Impact of the SRC inhibitor dasatinib on the metastatic phenotype of human prostate cancer cells.

SRC, a non-receptor tyrosine kinase, is frequently over-expressed and highly activated in blood as well as solid tumors in various organs, including prostate, and has been associated with aggressive disease and a poor patient prognosis. Prostate cancer patients with a high risk of developing metastases have few treatment options, none of which can result in a durable cure. Therefore, the aim of the present study was to examine the impact of a SRC inhibitor, dasatinib, on the ability of human prostate cancer cell to complete key steps in the metastatic process, including invasion and angiogenesis. Dasatinib treatment impaired the metastatic phenotypes of the human prostate cancer cell lines, PC-3, DU-145, and LNCaP, by significantly reducing migration and invasion in modified Boyden chambers. Inhibition of phosphorylation, and therefore enhanced activation, of SRC and key downstream signaling pathway elements, including FAK, STAT3, Paxillin, and Akt, as determined by Western blotting, also was observed. This suggests that dasatinib interferes with critical cell functions associated with the metastatic cascade. Dasatinib also had direct effects on the ability of microvascular endothelial cells to form tubes in vitro and impaired the ability of PC-3 cells to induce angiogenesis in vivo. In conclusion, the present findings suggest that SRC inhibition by dasatinib may have utility in reducing the metastatic spread of prostate cancer cells.