title: Variations in DNA methylation patterns during the cell cycle of HeLa cells.
abstract: DNA methylation has been viewed as a stable component of the epigenome, established during development and fixed thereafter. Here we have found that the DNA methylation pattern varies during a single cell cycle, with the global levels of DNA methylation decreased in G(1) and increase during S phase. There was little change in the DNA methylation levels in repetitive sequences throughout the cell cycle. However using a human CpG island microarray it was revealed that 174 CG-containing sequences were differentially methylated between G(1) and S. Seventy-five percent of all the variations in DNA methylation detected in unique sequences represented hypomethylation at G(0), with changes occurring in both CpG islands and non-CpG islands. This is the first demonstration of a dynamic DNA methylation pattern within a single cell cycle of a mature somatic cell. These data are important for our understanding of the stability of DNA methylation patterns in somatic cells.
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
authors.forename: Shelley E
authors.initials: SE
authors.lastname: Brown
authors.forename: Mario F
authors.initials: MF
authors.lastname: Fraga
authors.forename: Ian C G
authors.initials: IC
authors.lastname: Weaver
authors.forename: Maria
authors.initials: M
authors.lastname: Berdasco
authors.forename: Moshe
authors.initials: M
authors.lastname: Szyf
mesh_terms: D002453:Cell Cycle / Q000502:physiology*; D002478:Cells, Cultured; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D016193:G1 Phase; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D010902:Pituitary Gland / Q000166:cytology / Q000502:physiology; D016196:S Phase
chemical_list: D004273:DNA, Neoplasm