Journal
BIOMEDICINE & PHARMACOTHERAPY
Volume 67, Issue 1, Pages 78-87Publisher
ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
DOI: 10.1016/j.biopha.2012.10.015
Keywords
5-Aza-2 '-deoxycytidine; ATM-dependence; P53; P21; P16(INK4A)
Funding
- Wuhan University Foundation
Ask authors/readers for more resources
The DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-Aza-CdR) has increasingly attracted worldwide attention for its antineoplastic potential. The cytotoxitic mechanisms, however, especially, the relative contribution of silenced genes reactivation by demethylation and enzyme-DNA adduct formation to the efficacy of 5-Aza-CdR is still a crucial unresolved question. In this investigation, we demonstrated that 5-Aza-CdR treatment resulted in growth suppression in a concentration and time-dependent manner and G2 phrase arrest - hallmarks of a DNA damage response in gastric cancer AGS cells. Formation of DNA double-strand breaks, as monitored by comet assay was examined in an ATM (ataxia-telangiectasia mutated)-dependent manner based on the fact that PI3K inhibitor Wortmannin abolished the action of cytotoxicity of 5-Aza-CdR. Upon treatment with 5-Aza-CdR, ATM activation was clearly associated with P53 phosphorylation at Ser(15), which was directly responsible for 5-Aza-CdR modified P21(Waf1/Cip1) expression. Further exploration revealed that demethylation of P16(INK4A) correlated with the strikingly down-regulated expressions of DNA methyltransferase 3A as well as 3B was, at least in part, attributed to the cytotoxicity of 5-Aza-CdR in AGS cells. Conclusively, these results greatly enhance our understanding of the mechanisms of cytotoxicity of 5-Aza-CdR and strongly provide the preclinical rationale for an assessment of 5-Aza-CdR to ameliorate patient outcome with gastric cancer. (C) 2012 Elsevier Masson SAS. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available