Figure 4.

Effects of TBBX on the expression of CDK inhibitors, p21^Waf1/Cip1 and p27^Kip1, in lung carcinoma H1299 cells. H1299 lung cancer cells were initially synchronized by serum-free medium and then serum-supplemented medium containing various doses of TBBX (0, 2.5, 5, 7.5, and 10 μM) for 24 h. After the cells were harvested, (A) Western blot analyses were performed with anti-p21^Waf1/Cip1, p27^Kip1 and anti-β-actin antibodies. (B) H1299 cells were treated with TBBX for 12 h and total mRNAs were extracted afterward. After the extraction of total mRNAs, p21^Waf1/Cip1 and GAPDH RT-PCR were performed as described in Materials and Methods. Data shown are representative of at least three independent experiments. Significant difference was observed from the control group (* p < 0.05).