Abstract SY31-01: Remodeling of the cell surface proteome in cancer

Abstract

Abstract The cell surface proteome (surfaceome) is the primary hub for cells to communicate with the outside world, and are major targets for immunotherapy. Oncogenes are known to cause huge changes in cells (see Figure 1). Our group has applied state-of-the-art proteomics methods to quantitatively compare the surfaceomes of oncogene transformed (KRAS, HER2, EGFR, BRAF, MEK, AKT and MYC) versus isogenic controls (1-3). Oncogenes lead to large and bi-directional remodeling of the surfaceomes of isogenic cell lines that can be exploited for target ID. Each oncogene has a unique signature that depends on cell line, but broadly similar across cell lines. Differences among related oncogenes converge when viewed at functional level by Geneset analysis. Proliferative oncogenes (EGFR, HER2, KRAS, BRAF, MEK) remodel the surfaceome primarily through MAPK pathway. MYC is much more unique, especially in the large changes induced in solute carrier proteins. We have also recently developed a technology to identify proteolytic cut sites in membrane proteins (4) which also show bi-direction remodeling. We show proteolysis is an orthogonal remodeling event, and the union with expression data offers new neo-epitope markers for immunotherapy.