MiR-218 increases sensitivity to cisplatin in esophageal cancer cells via targeting survivin expression

OBJECTIVES Increasing evidence showed that microRNAs (miRNAs) were implicated in the chemical resistance of human cancers. We intended to investigate the role of miR-218 in cisplatin sensitivity of esophageal cancer cells. METHODS Quantitative real-time polymerase chain reaction (qRT-PCR) was carried out to analyze miR-218 expression in human esophageal cancer cell line Eca9706 and a cisplatin-resistant subline (ECa9706-CisR cells). The effects of miR-218 transfection on ECa9706 and ECa9706-CisR cell viability, including cell viability and apoptosis rate were confirmed using MTT assay, or flow cytometry, respectively. qRT-PCR was used to validate survivin as a direct target gene of miR-218 in our system. RESULTS We found that miR-218 was significantly decreased in ECa9706-CisR cells compared with parent Eca9706 cells. Overexpression of miR-218 by mimics transfection would enhance cisplatin sensitivity evaluated by cell viability inhibition and apoptosis promotion. We validated here survivin as a direct target of miR-218 in ECa9706 cells, which might contribute to the chemoresistance of esophageal cancer cells to cisplatin. CONCLUSIONS In summary, our data suggest that miR-218 might represent as a promising sensitizer of cisplatin therapy in clinical esophageal cancer patients.