These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: DNA-PK inhibitor wortmannin enhances DNA damage induced by bleomycin in V79 Chinese hamster cells.
    Author: Oliveira NG, Castro M, Rodrigues AS, Gil OM, Toscano-Rico JM, Rueff J.
    Journal: Teratog Carcinog Mutagen; 2002; 22(5):343-51. PubMed ID: 12210497.
    Abstract:
    The fungal metabolite wortmannin (WM) is a potent and irreversible inhibitor of the enzyme DNA-dependent protein kinase (DNA-PK), a nuclear serine-threonine kinase, member of the phosphaditylinositol-3 kinase related kinase family. WM has been used in the last few years as a promising radiosensitizer mainly throughout cell survival experiments. However, few studies have addressed the role of DNA-PK inhibition in the repair of DNA lesions generated by antitumor agents. Bleomycin (BLM) is an antitumor agent used in the treatment of various neoplasia with a unique genotoxicity profile that mimics the ionizing radiation effects. In this study, we evaluated the effect of different concentrations of WM on the DNA damage induced by BLM. The cytokinesis-block micronucleus assay (CBMN) in V79 Chinese hamster cells was used as the end-point. WM significantly increased the frequency of micronucleated cells (%MNBN) by about 2.2-fold, the number of micronuclei per binucleated cell (MN/BN) by about 2.4-fold, and also changed the pattern of the distribution of micronuclei induced by BLM. The frequency of micronucleated cells with 2 MN per cell and with > or = 3 MN per cell increased, whereas the frequency of micronucleated cells with 1 MN per cell decreased. WM was not genotoxic but decreased cell proliferation as assessed by the frequency of binucleated cells. Our results show that WM clearly enhances the efficacy of BLM in terms of DNA damage inflicted and therefore reinforces its use as a chemosensitizer.
    [Abstract] [Full Text] [Related] [New Search]