Research Paper Volume 8, Issue 7 pp 1442—1456

Figure 6. The down-regulated miR-638 in U2OS cells enhances DNA damage repair ability and reduces the cellular sensitivity to cisplatin. (A) U2OS cells that transfected with control virus (SD-control) or retroviruses expressing miR-638 (SD-miR-638) were treated with cisplatin (5 μM) or bleomycin (0.2 μg/ml) for 18 h, and DNA damage was measured by comet assay after 18 h. Representative blots are shown. (B) The comet tail moment of the cells in (A) were analyzed. The comet tail moment was counted, and 50 cells were analyzed in each group. (C) The expression levels of miR-638 in the virus transfected cells were measured by qRT-PCR. (D) The protein levels of SMC1A in the virus transfected cells were measured by western blotting. (E) SD-control or SD-miR-638 U2OS cells were re-plated on 96-well plates and treated with five final concentrations of cisplatin (0, 20, 100, 200, or 400 μM), which were dissolved in DMEM medium, for 48 h. Relative cell viability was measured by the MTT assay. Data are presented as a column chart. NS: not significant, **: p<0.01, ***: p<0.001, compared to control with the Student's t test. Error bars, S.D.