The long term goals of this project are to characterize the signaling pathways involved in transformationby activated Src, and to extend these studies to an analysis of the role of Src and its effectors in human cancer. The first specific aim concerns the mechanisms by which Src induces cellular invasion of theextracellular matrix. We have observed that the small GTPase Rho is required for the formation of invasive adhesions, termed podosomes or invadopodia, and propose to identify the Rho isoforms and Rho effectors required for the induction of podosomes by activated Src. We have also observed that atypical PKC activity is required for matrix invasion by Src-transformed cells, and will identify aPKC substrates required for Src-induced matrix invasion. In addition we will examine the effects of Src-dependent tyrosine phosphorylation of actin binding proteins such as Eps8 and vinculin on actin dynamics within podosomes. Src induces entry into S phase in part by inducing the expression of the transcription factor Myc. We have recently observed that Src abrogates the Myc requirement for GO/G1but not the Myc requirement for G1/S. The second specific aim concerns the mechanism by which Src abrogates the Myc requirement for GO/G1. We hypothesize that chromatin changes at Myc target loci underlie both this phenomenon and the phenomenon of myc oncogene addiction. We will test this hypothesis by characterization of chromatin modifications at the promoters of Myc target loci. Src is overexpressed and/or activated in many types of human cancer. We have shown that inhibition of Src induces reversion of some aspects of the malignant phenotype of human breast cancer cell lines;in certain lines acinar morphogenesis in three-dimensional basement membrane cultures is restored, while in others invadopodium formation and matrix degradation are blocked. We will examine the roles of different Src effectors in mediating these effects. Inhibitors of Src are in clinical trials as anti-cancer agents, and inhibitors of Myc are also under development. A deeper understanding of how these proteins act to induce cancer and how their functions are inter-related will provide insights into how these agents should be deployed.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37CA017542-35
Application #
7750615
Study Section
Special Emphasis Panel (NSS)
Program Officer
Read-Connole, Elizabeth Lee
Project Start
1978-12-01
Project End
2011-12-31
Budget Start
2010-01-01
Budget End
2011-12-31
Support Year
35
Fiscal Year
2010
Total Cost
$536,226
Indirect Cost
Name
University of California Berkeley
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Gottlieb-Abraham, Efrat; Shvartsman, Dmitry E; Donaldson, John C et al. (2013) Src-mediated caveolin-1 phosphorylation affects the targeting of active Src to specific membrane sites. Mol Biol Cell 24:3881-95
Rodriguez, Elena M; Dunham, Elizabeth E; Martin, G Steven (2009) Atypical protein kinase C activity is required for extracellular matrix degradation and invasion by Src-transformed cells. J Cell Physiol 221:171-82
Martin, G Steven (2009) SRC substrate surprise. Cancer Cell 16:176-8
Shvartsman, Dmitry E; Donaldson, John C; Diaz, Begona et al. (2007) Src kinase activity and SH2 domain regulate the dynamics of Src association with lipid and protein targets. J Cell Biol 178:675-86
Zhu, Qingwei; Krakowski, Ariel R; Dunham, Elizabeth E et al. (2007) Dual role of SnoN in mammalian tumorigenesis. Mol Cell Biol 27:324-39
Jackson, William T; Martin, G Steven (2006) Transcription of the Schizosaccharomyces pombe gene cdc18+: roles of MCB elements and the DSC1 complex. Gene 369:100-8
Prathapam, Tulsiram; Tegen, Sarah; Oskarsson, Thordur et al. (2006) Activated Src abrogates the Myc requirement for the G0/G1 transition but not for the G1/S transition. Proc Natl Acad Sci U S A 103:2695-700
Berdeaux, Rebecca L; Diaz, Begona; Kim, Lomi et al. (2004) Active Rho is localized to podosomes induced by oncogenic Src and is required for their assembly and function. J Cell Biol 166:317-23
Martin, G Steven (2004) The road to Src. Oncogene 23:7910-7
He, Jun; Tegen, Sarah B; Krawitz, Ariel R et al. (2003) The transforming activity of Ski and SnoN is dependent on their ability to repress the activity of Smad proteins. J Biol Chem 278:30540-7

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