Effects of U0126 on HepG2 cell viability and proliferation. HepG2 cells were grown and treated with 0.1% DMSO or escalating doses of U0126 in PSF medium. Cell proliferation and cell viability were determined by BrdU incorporation and MTT assay, respectively as described under Experimental Procedures. HepG2 cell proliferation at 48-h (A) and cell viability at 24 and 48 h (B) are shown. Experiments were performed in quadruplicate, with the results reflecting the mean of the quadruplicate of each group. Bars with different letters are significantly different from one another at (p < 0.01) as determined by ANOVA test. The results represent the mean of 3 experiments ± SE is shown.