Effect of siRNA-induced Atg7 gene silencing on the sensitivity of ovarian cancer SKOV3 cells to cisplatin.

Ovarian cancer is one of the most common types of gynecological malignant tumors. A proclivity for, or the development of chemoresistance severely affects treatment efficacy for ovarian cancer. Herein we found that as concentrations of cisplatin (DDP) used in SKOV3 cells increased, expression of intracellular reactive oxygen species (ROS) increased as did amounts of proteins of Beclin-1 and Autophagy-Related Gene 7 (Atg7) whereas in contrast, expression of P62 protein decreased gradually. Expression of Atg7 protein in SKOV3 cells in the siRNA-Atg7 transfection treatment group was significantly reduced compared to the negative control group. Post-application of DDP treatments, the apoptotic ratio of SKOV3 cells in the siRNA-Atg7 transfection group increased, and the cell survival rate decreased to a level significantly lower than in the negative control group. Cellular morphological analyses revealed remarkably decreased measures of cell density, as well as shrunk, deformed, and rounded cells with unclear boundaries, and revealed a decreased measures of mitochondrial membrane potential. Taken together, autophagy may be involved in the dynamics and mechanistics underlying DDP resistance in ovarian cancer SKOV3 cells. Thus, inhibition of autophagy through down-regulation expression of Atg7 may have beneficially enhanced the sensitivity of SKOV3 cells to DDP-based chemotherapy which could help improve treatment outcomes for patients afflicted by ovarian cancer.