ZHU Han-yu, Liu Mo-yan, HONG Quan, ZHANG Dong, GENG Wen-jia, XIE Yuan-sheng , CHEN Xiang-mei

Background  Cisplatin (DDP) is one of most effective and most commonly used therapeutic agent in treating tumors, it can accumulate in the kidney and lead to acute renal failure. MicroRNA-181a can induce cell apoptosis by suppressing the expression of Bcl-2 family. In the present study, we investigated the role of microRNA-181a in the apoptosis of tubular epithelial cell induced by DDP.
Methods  HK-2 cells were cultured, transfected with microRNA-181a inhibitor for 48 hours, and stimulated with 50 µmol/L cisplatin for 24 hours. MicroRNA-181a expression was analyzed by real time PCR, and cell apoptosis was detected by flow cytometry. Moreover, Bcl-2 and Bcl-2-associated X protein (Bax) expression were measured by Western blotting.
Results  MicroRNA-181a expression significantly down-regulated in cells transfected with microRNA-181a inhibitor, compared with that in untransfectd cells (21.19±2.01 vs. 38.87±1.97, P <0.05). Cell apoptosis induced by DDP significantly decreased in cells transfected with MicroRNA-181a inhibitor. Compared with DDP treated cells alone, Bcl-2 expression strikingly was up-regulated and Bax expression was down-regulated in cells transfected with microRNA-181a inhibitor.
Conclusion  One pathway of DDP induces apoptosis of tubular epithelial cell by suppressing Bcl-2 expression is achieved by regulating the target gene of MicroRNA-181a.