The broad objective of this renewal application remains an analysis of the role of cell-matrix interactions in the process of tumor cell malignancy. The specific focus is on signaling events mediated by the avb3 and avb5 integrins, which have been shown to play a role in angiogenesis and the migratory properties of tumor cells in vivo and in vitro. Although both avb3 and avb5 promote cell attachment to vitronectin, only avb3 directly leads to motility. However, cytokine or phorbol ester stimulation results in avb5-dependent cell motility.
Aims 1 and 2 of this proposal will test the hypothesis that avb3 and avb5 differ in their ability to activate protein kinase C, focal adhesion kinase, and MAP kinase after cell attachment to vitronectin. A requirement for activation of the MAP kinase pathway for cell motility and invasion will also be investigated.
Aims 3 and 4 will extend preliminary studies demonstrating the specific binding of the collagenase matrix metalloproteinase 2 (MMP-2) to avb3 in a functionally active form on the cell surface.
Aim 3 will characterize the structural basis of this interaction and Aim 4 will determine its potential biological relevance in two models of tumor relevance in vivo. These studies will elucidate key molecular events in integrin-mediated signal transduction leading to post-ligand binding events that are important for the invasive behavior of transformed cells.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
Project #
Application #
Study Section
Pathobiochemistry Study Section (PBC)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Scripps Research Institute
La Jolla
United States
Zip Code
Seguin, Laetitia; Camargo, Maria F; Wettersten, Hiromi I et al. (2017) Galectin-3, a Druggable Vulnerability for KRAS-Addicted Cancers. Cancer Discov 7:1464-1479
Cosset, Érika; Ilmjärv, Sten; Dutoit, Valérie et al. (2017) Glut3 Addiction Is a Druggable Vulnerability for a Molecularly Defined Subpopulation of Glioblastoma. Cancer Cell 32:856-868.e5
Seguin, Laetitia; Desgrosellier, Jay S; Weis, Sara M et al. (2015) Integrins and cancer: regulators of cancer stemness, metastasis, and drug resistance. Trends Cell Biol 25:234-40
Franovic, Aleksandra; Elliott, Kathryn C; Seguin, Laetitia et al. (2015) Glioblastomas require integrin ?v?3/PAK4 signaling to escape senescence. Cancer Res 75:4466-73
Desgrosellier, Jay S; Lesperance, Jacqueline; Seguin, Laetitia et al. (2014) Integrin ?v?3 drives slug activation and stemness in the pregnant and neoplastic mammary gland. Dev Cell 30:295-308
Seguin, Laetitia; Kato, Shumei; Franovic, Aleksandra et al. (2014) An integrin ??-KRAS-RalB complex drives tumour stemness and resistance to EGFR inhibition. Nat Cell Biol 16:457-68
Cheresh, David A; Stupack, Dwayne G (2014) Tumor angiogenesis: putting a value on plastic GEMMs. Circ Res 114:9-11
Seguin, Laetitia; Gozo, Maricel; Weis, Sara M et al. (2014) Targeting the Achilles' heel of drug-resistant cancer stem cells. Cell Cycle 13:2017-8
Lau, Steven K M; Shields, David J; Murphy, Eric A et al. (2012) EGFR-mediated carcinoma cell metastasis mediated by integrin ?v?5 depends on activation of c-Src and cleavage of MUC1. PLoS One 7:e36753
Huang, M; Anand, S; Murphy, E A et al. (2012) EGFR-dependent pancreatic carcinoma cell metastasis through Rap1 activation. Oncogene 31:2783-93

Showing the most recent 10 out of 96 publications