Figure 4
Statins increase sorafenib-induced apoptosis under hypoxia by suppressing YAP target genes.
(A) The percentage of apoptotic cells was measured by PI staining. Bel-7402 cells were treated with sorafenib (10 μM) or atorvastatin (10 μM) alone or both sorafenib (10 μM) and atorvastatin (10 μM) for 48 h under hypoxia. Data are representative of 3 independent experiments and are expressed as the mean ± SD. (B) PARP, cleaved-PARP in Bel-7402, HepG2 and SMMC-7721 cells was detected by western blot analysis in the same conditions as (A). Data are representative of 3 independent experiments. (C) Apoptotic cells following sorafenib treatment (48 h) in YAP-depleted HepG2 cells were measured by PI staining. (D) PARP cleavage and YAP protein levels in sorafenib-treated and/or YAP-deleted HepG2 cells were measured. (E) qRT-PCR analysis of the YAP target genes Bcl-xL, CTGF and Cyr61 in HepG2 cells. Cells were exposed to normoxia or hypoxia for 24 h. Data are representative of 3 independent experiments and are expressed as the mean ± SD. (F) The protein level of phosphorylated YAP-S127 and the YAP target genes Bcl-xL, CTGF and Cyr61 were detected by western blotting in HepG2 cells. Cells were cultured under normoxia or hypoxia for 24 h. (G) qRT-PCR analysis of YAP target genes in HepG2 cells after silencing YAP under hypoxia. (H) The IC50 values of sorafenib combined with vehicle or ABT-737 (5 μM) in HepG2 cells under normoxia or hypoxia. HepG2 cells were incubated with ABT-737 (5 μM) under normoxia or hypoxia for 8 h, then treated with sorafenib at serial concentrations (48 h). ***P < 0.001.
