Impact of miRNA-192 for cisplatin resistance of non-small cell lung cancer A549/DDP cells

Objective To explore the effect of microRNA-192( miR-192) in enhancing cisplatin( DDP) resistance of nonsmall cell lung( NSCLC) A549 /DDP cell line and elucidate its related mechanism. Methods The real-time quantitative PCR( qRTPCR) was used to detect miR-192 expression in A549 cells and A549 /DDP cells. The A549 /DDP cells were transfected with miR-192inhibitor or miR-negative control( NC) and qRT-PCR was used to test the transfection efficiency. Drug sensitivity to DDP 48h after transfection was tested by MTT assay. Colony formation assay was used to detect the proliferation of A549 /DDP cells 48h after transfection. Flow cytometric analysis was used to observe apoptosis of A549 /DDP cells 48h after transfection on treatment with DDP. The protein expressions of Bax and Bcl-2 in A549 /DDP cells after transfection were detected by Western blotting method. Results The miR-192 expression in A549 /DDP cell line was significantly higher than that in A549 cell line( P 0. 05). The miR-192 expression was significantly decreased at 48h after transfection of miR-192 inhibitor than that of miR-NC( P 0. 05). The half inhibition concentration of DDP was significantly lower in A549 /DDP cells transfection of miR-192 inhibitor than miR-NC( P 0. 05). Colony formation assay showed that the proliferation of miR-192 inhibitor transfected A549 /DDP cells was significantly inhibited( P 0. 05). Compared with miR-NC A549 /DDP cells,the apoptosis of cells transfected with miR-192 inhibitor increased after treatment with DDP( P 0. 05).Furthermore,the down-regulated Bcl-2 and up-regulated Bax were observed in A549 /DDP cells transfection of miR-192 inhibitor versus miR-NC( P 0. 05). Conclusion Inhibiting expression of miR-192 could reduce the resistance of A549 /DDP cells to DDP with the possible mechanism of inducing apoptosis,down-regulating the expressions of Bcl-2 protein and up-regulating the expression of Bax protein.