title: Epigallocatechin gallate induces telomere fragmentation in HeLa and 293 but not in MRC-5 cells.
abstract: Telomeres are the tandem repetitive sequence at the end of chromosomes and its integrity is crucial for cell vitality. We studied the effect of (-)-epigallocatechin-3-gallate (EGCG), one of the major tea polyphenols, on telomeres in HeLa, 293 cells and MRC-5 fibroblasts. At concentrations of above 50 microM, EGCG was found to causes telomere fragmentation in HeLa cells as a result of single-strand breaks in a dose-dependent manner. Treatment of EGCG also caused telomere fragmentation in 293 cells but had little or only marginal effect on MRC-5 fibroblasts. The telomere fragments detected by electrophoresis showed a unique size distribution that seems to suggest that the strand breaks were not produced randomly, but with preference at some specific sites. We speculate that the differential effect of EGCG in inducing telomere fragmentation in HeLa and 293 verse MRC-5 cells might be relevant to the apoptosis-inducing effect of EGCG on cancerous cells but not on normal cells.
authors.affiliation: The State Key Lab of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China.
authors.forename: Wei-guo
authors.initials: WG
authors.lastname: Li
authors.forename: Qing-huan
authors.initials: QH
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Tan
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D017382:Reactive Oxygen Species; D016615:Telomere
chemical_list: D016588:Anticarcinogenic Agents; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D002392:Catechin; C045651:epigallocatechin gallate