Figure 3

Effect of RPL15 expression on cell proliferation. A, SGC7901 cells transfected with pSilencer-RPL15A, pSilencer-RPL15B or empty vector were selected with G418 (400 ng/ml) for 2 months. The mixed clones were used for analyzing the expression of RPL15, Cyclin B1 and Cyclin D1 by western blot. Anti-β-actin antibody was set as an internal control. B, Cell proliferation was determined by MTT assay. Cells stably transfected with pSilencer-RPL15A or empty vector were plated in quadruplicate in 96-well plates. At the indicated time intervals, the monolayer cells were processed for MTT assay and the absorbance was read at 490 nm in an enzyme-linked immunosorbent assay reader. **p < 0.05 and *p < 0.01 vs SGC7901 and SGC7901-pcDNA. C, cell cycle distribution of log-phase transfected cells was evaluated by FACScan. Cell proliferation index was calculated as described in Materials and Methods (low right panel). Each number represents mean ± SD of four different experiments. *p < 0.01 vs SGC7901 and SGC7901-pcDNA.