FIGURE 7.

PrxII knockdown retards DNA repair in JNK-dependent manner. A and B, effect of PrxII knockdown on repair of DNA damage induced by etoposide (ETO). HeLa cells were treated with etoposide for 1 h, and further cultured in fresh media for the indicated times after removal of etoposide. The amount of double strand breaks was indirectly assessed by comet assay (A) and γ-H2AX focus assay (B). Data in A are means ± S.D. of the percent of averaged tail length versus zero time of recovery (n = 3; *, p < 0.01). Data in B are means ± S.D. of number of foci per cell averaged from 25 to 35 cells versus zero time of recovery (n = 3; *, p < 0.05; **, p < 0.001). C and D, effect of JNK inhibition on repair of DNA damage induced by etoposide. HeLa cells were pretreated with or without SP600125 (10 μm) for 1 h before etoposide treatment. Comet assay (C) and γ-H2AX focus assay (D) were done zero time and 20 h after removal of etoposide (n = 3; *, p < 0.01). Representative images are shown (DAPI for nuclei).