DSG3 knockdown inhibits colony formation in three HNC cell lines. (a) Effects of DSG3-RNAi on colony formation, with experiments performed in duplicate. After transfection with DSG3-RNAi or vector plasmids, various numbers of cells (300–1000 for OECM1 and BM1, 1000–3000 for KB) were seeded in a six-well plate and incubated for 7 days to allow colony formation. Cell colonies were visualized by 5% crystal violet staining. (b) Quantitative determination of colony numbers in DSG3-RNAi or vector treatment cells. Cell number over 50 in a cluster was defined as a signal colony. Cell samples with initial seeding of 300 in OECM1 or BM1, and 1000 in KB were determined in duplicate as indicated at the bottom of the figure.