Figure 4.

Effects of TG2 knock-down on A23187-induced cell death. (A) TG activity of TG2 knock-down (HeLa^shTG2) and control (HeLa^shGFP) HeLa cells. TG activity is expressed as relative value using HeLa^shGFP cells as a control. The level of TG2 expression is estimated by Western blot analysis. (B) A23187-induced cell death in HeLa^shGFP and HeLa^shTG2 cells. Cell death was quantitated by trypan blue staining after 48 h of treatment with 5 µM A23187. (C) Western blot analysis of caspase-3 and cytochrome c after 48 h of treatment with 5 µM A23187 (C, cytosolic fraction; M, mitochondrial fraction). α-tubulin and ATP synthase F1α were used as cytosolic and mitochondrial markers, respectively. Asterisks indicate statistically significant differences (^*, P < 0.05; ^**, P < 0.01) compared with HeLa^shGFP cells.