CMA down-regulates p53 expression through degradation of HMGB1 protein to inhibit irradiation-triggered apoptosis in hepatocellular carcinoma

Figure 3 p53 expression was regulated by HMGB1 in hepatocellular carcinoma cells on irradiation. A: HepG2 and SMMC7721 cells were irradiated with doses of 6 Gy. At different post-irradiation times, the levels of HMGB1 were determined by western blot; B: In the presence of EP (10 μg/mL). HMGB1, Caspase3 (cleaved) were detected by western blot in representative cells irradiated at 6 Gy after 48 h; C: HepG2 and SMMC7721 were exposed to EP(10 μg/mL) and the ability of proliferation was detected by clone formation assay; D: The ability of proliferation in HepG2 and SMMC7721 cells affected by HMGB1 siRNA was detected by clone formation assay after 6 Gy irradiation; E: In the presence of EP (10 μg/mL), the levels of p53 and p21 were detected in HepG2 and SMMC7721 cells irradiated at 6 Gy after 48 h; F: After si-HMGB1 HepG2 and si-SMMC7721 cells were irradiated at doses of 6 Gy, the levels of p53 and p21 were determined after 48 h. ^aP < 0.05, vs control group or si-NC group; ^cP < 0.05, vs control group or control + EP group; ^eP < 0.05, vs IR group. Each experiment was repeated three times and similar results were obtained.