Fig. 3: Bmi-1 is required for LSD1-driven HNSCC oncogenesis.

A The correlations between the expression levels of LSD1 and Bmi-1 in HNSCC. B Western blot analysis of LSD1, Bmi-1, and Sox2 expression in the control and LSD1-silenced groups of HN12 and HN30 cells. C Western blot analysis of LSD1, Bmi-1, and Sox2 expression in the control and LSD1-overexpressing groups of HN13 and CAL27 cells. D Western blot analysis of LSD1 and Bmi-1 expression in the control, LSD1-silenced, and Bmi-1-rescued groups of HN30 cells. E, F Representative images and quantitative analysis of a sphere-formation assay performed with the control, LSD1-silenced, and Bmi-1 rescued groups of HN30 cells. *P < 0.01, error bar values represent the SD. G The expression of endogenous LSD1 and Bmi-1 in various tumor cell lines was analyzed by western blotting. H Values are normalized to the value of GAPDH. I The expression of LSD1 and Bmi-1 in 14 fresh-frozen human HNSCC tumors was examined by western blotting. J, K Eighty-five HNSCC specimens were immunostained using antibodies against LSD1 and Bmi-1 and control serum (data not shown). Representative images of immunohistochemical (IHC) staining of the same tumor samples are shown in J, and the statistical analysis is shown in K.