Figure 4

Mirk modulates cell survival associated with activation of MAPK/ERK. H292 cells exposed to 20 nM siRNAs with/without a range of concentrations of U0126 for 72 h were collected, and followed by (A) the protein expressions of Mirk (69 and 71 Kda), PARP (full length 116 kDa and cleaved 89 kDa), ERK1/2 and P-ERK1/2 (42/44 kDa), as well as alterations of cyclin D1 (36 Kda) and p27kip1 (27 kDa) were measured by western blot analyses. Equal loading and transfer were shown by repeat probing with β-actin (42 kDa); (B) cell apoptosis (fold of control) evidenced by positive cells with active caspase-3 was assessed by flow cytometry analysis. MAPK, mitogenic-activated protein kinase; ERK, extracellular signal-regulated kinase; PARP, poly(ADP-ribose) polymerase. Ctrl si, control siRNA; Mirk si, Mirk siRNA.