title: DNA methylation is stable during replication and cell cycle arrest.
abstract: DNA methylation is an epigenetic modification with important functions in development. Large-scale loss of DNA methylation is a hallmark of cancer. Recent work has identified large genomic blocks of hypomethylation associated with cancer, EBV transformation and replicative senescence, all of which change the proportion of actively proliferating cells within the population measured. We asked if replication or cell-cycle arrest affects the global levels of methylation or leads to hypomethylated blocks as observed in other settings. We used fluorescence activated cell sorting to isolate primary dermal fibroblasts in G0, G1 and G2 based on DNA content and Ki67 staining. We additionally examined G0 cells arrested by contact inhibition for one week to determine the effects of extended arrest. We analyzed genome wide DNA methylation from sorted cells using whole genome bisulfite sequencing. This analysis demonstrated no global changes or large-scale hypomethylated blocks in any of the examined cell cycle phases, indicating that global levels of methylation are stable with replication and arrest.
authors.affiliation: Center for Epigenetics, Johns Hopkins University School of Medicine.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Vandiver
authors.affiliation: Center for Epigenetics, Johns Hopkins University School of Medicine.
authors.forename: Adrian
authors.initials: A
authors.lastname: Idrizi
authors.affiliation: Center for Epigenetics, Johns Hopkins University School of Medicine.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Rizzardi
authors.affiliation: Center for Epigenetics, Johns Hopkins University School of Medicine.|Department of Medicine, Johns Hopkins University School of Medicine.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Feinberg
authors.affiliation: Center for Epigenetics, Johns Hopkins University School of Medicine.|McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine.|Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health.
authors.forename: Kasper D
authors.initials: KD
authors.lastname: Hansen
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints; D016922:Cellular Senescence / Q000235:genetics; D018899:CpG Islands; D019175:DNA Methylation; D004261:DNA Replication; D044127:Epigenesis, Genetic; D057890:Epigenomics; D005347:Fibroblasts; D016678:Genome; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism
chemical_list: D019394:Ki-67 Antigen