In collaboration with Todd Golub at the Broad Institute, we have performed a luminex assay to quantitate tyrosine phosphorylation in tyrosine kinases. Active tyrosine kinases are also generally associated with increased overall tyrosine phosphorylation. Our assay captured more than 150 tyrosine kinases in a multiplex assay and detected the level of tyrosine phosphorylation in all these kinases using a pan-phosphotyrosine antibody (4G10). We used 150 human lung adenocarcinoma tumor tissue and corresponding adjacent normal lung tissue to profile tyrosine phosphorylation of these tyrosine kinases. We identified around 30 specific tyrosine kinases differentially phosphorylated in tumor tissue compared to adjacent normal lung. Examples of such potentially active tyrosine kinases are NTRK1, EPHA2, DDR. We then completed a nanostring assay in collaboration with Dr. Marc Ladanyi at MSKCC to measure transcript expression of majority of tyrosine kinases in a multiplex assay. Interestingly, as we had predicted, expression of several tyrosine kinases do not change at least at the level of trasnscription, however there is significant change in tyrosine phosphorylation, which is generally a surrogate of activation. Currently, in collaboration with Dr. Paul Meltzer in the NCI intramural program, we are sequencing around 1300 cancer-related genes, including the tyrosine kinases used in our luminex assay to identify specific mutations in a targeted manner. We are awaiting the sequencing results from Dr. Paul Meltzer's group for further validation of specific targets.
