Effect of downregulation of microRNA-373 expression on cell cycle and apoptosis of a cutaneous squamous cell carcinoma cell line A431 / 中华皮肤科杂志

ABSTRACT

Objective To evaluate the effect of downregulation of microRNA (miR)-373 expression on cell cycle and apoptosis of a cutaneous squamous cell carcinoma (CSCC) cell line A431.Methods A431 cells at exponential growth phase were classified into 3 groupsmiR-373 inhibitor group and negative control group transfected with miR-373 inhibitor and negative control miRNA respectively,and untreated group receiving no treatment.At 48 hours after the transfection,real-time PCR was performed to determine the expression of miR-373 in the above 3 groups,cell counting kit-8 (CCK-8) assay to evaluate the effect of downregulated expression of miR-373 on the proliferation of A431 cells,flow cytometry to investigate the distribution of cell cycle and changes in apoptosis of A431 cells in different treatment groups,and colorimetric analysis to detect the changes in caspase-3 activity in different treatment groups.Statistical analysis was carried out with SPSS 17.0 software by using two-sample t test for the comparison between two groups,one-way analysis of variance (ANOVA) for the comparison among 3 groups,and least significant difference (LSD)-t test for multiple comparisons.Results The expression of miR-373 was significantly lower in the miR-373 inhibitor group (0.120 ± 0.036) than in the untreated group (1.002 ± 0.022) and negative control group (1.037 ± 0.028,LSD-t =36.21,34.83,respectively,both P ＜ 0.001).At 48,72 and 96 hours,the miR-373 inhibitor group showed significantly decreased proliferative activity of A375 cells compared with the untreated group and negative control group (F =10.805,13.720 and 30.907 respectively,P =0.038,0.010 and 0.001 respectively).The proportion of A375 cells in G0/G1 phase was significantly higher in the miR-373 inhibitor group (64.69％ ± 1.18％) than in the untreated group (52.74％ ± 0.66％,t =15.51,P ＜ 0.001) and negative control group (53.80％ ± 0.80％,t =13.24,P ＜ 0.001).The proportion of total apoptotic cells and activity of caspase-3 in the miR-373 inhibitor group were 22.69％ ± 1.24％ and 1.238 ± 0.057 respectively,which were significantly higher than those in the untreated group (9.62％ ± 1.14％,0.413 ± 0.028 respectively,both P ＜ 0.001)and negative control group (9.66％ ± 0.97％,0.437 ± 0.036 respectively,both P ＜ 0.001).Conclusion MiR-373 may play an important role in the regulation of cell cycle and induction of apoptosis of the CSCC cell line A431.