Figure 2. STAT3/miR-21 axis was upregulated in the DDP-resistant Tca8113/DDP cells.
(a) MTT assay indicated that Tca8113/DDP and Tca8113 cells showed different sensitivity to DDP treatment. The cells were incubated in different doses of DDP (0.1, 0.2, 0.5, 1, 2, 4, 8, 12 and 16 μg/ml) for 48 h, and survival rate was determined by MTT assay. (b) QPCR showed that miR-21 was 3.7 folds higher in Tca8113/DDP cells than in Tca8113 cells (P < 0.05). (c) Western blot assay indicated that STAT3 protein expression was 3 folds higher in Tca8113/DDP cells than in Tca8113 cells (P < 0.05). Anti-GAPDH antibody was used as a loading control.