title: Genes methylated by DNA methyltransferase 3b are similar in mouse intestine and human colon cancer.
abstract: Human cancer cells frequently have regions of their DNA hypermethylated, which results in transcriptional silencing of affected genes and promotion of tumor formation. However, it is still unknown whether cancer-associated aberrant DNA methylation is targeted to specific genomic regions, whether this methylation also occurs in noncancerous cells, and whether these epigenetic events are maintained in the absence of the initiating cause. Here we have addressed some of these issues by demonstrating that transgenic expression of DNA methyltransferase 3b (Dnmt3b) in the mouse colon initiates de novo DNA methylation of genes that are similar to genes that become methylated in human colon cancer. This is consistent with the notion that aberrant methylation in cancer may be attributable to targeting of specific sequences by Dnmt3b rather than to random methylation followed by clonal selection. We also showed that Dnmt3b-induced aberrant DNA methylation was maintained in regenerating tissue, even in the absence of continuous Dnmt3b expression. This supports the concept that transient stressors can cause permanent epigenetic changes in somatic stem cells and that these accumulate over the lifetime of an organism in analogy to DNA mutations.
authors.affiliation: Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, USA.
authors.forename: Eveline J
authors.initials: EJ
authors.lastname: Steine
authors.forename: Mathias
authors.initials: M
authors.lastname: Ehrich
authors.forename: George W
authors.initials: GW
authors.lastname: Bell
authors.forename: Arjun
authors.initials: A
authors.lastname: Raj
authors.forename: Seshamma
authors.initials: S
authors.lastname: Reddy
authors.forename: Alexander
authors.initials: A
authors.lastname: van Oudenaarden
authors.forename: Rudolf
authors.initials: R
authors.lastname: Jaenisch
authors.forename: Heinz G
authors.initials: HG
authors.lastname: Linhart
mesh_terms: D000818:Animals; D003106:Colon / Q000378:metabolism; D003110:Colonic Neoplasms / Q000378:metabolism*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007413:Intestinal Mucosa / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D000097584:DNA Methyltransferase 3B
chemical_list: D004248:DNA (Cytosine-5-)-Methyltransferases; D043562:Receptors, G-Protein-Coupled; D000097584:DNA Methyltransferase 3B; C116884:LGR5 protein, human; C493597:Lgr5 protein, mouse