Objective:To investigate the expression changes of miR-27a in human lung adenocarcinoma cell line SPC-A1 after cisplatin chemotherapy in virto,and to discuss its relationship with cell apoptosis and clinical significance. Methods:SPC-A1 cells were cultured in vitro and treated with DDP at 2.5 μg/ml for 12,24,48 and 72 h. Cell morphology was observed by phase contrast microscope,as well as cell apoptosis was detected by flow cytometry;expression changes of miR-27a both in cultural supernatants and SPC-A1 cells were analyzed by real-time PCR. Results:SPC-A1 cells showed morphological changes of apoptosis in the DDP (2.5 μg/ml) group. The apoptotic rates of SPC-A1 cells at 48 and 72 h in the DDP (2.5 μg/ml) group[(59.3 ± 2.5)% and (76.4 ± 3.1)%,respectively] were higher than that in the control group (P < 0.05). PCR analysis demonstrated that the levels of miR-27a were significantly increased in the DDP (2.5 μg/ml) group both in cultural supernatants and SPC-A1 cells compared to the level of the control group(P < 0.05). Conclusion:The level of miR-27a raised in human lung adenocarcinoma cell line SPC-A1 after cisplatin chemotherapy in virto. Quantitative analysis of miR-27a may have important value for chemotherapy monitoring of lung adenocarcinoma.