Sulforaphane enhances the cisplatin sensitivity through regulating DNA repair and accumulation of intracellular cisplatin in ovarian cancer cells

Objectives: Cisplatin is commonly applied as anticancer agent for various cancers, including ovarian cancer. Unfortunately, the drug resistance frequently occurred which obstructing the effect of cisplatin on tumors. The goal of our research was to investigate the reversal actions and the potential mechanisms of sulforaphane (SFN) on cisplatin resistance in ovarian carcinoma.

Methods: The A2780 and IGROV1 cells and their cisplatin resistance cells A2780/CP70 and IGROV1-R10 were used in this study. Cell viability was detected by CCK-8. The DNA repair was measured by comet assay. The cisplatin transporter proteins were measured with western blotting. The concentration of intracellular cisplatin was detected by HPLC. The luciferase activity assay was applied to determine the target site of miR-30a-3p on the 3'UTR of ERCC1 and ATP7A. A2780/CP70 and IGROV1-R10 xenograft mouse model were established to confirm the antineoplastic action of SFN combined with cisplatin.

Results: SFN reversed the resistance of A2780/CP70 and IGROV1-R10 ovarian carcinoma cells to cisplatin through inducing DNA damage and accumulation of intracellular cisplatin. SFN treatment notably increased miR-30a-3p expression, which was decreased in cisplatin-resistant cells. Moreover, overexpressed miR-30a-3p enhanced the sensitivity of A2780/CP70 and IGROV1-R10 cells to cisplatin treatment, and inhibiting miR-30a-3p activity abated the reversal actions of SFN on cisplatin resistance. The luciferase assay findings showed that miR-30a-3p binds to ERCC1 and ATP7A which are the key regulators for DNA repair and cisplatin transportation.

Conclusions: Our findings indicated that SFN could enhance cisplatin sensitivity of ovarian carcinoma cells through up-regulating miR-30a-3p to induce DNA damage and accumulation of intracellular cisplatin.

Keywords: Cisplatin; Drug resistance; Ovarian cancer; Sulforaphane; miR-30a-3p.