The effects of HDAC2 knockdown on cell-cycle proteins. The effects of HDAC2 knockdown on cell-cycle proteins. A, HDAC2 gene silencing was conducted by transfecting MKN-1 cells with HDAC2 shRNA expression plasmids for 48 hours, and then microarray analysis was done as described in materials and methods section. Heatmap of the gene expressions changes associated with cell cycle and apoptosis: green, reduced expression; red, induced expression when compared with the control (black). B, the effects of HDAC2 siRNA (si-HDAC2) or scramble sequence (s-Scr) on cell-cycle transition of MKN-1 cells. Data were obtained by flow cytometry and cells were synchronized in their cell-cycle progression by treatment with 50 ng/mL nocodazole. N, nontransfected cell line (mother cells, MKN-1); R, transfection reagents-treated cells. C, Western blot analysis of cell-cycle regulatory proteins in MKN-1 cells treated with HDAC2 siRNA or scrambled RNA. β-actin served as a loading control. The blot is representative for at least 3 separate experiments. D, the effects of HDAC2 and p16INK4a knockdown on cell proliferation of MKN-1 and SNU-484 cells. Immublotting of HDAC2 and p16INK4a (Top). MTT assay (Bottom). *, P < 0.05; **, P < 0.01; N.S., not significant. Jeong Kyu Kim et al. Mol Cancer Res 2013;11:62-73 ©2013 by American Association for Cancer Research