Imran H. Khan
Clinical Proteomics Core, Dept. of pathology and laboratory medicine, University of California, Davis, CA 95616, USA

Abstract:

Intracellular signaling abnormalities are the molecular basis of pathogenesis in a variety of cancers. Understanding of signaling pathways by phosphoproteomic analysis in cancer cells has lead to, and continues to lead, the development of next generation cancer drugs and diagnostics. To study phosphoproteomic profiles of signaling proteins, protein-protein interactions and expression by conventional biochemical approaches is laborious, time-consuming, and difficult to adapt for high throughput analysis.  We have developed multiplex suspension array immunoassays to investigate intracellular signaling in cell lines from solid tumors (breast, and prostate cancers), and liquid tumors (chronic lymphocytic leukemia and lymphoma).  These multiplex assays are focused on the phosphoproteomic and expression profiles of T-cell and B-cell activation pathways, EGFR-family of receptor tyrosine kinases (EGFR, ErbB2, ErbB3, and ErbB4) and Src-family of kinases (Src, Lck, Yes, Fyn, Lyn, Blk, Hck, and Fgr).  The multiplex assays were used in a variety of cell lines from liquid and solid tumors.  In addition, time course studies at several time points after cell stimulation provided understanding of kinetics and dynamics of activation of T-cell activation pathway, and EGFR and Src families of proteins. These examples of signaling pathway analyses demonstrate the utility of the suspension arrays to investigate phosphoproteomic profiles of signaling proteins in key pathways regulating tumor cell phenotypes in different cancers.