Le mélanome est un cancer en recrudescence depuis 10 ans. Il est devenu de ce fait une préoccupation majeure de santé publique. Au cours de la progression tumorale, l’expression des molécules d’adhérence (intégrines et cadhérines) ainsi que le récepteur à l’IGF de type I (IGF-IR) sont modulées. Notamment, il est observé un « switch des cadhérines » de la E vers la N, une surexpression des intégrines α2 et αv, et de l’IGF-IR. C’est dans cette optique que nous nous sommes intéressés aux dialogues croisés entre les molécules d’adhérence et l’IGF-IR. Dans un premier temps, nous avons mis en évidence un dialogue entre la N-cadhérine et l’intégrine αv lors de la migration des mélanomes. Dans un second temps, nous avons démontré que les dialogues entre l’IGF-IR, l’intégrine α2 et les cadhérines différent selon la nature de la cadhérine incriminée. Ces modifications de dialogues ont un impact important sur la propension migratoire des mélanomes. / Cutaneous malignant melanoma is an aggressive melanocyte malignancy that is characterized by early metastasis, bad prognosis, and poor survival. Altered cell-cell adhesion (cadherins), cell-extracellular matrix (integrins) interaction, and IGF type I receptor (IGF-IR) are playing an important role in melanoma progression. In particular, we observed a "cadherins switch" from E to N, and α2- αv-integrins and IGF-IR over-expression. In this optics, we were interested in the crosstalk between adhesion molecules and IGF-IR. First, we brought to light a crosstalk between N-cadherin and αv-integrin during melanoma migration. Secondly, we demonstrated that the dialogues between the IGF-IR, α2-integrin and cadherins are different according to the nature of the cadherin involved. Such modulation in the crosstalk may have an important impact on the migratory inclination of melanomas.

Comprehensive genomic profiling has an emerging role in cancer therapeutics. As treatment options remain needed for advanced cancers, patients are relying increasingly more on tumor genomic alterations as possible targets for cancer treatment. Frequent tumor fibroblast growth factor receptor (FGFR) alterations are seen in many cancers, and include genetic amplifications, mutations, rearrangements and fusions. FGFR inhibitors target these receptor alterations and show promise as a drug class. Currently 2 medications are currently FDA approved: erdafitinib and pemigatinib. Through the FDA accelerated approval process, erdafitinib is indicated to treat metastatic urothelial carcinoma with FGFR2 and FGFR3 alterations, whereas pemigatinib is indicated to treat unresectable cholangiocarcinoma with FGFR2 alterations. Despite growing knowledge about such advanced cancers, treatment is usually palliative. With multiple FGFR inhibitors in the pipeline, further FDA approvals are possible, and it is likely their role in therapy will extend to other cancer types. This review outlines erdafitinib, pemigatinib, their role in cancer, as well as outlining the possible future use of other FGFR inhibitors in urothelial carcinoma, cholangiocarcinoma, and other malignancies.

Indiana University-Purdue University Indianapolis (IUPUI) / Diabetes occurs as a result of the failure of pancreatic insulin-producing β cells. The preservation or renewal of β cells is a strategy that can prevent diabetes by targeted manipulation of mechanisms associated with autoimmune β cell destruction or β cell regeneration. ErbB signaling, specifically epidermal growth factor receptor (EGFR) signaling, is associated with cell survival, growth, and proliferation. Thus, we investigated the role of the ErbB inhibitor, mitogen-inducible gene 6 (mig6), in pancreas development and in the progression to diabetes. Using morpholino knockdown in a zebrafish model of development, we discovered that mig6 is required for the generation of α and β cells as well as the formation of the exocrine pancreas. We suspect that the loss of mig6 function causes premature differentiation of ductal progenitor cells, and acts as a switch between progenitor differentiation and endocrine transdifferentiation. Furthermore, we established a pancreas-specific mig6 knockout mouse that maintained glucose tolerance and had a higher β cell mass after chemically-induced β cell injury by way of increased β cell proliferation. Our data suggests that mig6 is required during pancreas development and may be employed as a switch to direct the production of new β cells, but that during adulthood, it is detrimental to the recovery of β cell mass, making it a therapeutic target for β cell preservation after the onset of diabetes.

Comprehensive genomic profiling has an emerging role in cancer therapeutics. As treatment options remain needed for advanced cancers, patients are relying increasingly more on tumor genomic alterations as possible targets for cancer treatment. Frequent tumor fibroblast growth factor receptor (FGFR) alterations are seen in many cancers, and include genetic amplifications, mutations, rearrangements and fusions. FGFR inhibitors target these receptor alterations and show promise as a drug class. Currently 2 medications are currently FDA approved: erdafitinib and pemigatinib. Through the FDA accelerated approval process, erdafitinib is indicated to treat metastatic urothelial carcinoma with FGFR2 and FGFR3 alterations, whereas pemigatinib is indicated to treat unresectable cholangiocarcinoma with FGFR2 alterations. Despite growing knowledge about such advanced cancers, treatment is usually palliative. With multiple FGFR inhibitors in the pipeline, further FDA approvals are possible, and it is likely their role in therapy will extend to other cancer types. This review outlines erdafitinib, pemigatinib, their role in cancer, as well as outlining the possible future use of other FGFR inhibitors in urothelial carcinoma, cholangiocarcinoma, and other malignancies.

Thesis advisor: Jianmin Gao / Protein-protein interactions (PPIs) are essential for all biological functions. Developing peptides that disrupt these PPIs is an avid research effort, as peptides possess several advantages over small molecules and monoclonal antibodies. Peptide phage display is a useful tool in identifying peptides for targeting PPIs. This technology displays up to 10^10 unique polypeptides on the surface of bacteriophage, which after several rounds of panning enriches high affinity peptide sequences towards a target protein. Phage display is classically done on immobilized discrete protein; however, we propose to use this technology to identify peptides ligands for overexpressed oncogenic proteins on live cells in-vitro. This is a more accurate representation of the therapeutic target landscape and resembles how the peptide will interact with the receptor in-vivo. Several groups have explored live cell panning, such as Ruoslahti et al. and Cieslewicz et al., and while they demonstrate the capabilities of in-vitro style phage display, there are areas for improvement. We intend to improve on this previous work by 1. Identifying a peptide ligand against specific receptor/protein, and 2. By incorporating the use of covalent phage libraries to elucidate a high affinity binder. This work will be accomplished using the mammalian epidermal oncogenic cell line, A431, that is known to overexpress epidermal growth factor receptor (EGFR). Epidermal growth factor receptor (EGFR) is responsible for cellular proliferation, survival, differentiation and metastasis, which makes it an attractive target to inhibit oncogenic proliferation. Despite successfully marketed monoclonal antibodies and tyrosine kinase inhibitors, EGFR can mutate and develop resistance as diseases progress; this phenomenon, in addition to the benefits of peptides as therapeutics, are driving factors for pursuing this project. Despite our best efforts using non-covalent phage libraries to identify a viable ligand, screening against EGFR extracellular domain (ECD) has proven to be more difficult than anticipated. We hypothesize that non-covalent phage libraries do not possess any sequences with a high enough binding affinity for this protein, and that the use of covalent libraries will be needed to pull out a positive hit. Due to these findings, we have successfully constructed two phage libraries, a ACX7C and a ACX7C-TEV, where the latter introduced a TEV protease cleavage site on the C’-terminal side of the randomized amino acids suitable for covalent warhead modification and screening. Further, we have begun work on constructing an EGF-displaying phage construct to aid in optimizing a live cell panning protocol. In the future, we plan to evaluate ligand affinity and protein density, as well as determine the optimal covalent warhead/peptide combination for live cell screenings. With this information, we intend to apply this to other oncogenic cell lines, such as MCF-10CA1a, to identify potent peptide ligands for overexpressed oncogenic proteins. / Thesis (MS) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

No description available.

Receptor tyrosine kinases (RTK) are key regulators of growth, differentiation and survival of epithelial cells and play a significant role in the development and progression of cancers derived from these tissues. In malignant cells, these receptors and their downstream signalling pathways are often deregulated, leading to cell hyper-proliferation, enhanced cell survival and increased metastatic potential. Furthermore, endothelial expressed RTKs regulate tumor angiogenesis allowing for tumor growth and maintenance by promoting their vascularization. Epithelial malignancies such as squamous cell carcinomas (SCC), non-small cell lung (NSCLC) and malignant mesotheliomas have very limited treatment options when presenting as metastatic disease. RTKs, particularly the epidermal growth factor (EGFR) and the vascular endothelial growth factor (VEGFR) receptors, have been shown to play significant roles in the pathogenesis of these tumor types. Statins are potent inhibitors of HMG-CoA reductase, the rate limiting enzyme of the mevalonate pathway, that are widely used as hypercholesterolemia treatments. The mevalonate pathway produces a variety of end products that are critical for many different cellular pathways, thus, targeting this pathway can affect multiple signalling pathways. Our laboratory has previously shown that lovastatin can induce tumor specific apoptosis especially in SCC and that 23% of recurrent SCC patients treated with lovastatin as a single agent showed disease stabilization in our Phase I clinical trial. Subsequently, our lab was able to demonstrate that lovastatin in combination with gefitinib, a potent inhibitor of the EGFR showed co-operative cytotoxicity when combined (Chapter 2). Furthermore, the pro-apoptotic and cytotoxic effects of these agents were found to be synergistic and to be manifested in several types of tumor cell lines including SCC, NSCLC and glioblastoma. I was able to expand upon these important findings and demonstrated that lovastatin, through its ability to disrupt the actin cytoskeleton, inhibited EGFR dimerization and activation (Chapter 3). This novel mechanism targeting this receptor has clinical implications as lovastatin treatment combined with gefitinib showed co-operative inhibitory effects on EGFR activation and downstream signalling. The RTK family of proteins share similar features with respect to activation, internalization and downstream signalling effectors. I further demonstrated that lovastatin can inhibit the VEGFR-2 in endothelial cells and mesotheliomas, where VEGF and its receptor are co-expressed driving their proliferation, and induces synergistic cytotoxicity in mesothelioma cells in combination with VEGFR-2 tyrosine kinase inhibitors (Chapter 4). These findings suggest that statins may augment the effects of a variety of RTK inhibitors in a similar fashion representing a novel combinational therapeutic approach in a wide repertoire of human cancers. More importantly, based on this work, we initiated a Phase I/II study evaluating high dose rosuvastatin and the EGFR inhibitor tarceva in SCC and NSCLC patients at our institute. This clinical evaluation will provide invaluable data that will play a role in developing this novel therapeutic strategy. Together, the work embodied in this thesis provides a model for the regulation of EGFR/VEGFR-2 activation and signalling by targeting the rho family of proteins that demonstrates a novel mechanism that can be exploited to refine current therapeutic paradigms.

Receptor tyrosine kinases (RTK) are key regulators of growth, differentiation and survival of epithelial cells and play a significant role in the development and progression of cancers derived from these tissues. In malignant cells, these receptors and their downstream signalling pathways are often deregulated, leading to cell hyper-proliferation, enhanced cell survival and increased metastatic potential. Furthermore, endothelial expressed RTKs regulate tumor angiogenesis allowing for tumor growth and maintenance by promoting their vascularization. Epithelial malignancies such as squamous cell carcinomas (SCC), non-small cell lung (NSCLC) and malignant mesotheliomas have very limited treatment options when presenting as metastatic disease. RTKs, particularly the epidermal growth factor (EGFR) and the vascular endothelial growth factor (VEGFR) receptors, have been shown to play significant roles in the pathogenesis of these tumor types. Statins are potent inhibitors of HMG-CoA reductase, the rate limiting enzyme of the mevalonate pathway, that are widely used as hypercholesterolemia treatments. The mevalonate pathway produces a variety of end products that are critical for many different cellular pathways, thus, targeting this pathway can affect multiple signalling pathways. Our laboratory has previously shown that lovastatin can induce tumor specific apoptosis especially in SCC and that 23% of recurrent SCC patients treated with lovastatin as a single agent showed disease stabilization in our Phase I clinical trial. Subsequently, our lab was able to demonstrate that lovastatin in combination with gefitinib, a potent inhibitor of the EGFR showed co-operative cytotoxicity when combined (Chapter 2). Furthermore, the pro-apoptotic and cytotoxic effects of these agents were found to be synergistic and to be manifested in several types of tumor cell lines including SCC, NSCLC and glioblastoma. I was able to expand upon these important findings and demonstrated that lovastatin, through its ability to disrupt the actin cytoskeleton, inhibited EGFR dimerization and activation (Chapter 3). This novel mechanism targeting this receptor has clinical implications as lovastatin treatment combined with gefitinib showed co-operative inhibitory effects on EGFR activation and downstream signalling. The RTK family of proteins share similar features with respect to activation, internalization and downstream signalling effectors. I further demonstrated that lovastatin can inhibit the VEGFR-2 in endothelial cells and mesotheliomas, where VEGF and its receptor are co-expressed driving their proliferation, and induces synergistic cytotoxicity in mesothelioma cells in combination with VEGFR-2 tyrosine kinase inhibitors (Chapter 4). These findings suggest that statins may augment the effects of a variety of RTK inhibitors in a similar fashion representing a novel combinational therapeutic approach in a wide repertoire of human cancers. More importantly, based on this work, we initiated a Phase I/II study evaluating high dose rosuvastatin and the EGFR inhibitor tarceva in SCC and NSCLC patients at our institute. This clinical evaluation will provide invaluable data that will play a role in developing this novel therapeutic strategy. Together, the work embodied in this thesis provides a model for the regulation of EGFR/VEGFR-2 activation and signalling by targeting the rho family of proteins that demonstrates a novel mechanism that can be exploited to refine current therapeutic paradigms.

Receptor tyrosine kinases (RTK) are key regulators of growth, differentiation and survival of epithelial cells and play a significant role in the development and progression of cancers derived from these tissues. In malignant cells, these receptors and their downstream signalling pathways are often deregulated, leading to cell hyper-proliferation, enhanced cell survival and increased metastatic potential. Furthermore, endothelial expressed RTKs regulate tumor angiogenesis allowing for tumor growth and maintenance by promoting their vascularization. Epithelial malignancies such as squamous cell carcinomas (SCC), non-small cell lung (NSCLC) and malignant mesotheliomas have very limited treatment options when presenting as metastatic disease. RTKs, particularly the epidermal growth factor (EGFR) and the vascular endothelial growth factor (VEGFR) receptors, have been shown to play significant roles in the pathogenesis of these tumor types. Statins are potent inhibitors of HMG-CoA reductase, the rate limiting enzyme of the mevalonate pathway, that are widely used as hypercholesterolemia treatments. The mevalonate pathway produces a variety of end products that are critical for many different cellular pathways, thus, targeting this pathway can affect multiple signalling pathways. Our laboratory has previously shown that lovastatin can induce tumor specific apoptosis especially in SCC and that 23% of recurrent SCC patients treated with lovastatin as a single agent showed disease stabilization in our Phase I clinical trial. Subsequently, our lab was able to demonstrate that lovastatin in combination with gefitinib, a potent inhibitor of the EGFR showed co-operative cytotoxicity when combined (Chapter 2). Furthermore, the pro-apoptotic and cytotoxic effects of these agents were found to be synergistic and to be manifested in several types of tumor cell lines including SCC, NSCLC and glioblastoma. I was able to expand upon these important findings and demonstrated that lovastatin, through its ability to disrupt the actin cytoskeleton, inhibited EGFR dimerization and activation (Chapter 3). This novel mechanism targeting this receptor has clinical implications as lovastatin treatment combined with gefitinib showed co-operative inhibitory effects on EGFR activation and downstream signalling. The RTK family of proteins share similar features with respect to activation, internalization and downstream signalling effectors. I further demonstrated that lovastatin can inhibit the VEGFR-2 in endothelial cells and mesotheliomas, where VEGF and its receptor are co-expressed driving their proliferation, and induces synergistic cytotoxicity in mesothelioma cells in combination with VEGFR-2 tyrosine kinase inhibitors (Chapter 4). These findings suggest that statins may augment the effects of a variety of RTK inhibitors in a similar fashion representing a novel combinational therapeutic approach in a wide repertoire of human cancers. More importantly, based on this work, we initiated a Phase I/II study evaluating high dose rosuvastatin and the EGFR inhibitor tarceva in SCC and NSCLC patients at our institute. This clinical evaluation will provide invaluable data that will play a role in developing this novel therapeutic strategy. Together, the work embodied in this thesis provides a model for the regulation of EGFR/VEGFR-2 activation and signalling by targeting the rho family of proteins that demonstrates a novel mechanism that can be exploited to refine current therapeutic paradigms.

Receptor tyrosine kinases (RTK) are key regulators of growth, differentiation and survival of epithelial cells and play a significant role in the development and progression of cancers derived from these tissues. In malignant cells, these receptors and their downstream signalling pathways are often deregulated, leading to cell hyper-proliferation, enhanced cell survival and increased metastatic potential. Furthermore, endothelial expressed RTKs regulate tumor angiogenesis allowing for tumor growth and maintenance by promoting their vascularization. Epithelial malignancies such as squamous cell carcinomas (SCC), non-small cell lung (NSCLC) and malignant mesotheliomas have very limited treatment options when presenting as metastatic disease. RTKs, particularly the epidermal growth factor (EGFR) and the vascular endothelial growth factor (VEGFR) receptors, have been shown to play significant roles in the pathogenesis of these tumor types. Statins are potent inhibitors of HMG-CoA reductase, the rate limiting enzyme of the mevalonate pathway, that are widely used as hypercholesterolemia treatments. The mevalonate pathway produces a variety of end products that are critical for many different cellular pathways, thus, targeting this pathway can affect multiple signalling pathways. Our laboratory has previously shown that lovastatin can induce tumor specific apoptosis especially in SCC and that 23% of recurrent SCC patients treated with lovastatin as a single agent showed disease stabilization in our Phase I clinical trial. Subsequently, our lab was able to demonstrate that lovastatin in combination with gefitinib, a potent inhibitor of the EGFR showed co-operative cytotoxicity when combined (Chapter 2). Furthermore, the pro-apoptotic and cytotoxic effects of these agents were found to be synergistic and to be manifested in several types of tumor cell lines including SCC, NSCLC and glioblastoma. I was able to expand upon these important findings and demonstrated that lovastatin, through its ability to disrupt the actin cytoskeleton, inhibited EGFR dimerization and activation (Chapter 3). This novel mechanism targeting this receptor has clinical implications as lovastatin treatment combined with gefitinib showed co-operative inhibitory effects on EGFR activation and downstream signalling. The RTK family of proteins share similar features with respect to activation, internalization and downstream signalling effectors. I further demonstrated that lovastatin can inhibit the VEGFR-2 in endothelial cells and mesotheliomas, where VEGF and its receptor are co-expressed driving their proliferation, and induces synergistic cytotoxicity in mesothelioma cells in combination with VEGFR-2 tyrosine kinase inhibitors (Chapter 4). These findings suggest that statins may augment the effects of a variety of RTK inhibitors in a similar fashion representing a novel combinational therapeutic approach in a wide repertoire of human cancers. More importantly, based on this work, we initiated a Phase I/II study evaluating high dose rosuvastatin and the EGFR inhibitor tarceva in SCC and NSCLC patients at our institute. This clinical evaluation will provide invaluable data that will play a role in developing this novel therapeutic strategy. Together, the work embodied in this thesis provides a model for the regulation of EGFR/VEGFR-2 activation and signalling by targeting the rho family of proteins that demonstrates a novel mechanism that can be exploited to refine current therapeutic paradigms.