Effect of TAT-BID on viability of different cancer cell lines treated with TRAIL. A. Levels of endogenous BID in the studied cells. Endogenous BID was identified in cell extracts using anti-BID antibodies. GAPDH was used as a loading control. B, D, F – Time-dependence of the uptake of TAT-BID by the cells expressed as increase of cellular BID level (endogenous level of BID is 100%). Cells were treated with either 30 μg/ml (LNCaP) or 40 μg/ml of TAT-BID (A549 and HeLa) for 120 min. BID was identified in the cell extracts using anti-BID antibodies. GAPDH was used as a loading control. C, E, G - Viability of cells treated with TAT-BID and TRAIL (100 ng/ml) for 24 h, measured by MTT test. The average of cells viability (±SD) was shown. B, C – LNCaP. There is no statistically significant difference between viability of TAIL- and TAT-BID-treated LNCaP cells. D, E – A549. F, G – HeLa.