Ovarian cancer is the deadliest of gynecologic
cancers, largely due to the development of drug resistance in
chemotherapy.
Prostasin may have an essential role in the
oncogenesis. In this study, we show that
prostasin is decreased in an
ovarian cancer drug-resistant cell line and in
ovarian cancer patients with high levels of excision repair cross-complementing 1, a marker for chemoresistance. Our cell cultural model investigation demonstrates
prostasin has important roles in the development of drug resistance and
cancer cell survival. Forced overexpression of
prostasin in
ovarian cancer cells greatly induces cell death (resulting in 99% cell death in a
drug-resistant cell line and 100% cell death in other tested cell lines). In addition, the surviving cells grow at a much lower rate compared with non-overexpressed cells. In vivo studies indicate that forced overexpression of
prostasin in
drug-resistant cells greatly inhibits the growth of
tumors and may partially reverse drug resistance. Our investigation of the molecular mechanisms suggests that
prostasin may repress
cancer cells and/or contribute to chemoresistance by modulating the CASP/P21-activated
protein kinase (PAK2)-p34 pathway, and thereafter PAK2-p34/JNK/c-jun and PAK2-p34/mlck/actin signaling pathways. Thus, we introduce prostain as a potential target for treating/repressing some ovarian
tumors and have begun to identify their relevant molecular targets in specific signaling pathways.