Synergistic antitumor effect of NVP-BEZ235 and sunitinib on docetaxel-resistant human castration-resistant prostate cancer cells.

According to recent studies, mTOR (mammalian target of rapamycin) inhibitor and tyrosine kinase inhibitor (TKI) can be used as combinational agents to enhance the antitumor effect or overcome resistance to one of the agents. In the present study, we investigated the synergistic interaction between NVP-BEZ235, a PI3K (phosphoinositide 3-kinase)/mTOR dual inhibitor, and sunitinib, a TKI, in castration-resistant prostate cancer (CRPC) cells with docetaxel resistance. Prostate cancer cells with different sensitivities to hormones and docetaxel levels were exposed to escalating doses of NVP-BEZ235 alone and in combination with sunitinib.