Figure 4.

Autophagy is involved in apoptosis and antiproliferative effects of metformin. A375 cells were transfected with either control or LC3b-specific siRNAs. Cells were next preincubated with or without Q-VD-OPH (20 μM) and exposed to metformin (5 or 10 mM) for 96 h. (a) LC3-b expression and PARP cleavage were analyzed by western blotting. HSP60 was used as a loading control. (b) FACS analysis using propidium iodide was used to determine cell death. The results are expressed as percentage of cell death compared with control. Data are expressed as percentage of apoptotic cells and represent the mean±S.D. of six independent experiments. Significantly different from the corresponding control ^**P<0.01; ^***P<0.001