Fig. 4

(a) The expression of Col2A1, p16INK4a and E2F2 determined by RT-PCR. (b-c) The expressions of Col2A1, p16INK4a and E2F2 determined by Western blot assay. Empty group, cells were transfected with over-expression empty vector and siRNA negative control; p16INK4a group, cells were transfected with p16INK4a over-expression vector and siRNA negative control; E2F2 group, cells were transfected with E2F2 over-expression vector and siRNA negative control; p16INK4a + E2F2 group, cells were over-expressed with E2F2 and p16INK4a and siRNA negative control; si-E2F2 group, cells were transfected with si-E2F2 and over-expression empty vector; p16INK4a + si-E2F2 group, cells were transfected with si-E2F2 and p16INK4a. *P < 0.05 vs. empty, #P < 0.05 vs. p16INK4a. Data were shown as mean ± SD, n = 4