Figure 3

Apoptosis after inhibitor and doxorubicin treatment. (A) Microscopic pictures after inhibitor and doxorubicin treatment are shown. Chondrosarcoma cells treated with 10 μM of Bcl-2 inhibitor, 10 μM of C-4 (P-glycoprotein inhibitor) or 10 μM of embelin (XIAP inhibitor) showed more apoptotic cells than control groups after doxorubicin treatment. (Bcl-2 inh: Bcl-2 inhibitor, original magnification ×100). (B) The effect of inhibitors on chemosensitivity in chondrosarcoma cells is shown. Inhibitor treatment enhanced chemosensitivity. Inhibitor treated chondrosarcoma cells demonstrated increased apoptosis after doxorubicin treatment in comparison to the control groups (up to 4.5 fold increase). Combination treatment of inhibitors (Bcl-2 inh + C-4 and embelin + C-4) showed significant increase in apoptosis. (Bcl-2 inh: Bcl-2 inhibitor, *: p < 0.05 and **: p < 0.01) (C) Immunoblotting demonstrates cytochrome c release from mitochondria to cytosol after treatment with doxorubicin and inhibitors. Cytochrome oxidase IV (COX IV) serves as a marker for mitochondria.