PEITC induced mitochondria-mediated apoptosis in human OS cells. (a) Mitochondrial and nuclear morphological changes in MNNG/HOS, U-2 OS, MG-63, and 143B cells treated with the indicated concentrations of PEITC for 24 h by MitoTracker Green/Hoechst 33342 staining. (b) Mitochondrial transmembrane potential in MNNG/HOS, U-2 OS, MG-63, and 143B cells treated with the indicated concentrations of PEITC for 24 h by using JC-1. (c) Protein expression levels of Caspase3, C-caspase3, Bcl2, Bax, and C-PARP in MNNG/HOS, U-2 OS, MG-63, and 143B cells treated with the indicated concentrations of PEITC for 20 h or 30 μM PEITC for 4 h, 12 h, 24 h, and 48 h.