Hsa_circ_0000585 promotes chemoresistance to cis-platin in epithelial cells of ovarian cancer by modulating autophagy

Background: Chemoresistance, i.e., resistance to cisplatin (DDP), has been a major obstacle to ovarian cancer treatment. It has been found that circular RNAs (circRNAs) play vital roles in the tumorigenesis various cancers by regulating autophagy, while few studies focusing on cisplatin-resistance ovarian cancer (CROC). Methods: The expressions of the circRNAs were detected by qRT-PCR. Short hairpin RNA targeting circRNA was used to explore the biological functions of the circRNA. Cell viability, autophagic flux, immunofluorescence, and xenograft tumors experiments were performed to further illustrate the underlying mechanisms.Results: Hsa_circ_0000585 was increased in cisplatin-resistant SKOV3/DDP cells. Stably knocking down hsa_-circRNA_0000585 expression in SKOV3/DDP cells was established by RNA interference. We found that down-regulation of hsa_circ_0000585 significantly enhanced the sensitivity of DDP/SkOV3 cells to DDP. In vivo study, hsa_circRNA_0000585 knockdown significantly decreased tumor volume in nude mice. Under the measurements of western blot and cellular immunofluorescence, hsa_circ_0000585 knockdown significantly inhibited the expression of Beclin1 and P62, indicating the autophagic flux was inhibited. Administrations with autophagic inhibitor Chloroquine (CQ) and autophagy activator QX77 further confirmed that hsa_circ_0000585 knockdown resulted in autophagy inhibition.Conclusions: Overall, this study provided a new insight into the role of circRNAs in the mechanism of DDP-resistance in ovarian cancer. Hsa_circRNA_0000585 may be promising therapeutic targets for the enhance-ment of the sensitivity of ovarian cancer cells to cisplatin-mediated chemotherapy.

Automated summary

This study provides new insights into the role of circRNAs in the mechanism of cisplatin-resistance in ovarian cancer. Hsa_circRNA_0000585 may be a promising therapeutic target for enhancing the sensitivity of ovarian cancer cells to cisplatin-mediated chemotherapy.