α-solanine enhances the chemosensitivity of esophageal cancer cells by inducing microRNA‑138 expression.

Esophageal cancer is a common malignant tumor worldwide. Inherent and acquired drug resistance are the major challenges faced in anticancer chemotherapy. This study aimed to explore the effects of α-solanine in regards to the chemosensitivity of esophageal cancer cells. We found that α-solanine enhanced the sensitivity of EC9706 and KYSE30 cells to 5-flurouracil (5-FU) and cisplatin (Cis) by promoting drug-induced apoptosis. qRT-PCR and western blotting results showed that α-solanine treatment promoted miR-138 expression and decreased survivin expression in EC9706 and KYSE30 cells. α-solanine also enhanced the inhibitory effects of 5-Fu and Cis in EC9706 transplanted tumors in mouse models. Dual-Luciferase reporter assay results confirmed survivin as the direct target gene of miR-138. MiR-138 inhibited survivin expression in EC9706 and KYSE30 cells. And miR-138 mimic and si-survivin had similar effects with α-solanine in suppressing survivin expression and promoting cancer cell death. miR-138 inhibitor reversed the chemosensitivity-enhancing effect of α-solanine. In EC9706 and KYSE30 cells, survivin overexpression rescued the cancer cells from apoptosis caused by α-solanine and miR-138 mimic expression. From these findings, we conclude that α-solanine enhanced the chemosensitivity of esophageal cancer cells to chemotherapy via the miR-138/survivin pathway. This study provides insight into the molecular mechanism underlying the chemosensitivity-enhancing function of α-solanine and suggests a new chemotherapeutic strategy for esophageal cancer treatment.