Fig. 6.

Effect of TCTP knockdown in the γ-ray–induced G₁ and G₂ checkpoints in AG1522 fibroblasts. (A) Confluent cultures of Scr or TCTP siRNA-treated cells were exposed to no or 400-cGy radiation, were subcultured to lower density within 10 min after irradiation, and were grown in the presence of [³H]-thymidine. Cumulative labeling indices were measured as a function of time after subculture. (B) Western blot analyses reveal that knockdown of TCTP attenuates p21^Waf1 induction in irradiated confluent cells that subsequently were subcultured to lower density or were maintained in the confluent, density-inhibited state. (C) The γ-ray–induced G₂ delay in Scr or siTCTP asynchronous cells.