Detection of Activated Src in Human Tumor Samples Using 2D SDS Polyacrylamide Gel Electrophoresis

Dasatinib, an inhibitor of Src family kinases, has been observed to produce marked tumor response in one patient and prolonged stable disease in four others in a small clinical trial involving 34 advanced NSCLC patients. (1) The side effects of this drug are harsh. A biomarker showing which patients are likely to respond to dasatinib would be useful. 2D SDS PAGE in combination with phosphotyrosine (pTyr) and Src western blotting was used to detect pTyr Src in a set of 14 human NSCLC tumor samples purchased from a biobank and prepared by homogenization with sodium dodecyl sulfate buffer. A total of 4 /14 tumors showed a pTyr-Src signal indicating active tyrosine kinase. The method of 1D and 2D SDS PAGE has potential to be a biomarker test for active Src.

1. Johnson, F. M., Bekele, B. N., Feng, L., Wistuba, I., Tang, X. M., Tran, H. T., Erasmus, J. J., Hwang, L. L., Takebe, N., Blumenschein, G. R., Lippman, S. M., and Stewart, D. J. (2010) Phase II study of dasatinib in patients with advanced non-small-cell lung cancer, J Clin Oncol 28, 4609-4615.