title: Inhibition of p16 tumor suppressor gene expression via promoter hypermethylation in canine lymphoid tumor cells.
abstract: To investigate the epigenetic regulation of the p16 gene in canine lymphoid tumor cells, its methylation status was examined in four canine lymphoid tumor cell lines. In three canine lymphoid tumor cell lines (CLBL-1, GL-1, and UL-1) with low-level p16 mRNA expression, 20 CpG sites in the promoter region of p16 gene were consistently methylated although all of the CpG sites were not methylated in another cell line (CL-1) and normal lymph node cells. The expression level of p16 mRNA in these three cell lines was restored after cultivation in the presence of a methylation inhibitor, 5-Aza-2'-deoxycitidine, indicating inactivation of p16 gene via hypermethylation. This study revealed the inactivation of p16 gene through hypermethylation of its CpG island in a fraction of canine lymphoid tumor cells.
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Fujiwara-Igarashi
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Goto-Koshino
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mochizuki
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sato
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Fujino
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Ohno
authors.affiliation: Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Electronic address: atsuji@mail.ecc.u-tokyo.ac.jp.
authors.forename: Hajime
authors.initials: H
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D001483:Base Sequence; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000235:genetics; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics*; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D004283:Dog Diseases / Q000235:genetics*; D004285:Dogs; D044127:Epigenesis, Genetic; D015973:Gene Expression Regulation, Leukemic; D016147:Genes, Tumor Suppressor; D008223:Lymphoma / Q000235:genetics* / Q000662:veterinary*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D017931:DNA Primers; D001374:Azacitidine
keywords: Dog; Hypermethylation; Lymphoma; Tumor suppressor gene; p16