Fig. 7

Xanthohumol overcomes radioresistance in OSCC cells. a IB analysis of the expression of survivin in CAL27/CAL27-IR and SCC25/SCC25-IR cells. b The effect of irradiation (IR) on cell viability of CAL27/CAL27-IR cells. CAL27 and CAL27-IR cells were treated with 4 Gy IR, cell viability was examined 72 h later by MTS assay. c The effect of IR on colony formation of CAL27/CAL27-IR cells. CAL27 and CAL27-IR cells were treated with 4 Gy IR, colony number was examined 2 weeks later. d IB analysis of survivin protein level in CAL27-IR cells treated with xanthohumol (5 μM), IR (4 Gy), or a xanthohumol + IR combination. e and f The cell viability (e) and colony formation (f) of CAL27-IR cells treated with xanthohumol, IR, or a xanthohumol + IR combination. g and h Immunofluorescence (g) or IB (h) analysis of γ-H2AX in CAL27-IR cells treated with xanthohumol, IR, or a xanthohumol + IR combination. Scale bar, 5 μm. i IB analysis of apoptosis in CAL27-IR cells treated with xanthohumol, IR, or a xanthohumol + IR combination. j In vivo tumorigenesis of CAL27 cells treated with vehicle control, xanthohumol, IR, or a xanthohumol + IR combination. k In vivo tumorigenesis of CAL27-IR cells treated with vehicle control, xanthohumol, IR, or a xanthohumol + IR combination. ***p < 0.001. ns, not statistically significant