title: Comparison of the age- and tumor-associated changes in the c-myc gene methylation in mouse liver.
abstract: Study of DNA methylation of the c-myc gene in liver tumors of BCF1 mice treated with various agents revealed frequent alteration from that in normal liver. The alteration, however, was complex and showed either an increase or a decrease of methylation to various degrees. On the other hand, the tumors obtained from middle-aged C3H/He mice, which develop liver tumors spontaneously at a high incidence rate starting in middle age, showed predominantly increases of methylation in the c-myc gene, while the large tumors found in older mice revealed decreases. The normal part of the liver showed a slight gradual age-dependent increase. These suggest that hypermethylation of the c-myc gene is common to aging and early tumor development in liver. Thus the alteration of DNA methylation seems to be a good clue to investigate why the tumor incidence rate increases rapidly as individuals grow older.
authors.affiliation: Department of Radiation Research, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Miyamura
authors.forename: H
authors.initials: H
authors.lastname: Ohtsu
authors.forename: O
authors.initials: O
authors.lastname: Niwa
authors.forename: A
authors.initials: A
authors.lastname: Kurishita
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Sado
authors.forename: T
authors.initials: T
authors.lastname: Ono
mesh_terms: D000375:Aging / Q000235:genetics*; D000818:Animals; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics; D016259:Genes, myc; D008099:Liver / Q000737:chemistry; D008114:Liver Neoplasms, Experimental / Q000737:chemistry / Q000235:genetics*; D008745:Methylation; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL
chemical_list: D004273:DNA, Neoplasm; D004247:DNA