatinib, also known as giotrif, (a second-generation) are tyrosine kinase inhibitors (TKIs) of EGFR. These TKIs are recognized therapeutic agents in these tumor types, as they inhibit EGFR signaling but show limited activity as single agents. Novel strategies will likely require EGFR-TKIs combination with an agent(s) that will enhance their therapeutic efficacy. Recently, we have demonstrated that combining statins, inhibitors of the mevalonate pathway, with erlotinib enhanced EGFR inhibition and induced synergistic cytotoxicity through the activation of cellular integrated stress response pathway (ISR) regulated by the induction of activating transcription factor 3 (ATF3). In our Phase I clinical trial, combining rosuvastatin with erlotinib, while demonstrating clinical activity, this treatment also showed statin-induced myopathies likely the result of diminished ubiquinone levels, which limited their utilization. Therefore, alternative strategies are warranted. Targeting geranylgeranyl diphosphate (GGPP) synthesis or its incorporation, a downstream mevalonate metabolite, represents such an approach with the potential to circumvent statin-associated toxicities but retain the efficacy in combination with EGFR inhibitors. In this project, we evaluated the effect of the combination of geranylgeranyl transferase-I inhibitor (GGTI-298) with the EGFR inhibitor, tarceva, (aim 1) and a GGPP synthase inhibitor, digeranyl bisphosphonate (DGBP), with the EGFR inhibitor, afatinib, (aim 2). For aim 1, we demonstrated that GGTI-298 treatment induced ATF3 expression in SCC9 and SCC25 cells and in a cohort of ex-vivo tumor tissues. Furthermore, GGTI-298 and tarceva induced synergistic cytotoxicity in SCC cells that was dependent on ATF3 expression, as ATF3 deficient murine embryonic fibroblasts (ATF3-/- MEFs) displayed attenuated cytotoxicity in response to GGTI-298 alone and in combination with tarceva. Similarly, SCC9 sub-lines that were selected as resistant to GGTI-298 through prolonged exposure to this agent also failed to demonstrate synergy with treatment of GGTI-298 in combination with tarceva. For aim 2, we demonstrated that the specific GGPP synthase inhibitor, DGBP, induced cytotoxicity in SCC cells. We further demonstrated this specificity as specific shRNA targeting of GGPP synthase as well as the inhibitor DGBP significantly enhanced the cytotoxic activity of the EGFR-TKI afatinib in SCC cells. DGBP as well as afatinib treatments induced ATF3 expression in SCC cells in vitro and in a cohort of ex-vivo tumor tissues. Co-administration of the downstream metabolite GGPP inhibits the induction of ATF3 and the cytotoxic and apoptotic effects associated with DGBP treatment. Furthermore, the synergistic cytotoxicity induced by the combination of DGBP and afatinib in SCC cells was also dependent on the expression of ATF3 through the induction of cellular stress response pathways. Taken together, these results suggest the potential clinical utility of combining downstream mevalonate inhibitors (GGTI-298 or DGBP) with EGFR inhibitors in HNSCC patients as a novel and more refined combination therapeutic approach.
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Hamilton, Julie Anne. "Targeting epithelial-to-mesenchymal transition (EMT) in feline oral squamous cell carcinoma (FOSCC)." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31357.
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Squamous cell carcinoma of the head and neck (HNSCC) is an extremely common and devastating disease with a bleak prognosis. Despite intensive research, survival rates have not improved over the past 30 years principally due to untreatable recurrent/metastasising disease. Feline oral squamous cell carcinoma (FOSCC) is an equally common disease in cats with an even less favourable prognosis than humans. Human and feline squamous cell carcinomas share similar etiopathogenesis, molecular markers, tumour biology and treatment thus making FOSCC an excellent model for HNSCC. Epithelial to mesenchymal transition (EMT), under the direction microRNAs (miRNAs/mirs) could be a key driver in oncogenic transformation and chemoresistance. The aim of this study was to induce resistance to characterise the EMT/resistance phenotype and to investigate whether common miRNA-mediated pathways are present in HNSCC and FOSCC that drive this phenomenon. We used epidermal growth factor (EGFR)-inhibitor gefitinib to induce resistance in HNSCC and FOSCC and investigated the associated EMT-related molecular changes. In vitro and in vivo invasive and migratory properties of both species were explored to determine whether resistance and/or EMT status conferred a functional advantage. We determined the miRNA expression pattern during acquisition of resistance to gefitinib in both species by next generation sequencing and screened candidate miRNAs as potential therapeutics. We found that gefitinib-resistance produced a previously unrecognised biphasic response that consisted of two distinct phenotypes, a highly invasive mesenchymal phenotype during early resistance, and a more epithelial phenotype associated with established resistance. The biphasic nature of this transition may prove critical in establishing effective therapeutic targets and the timing of treatment to overcome resistance or in preventing local invasion or metastatic spread of squamous cell carcinoma. We found that the major anti-apoptotic PI3K/AKT pathway was activated in transitioning and resistant cells of both species as demonstrated upregulation of AKT, pAKT and c-FLIP together with inactivation of PTEN by phosphorylation. This indicates that avoidance of apoptosis may be a major pathway in resistance that could be targeted therapeutically. We showed that three miRNAs were differentially expressed in both gefitinib-resistant human and feline cell lines: miR-107 was downregulated, and miR-551b and miR-574 were upregulated. These microRNAs provide potential therapeutic targets in the fight against drug resistance in head and neck cancer although much further research needs to be conducted to elucidate the complex network of interactions that may be affected by targeting these powerful regulatory molecules.
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Fujita, Haruyuki. "The tyrosine kinase inhibitor dasatinib suppresses cytokine production by plasmacytoid dendritic cells by targeting endosomal transport of CpG DNA." Kyoto University, 2013. http://hdl.handle.net/2433/174784.
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Katsoulas, Athanasia. "Design and mechanism of action of novel agents termed "combi-molecules" engineered for tandem targeting for Bcr-abl expressing leukemia cells." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111884.
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Bcr-abl expression being associated with anti-apoptotic signaling and expression of DNA repair enzymes, we surmised that single molecules capable of blocking abl tyrosine kinase (TK) function and damaging DNA should lead to compounds with potency superior to that of GleevecRTM. To this end, we designed novel agents termed "combi-molecules" programmed to not only behave as bcr-abl inhibitors on their own, but also to further degrade to another inhibitor and a DNA damaging species. The released inhibitor was designed to sustain bcr-abl inhibition following degradation of the combi-molecule and the DNA damaging species to activate pathways leading to apoptosis. To model this strategy termed "combi-targeting", we synthesized ZRCM5 (a monoalkyltriazene) that showed antiproliferative activity superior to that of the classical DNA damaging agent TemodalRTM, but not to that of Gleevec RTM. This result was imputed to the rather weak bcr-abl inhibitory activity of ZRCM5 and its strong DNA damaging property. Another prototype designed to contain an aniline mustard moiety (AK04) was a strong bcr-abl inhibitor but a poor DNA alkylating agent. Its cytotoxic activity was again stronger than that of the clinical alkylating agent chlorambucil but inferior to that of GleevecRTM. Further chemical studies directed at structural modification of the benzamide moiety led to the synthesis of ZRF1 with strong potency against bcr-abl TK and strong DNA damaging property. This novel optimized combi-molecule showed a 1.6-3-fold greater potency than GleevecRTM against bcr-abl expressing cells. Further investigation with ZRF1, showed that its cytotoxic potency was dependent on the p53 wild-type status of the cells. In cells expressing wild-type p53, p21 transactivation was associated with cell cycle arrest and that of Bax with apoptosis. In addition to, the pro-apoptotic effect of bcr-abl inhibition, these multiple mechanisms of action may synergistically enhance the cytotoxic potency of ZRF1 in p53 wild-type cells. The study conclusively demonstrated that p53 is a major determinant for the cytotoxic advantage of the novel combi-molecular approach in chronic myelogenous leukemia (CML), a disease in which 70-85% of all cases express wild-type p53.
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Lai, Damian. "Targeting tyrosine kinase inhibitor-insensitive chronic myeloid leukemia stem/progenitor cells by effective inhibition of a novel PP2A-AHI-1-BCR-ABL-JAK2-complex." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54591.
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Imatinib Mesylate (IM) and other tyrosine kinase inhibitors (TKIs) have had a major impact on treatment of early phase Chronic Myeloid Leukemia (CML) patients. However, TKI monotherapies are not curative and initial and acquired resistance remain challenges. Particularly, CML stem cells are less responsive to TKIs and are a critical target population for TKI resistance. Thus, improved treatments targeting key elements active in CML stem cells are needed. One candidate is Abelson helper integration site-1 (AHI-1), an oncogene that is highly upregulated in CML stem cells and interacts with multiple kinases, including BCR-ABL and JAK2. AHI-1-mediated complexes regulate TKI response/resistance of CML stem/progenitor cells, indicating that AHI-1 is a new therapeutic target in CML. By screening the Prestwick Chemical Library, a specific growth inhibitory compound that potentially targets AHI-1 was identified: Cantharidin (CAN), an inhibitor of protein phosphatase 2A (PP2A). CAN is toxic however, so two new PP2A inhibitors, LB100 and LB102, were identified for this study. These new inhibitors specifically inhibit PP2A activity and suppress growth of CML cell lines. Importantly, these new PP2A inhibitors selectively target CML stem/progenitor cells while sparing healthy stem/progenitor cells. When combined with TKIs there is significant further suppression of growth in cell lines and in CD34+ treatment-naïve IM-nonresponder cells. Furthermore, this combination effect was determined to be synergistic. Cell cycle analysis showed that treatment with PP2A inhibitors alone induced a shift from G1 to G2/M phase. Confocal microscopy confirmed that the G2/M arrest led to mitotic catastrophe. However a similar shift in cell population was observed after combination with IM, suggesting that the G2/M phase arrest is solely due to PP2A inhibition. Mechanistically, the PP2A-PR55α subunit was identified as a new AHI-1 interacting protein. Western blot analysis showed that, compared to single agents, the combination treatment greatly suppresses protein expression of AHI-1, BCR-ABL, JAK2, STAT5, AKT, β-catenin, P-38 and JNK. The combination treatment also affected PP2A and BCR-ABL-mediated β-catenin dephosphorylation/phosphorylation. These results indicate that simultaneously targeting both BCR-ABL and PP2A activities in CML stem/progenitor cells may provide a novel treatment option for CML patients, through destabilization of the protein-protein interactions mediated by AHI-1.Medicine, Faculty of
Medicine, Department of
Experimental Medicine, Division of
Graduate
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Sørum, Christopher. "Synthesis of new tyrosine kinase inhibitors." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for kjemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-6863.
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Doepfner, Kathrin T. "Targeting receptor tyrosine kinase signaling in acute myeloid leukemia /." Zürich, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000253043.
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McHugh, Lynsey A. "Tyrosine kinase inhibitors as adjuncts to chemotherapy in bladder cancer." Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/29860.
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Walter, Harriet Sarah. "Studies of Bruton's tyrosine kinase inhibitors in B-cell malignancies." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/42887.
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Despite significant advances, the prognosis in relapsed/refractory (R/R) B-cell malignancies remains poor. In the Phase I study of the selective Bruton’s Tyrosine Kinase inhibitor (BTKi) tirabrutinib in R/R B-cell malignancies, I showed that targeting BTK demonstrated remarkable clinical responses and tolerability in Chronic Lymphocytic Leukaemia and Mantle Cell Lymphoma. Targeted DNA sequencing demonstrated that no mutations were associated with a lack of response in CLL. However, in activated B-cell like diffuse large B-cell lymphoma (ABC DLBCL), only 35% of patients responded to treatment and median duration of response was 12 weeks. This prompted my laboratory studies to explore mechanisms of resistance to BTKi in ABC DLBCL. Using BTKi resistant cell lines TMD8 RO and TMD8 RI, I undertook biological and genetic studies. BTK expression and subcellular localisation was not altered in the resistant cell lines. Apoptosis induced by the BTKi ibrutinib and tirabrutinib occurred 24 hours following drug exposure. A decrease in the expression of the anti-apoptotic proteins MCL1, BCLxL and BCL2A1 was observed in TMD8 but not TMD8 RO following treatment with tirabrutinib, consistent with modulation of the BCR pathway. No significant change was identified in apoptotic gene expression. Study of the BCR signalling pathway showed an increase in cell surface expression of sIgM and CD20 in the resistant cell lines. No change in IgM RNA levels nor CD20 were observed. However, gene expression of IGJ was downregulated in the resistant cell lines. Both TMD8 RO and TMD8 RI showed increased basal levels of phosphor-tyrosine phosphorylation and amplified BCR signalling following BCR ligation. Collectively, these studies indicate hyperactivation of the BCR signalling pathway in the development of resistance to BTKi, with changes occurring upstream of BTK. Further studies to characterise changes at the cell surface are required to identify novel therapeutic approaches to the development of BTKi resistance.
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Recondo, Gonzalo. "Resistance Mechanisms to ALK Tyrosine Kinase Inhibitors (TKIs) in NSCLC." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS248/document.
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Les analyses moléculaires et la classification des adénocarcinomes bronchiques ont conduit au développement de thérapies ciblées sélectives visant à améliorer le contrôle de la maladie et la survie des patients. ALK (anaplastic lymphoma kinase) est un récepteur tyrosine kinase de la famille des récepteurs de l'insuline. Des réarrangements chromosomiques impliquant le domaine kinase d’ALK sont présents dans environ 3 à 6% des patients atteints d'un adénocarcinome bronchique. La protéine de fusion provoque une activation du domaine kinase de manière constitutive et indépendante du ligand. Lorlatinib est un inhibiteur d’ALK de troisième génération avec une efficacité et une sélectivité optimale, ainsi qu’une pénétration élevée vers le système nerveux central. Lorlatinib peut vaincre la résistance induite par plus de 16 mutations secondaires dans le domaine kinase d’ALK acquises lors de la progression aux ALK TKI de première et deuxième générations. Le traitement par lorlatinib est donc efficace chez les patients préalablement traités par un ALK TKI de première ou deuxième génération, et est actuellement approuvé pour cette indication. Le spectre complet de mécanismes de résistance au lorlatinib chez les patients reste à élucider. Il a récemment été rapporté que l'acquisition séquentielle de deux mutations ou plus dans le domaine kinase, également appelées mutations composées, est responsable de la progression de la maladie chez environ 35% des patients traités par le lorlatinib, principalement en altérant sa liaison au domaine kinase d’ALK. Cependant, l’effet de ces mutations sur la sensibilité aux différents inhibiteurs d’ALK peut varier, et les autres mécanismes de résistance survenant chez la plupart des patients restent inconnus. Mon travail de thèse avait pour but d’explorer la résistance au lorlatinib chez des patients atteints d'un cancer du poumon ALK réarrangé par la mise en œuvre de biopsies spatiales et temporelles et le développement de modèles dérivés de patients. Dans le cadre de l’étude institutionnelle MATCH-R (NCT02517892), nous avons effectué un séquençage à haut débit de l’exome, de l’ARN et ciblé, ainsi qu’un séquençage des ctDNA afin d’identifier les mécanismes de résistance. Nous avons établi des lignées cellulaires dérivées de patients et caractérisé de nouveaux mécanismes de résistance et identifiés de nouvelles stratégies thérapeutiques in vitro et in vivo. Nous avons identifié trois mécanismes de résistance chez quatre patients avec des biopsies appariées. Nous avons étudié l'induction de la transition épithélio-mésenchymateuse (EMT) par l'activation de SRC dans une lignée cellulaire, dérivée d’un patient, exposée au lorlatinib. Les cellules mésenchymateuses étaient sensibles à l’inhibition combinée de SRC et d'ALK, montrant que même en présence d'un phénotype agressif, des stratégies de combinaison peuvent surmonter la résistance aux ALK TKI. Nous avons identifié deux nouvelles mutations composées du domaine kinase d’ALK, F1174L / G1202R, C1156Y / G1269A survenues chez deux patients traités par le lorlatinib. Nous avons développé des modèles de cellules Ba / F3 exprimant les mutations simples et composées pour étudier leur effet sur la résistance au lorlatinib. Enfin, nous avons caractérisé un nouveau mécanisme de résistance provoqué par la perte de fonction de NF2 au moment de la progression du lorlatinib par l’utilisation de PDX et de lignées cellulaires dérivées de patients, et par CRISPR / CAS9 knock-out de NF2. Nous avons constaté que l'activation de mTOR par la perte de fonction de NF2 provoquait la résistance au lorlatinib et qu'elle pouvait être surmontée par le traitement avec des inhibiteurs de mTOR.Cette étude montre que les mécanismes de résistance au lorlatinib sont plus divers et complexes que prévu. Nos résultats démontrent également comment les études longitudinales de la dynamique tumorale permettent de déchiffrer la résistance aux TKI et d'identifier des stratégies thérapeutiquesThe molecular study and classification of lung adenocarcinomas has led to the development of selective targeted therapies aiming to improve disease control and survival in patients. The anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor from the insulin tyrosine kinase receptor family, with a physiologic role in neural development. Gene rearrangements involving the ALK kinase domain occur in ~3-6% of patients with lung adenocarcinoma. The fusion protein dimerizes leading to transactivation of the ALK kinase domain in a ligand-independent and constitutive manner. Lorlatinib is a third generation ALK inhibitor with high potency and selectivity for this kinase in vitro and in vivo, and elevated penetrance in the central nervous system. Lorlatinib can overcome resistance mediated by over 16 secondary kinase domain mutations occurring in 13 residues upon progression to first - and second - generation ALK TKI. In addition, treatment with lorlatinib is effective for patients who have been previously treated with a first and a second generation or a second generation ALK TKI upfront and is currently approved for this indication. The full spectrum of biological mechanisms driving lorlatinib resistance in patients remains to be elucidated. It has been recently reported that the sequential acquisition of two or more mutations in the kinase domain, also referred as compound mutations, is responsible for disease progression in about 35% of patients treated with lorlatinib, mainly by impairing its binding to the ALK kinase domain. However, the effect of these compound mutations on the sensitivity to the repertoire of ALK inhibitors can vary, and other resistance mechanisms occurring in most patients are unknown. My PhD thesis aimed at exploring resistance to lorlatinib in patients with ALK-rearranged lung cancer through spatial and temporal tumor biopsies and development of patient-derived models. Within the institutional MATCH-R study (NCT02517892), we performed high-throughput whole exome, RNA and targeted next-generation sequencing, together with plasma sequencing to identify putative genomic and bypass mechanisms of resistance. We developed patient-derived cell lines and characterized novel mechanisms of resistance and personalized treatment strategies in vitro and in vivo. We characterized three mechanisms of resistance in four patients with paired biopsies. We studied the induction of epithelial-mesenchymal transition (EMT) by SRC activation in a patient-derived cell line exposed to lorlatinib. Mesenchymal cells were sensitive to combined SRC and ALK co-inhibition, showing that even in the presence of an aggressive and challenging phenotype, combination strategies can overcome ALK resistance. We identified two novel ALK kinase domain compound mutations, F1174L/G1202R, C1156Y/G1269A, occurring in two patients treated with lorlatinib. We developed Ba/F3 cell models harboring single and compound mutations to study the differential effect of these mutations on lorlatinib resistance. Finally, we characterized a novel mechanism of resistance caused by NF2 loss of function at the time of lorlatinib progression through the development of patients derived PDX and cell lines, and in vitro validation of NF2 knock-out with CRISPR/CAS9 gene editing. Downstream activation of mTOR was found to drive lorlatinib resistance by NF2 loss of function and was overcome by providing treatment with mTOR inhibitors.This study shows that mechanisms of resistance to lorlatinib are more diverse and complex than anticipated. Our findings also emphasize how longitudinal studies of tumor dynamics allow deciphering TKI resistance and identifying reversing strategies
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Luzac, Michal Leonie. "Small Molecules as Potential Inhibitors of the Met Tyrosine Kinase Receptor." Thesis, University College London (University of London), 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498510.
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Myers, Samuel Harry. "Development of novel receptor tyrosine kinase inhibitors by a chemocentric approach." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28769.
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In recent years, there has been a major movement in the pharmaceutical industry towards the development of molecules that selectivity inhibit a previously-validated specific target. This is referred to as target-based drug discovery. It was hoped that adopting this approach would usher in a new golden age of drug discovery. However, this has not been the case, with issues arising such as the target’s mechanism of action being poorly understood, with it not playing the expected role in the disease progression, or feedback resistance mechanisms causing the target to lose its role in the disease. In contrast to this, in the past 20 years it has been argued that developing drugs in a target-agnostic way and screening them against an expressed phenotype i.e. phenotypic drug discovery, has been more successful, despite fewer programs being run in the manner. The AXL kinase is a receptor tyrosine kinase (RTK) and a member of the TAM family, along with MER and TYRO3. AXL has long been associated with numerous types of cancer. Having been first discovered in 1991 in acute myeloid leukaemia (AML), it has gone on to be more associated with advanced solid tumours such as brain, breast, and lung, with the trend being that increased AXL correlates with a poorer prognosis for the patient. Upon the activation of AXL by the vitamin K ligand GAS6, a series of downstream pathways are activated that go on to encourage cell survival, proliferation, and migration. In addition to this, AXL has been shown to be involved in crosstalk with other kinase pathways, resulting in AXL expression being associated with chemoresistance and survival mechanisms. Despite the promising outlook for AXL inhibitors, to date only one selective AXL inhibitor, BGB324 (formally R428) has entered clinical trials, with selective AXL inhibitors being difficult to develop due to a lack of a crystal structure or a reliable homology model. To address the aforementioned issues that target-based approaches can suffer from, and due to AXL lacking a crystal structure, the work in this thesis utilised a pragmatic drug design method that started from ligands/existing scaffolds known to inhibit the target from the literature (publications, clinical trials and patents). A series of small libraries were prepared and then tested against a selected phenotype e.g. cell viability, in at least two cell types: one that expressed the target (e.g. AXL) and one that did not. Hits were optimised for potency against the desired phenotype. The compounds then went through target deconvolution (kinase screening) to confirm the target of the inhibitors. Employing this approach, we initially synthesised two small libraries of potential AXL inhibitors. The potency of these compounds was tested using cell-based phenotypic assays, by evaluating cell viability in both native and chemo-resistant breast cancer cells. These libraries were optimised through focused combinatorial synthesis and phenotypic screening, to yield a small collection of antiproliferative hits. These hits were then profiled against a panel of twelve select kinases. The first library, while giving some important structural information, did not inhibit the kinases screened in a meaningful manner. However, the second library gave several potent compounds, inhibiting AXL, FLT3, and RET, with one compound being selective for AXL. The leads from this series were optimised further, through SAR studies, gaining important structural information in order to improve potency and selectivity of the compounds. The flexibility of the phenotypic cell-based approach allowed the pursuit of FLT3 inhibitors, resulting in the synthesis of one of the most potent FLT3 inhibitors synthesised to date.
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Cooper, Margaret S. "Anti-cancer peptides containing modified tyrosine residues." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246193.
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Bibi, Siham. "Nouvelles approches thérapeutiques au cours des mastocytoses systémiques avancées KIT D816V+ résistantes aux inhibiteurs de tyrosine kinases." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS551.
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Les mastocytoses systémiques (SM) constituent un groupe hétérogène de maladies rares, caractérisées par l’accumulation anormale de mastocytes malins dans la moelle osseuse et dans d’autres organes extra-cutanés. La majorité des patients avec SM ont une mutation activatrice du gène KIT, le plus souvent la mutation KIT D816V, retrouvée chez plus de 90% de tous les patients. Cette mutation induit l’activation constitutive du récepteur KIT en déclenchant de façon aberrante une cascade de voies de signalisation, dont la voie PI3K/AKT et JAK/STAT5, aboutissant à l’inhibition de l’apoptose et à l’augmentation de la prolifération et de la survie des mastocytes malins. Cependant, l’efficacité des inhibiteurs de tyrosines kinases (ITKs) sur cette mutation est limitée à cause de la résistance et/ou de toxicité liée à un manque de spécificité. Il est donc nécessaire de trouver de nouvelles approches thérapeutiques afin de contourner cette résistance au cours des SM KIT D816V+ avancées. Nous avons utilisé une approche consistant à cibler de façon combinée des molécules activées en aval de KIT D816V, comme AKT et STAT5, par des inhibiteurs pharmacologiques. Ceci nous a permis d’identifier une combinaison synergique entre un inhibiteur d’AKT (GSK690693) et un inhibiteur de STAT5 (BP-1-102). Ces composés sont capables d’inhiber la prolifération des cellules KIT D816V+ seuls ou en combinaison, mais à de très fortes concentrations, malheureusement non utilisables en thérapeutique. Néanmoins, ces premiers résultats ont permis de valider AKT et STAT5 comme cibles potentielles dans le traitement des SM avancées. La seconde approche employée a été de cibler directement le récepteur KIT D816V par des inhibiteurs pharmacologiques. A l’issu d’un criblage, nous avons identifié trois composés - BLU2317, BLU2718 et DCC-2618 - capables d’inhiber sélectivement la phosphorylation de KIT D816V. Ces composés inhibent la prolifération des cellules ROSAKIT D816V et HMC-1.2, et induisent l’apoptose des cellules de façon dose-dépendante. Bien que les effets de ces trois composés soient similaires, DCC-2618 agit à des concentrations plus faibles par rapport aux composés BLU2317 et BLU2718. Afin d’apprécier l’efficacité in vivo de DCC-2618, nous avons d’abord établi un nouveau modèle de SM basé sur l’injection intraveineuse des cellules ROSAKIT D816V-Gluc exprimant la Gaussia luciferase (Gluc) dans des souris NSG. La présence de la Gluc sécrétée par les cellules ROSAKIT D816V-Gluc facilite la mise en évidence de prise de greffe et permet un contrôle précis de la progression de la maladie. Ce modèle reproduit, au bout de 4 semaines, chez toutes les souris greffées, une SM avancée similaire à celle retrouvée chez l’homme, avec atteinte de la moelle osseuse, du sang, de la rate et du foie, tandis que la dégradation de l’état général des souris n’est observée qu’à partir de 12 semaines. Ce nouveau modèle offre suffisamment de temps pour explorer la cinétique de la progression de la maladie et surtout pour effectuer des études pharmacologiques précliniques. L’évaluation de l’effet de DCC-2618 in vivo a été réalisée sur ce modèle. Etonnamment, DCC-2618 n’a pas été capable d’inhiber la progression de la maladie chez les souris traitées, bien qu’atteignant des concentrations élevées dans la moelle osseuse et le plasma des souris traitées. Néanmoins, DCC-2618 s’est montré capable d’inhiber la phosphorylation de KIT dans les cellules issues de la moelle osseuse des souris traitées. En revanche, contrairement aux effets observés in vitro, DCC-2618 a induit une surexpression de phospho-ERK1/2 dans les cellules malignes des souris greffées. Ceci suggère qu’ERK1/2 joue un rôle important dans la résistance au composé DCC-2618 et éventuellement à d’autres ITKs, indépendamment du récepteur KIT. ERK1/2 pourrait donc être une nouvelle cible thérapeutique d’intérêt dans le traitement des SM résistantes aux ITKsSystemic mastocytosis (SM) is a heterogeneous group of rare diseases characterized by abnormal accumulation of malignant mast cells (MCs) in the bone marrow (BM) and other extra-cutaneous organs. The majority of SM patients have an activating mutation in the KIT gene, usually the D816V point mutation, which is found in more than 90% of all patients. This mutation induces constitutive activation of the KIT receptor by triggering a cascade of signaling pathways, including the PI3K/AKT and the JAK/STAT5 pathways, resulting in the inhibition of apoptosis and increased survival and proliferation of malignant mast cells. However, the efficacy of the tyrosine kinase inhibitors (TKIs) on this mutation is limited due to resistance and/or toxicity associated with a lack of specificity. It is therefore critical to find new therapeutic approaches to overcome this resistance to TKIs, particularly for advanced KIT D816V+ SM. In the present thesis, we have used an approach consisting in targeting molecules activated downstream of KIT D816V, such as AKT and STAT5, using pharmacological inhibitors in combination. This allowed us to identify a synergistic combination of an AKT inhibitor (GSK690693) and an inhibitor of STAT5 (BP-1-102). These compounds are able to inhibit proliferation of KIT D816V+ cells, alone or in combination, but at very high concentrations, unfortunately not useful therapeutically. Nevertheless, these initial results have validated STAT5 and AKT as potential targets for the treatment of advanced SM. The second approach used was to target directly the KIT D816V receptor by pharmacological inhibitors. After a large screening, we identified three compounds - BLU2317, BLU2718 and DCC-2618 - which selectively inhibit the phosphorylation of KIT D816V. These compounds inhibit the proliferation of ROSAKIT D816V and HMC-1.2 cells, and induce apoptosis of these cells in a dose-dependent manner. Although the effects of these three compounds are similar, the DCC-2618 compound acts at lower concentrations relative to BLU2317 and BLU2718 compounds. In order to assess the in vivo efficacy of DCC-2618, we first established a new model of SM based on intravenous injection of cells expressing Gaussia luciferase (Gluc), ROSAKIT D816V-Gluc cells, in NSG mice. The presence of the secreted Gluc in ROSAKIT D816V-Gluc cells facilitates the detection of engraftment and allows precise monitoring of disease progression. This model reproduced within four weeks, in all grafted mice, an advanced SM similar to the one found in humans, with neoplastic MCs infiltration in BM, blood, spleen and liver, while the terminal deterioration of the clinical condition of the mice was observed after 12 weeks. Thus, this new in vivo model allows modulating the aggressiveness of the disease by varying the number of injected cells. It provides sufficient time to explore the kinetics of disease progression and especially to conduct preclinical pharmacological studies. We then evaluated the effect of DCC-2618 compound in vivo on this model. Surprisingly, DCC-2618 was not able to inhibit disease progression in treated mice, although it reached high concentrations in the BM and the plasma of treated mice. Nevertheless, we showed that the compound was able to inhibit the phosphorylation of the KIT receptor in cells derived from the BM of treated mice. In addition, contrasting to the effects observed in vitro, DCC-2618 induced an over-expression of phospho-ERK1/2 in the malignant cells of transplanted mice. This suggests that ERK1/2 may play a critical role in the resistance to DCC-2618, and possibly to other TKIs, independently of the KIT receptor. ERK1/2 could thus be a new interesting therapeutic target in the treatment of advanced SM resistant to TKIs
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Dominguez-Escrig, J. L. "Tyrosine kinase and prenyl transferase inhibitors as potential therapeutics in urothelial carcinoma." Thesis, University of Newcastle upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427275.
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Francis, Sebastian. "Factors affecting the response to tyrosine kinase inhibitors in chronic myeloid leukaemia." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2050461/.
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Chronic myeloid leukaemia (CML) is a clonal stem cell disorder characterised by the Philadelphia chromosome. The treatment and outcomes of CML patients have improved with the introduction of tyrosine kinase inhibitors (TKI). Imatinib is associated with complete cytogenetic response (CCR) rate of 71% at 12 months, as documented by large phase 3 clinical trials. I carried out a large population study in the Merseyside, Cheshire and North Wales area, which showed a maximal CCR rate of 65% over 5 years of observation. This suggests there is a higher rate of imatinib failure in a general unselected CML population compared to large clinical studies which have strict exclusion criteria. My population study also confirmed that second generation TKIs can produce high CCR rates in imatinib intolerant/resistant patients. There are a number of mechanisms of imatinib resistance. The hOCT1 transporter has been shown to be an important predictor of response to imatinib treatment. However, it has been suggested there are other drug transporters involved in imatinib transport which may have prognostic significance. This thesis examined the role of SLCO1A2, OCTN1 and OCTN2 in the transport of TKIs. Transfected cell lines expressing high levels of the respective drug transporter were made using the AMAXA nucleofection process. The cell lines with the highest gene expression, as quantified by TaqMan PCR, were then selected and used in radioactive uptake experiments. Imatinib was confirmed to be a substrate for SLCO1A2. However, the mRNA expressions levels of SLCO1A2 did not have any prognostic correlation to outcome. A review of patient co-medication also showed inhibitors of SLCO1A2 had no effect on CCR and major molecular response (MMR) rates in imatinib treated patients. OCTN1 and OCTN2 did not transport imatinib. Nilotinib and dasatinib are not substrates for SLCO1A2, OCTN1 or OCTN2. Drug drug interactions have also been implicated in drug resistance. Imatinib and metformin are actively transported by hOCT1. It was postulated that varying concentrations of metformin could potentially affect the uptake of imatinib by competitive inhibition. A metformin concentration of 768µM was required reduce imatinib uptake by 50%. However, this concentration is much higher than therapeutic metformin levels, therefore these drugs do not interact at therapeutic concentrations. This thesis shows imatinib is an effective treatment in CML but the CCR rate is lower than in published phase 3 trials. SLCO1A2 transports imatinib but RNA levels have no prognostic significance. Imatinib and metformin do not interact at normal therapeutic concentrations.
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Reiff, Sean. "Utilizing Reversible Bruton’s Tyrosine Kinase Inhibitors to Circumvent Acquired Resistance to Ibrutinib." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1523372591057698.
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D'Cunha, Ronilda Raymond. "Treatment strategies to reverse efflux transporter-mediated resistance to Tyrosine kinase inhibitors." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6563.
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Multidrug resistance (MDR), a phenomenon in which tumors that were initially sensitive, recur and start showing resistance not only to the initial chemotherapeutic agent but also to various anticancer drugs that are structurally and functionally different from the initial drug, constitutes one of the main reasons for the failure of chemotherapy. An important mechanism of MDR is the enhanced cellular efflux of anticancer agents due to an overexpression of ATP-binding cassette (ABC) transporters (i.e. efflux transporters), especially P-glycoprotein (Pgp), Multidrug Resistance-associated Protein 1 (MRP1) and Breast Cancer Resistance Protein (BCRP), in cancer cells. In order to reverse this resistance, there has been a lot of emphasis on the development of Pgp, MRP1 and BCRP inhibitors. Although this search has been ongoing for three decades, there are still no clinically available efflux transporter modulators.
Tyrosine kinase inhibitors (TKIs) are a novel, rapidly growing class of anticancer agents that have a target-based mechanism of action, and their use transformed cancer chemotherapy due to higher specificity and enhanced safety profiles compared to conventional chemotherapeutic agents. Despite their tremendous success in treating various types of tumors, patients develop resistance to TKIs over time. Most of the FDA- approved TKIs are substrates of Pgp and/or BCRP, and as a result, these efflux transporters are also an important cause of conferred resistance against TKIs in cancer cells. Additionally, none of the 31 approved TKIs have an indication for use in brain tumors and interestingly, this may also due to the presence of Pgp and BCRP at the blood-brain barrier (BBB) and in the tumor cells, which prevent the TKI from crossing the BBB and reaching its target tumor site. Since Pgp- and BCRP- mediated TKI efflux has been shown to be involved in TKI resistance, the inhibition of these transporters could represent a potential TKI resistance reversal strategy.
Over the last three decades, a large number of Pgp and/or BCRP inhibitors have been identified, but none of them have successfully made it to the clinic. It was observed that most drugs identified as inhibitors were either unable to achieve Pgp and BCRP inhibitory concentrations in-vivo without imparting severe toxicity, or did not possess adequate bioavailability and tissue distribution profiles in order to reach the tumor site. From these identified candidate inhibitors, after much thought and consideration, we chose to investigate TKIs and methylated flavones as modulators of efflux transporter-mediated TKI resistance.
The overall goal of this project was to investigate the promising chemosensitizing potential of TKIs and methylated flavones in efflux transporter-mediated TKI resistance, both in-vitro and in-vivo. To identify potent efflux transporter inhibitor TKIs, we evaluated the effect of various TKIs on the accumulation of afatinib, the model TKI substrate, in Pgp- and BCRP- overexpressing cell lines. Afatinib was chosen as the model TKI substrate for our study because it undergoes very minimal metabolism in several species. Afatinib is a substrate of both Pgp and BCRP, but is not a substrate of uptake transporters. Therefore, it was anticipated that an in-vivo efflux transporter-mediated interaction with afatinib would most likely not be confounded or masked by other factors influencing its disposition. From the in-vitro cell uptake studies, we found that nilotinib is a potent inhibitor of both Pgp and BCRP, and it reversed Pgp- and BCRP- mediated afatinib efflux. Subsequently, an in-vivo study was carried out in mice to investigate the interaction between afatinib and nilotinib; and also the impact of nilotinib on the pharmacokinetics and tissue distribution of afatinib. Afatinib exposure in the plasma and in most tissues, namely liver, lung, kidney, heart, muscle, fat, and skin, was found to be significantly increased when nilotinib was coadministered with afatinib. Further, the nilotinib concentrations in most mice tissues was above that needed for Pgp and BCRP inhibition. These results showed that nilotinib could be a potent chemosensitizing agent for Pgp- and BCRP- mediated TKI resistance. Additionally, a significant increase in afatinib brain exposure was observed in the mice which were administered afatinib in combination with nilotinib. This is an interesting and important finding that could potentially be very useful in the treatment of primary and metastasized brain tumors. We also developed a physiologically based pharmacokinetic model of afatinib to characterize its tissue disposition in mice organs, and this model was then scaled up to humans. The developed model accurately predicted afatinib plasma exposure in healthy volunteers and patients with solid malignant tumors, renal impairment, and hepatic impairment.
To investigate the chemosensitizing potential of methylated flavones in efflux transporter-mediated TKI resistance, the Bcrp1 inhibitory effect of 5,7-DMF and its effect on sorafenib accumulation was evaluated in-vitro. 5,7- DMF was found to be a potent inhibitor of Bcrp1 and consequently, its impact on the pharmacokinetics and tissue distribution of sorafenib was evaluated in mice. Results showed that co-administration with 5,7-DMF led to significantly greater sorafenib exposure in plasma and in most tissues collected. This indicated that 5,7-DMF may represent a promising chemosensitizing agent for Bcrp1-mediated TKI resistance due to its low toxicity and potent Bcrp1 inhibition.
Our results may have important clinical implications as TKIs are currently the most widely used anticancer agents. 5,7-DMF may show great potential in reversing MDR in tumors expressing BCRP. On the other hand, TKI-TKI combination therapy, especially with nilotinib as the perpetrator, is an attractive strategy to combat both Pgp- and BCRP-mediated TKI resistance. Additionally, since nilotinib has a wide volume of distribution and can reach various tissues at concentrations sufficient enough to inhibit Pgp and BCRP; it could potentially be used as a chemosensitizer in the treatment of numerous types of cancers. Furthermore, its chemosensitizing potential could particularly be useful in the treatment of primary and metastatic brain tumors. Further studies are warranted to assess the chemosensitizing effect of nilotinib in tumor xenograft models.
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Logan, John Gordon. "Targeting bone-microenvironment-tumour cell interactions : IGF-1 receptor kinase inhibitors." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/8184.
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Bone metastases are a frequent clinical complication associated with cancer. The aim of this PhD thesis was to set up a model system for the study of tumour cell – bone cell interactions in vitro, ex vivo and in vivo and to use this system to test the efficacy of a novel therapeutic agent for the treatment of osteolytic bone disease. Co-culture or conditioned medium studies using human or mouse cancer cell lines were used to develop an in vitro model system of tumour cell – bone cell interactions. This showed that osteolytic tumour cells enhance osteoclast formation, fusion and resorption through the production of various factors that act directly on osteoclasts and their precursors. And in addition, that osteolytic tumour cells also enhance osteoclastogenesis indirectly via increasing the production of RANKL in osteoblasts. Other effects on osteoblasts included reductions in differentiation, migration and adhesion. Successful ex vivo and in vivo models for the study of tumour – induced osteolysis were created using adapted organ cultures and intratibial injection techniques respectively. IGF-1 and its receptor are known to play important roles in both bone metabolism and breast cancer. Therefore a study of the effects of IGF-1 receptor inhibition on tumour cell – bone cell interactions was performed. In vitro studies showed that the novel IGF-1 receptor tyrosine kinase inhibitor PQIP significantly inhibited IGF-1 and breast cancer enhanced osteoclast formation. Western blot analysis suggested this may be due to the inhibition of both IGF-1 and cancer conditioned medium induced PI3k/Akt activation. Moreover, treatment of osteoblasts with PQIP inhibited cancer cell conditioned medium induced increases in RANKL production. Ex vivo studies using human MDA-MB-231 – mouse calvarial organ co-cultures demonstrated that MDA-MB-231 cells caused osteolysis and this was completely prevented by PQIP without affecting cancer cell viability. Furthermore, once daily oral administration of PQIP significantly decreased trabecular bone loss and reduced the size of osteolytic bone lesions following mouse 4T1 breast cancer cell intratibial injection in mice. Quantitative histomorphometry showed a significant reduction in breast cancer-induced osteoclast number and activity. Consistent with the significant inhibition of osteoblast differentiation, spreading, migration and bone nodule formation observed in vitro, PQIP also inhibited osteoblast number and bone formation in vivo. No inhibition of in vivo tumour volume was observed. These findings clearly suggest that oral PQIP treatment reduced the rate of cancer associated bone turnover. In conclusion, this thesis successfully demonstrates a model system for investigating tumour cell-bone cell interactions in vitro, ex vivo and in vivo. Using this model system I showed that pharmacologic inhibition of IGF-1 receptor kinase activity using PQIP inhibits osteoclast and osteoblast changes induced by breast cancer cells in vitro and in vivo and prevents osteolysis ex vivo and in vivo. This indicates that PQIP and its novel derivatives which are now in advanced clinical development may be of value in the treatment of osteolytic bone disease associated with breast cancer.
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Dillon, Anne M. R. "An investigation of protein tyrosine phosphorylation in equine blood platelets." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390250.
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Knights, Victoria E. E. "Tumour cell responses to novel fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608393.
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Filho, Pedro Aurio Maia. "Genotoxicity and mutagenicity in patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors." Universidade Federal do CearÃ, 2017. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=19044.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoChronic myelogenous leukemia (CML) is a myeloproliferative disease of hematopoietic stem cells, characterized by the presence of the Philadelphia (Ph) chromosome, originating from a reciprocal translocation between the long arms of chromosomes 9 and 22, forming the gene BCR-ABL, which encodes a BCR-ABL oncoprotein with constitutive tyrosine kinase activity. The clinical course of CML is often divided into three phases: chronic, accelerated, and blast. The treatment of choice for the chronic phase is the first-generation tyrosine kinase inhibitor (TKI), imatinib mesylate, and for refractory patients, second-generation TKIs (dasatinib or nilotinib) are used. Studies have shown that residual leukemia may persist even in the best responders to TKI, since therapy is not curative. In this context, the present study aimed to evaluate the genotoxicity and mutagenicity of TKI in patients with CML followed at the hematology clinic of the Walter CantÃdio University Hospital (HUWC). It is a cross-sectional study with 44 patients with clinical and molecular diagnosis of CML. Patients were stratified into three groups: diagnosis (CML D) (n = 5), use of first generation TKI (CML) (n = 31) and use of second generation TKI (CML) (n = 8). The control group (CG) consisted of apparently healthy individuals. Genotoxicity and mutagenicity were analyzed by the comet assay and micronucleus test. Statistical analysis of the data was performed using the GraphPad Prism 6.0 program using the Kruskal-Wallis or ANOVA, Mann Whitney or T-student tests, depending on the normality of the data and the level of significance was 5% (p < 0.05). Patients with CML had a statistically higher ADN damage index (DI) compared to CG (p < 0.0001). When the patients were stratified, a progressive increase of the DNA ID was verified in the groups: CML D, CML G1 and CML G2, respectively, relative to GC (p < 0.05). Patients with CML had a statistically higher micronucleus index (NMI), nucleoplasmic bridge index (NPI) and nuclear bud index (NBI) compared to the CG (p < 0.05). By stratifying patients with CML, it was found that patients in the G1 and G2 CML groups had statistically higher NMI and NPI compared to CG (p <0.001). NMI was also elevated in the CML G2 group in relation to the patients in the CML D group (p <0.01). The nuclear bud index (NBI) did not present statistical difference in the analyzes performed after the stratification of the groups. The TKI revolutionized CML therapy, improving patient survival. However, these results point to the relevance of studies that evaluate the possible genotoxic and mutagenic effects of this therapy in the long term. The mechanisms involved should be elucidated for the purpose of improving treatment as well as assessing the clinical impact this harm may cause.
A leucemia mielÃide crÃnica (LMC) à uma doenÃa mieloproliferativa das cÃlulas-tronco hematopoÃticas, caracterizada pela presenÃa do cromossomo Philadelphia (Ph), originado a partir de uma translocaÃÃo recÃproca entre os braÃos longos dos cromossomos 9 e 22, formando o gene BCR-ABL, que codifica uma oncoproteÃna BCR-ABL com atividade tirosino-quinase constitutiva. O curso clÃnico da LMC à frequentemente dividido em trÃs fases: crÃnica, acelerada e blÃstica. O tratamento de escolha para a fase crÃnica à o inibidor de tirosino-quinase (ITK) de primeira geraÃÃo, mesilato de imatinibe, e para os pacientes refratÃrios, utiliza-se os ITK de segunda geraÃÃo (dasatinibe ou nilotinibe). Estudos tÃm demonstrado que a leucemia residual pode persistir mesmo nos melhores respondedores aos ITK, uma vez que a terapia nÃo à curativa. Nesse contexto, o presente estudo objetivou avaliar a genotoxicidade e mutagenicidade dos ITK em pacientes com LMC acompanhados no ambulatÃrio de hematologia do Hospital UniversitÃrio Walter CantÃdio (HUWC). Trata-se de um estudo transversal com 44 pacientes com diagnÃstico clÃnico e molecular de LMC. Os pacientes foram estratificados em trÃs grupos: ao diagnÃstico (LMC D) (n=5), em uso de ITK de primeira geraÃÃo (LMC G1) (n=31) e em uso de ITK de segunda geraÃÃo (LMC G2) (n=8). O grupo controle (GC) foi composto por indivÃduos aparentemente saudÃveis. A genotoxicidade e mutagenicidade foram analisadas atravÃs do ensaio cometa e teste de micronÃcleos. A anÃlise estatÃstica dos dados foi realizada atravÃs do programa GraphPad Prism 6.0 utilizando-se os testes de KruskalâWallis ou ANOVA, Mann Whitney ou T-student, dependendo da normalidade dos dados e o nÃvel de significÃncia foi de 5% (p < 0,05). Pacientes com LMC apresentaram Ãndice de dano (ID) no DNA estatisticamente mais elevado em comparaÃÃo ao GC (p < 0,0001). Quando os pacientes foram estratificados, foi verificado um aumento progressivo do ID no DNA nos grupos: LMC D, LMC G1 e LMC G2, respectivamente, em relaÃÃo ao GC (p < 0,05). Pacientes com LMC apresentaram Ãndice de micronÃcleos (IMN), Ãndice de pontes nucleoplasmÃticas (IPN) e Ãndice de buds nucleares (IBN) estatisticamente mais elevados em comparaÃÃo com o GC (p < 0,05). Ao se estratificar os pacientes com LMC, foi verificado que pacientes dos grupos LMC G1 e G2 apresentaram IMN e IPN estatisticamente mais elevados em comparaÃÃo ao GC (p < 0,001). O IMN tambÃm foi elevado no grupo LMC G2 em relaÃÃo aos pacientes do grupo LMC D (p < 0,01). O Ãndice de bud nuclear (IBN) nÃo apresentou diferenÃa estatÃstica nas anÃlises realizadas apÃs a estratificaÃÃo dos grupos. Os ITK revolucionaram a terapia da LMC, melhorando a sobrevida dos pacientes. No entanto esses resultados alertam para a relevÃncia de estudos que avaliem os possÃveis efeitos genotÃxicos e mutagÃnicos dessa terapia a longo prazo. Os mecanismos envolvidos devem ser elucidados com a finalidade de aprimorar o tratamento, bem como avaliar o impacto clÃnico que esse dano pode causar.
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Gregory, T., and John Bossaer. "Pharmacogenomics Guided Dosing of Tyrosine Kinase Inhibitors in a Patient with Renal Cell Carcinoma." Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/etsu-works/7796.
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Cytochrome P450 (CYP) enzymes play a crucial role in the human body. These enzymes are responsible for the synthesis of steroid hormones and cholesterol, as well as the metabolism of external substances such as medications. While more than 50 CYP enzymes have been identified, just 6 are credited with metabolizing most drugs. Of note is CYP 3A4, which metabolizes ~34% of medications that use the CYP enzyme system. CYP enzymes are polymorphic, meaning there are different versions of the same enzyme; therefore there is variability from individual to individual in their ability to metabolize medications. In the oncology field tyrosine kinase has been identified as an important target controlling cell regulatory functions and proliferation. Thus, tyrosine kinase inhibitors have become widely used for a variety of malignancies. Many of these tyrosine kinase inhibitors rely on CYP 3A4 for metabolism and are subject to variable toxicities based on an individual patient’s genome.
A 62-year-old female was diagnosed with Renal Cell Carcinoma (RCC). After undergoing a left nephrectomy, a surveillance scan 21 months after diagnosis was concerning for metastatic disease, which was then confirmed through biopsy. The patient was started on sunitinib 50 mg on days 1-28 of a six-week cycle for metastatic RCC. The patient suffered from Grade 3 myelosupression/mucositis within two weeks of the initiation of therapy. The early onset and severity of the toxicity lead to CYP 3A4 pharmacogenetic testing. She was subsequently found to have a 3A4 polymorphism (*1/*28). The dose of sunitinib was reduced to 25 mg followed by a further reduction to 12.5 mg due to toxicity. Eighteen months after starting sunitinib, a CT scan showed disease progression and therapy was changed to pazopanib. Due to her 3A4 polymorphism, the starting pazopanib dose was empirically reduced by 50% and was started at 400 mg/daily. Pazopanib was held for episodes of severe diarrhea and was further reduced to 200 mg/daily. Nine months after starting pazopanib, new imaging showed lesions in the patient’s liver, confirming disease progression. The patient was subsequently started on nivolumab but quickly progressed. She was then started on cabozantinib at a dose reduced 20 mg/daily. This initial dosing was tolerated well by the patient, so a decision was made to alternate between 20 and 40 mg/daily to increase to an average of 30 mg/daily. She is currently tolerating the 30 mg/daily and continues treatment for metastatic RCC.
As described above, CYP 3A4 polymorphisms can result in severe toxicities that present earlier in the treatment course than traditionally expected. Moving forward there may be a role in testing for these polymorphisms to determine an individual’s optimal dose before initiating therapy with tyrosine kinase inhibitors. The advantage of performing such testing would be to limit the severity of toxicities experienced by this patient population, while retaining the overall benefit of these medications.
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Junker, Bernd. "Lokale Therapie der Sauerstoff-induzierten angioproliferativen Retinopathie im Mausmodell small molecule receptor tyrosine kinase inhibitors /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971428387.
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Abe, Mineo. "Development of peptide inhibitors of the receptor tyrosine kinase activity in a novel inhibitory mechanism." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120515.
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Nuseibeh, Samir. "Modulation of mucin expression in respiratory epithelial cells : effect of ErbB receptor tyrosine kinase inhibitors." Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/8229.
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Secretion of mucins (e.g. MUC5AC) by the airway epithelium into the respiratory tract mucus layer is an important homeostatic mechanism which safeguards the lung from invasive pathogens and harmful particles. Airway mucus hypersecretion features in the pathophysiology of inflammatory-based airway diseases such as chronic obstructive pulmonary disease (COPD) and asthma. Signalling of the ErbB receptor tyrosine kinase subfamily, particularly the ErbB1 and ErbB2 receptor subtypes, has been implicated in the process of airway mucus hypersecretion, and upregulation of ErbB1 receptor occurs in the lungs of asthmatics, COPD sufferers, and cigarette smokers. Thus, ErbB receptor tyrosine kinase inhibitors (RTKIs) offer a potential treatment for airway mucus hypersecretion. This thesis studied the effects of five such inhibitors; an ErbB1, an ErbB2, and three dual ErbB1+B2 inhibitors, in an in vitro system of mucin synthesis using NCI-H292 cells - a carcinoma-based lung epithelial cell line. After pharmacological characterisation of the NCI-H292 cell in vitro system, Taqman RT-qPCR was used to measure the effect of the five inhibitors on EGF-induced MUC5AC mRNA expression (as a marker of mucin synthesis). The effect of the five ErbB RTKIs on cell proliferation was also measured (as a positive control) by analysing DNA synthesis. All five inhibitors attenuated DNA synthesis with similar potencies suggesting all drugs were pharmacologically active, but only the single ErbB1 RTK inhibitor attenuated EGF-induced MUC5AC mRNA expression. To address the discrepancy in pharmacological activity between the five ErbB RTKIs, activity of the ERK1/2-dependent signal pathway involved in ErbB receptor-mediated MUC5AC synthesis was analysed by measuring ErbB receptor autophosphorylation (measuring phosphorylation of four specific tyrosine residues involved in ERK1/2 induction) and ERK1/2 phosphorylation by Western blot or ELISA. Although all five ErbB RTKI compounds inhibited ErbB1 and ErbB2 receptor autophosphorylation to some extent (particularly at 10 μM), only the single ErbB1 RTK inhibitor convincingly inhibited autophosphorylation of all four tyrosine residues implicated in ERK1/2 signalling. Most importantly, the single ErbB1 RTK inhibitor was the only inhibitor to block downstream phosphorylation of ERK1/2. The reason for the varying potencies exhibited by the five ErbB1 RTK inhibitors was unclear but most likely reflects a difference in the pharmacological properties (for example, the receptor dissociation rate) of each compound. These data indicate that selective ErbB1 RTK inhibitors would be of therapeutic benefit for the airway mucus hypersecretion of asthma and COPD.
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Hervieu, Vilches Alexia. "Understanding and targeting PI3K downstream of oncogenic Met mutant." Thesis, Queen Mary, University of London, 2015. http://qmro.qmul.ac.uk/xmlui/handle/123456789/33935.
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The Receptor Tyrosine Kinase (RTK) Met, overexpressed or mutated in cancer, plays a major role in cancer progression and represents an attractive target for cancer therapy. This study aimed to investigate whether PI3K plays a role in Met oncogenicity. Three cell models were used: (i) NIH3T3 cells expressing WT Met or the constitutively active mutant M1268T Met; (ii) U87MG glioblastoma cells, with endogenous WT Met constitutively activated due to an autocrine loop; (iii) A549 lung cancer cells expressing endogenous WT Met, activated upon binding exogenous HGF. Met dependent Rac1 translocation to the plasma membrane, actin cytoskeleton organisation, cell migration, anchorage independent growth in soft agar and tumour growth were studied in the presence of inhibitors of pan-PI3K / mTOR, various PI3K Class I isoforms, mTOR or Akt, or following siRNA knock-down of PI3K isoforms. We report that PI3K class I (but not class III) regulates Met dependent cell migration. The PI3K class I isoforms required varies among the cell models. Interestingly, the combined inhibition of all p110 Class I isoforms lead to the strongest reduction of Met dependent cell migration. Met dependent phosphorylation of Akt, an effector of PI3K class I, is reduced upon endocytosis inhibition, suggesting that Met signals to PI3K Class I on endosomes. Our results indicate that mTOR is responsible for Met dependent anchorage independent growth and tumour growth in vivo. Surprisingly, PI3K class I (and class III) are not required. Moreover, Rac1 is required for Met dependent mTOR activation, (phosphorylation of mTORC1's effector, p70 S6K) subcellular translocation of mTOR and anchorage independent growth. Finally, our results suggest that this Met-Rac1- mTOR pathway occurs on endosomes. Thus while PI3K class I regulates Met dependent cell migration, mTOR regulates Met driven anchorage independent growth and in vivo tumorigenesis. Thus PI3K Class I / mTOR may be targeted in Met driven cancers.
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Lougheed, Caroline. "Targeting focal adhesion signaling in cancer and acquired resistance to focal adhesion kinase inhibitors." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=94996.
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In cancer progression, the development of metastases is characteristic of late stage disease and makes treatment and cure more difficult. In order for metastasis to occur, cancer cells must gain motile and invasive phenotypes. As one of the keystone proteins involved in cell motility and invasion, Focal Adhesion Kinase (FAK) has emerged as a good therapeutic target for the inhibition of metastases via targeted drug design and small molecule inhibitors. Accordingly, a small molecule inhibitor has recently been developed against FAK activation and signaling. However, drug resistance is common among targeted therapies. Development and classification of drug resistant cells elucidated the possible mechanism behind FAK inhibitor resistance such that second-line therapy drugs can be designed to overcome or avoid resistance. The overall data presented herein support the role of FAK as an important drug target in cancer metastasis as well as provide insight and direction for future FAK inhibitor design.Dans la progression du cancer, le développement de métastases est caractéristique de la phase terminale et rend le traitement difficile. Afin que des métastases se dévelopment, les cellules cancéreuses doivent acquérir de la motilité ainsi qu'un phénotype invasif. Considéré come l'une des plus importantes protéines participant dans la motilité cellulaire, la prot éine Focal Adhesion Kinase (FAK) a émergé comme une bonne cible thérapeutique pour l'inhibition de métastases par la création de drogues ciblées et de petites molécules inhibitrices. Par conséquent, une molécule inhibitrice de l'activation de FAK et sa signalisation a été récemment développée. Cependant, J'ai demontré que la résistance est commune parmis ces drogues. Le dévelopement et la classification des clones de cellules résistantes ont permi d'élucider un mécanisme impiquant en partie une amplification de l'activité FAK; ce mécanisme permetter a de découvrir des analogues de deuxième génération pour surmonter ou éviter la résistance. L'ensemble de données présentées ci-dessous supportet le rôle de FAK comme une cible importante dans la prévention de métastases et exposent les futur directions pour contourner la résistance aux inhibiteurs de FAK.
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Lazrek, Yassamine. "Ciblage tumoral du récepteur HER3 à l’aide d’anticorps : vers de nouvelles pistes thérapeutiques." Thesis, Montpellier 1, 2013. http://www.theses.fr/2013MON13524.
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De part, leur implication dans la prolifération cellulaire, l'invasion et leur surexpression dans de nombreux cancers, les récepteurs à tyrosine kinase de la famille HER constituent des cibles de choix en oncologie. Parmi ces récepteurs, le récepteur HER3 semble pertinent car il est impliqué dans la tumorigenèse de nombreux cancers (sein, ovaire, pancréas, mélanome…) et il est associé à un mauvais pronostic. De plus, la surexpression du récepteur HER3 est souvent associée à l'apparition de résistance aux thérapies ciblées. Nous avons sélectionné plusieurs anticorps anti-HER3 humains et murins respectivement par « phage display » et fusion cellulaire. Ces derniers reconnaissent spécifiqument le récepteur HER3. Parmi les nombreux anticorps découvert, nous avons sélectionné un anticorps anti-HER3 humain H4B-121 et 2 anticorps anti-HER3 murins 9F7-F11 et 16D3-C1. Ces derniers ont la capacité à faire régresser des tumeurs épidermoide, pancréatique et triple négative chez la souris, en présence ou en abscence de neuréguline et indépendamment du status HER2 et P53/PTEN. Cette inhibition est possible grâce à un blocage du cycle cellulaire en phase G1, une inhibition de la prolifération ainsi qu'une induction de l'apoptose. Ces trois anticorps sont capables de bloquer l'hétérodimérisation des récepteurs HER2/HER3 ainsi que la phosphorylation du récepteur HER3. Ils sont aussi capables d'inhiber la phosphorylation de la protéine AKT ainsi que de ses cibles (MDM2, FOXO et XIAP). De plus, nous avons montré que nos anticorps sont capables de lyser les cellules tumorales par ADCC (Antibody-dependent cell-mediated cytotoxicity). Cette étude démontre que ces anticorps anti-HER3 représentent une nouvelle thérapie pour les cancers du pancréas et du sein triple négatifDue to their implication in the cellular proliferation, the invasion and their surexpression in numerous cancers, the tyrosine kinase receptors of HER family constitute one of the best targets in oncology. Within this family, the human epidermal growth factor receptor 3 (HER3) plays a role in tumorigenesis of different cancers (Breast, melanoma, pancreas and ovary). This receptor is implicated in drug resistance and he is over expressed in cancers that are not eligible for the currently approved targeted therapies. To this end, we generated specific antibodies (Abs) against domain 1 (D1) and domain 3 (D3) of HER3 that recognize epitopes that do not overlap with the neuregulin-binding site. The fully human H4B-121 Ab and the mouse monoclonal Abs 16D3-C1 and 9F7-F11 inhibited tumor growth in nude mice xenografted with epidermoid, pancreatic, or triple-negative breast cancer cells independently of NRG addiction, HER2 status and p53/PTEN mutations. The combination of one anti-HER3 Ab and trastuzumab improved tumor growth inhibition in mice xenografted with HER2(low) cancer cell lines, for which trastuzumab alone shows no or moderate efficiency. Ab-induced disruption of tumor growth was associated with G1 cell cycle arrest, proliferation inhibition, and apoptosis of cancer cells. Anti-HER3 Abs blocked HER2/HER3 heterodimerization and HER3 phosphorylation at the cell membrane, leading to inhibition of phosphorylation of the downstream AKT targets murine double minute 2, X-linked inhibitor of apoptosis, and forkhead box O1. Anti-HER3 Abs can also induice antibody dependant cell-mediated cytotoxicity. This study demonstrates that anti-HER3 D1 and D3 Abs could represent a new option for immunotherapy of pancreatic and triple-negative breast cancers
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Lella, Divya Jyothi. "Functionalization and Modification of Naphthaquinone Analogs as HER2 Kinase Inhibitors." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1325.
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HER2 overexpression in breast cancer tumors predicts lower overall survival. Because of the aggressive nature of HER2 tumors and the association with metastatic disease, the HER2 receptor holds great promise as a therapeutic target in metastatic breast cancer. We are developing small molecule inhibitors that bind to the ATP binding site of the tyrosine kinase domain in order to inhibit tyrosine auto-phosphorylation. This process controls biological pathways that mediate the cell growth. In normal cells this process is highly controlled. We are targeting the modification of the side chain of the hydroxy methyl group of 2-Hydroxy methyl-5,8-dimethoxy-1,4-naphthaquinone. These compounds should inhibit the tyrosine kinase cascade of reactions thereby suppressing the overexpression of HER2 shutting down the tumor growth. The synthesis and characterization of a series of substituted naphthaquinone analogs with different increasing chain lengths will be reported.
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Broadbridge, Robert James. "Design and synthesis of novel inhibitors to the SH2 domain of the protein tyrosine kinase p56lck." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494712.
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Grockowiak, Élodie. "Role of the Bone Morphogenetic Proteins pathway in tyrosine kinase inhibitors resistance in Chronic Myeloid Leukemia." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1253.
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La leucémie Myéloïde Chronique est un néoplasme myéloprolifératif causé par l'expression de la kinase oncogène BCR-ABL. Les Inhibiteurs de Tyrosine Kinase (ITK) spécifiques de BCR-ABL ont révolutionné la prise en charge de la maladie. Les ITK ne sont cependant pas curatifs ; en effet, certaines cellules souches leucémiques (CSL) sont résistantes aux ITK, et persistent dans la moelle osseuse des patients même en rémission prolongée. Ces CSL sont probablement responsables de la rechute chez 60% de ces patients après arrêt des ITK. 30% des patients développent une résistance aux ITK via des mécanismes inconnus. Dans un contexte sain, les Bone Morphogenetic Proteins (BMP) régulent différentes propriétés des cellules souches hématopoïétiques. Nous avons mis en évidence que les patients atteints de LMC présentent une altération de la voie BMP avant leurs mises sous traitement, avec une hausse de l'expression du récepteur dans les cellules leucémiques immatures, amplifiée par de forts taux de BMP2/4 produits par le microenvironnement des CSL, la niche. Ici, nous démontrons que ces altérations sont maintenues chez les patients sous traitement, et sont activement impliquées dans la résistance aux ITK. Les patients résistants présentent une surexpression de BMPR1b dans les CSL et un maintien de forts taux de BMP produits à la fois par les cellules leucémiques mais aussi par les cellules stromales. Les BMP permettent la survie des CSL via l'expression du récepteur BMPR1b et induisent l'expression de TWIST-1, un facteur de transcription précédemment identifié par l'équipe comme induisant la résistanceChronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm caused by the expression of the oncogenic protein kinase, BCR-ABL. The Tyrosine Kinase Inhibitors (TKI) specifics of BCR-ABL kinase dramatically changed the outcome of CML, turning a life-threatening disease into a chronic illness. However, TKI are not yet curative since most CML patients still retain progenitors and leukemic stem cells (LSC) in bone marrow permanently. Thus, approximately 60% of patients that achieve Complete Molecular Remission =2 years relapse following TKI withdraw. Moreover, some patients develop true resistance to TKI, with ~30% due to unknown mechanisms. In chronic phase CML (CP-CML), LSC survive, sustain interactions with their niche where resistance mechanisms can occur, responsible for disease persistence and relapse following treatment cessation. In normal bone marrow, Bone Morphogenetic Proteins (BMP) pathway regulate the fate and proliferation of normal hematopoietic stem cells, as well as interactions with their niche. The deregulations of this pathway drive early steps of CML development. In newly diagnosed CP-CML patients, high concentration of BMP2/4 in the leukemic niche allows LSC maintenance and sustains a permanent pool of leukemic progenitors expressing elevated levels of BMPR1b receptor. Here, we report that alterations of the BMP pathway persist in TKI-CML resistant patients. As compared to patients in Complete Cytogenetic Remission (CCyR), cells isolated from TKI-resistant patients display a high level of BMPR1b expression in immature cells and high levels of BMP2/4 in bone marrow, provided by the niche and by the leukemic immature cells themselves. BMP allow leukemic stem cells resistance to treatments through binding to BMPR1b. Interestingly, BMP2/4-treated cells overexpressed TWIST-1, a transcription factor that we previously identified as a predictive factor of CML resistance
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Šramel, Peter. "A synthesis and biological screening of predicted inhibitors of Tyrosine Kinases, e.g. KDR, designed in silico." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAF064.
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Les protéines kinases représentent le groupe d'enzymes qui servent d'intermédiaire pour la phosphorylation de protéines - le transfert d'un groupe phosphate de l'adénosine triphosphate(ATP) sur des chaînes latérales correspondantes de tyrosine, de serine ou de thréonine des acides aminées. La phosphorylation de protéines est un des outils les plus importants pour la régulation de l'activité cellulaire. La « signalisation » cellulaire par le récepteur de tyrosine kinase VEGFR2 (KDR) appartient aux réactions biochimiques clés influençant la croissance de tumeurs. L'inhibition thérapeutique de cette réaction à l'aide des composés de faible poids moléculaire spécifiques est devenue une stratégie utile dans le cadre des thérapies anticancéreuses. Ce travail a amené à la découverte de 16 substances biologiquement actives sur la base N,5-diaryloxazol-2-amine (IC50, VEGFR2 TK). D'excellents résultats ont été atteints notamment dans le cas des substances 189, 191, 211, 214, 220, 221, 223 et 4 qui montrent une activité inhibitrice inférieure à 500 nMProtein kinases represent a group of enzymes responsible for phosphorylation - transfer of aphosphate group from adenosine triphosphate (ATP) to tyrosine or serine/threonine residues. Protein phosphorylation is one of the most important tools regulating a cell activity. A cell "signalization" through an endothelial receptor tyrosine kinase VEGFR2 TK (KDR) is the important pathway influencing growth of a tumor. Small-molecule inhibitors of VEGFR2 TK (VEGFR2 TKls) have become an important tool for the treatment of various types of cancer. This dissertation thesis resulted in a discovery of 16 biologically active N,5-diaryloxazol-2-amines (IC50, VEGFR2 TK). Very good results were achieved especially with compounds 189, 191, 211, 214, 220, 221, 223 and 4 exhibiting the activity under 500 nM
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Atatreh, Noor Aldeen S. A. "Design, synthesis and evaluation of inhibitors for Src tyrosine kinase and their impact on colorectal cancer cells." Thesis, University of Manchester, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492836.
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Colorectal cancer is the highest cause of cancer-related death in the West. c-Src protein levels are elevated in colon cancer cells compared to non-malignant cells, In addition, Src signalling and transduction are directly involved in cell growth, cell cycle, malignant transformation and cell migration, providing opportunities for inhibition of Src.
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Rogers, Susanne Jane. "Towards the Mechanistic Effects of Tyrosine Kinase Inhibitors in Squamous Cell Carcinoma of the Head and Neck." Thesis, Institute of Cancer Research (University Of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516267.
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Bhosle, J. "Modulation of DNA strand break induction and repair by tyrosine kinase inhibitors targeted against EGFR and HER2." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1344180/.
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Purpose: The human epidermal growth factor receptors EGFR (erbB1) and HER2 (erbB2/neu) are involved in mediating resistance to chemotherapy and ionising radiation (IR). In vitro studies demonstrate that small molecule tyrosine kinase inhibitors (TKIs) which target these receptors can increase the effectiveness of DNA damaging agents. However, these combinations have failed to produce the clinical results anticipated and one potential explanation is that the inhibition of EGFR and HER2 cell signalling pathways by TKIs is short lived, with cells able to switch to alternative mechanisms of signalling through HER3. The purpose of this study was to examine whether the duration of exposure to TKIs modulates the induction and repair of DNA damage produced by chemotherapy or IR and describes attempts to elucidate the role of HER2 in mediating resistance to chemotherapy. Experimental design: Two HER targeting TKIs, lapatinib and gefitinib were investigated. The effect of lapatinib in combination with cisplatin and doxorubicin on the inhibition of cell proliferation and the role of schedule were examined in drug combination assays. The influence of the duration of exposure to TKIs on the induction and repair of DNA lesions induced by cisplatin, IR, doxorubicin, etoposide and m-AMSA were investigated using the alkaline and neutral Comet assays and measurement of γH2AX and RAD51 foci. DNA expression arrays were used to identify the potential mechanisms through which HER2 produces resistance to cisplatin in cells transfected with HER2. Results: Lapatinib is able to synergistically inhibit cell proliferation in combination with cisplatin or doxorubicin in a schedule dependent manner. Duration of exposure to TKIs has no effect on the induction of DNA lesions by cisplatin or IR, but significantly reduces the production of DNA double strand breaks by doxorubicin, etoposide and m-AMSA in part through the down-regulation of the expression of topoisomerase IIα (Topo IIα), increasing resistance to these drugs. Conclusions: These results indicate the scheduling of small molecule TKIs targeted against EGFR and HER2 is important and continuous exposure to these drugs induces resistance to doxorubicin, etoposide and m-AMSA, through reduced expression of their target, Topo IIα. The importance of schedule should be considered when combining TKIs with chemotherapy in clinical practice.
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Roos, Kelly. "The effect of sunitinib on neuroblastoma and glioblastoma cell growth." University of the Western Cape, 2020. http://hdl.handle.net/11394/7952.
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Magister Scientiae (Medical Bioscience) - MSc(MBS)Cancer is a global health catastrophe, with neuroblastoma, the most common solid childhood tumor, and glioblastoma, a deadly brain tumor, being aggressive and unresponsive to current treatment modalities. These tumors are known to utilize uncontrollable cell proliferative capabilities as a mechanism for tumor survival. Therefore, malignant cell growth can be mitigated by targeting the essential proteins that regulate cell growth, such as receptor tyrosine kinases (RTKs). Under normal physiological conditions, RTKs bind with varying affinity to mitogenic stimuli such as growth factors such as vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) which, in turn, leads to receptor phosphorylation and activation.
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Saleem, Mohammed Umer. "Preclinical evaluation of pharmacological strategies designed to enhance the activity of established and novel anti-cancer drugs : synopsis - evaluation of pharmacological strategies designed to modulate the Warburg effect, enhance the activity of tyrosine kinase inhibitors and novel analogues of Temozolomide." Thesis, University of Bradford, 2014. http://hdl.handle.net/10454/13842.
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Whilst progress has been made in reducing mortality in some cancers, mortality rates remain high in many cancers and there is a need to develop novel therapeutic strategies. In this thesis, various pharmacological strategies designed to enhance the activity of existing therapeutic drugs were evaluated. Cancer cells are dependent upon aerobic glycolysis (the Warburg effect) and glutamine uptake. Using clinically approved tyrosine kinase inhibitors and Bortezomib, significant enhancement of chemosensitivity was observed when used in combination with inhibitors of lactate dehydrogenase (Gossypol) and pyruvate kinase dehydrogenase (Dichloroacetate). In contrast, depletion of glutamine from media had to be extensive in order to induce cell death and cell death only occurred after prolonged exposure to glutamine-deprived conditions. This suggests that glutamine depletion strategies alone are unlikely to be successful but may be useful in combination with other agents targeting glutamine addiction in cancer cells. Finally, Temozolomide (TMZ) is an important drug in the treatment of glioblastomas but its activity is reduced by resistance mechanisms including O6 methyl guanine methyltransferase (MGMT) and mismatch repair (MMR). This thesis has identified analogues of TMZ (EA02-45, EA02-59, EA02-64 and EA02-65) that are MGMT and MMR independent in terms of inducing cell kill in vitro. These compounds are promising leads for future development. In conclusion, this thesis has demonstrated that interfering with the metabolic phenotype of cancer can enhance the activity of existing drugs and identified novel analogues of TMZ that circumvent drug resistance mechanisms that hamper the efficacy of TMZ.
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Graf, Michael Georg Eduard. "Inhibition of ErbB2 by receptor tyrosine kinase inhibitors causes myofibrillarstructural damage without cell death in adult rat cardiomyocytes /." [S.l.] : [s.n.], 2009. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Skoglund, Karin. "Influence of CYP3A enzymes and ABC transporters on the activity of tyrosine kinase inhibitors in chronic myeloid leukemia." Doctoral thesis, Linköpings universitet, Avdelningen för läkemedelsforskning, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97427.
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The introduction of imatinib, a tyrosine kinase inhibitor (TKI), in the treatment of chronic myeloid leukemia (CML) was a major break-through and the first drug that was successfully designed to target the specific mechanism of a malignant disease. Imatinib still remains as the standard treatment of newly diagnosed CML patients although a second generation of TKIs has also been approved for first-line CML treatment. Most patients achieve a good therapeutic effect with imatinib, but some patients are resistant to the drug and are at greater risk of disease progression. In order to further improve CML treatment, a better understanding of the underlying reasons for variable responses to imatinib and the second generation TKIs is important. A number of potential determinants of imatinib response have been suggested, including interindividual variability in pharmacokinetics. Variations in drug metabolism and cellular transport might contribute to the large variations observed in imatinib plasma concentrations and might, therefore, affect the amount of drug that reaches target CML cells. Imatinib is primarily metabolized by the CYP3A hepatic enzymes that are known to be highly variable in activity between different individuals. Imatinib is also a substrate of the ABCB1 and ABCG2 efflux pumps that potentially regulate the elimination of imatinib from the plasma. The ABCB1 and ABCG2 genes are polymorphic and contain single nucleotide polymorphisms (SNPs) that might influence the transport capacity of these proteins. The primary aim of the present thesis was to investigate the influence of CYP3A metabolic activity and cellular transport mediated by genetic variants of ABCB1 and ABCG2 on the response to imatinib and the second generation TKIs used for CML therapy. In vivo CYP3A activity and plasma concentrations of imatinib and its pharmacologically active metabolite CGP74588 were analyzed in CML patients treated with imatinib. CYP3A phenotypes were correlated to plasma concentrations and imatinib outcome 12 months after initiation of treatment. The influence of ABC transport on TKI efficacy was evaluated in vitro by the transduction of genetic variants of ABCB1 and ABCG2 into the CML cell line K562. Functionality of the transport proteins was evaluated by measuring protein expression levels on the cell surface, the intracellular accumulation of TKIs, and the ability of ABCB1 and ABCG2 variants to protect cells from TKI cytotoxicity. We found that CYP3A metabolic activity does not influence the drug plasma concentrations or the therapeutic outcome of imatinib in CML patients. These findings indicate that even though imatinib is primarily metabolized by CYP3A this metabolic activity is not the rate-limiting step in imatinib elimination. CYP3A activity, therefore, is not a suitable predictive marker of imatinib outcome. The in vitro studies revealed that the ABCB1 variants investigated here do not alter the transport of imatinib, CGP74588, dasatinib, or nilotinib. In contrast, the ABCG2 SNPs 421C>A, 623T>C, 886G>C, and 1574T>G significantly impaired the cellular efflux of imatinib, CGP74588, dasatinib, and nilotinib and could possibly influence transport of these TKIs in vivo. It was also found that CGP74588 is by far a better substrate than imatinib for both ABCB1 and ABCG2, and this might have implications in patients with high levels of CYP3A activity. In conclusion, our studies show that ABCG2 SNPs might be important for prediction of imatinib outcome in vivo. On the other hand, CYP3A activity and the ABCB1 SNPs investigated in this study are not likely to be useful as predictors of imatinib outcome.
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Lou, Qiang 1962. "Identification of peptide substrates and development of pseudosubstrate-based peptide inhibitors for p60(C-SRC) protein tyrosine kinase." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282230.
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Protein tyrosine kinases (PTKs) mediate important signaling events associated with cellular growth, differentiation, and mitogenesis. The p60c-src protein is the first described cellular protein tyrosine kinase. Human p60c-src PTK has been implicated in the development of colon and breast cancer, and leukemia. However, the exact physiological role of p60c-src PTK or its physiological target proteins are not well known, and the mechanism by which the p60c-src PTK activity is regulated is not completely understood. Peptide substrates can be used to determine the substrate specificity and kinetic parameters, and therefore to provide important information for understanding of the physiological role and mechanism of action of this enzyme. Peptide substrates can also be used to develop pseudosubstrate-based peptide inhibitors for p60c-src PTK. Combinatorial peptide library methods have proven to be very powerful in identifying ligands for receptors and in discovering peptide substrates for protein kinases. In this dissertation, a "one-bead one-compound" combinatorial peptide library method was applied to identify peptide substrates for p60c-src PTK, the structure-activity relationship of the identified peptide substrates was studied, and the pseudosubstrate-based peptide inhibitors for p60c-src PTK were developed. Using the "one-bead one-compound" combinatorial peptide library method, a novel peptide, YIYGSFK, was identified as an efficient substrate for p60c-src PTK. The structure-activity relationship study was performed on over 70 analogs of YIYGSFK. It was determined that -Ile-Tyr- were the two critical residues required for activity. Based on this dipeptide motif a secondary library was synthesized (XIYXXXX, wherein X = all 19 eukaryotic amino acids except cysteine, I = isoleucine, Y = tyrosine) and screened with p60c-src PTK. One of the identified peptides, GIYWHHY, was found to be more efficient for p60c-src PTK than the parental compound, YIYGSFK. Several potent psedosubstrate based inhibitors were developed using GIYWHHY as a template. Some of the more potent inhibitors have branched structure indicating the enzyme active site can accommodate more than a linear motif. These data demonstrate that the "one-bead one-compound" combinatorial library method is a powerful tool to discover novel peptide substrates, and to develop pseudosubstrate-based peptide inhibitors for PTKs.
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Kamath, Jayesh Ramrao. "Development of pseudosubstrate-based peptide and peptidomimetic inhibitors of p60ᶜ⁻ˢʳᶜ protein tyrosine kinase using combinatorial chemistry technology." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/289173.
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Several protein tyrosine kinases and the signaling pathways in which they participate have emerged as attractive targets for drug design. Specific and potent PTK inhibitors not only represent a new class of anticancer agents but may also be used as a powerful research tool to study the role of PTK-dependent cellular pathways in normal or tumor cell growth and to dissect the redundancy in signal transduction pathways. Dr. Lam's laboratory has previously reported identification of efficient and specific peptide substrates for p60ᶜ⁻ˢʳᶜ PTK using one-bead one-peptide combinatorial library method (Lam et al., 1995; Lou et al., 1996a and b). Based on the structure of these peptide substrates, I have identified and characterized potent and selective peptide inhibitors of p60ᶜ⁻ˢʳᶜ PTK. Some of the identified peptide inhibitors were used as a research tool in this dissertation to investigate the active site of the enzyme p60ᶜ⁻ˢʳᶜ PTK. In addition to potency and selectivity, a major criterion for a successful src inhibitor is its cell permeability as src is located inside the cell. Peptides are generally impermeable to cell membrane. A major accomplishment of this dissertation is development of cell permeable peptidomimetic inhibitors of p60ᶜ⁻ˢʳᶜ PTK based on the identified dipeptide motif --Ile-Tyr- (-I-Y-). This dissertation describes identification of tetrameric and trimeric peptidomimetic inhibitors using a combination of two combinatorial methods, the 'one-bead one-compound' combinatorial method and the 'iterative' combinatorial method. Some of the identified inhibitors seem to selectively affect transformed cells versus normal cells at lower concentrations. A lot of still needs to be done to optimize these inhibitors. However, the accomplished work in this dissertation proves the feasibility of the pseudosubstrate peptide-based approach for the development of cell permeable peptidomimetic inhibitors as anti-cancer therapeutic agents.
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Shor, Audrey Cathryn. "Src kinase inhibitors for the treatment of sarcomas : cellular and molecular mechanisms of action." [Tampa, Fla] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0001906.
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Filho, TarcÃsio Paulo de Almeida. "Expression and mutational profile of BCR-ABL gene in patients with chronic mieloid leukemia treated with tyrosine kinase inhibitors." Universidade Federal do CearÃ, 2017. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=19145.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoMost patients with chronic myeloid leukemia (CML) express the transcripts b2a2, b3a2 or both of the BCR-ABL gene. The role of these transcripts in the prognosis of patients undergoing treatment with tyrosine kinase inhibitors (ITKs) has been poorly investigated and remains unclear to date. In this study, we evaluated the prognostic value of the main transcripts in patients with CML, by evaluating the expression and mutational profile of the BCR-ABL gene in patients treated with ITKs. Sixty patients with CML were evaluated transversally. Demographic, hematological, and clinical data and mutation profile of CML patients treated with ITKs were obtained from medical records. Molecular analyzes for the determination of transcripts and mutations (T315, E255V and Y253H) were performed by the qPCR technique. Statistical analyzes were performed using the Kruskal-Wallis or one-way ANOVA tests, depending on the normality of the data. The level of significance was 0.05 and p values of less than 0.05 were considered significant. Of the sixty patients, 12 (20%) expressed the b2a2 transcript, 18 (30%) the b3a2 transcript, 10 (16.7%) both b2a2/b3a2 transcripts and 20 (33.3%) had undetectable levels. Twenty-eight patients (46.7%) were female and 32 (53.3%) were males, with a mean age of 46.5 Â 15.7 years (ranging from 19-82). The comparative analysis of hematological data with transcripts showed a significant difference in the number of leukocytes in patients expressing the b2a2 and b3a2 transcripts (p <0.05), with patients with the b2a2 transcript associated with lower amounts. The other data, hematological and clinical, did not show statistically significant differences in relation to transcripts (p>0.05). Regarding mutations of the kinase domain, the presence of the T315, E255V and Y253H mutations in the study patients was not evidenced. These are the first results found in this population, being necessary more studies with a greater number of individuals and evaluation of the cytogenetic and molecular responses to the treatment. If confirmed as a prognostic factor capable of providing better outcomes and response to treatment, the transcripts could be used in the elaboration of new mathematical models for patient risk stratification and in the selection of the best therapy with ITKs for patients with CML.
A maioria dos pacientes com leucemia mieloide crÃnica (LMC) expressam os transcritos b2a2, b3a2 ou ambos do gene BCR-ABL. O papel desses transcritos no prognÃstico dos pacientes em tratamento com inibidores de tirosina quinase (ITKs) tem sido pouco investigado e atà o momento permanece incerto. Neste estudo, foi avaliado o valor prognÃstico dos principais transcritos nos pacientes com LMC, atravÃs da avaliaÃÃo da expressÃo e perfil mutacional do gene BCR-ABL em pacientes tratados com ITKs. Sessenta pacientes com LMC foram avaliados transversalmente. Os dados demogrÃficos, hematolÃgicos, clÃnicos e o perfil de mutaÃÃes dos pacientes com LMC tratados com ITKs foram obtidos atravÃs dos prontuÃrios. As anÃlises moleculares para a determinaÃÃo dos transcritos e das mutaÃÃes (T315, E255V e Y253H) foram realizadas pela tÃcnica de qPCR. As anÃlises estatÃsticas foram realizadas atravÃs dos testes Kruskal-Wallis ou one-way ANOVA dependendo da normalidade dos dados. O nÃvel de significÃncia foi de 0,05 e valores de p inferiores a 0,05 foram considerados significativos. Dos sessenta pacientes, 12 (20%) expressavam o transcrito b2a2, 18 (30%) o transcrito b3a2, 10 (16,7%) ambos os transcritos b2a2/b3a2 e 20 (33,3%) apresentaram nÃveis indetectÃveis. Vinte e oito pacientes (46,7%) eram do sexo feminino e 32 (53,3%) do sexo masculino, com mÃdia de idade 46,5  15,7 anos (variando de 19-82). A anÃlise comparativa dos dados hematolÃgicos com transcritos mostrou diferenÃa significante na quantidade de leucÃcitos nos pacientes que expressavam os transcritos b2a2 e b3a2 (p<0,05), sendo os pacientes com o transcrito b2a2 associados a quantidades inferiores. Os demais dados, hematolÃgicos e clÃnicos, nÃo mostraram diferenÃa estatisticamente significantes com relaÃÃo aos transcritos (p>0.05). Quanto Ãs mutaÃÃes do domÃnio quinase, nÃo foi evidenciada a presenÃa das mutaÃÃes T315, E255V e Y253H nos pacientes em estudo. Estes sÃo os primeiros resultados encontrados nesta populaÃÃo, sendo necessÃrio mais estudos com um nÃmero maior de indivÃduos e avaliaÃÃo das respostas citogenÃticas e moleculares ao tratamento. Se confirmado como fator de prognÃstico capaz de proporcionar melhores desfechos e resposta ao tratamento, os transcritos poderÃo ser empregados na elaboraÃÃo de novos modelos matemÃticos para estratificaÃÃo de risco dos pacientes e na seleÃÃo da melhor terapia com ITKs para pacientes com LMC.
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Djerf, Emelie. "Studies on the effect of ErbB tyrosine kinase inhibitors on malignant melanoma growth and survival in vitro." Licentiate thesis, Linköping : Department of Clinical and Experimental Medicine, Linköping University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19949.
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De, Benedittis Caterina <1983>. "Next-Generation Sequencing-Based Mutations Scanning Strategy of the BCR-ABL Kinase Domain in Patients with PhiladelPhia-Chromosome Positive Leukemias Treated with Tyrosine Kinase Inhibitors." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6753/.
Full textAbstract:
In chronic myeloid leukemia and Philadelphia-positive acute lymphoblastic leukemia patients resistant to tyrosine kinase inhibitors (TKIs), BCR-ABL kinase domain mutation status is an essential component of the therapeutic decision algorithm. The recent development of Ultra-Deep Sequencing approach (UDS) has opened the way to a more accurate characterization of the mutant clones surviving TKIs conjugating assay sensitivity and throughput. We decided to set-up and validated an UDS-based for BCR-ABL KD mutation screening in order to i) resolve qualitatively and quantitatively the complexity and the clonal structure of mutated populations surviving TKIs, ii) study the dynamic of expansion of mutated clones in relation to TKIs therapy, iii) assess whether UDS may allow more sensitive detection of emerging clones, harboring critical 2GTKIs-resistant mutations predicting for an impending relapse, earlier than SS. UDS was performed on a Roche GS Junior instrument, according to an amplicon sequencing design and protocol set up and validated in the framework of the IRON-II (Interlaboratory Robustness of Next-Generation Sequencing) International consortium.Samples from CML and Ph+ ALL patients who had developed resistance to one or multiple TKIs and collected at regular time-points during treatment were selected for this study. Our results indicate the technical feasibility, accuracy and robustness of our UDS-based BCR-ABL KD mutation screening approach. UDS was found to provide a more accurate picture of BCR-ABL KD mutation status, both in terms of presence/absence of mutations and in terms of clonal complexity and showed that BCR-ABL KD mutations detected by SS are only the “tip of iceberg”. In addition UDS may reliably pick 2GTKIs-resistant mutations earlier than SS in a significantly greater proportion of patients.The enhanced sensitivity as well as the possibility to identify low level mutations point the UDS-based approach as an ideal alternative to conventional sequencing for BCR-ABL KD mutation screening in TKIs-resistant Ph+ leukemia patients
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Ananthula, Hari Krishna. "Pharmacokinetic Evaluation and Modeling of Tyrosine Kinase Inhibitors Nilotinib and Imatinib in Preclinical Species to Aid their Repurposing As Anti-Viral Agents." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504802233495176.
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