Figure 4 BTV induces apoptosis in renal cancer cells. (A) Apoptosis was analyzed by flow cytometry. The HPTEC, CAKI-1, and OR-SC-2 cells were pre-treated with a pan-caspase inhibitor Z-VAD-FMK (10 μM) for 24 h before BTV infection (MOI=10, 24 h). The untreated cells served as control. (B). Quantification of apoptosis. The cell population in the right 2 quadrants (Annexin V-positive) correspond to the apoptotic cells. Columns, mean; bars, SEM. (C) The ladder-like pattern of DNA fragmentation was observed in BTV-infected CAKI-1 cells at 48, 72, and 96 h after BTV infection (MOI=10).