FA 5 Progress Report WV-INBRE - Joan C. Edwards School of ...

Program Director/Principal Investigator (Last, First, Middle): Rankin, Gary O 74HOMER2 AS A SUPPRESSOR OF CELL INVASION AND PODOSOME FORMATION(0027)TYPE:Research Subproject%IDeA $: 5.000% IDeA $: 168,125INVESTIGATOR, DEGREEShurina, Robert PHDWeed, Scott PHDDEPARTMENTBiologyNeurobiology AndAnatomyNON-HOST INSTITUTION: STATE,COUNTRYWheeling Jesuit University, Wv UsaWest Virginia University, Wv UsaTotal # human subjects expected for entire study: 0Total # human subjects enrolled to date: 0SUBPROJECT DESCRIPTIONPodosomes are actin-rich projections of the cell membrane that are associated with cancer cell migrationand metastases. Their formation requires rearrangements of the actin cytoskeleton, which are mediatedthrough the interaction of a host of actin-binding proteins. Tumor-promoting phorbol esters cause actincytoskeletal rearrangements that result in podosome formation in a variety of cell types; including vascularsmooth muscle cells, osteoclasts, macrophages, endothelial cells, neural cells myoblasts and transformedfibroblasts. Tumor-promoting phorbol esters function by activating one or more PKC isoforms, resulting inthe reorganization of the actin cytoskeleton and src activation AFAP-110, an adaptor protein thatcross-links actin filaments, activates Src in response to phosphorylation by PKC- and is involved inpodosome formation. Increased levels of AFAP-110 are correlated with increases in podosome lifetime inA7r5 tumor cells and prostate cancer. Although the role of AFAP-110 as a Src activator is well established,the mechanism by which activated AFAP-110 is itself regulated remains incompletely characterized.Scaffolding proteins, such as Tks5, recruit AFAP-110 and other signaling proteins to podosomes. Homer2is a scaffolding protein that interacts with both actin filaments and activated Rho GTPases in mousecerebellar cells and can prevent podosome formation in cdc42-activated HeLa cells. Homer2 has beenidentified as a binding partner for AFAP-110 in two independent yeast two-hybrid studies. We hypothesizethat Homer2 is a binding partner and regulator for AFAP-110. In this proposal we will address themechanism by which Homer2 abrogates podosome formation.SUBPROJECT PROGRESSSpecific Aim #1: Identify protein binding partners that regulate AFAP-110 activity. We have shownthat Homer2 is expressed in a wide variety of human cancer cell lines, including HEK-293T cell line;the ovarian cancer CaOV3 cell line; the prostate cancer PC3 cell line; the neuroblastoma SY5Y cellline; and the epithelial cancer UMSSC-1 cell line.We have also demonstrated that Homer2 and AFAP-110 co-localize to lamellipodia in A7r5 tumorcell lines that are stimulated with phorbol myristate acetate (PMA).Other progressPresentations: Richards, T.D. and R.D. Shurina (2011). Homer2 binds AFAP-110 and localizes tothe cortical actin cytoskeleton in lamellipodia. Presented at the 10thAnnual WV-INBRE Summer Research Symposium, Huntington, WV, July 2011.Student research mentor: Eight undergraduate student researchers were supported by this award.Six of these students were awarded scholarships through the NASA-West Virginia Space GrantConsortiumNew research collaborations: Thanks to the expertise that I gained from support through theWV-INBRE research network, my lab is in the process of forming a research collaboration with Dr.Gregory Merrick at the Schiffler Cancer Center of the Wheeling Hospital (Wheeling, WV) toinvestigate whether proteins involved in the AFAP-110/Src signaling pathway can be used asprognostic indicators of prostate cancer.PHS 2590 (Rev. 06/09)Continuation Format Page