Increased autophagy in EOC re-ascites cells can inhibit cell death and promote drug resistance.

As the major and preferred treatment for ovarian cancer ascites, chemotherapy can reduce or inhibit recurrent ascites (hereafter re-ascites); however, some patients still experience re-ascites. Therefore, this study investigated cases in which epithelial ovarian cancer (EOC) patients experienced re-ascites. In re-ascites cases, CA125, MDR1, LC-3, and Beclin-1 were highly expressed. In addition, CASP-9 and c-CASP-3 expression levels were decreased, and serum CA125 levels (highest 4348 U/ml) were increased compared to chemosensitive cases. The results suggest that high expression levels of Beclin-1 and LC-3, thus increasing the level of autophagy and inhibiting apoptosis in the no-chemotherapy group. In the chemosensitive group, survivin expression was decreased and CASP-9 expression was increased, which led to c-CASP-3 activation and increased tumor cell apoptosis. The results of the cell lines confirm that inhibition of autophagy can increase the sensitivity of ovarian cancer cells to CDDP and promote CDDP-induced cell death. Re-ascites, which appears after chemotherapy, may be associated with drug resistance. In addition, increased autophagy may protect tumor cells from chemotherapeutic drugs, thus inhibiting tumor cell death.