[Effect of wortmannin on rejoining of telomeric DNA strand breaks].

Telomeres, which are the DNA-protein complex at the end of eukaryotic chromosome, play an important role in maintaining chromosomal stability, cell senescence and apoptosis. In this work, the effect of wortmannin (WM), an inhibitor of PI-3 kinases, including DNA-dependent protein kinase (DNA-PK), on the rejoining of strand breaks in telomeric DNA induced by H2O2 in HeLa cells was examined. The results show that WM strongly inhibited the rejoining of telomeric DNA strand breaks, and suggest that DNA-PK might be involved in the repair of telomeric DNA damage.