Figure 7. The ERBB3 knockdown-induced apoptosis and cell cycle arrest in human colon cancer cells.

Cells were treated with transfection reagent only (–) or siERBB3 (+) for 72 h. (A) Viable cells were counted after siRNA treatment and relative cell proliferation was compared to that of siCTRL in each cell line. (B) Cell cycle distribution was analyzed with FACS after siRNA treatment. (C) Western blotting was performed using an equal amount of protein extract (top), and the apoptotic index was determined by the ratio of cleaved to uncleaved Parp1 (bottom). (D) Protein extracts in the cytosolic or mitochondrial fraction were analyzed by western blotting in SW48 cells. The relative band intensities of the mitochondrial Bak to Vdac1 and of the mitochondrial Bax to cytosolic Bax were normalized to those of siCTRL. siERBB3 group was statistically compared to siCTRL group at each point.