ATO /miRNA-885-5p/MTPN axis induced reversal of drug-resistance in cholangiocarcinoma

Backgroud: In recent years, the incidence of cholangiocarcinoma (CCA) has increased, and it has become the second most malignant tumor of the hepatobiliary system. Chemotherapy has become the main treatment for cholangiocarcinoma due to its difficulty in diagnosis and rapid progress. Primary drug resistance is the main reason for the poor efficacy of chemotherapeutic drugs. Methods Western blot and quantitative real-time PCR assays were used to detect the expression levels of myotrophin (MTPN) and microRNA-885-5p(miR-885-5p) in CCA tissues and cells; Cell viabilities treated with arsenic trioxide (ATO), 5-fluorouracil (5-Fu) and cisplatin (CDDP) were analyzed by a CCK-8 kit. Luciferase reporter assay detected the relationship between miR-885-5p and MTPN. Kaplan-Meier analysis showed survival time curve. Results We found that ATO can reduce the resistance of CCA cells to 5-Fu and CDDP and promote the killing effect of 5-Fu and CDDP. Low-dose ATO played an anti-drug-resistance role through up-regulating the expression of miR-885-5p. Combined with sequencing results and database prediction, we found that MTPN was a direct target gene of miR-885-5p. The sensitivity of CCA cells to 5-Fu and CDDP was increased after MTPN was knocked out. After MTPN knockout, the sensitivity of cholangiocarcinoma cells to 5-FU and CDDP was increased. ATO can reverse chemotherapy resistance induced by overexpression of MTPN. Conclusions Our study suggests that the ATO/miR-885-5p/MTPN axis is a potential therapeutic strategy for improving the sensitivity of CCA to chemotherapy.