Figure 1: Detecting Changes in Cell Viability With Sunitinib Treatment Using a Rat CMT Model

(A) Activated caspase 3/7 levels in response to treatment with 0.1% dimethyl sulfoxide (vehicle), 1 μmol/l sunitinib, or 1 μmol/l staurosporine for 8 h (dimethyl sulfoxide and sunitinib) or 6 h (staurosporine). ****p < 0.0001 relative to vehicle (n = 3 experiments); ***p < 0.001 1 μmol/l sunitinib versus staurosporine (n = 3 experiments). (B) Time-dependent changes in caspase 3/7 activation. Fold changes (relative to vehicle) in caspase levels for cardiac microtissues (CMT) treated with 1 μmol/l or 10 μmol/l sunitinib for 4 h, 8 h, or 12 h. **p < 0.01 1 μmol/l sunitinib 4 h versus 8 h; *p < 0.05 1 μmol/l sunitinib 4-h versus 12-h time points (n = 2 experiments for all time points); ‡‡p < 0.01 10 μmol/l sunitinib 4 h versus 8 h; ‡p < 0.05 10 μmol/l sunitinib 4-h versus 12-h time points (n = 2 experiments for all time points). (C) Dose-dependent changes in caspase activation in CMT treated with 50 nmol/l, 200 nmol/l, 1 μmol/l, 10 μmol/l sunitinib for 8 h. *p < 0.05 50 nmol/l versus 200 nmol/l sunitinib (n = 2 experiments); *p < 0.05 200 nmol/l versus 1 μmol/l sunitinib (n = 2 experiments for 200 nmol/l; n = 4 experiments for 1 μmol/l); **p < 0.01 1 μmol/l versus10 μmol/l sunitinib (n = 4 experiments for 1 μmol/l; n = 2 experiments for 10 μmol/l). (D) Detecting necrotic/late apoptotic cells. Percentages of cells stained with trypan blue were manually measured and normalized to vehicle levels to express as a fold change. **p < 0.01 10 μmol/l sunitinib versus 1 μmol/l staurosporine (n = 2 experiments); ***p < 0.001 vehicle versus 10 μmol/l sunitinib (n = 2 experiments for sunitinib; n = 3 experiments for vehicle). RLU = relative light units.