Reversal of drug resistance in A549/DDP cells by silencing MT1H gene with MT1H siRNA / 肿瘤

ABSTRACT

Objective: To explore the feasibility of using siRNA targeting metallothionein 1H (MT1H) gene to reverse the drug resistance of A549/ DDP cells to cisplatin (DDP). Methods: The expressions of MT1H mRNA in A549 and A549/DDP cells were detected by reverse transcriptase polymerase chain reaction (RT-PCR). MT1H siRNA was transfected into A549/DDP cells with high expression of MT1H. The mRNA and protein levels of MT1H were detected by RT-PCR and Dot blotting, respectively. The chemosensitivity of A549/DDP cells to cisplatin was assessed by MMT assay. The apoptotic ratio induced by DDP was determined by TUNEL and flow cytometry analysis (FCM). The apoptosis-related protein levels of Bcl-2 and Bax were determined by immunohistochemistry. Results: MT1H mRNA was highly expressed in A549/DDP cells but not in A549 cells. The mRNA and protein levels of MT1H were significantly down-regulated at 48 h after transfection in MT1H siRNA group compared with the control group. The chemosensitivity of A549/DDP cells to DDP was significantly elevated. The apoptotic ratio induced by DDP was significantly increased. Expression of Bcl-2 was greatly down-regulated but the expression of Bax had little change. Conclusion: Silencing MT1H gene with MT1H siRNA reduces the expression of Bcl-2, enhanced the apoptosis-inducing effect of DDP on A549/DDP cells, and effectively reverses the drug resistance of A549/DDP cells.