Figure 5.

MGMT overexpression attenuated the chemosensitizing effect of U0126 in hepatocellular carcinoma cells. (A) After transfection with MGMT plasmid for 24 h, the expression of MGMT-GFP protein in HepG2 cells was observed by fluorescent microscope (representative fields at ×100 magnification). (B) After transfection with MGMT overexpression plasmids or NC, HepG2 cells were treated with 1 mM TMZ and 4 µM U0126 for 36 h. Western blot analysis of MGMT protein levels (*, P<0.05, **, P<0.01 vs. the indicated treatment). (C) After transfection with MGMT overexpression plasmids or NC, HepG2 cells were treated with TMZ and 8 µM of U0126 for 24 h. The cell inhibition rate was determined by MTT assay. IC50 value was calculated by SPSS (*, P<0.05, **, P<0.01 vs. the indicated treatment). TMZ, temozolomide; MGMT, methylguanine-DNA methyltransferase.