Figure 2

Down-regulation of CDK4 inhibited cell growth in vitro. A. Markedly reduced mRNA expression of CDK4 after shRNA-CDK4: 8 single clone cells(C1-C4,D1-D4) compared with PLV-Ctr by real-time PCR. B. Significantly decreased protein expression of CDK4 was found in shRNA-CDK4 cells(C1,C2,D2) compared with PLV-Ctr and A549 cells by western blot. ACTB was used as internal control. C. The cell growth of parental A549 cells and their stable derivatives, PLV-Ctr and shRNA-CDK4, was examined by MTT assay over a seven-day period. *P < 0.05, as compared to A549 and PLV-Ctr cells. D. The anchorage-dependent growth of parental A549 cells and their stable derivatives, PLV-Ctr and shRNA-CDK4, was examined by plate colony formation assay. *P < 0.05, as compared to A549 and PLV-Ctr cells.