Baran Y, Zencir S, Cakir Z, Ozturk E, Topcu Z. Imatinib-induced apoptosis: a possible link to topoisomerase enzyme inhibition.
J Clin Pharm Ther 2010;
36:673-9. [PMID:
21105880 DOI:
10.1111/j.1365-2710.2010.01224.x]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE
Imatinib is a specific BCR/ABL inhibitor, commonly used for the treatment of chronic myeloid leukaemia (CML), a hematological malignancy resulting from a chromosomal translocation that generates the BCR/ABL fusion protein. Recent studies showed that the imatinib has cytotoxic and apoptotic effects on many BCR/ABL-negative cancers. Numerous compounds with cytotoxic potential exert their functions by interfering with the DNA topoisomerase. In this study, we examined the effects of imatinib on tumour cell-killing in relation to DNA topoisomerase enzyme inhibition.
METHODS
We determined the cytotoxicity by cell proliferation assay (XTT; tetrazolium hydroxide), using the human K562 CML cells, and loss of mitochondrial membrane potential by monitoring the changes in caspase-3 enzyme activity. Type I and II topoisomerase activities were measured by supercoiled plasmid relaxation and minicircle DNA decatenation assays respectively.
RESULTS AND DISCUSSION
Imatinib-induced apoptosis and inhibited cell proliferation in a dose-dependent manner. We also found that the imatinib was effective in both type I and type II topoisomerase reactions to a varying degree between 94% and 7% for the concentration range of 1 mm-0.02 mm in a dose-dependent manner.
WHAT IS NEW AND CONCLUSION
Our results suggest that the inhibition of topoisomerases may be a significant factor in imatinib-induced apoptosis in CML.
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