title: Cyclin D1 overexpression in N-methyl-N'-nitro-N-nitrosoguanidine-induced rat gastric adenocarcinomas.
abstract: Changes in cell cycle regulation are involved in many human cancers, including gastric cancer. In the present study, cyclin D1 expression and localization were immunohistochemically analyzed in 23 N-methyl-N'-nitro-N-nitrosoguanidine-induced rat gastric adenocarcinomas and compared with findings for beta-catenin. Cyclin D1 nuclear overexpression was more frequently observed in tumors displaying nuclear (4/4=100%) and cytoplasmic (3/4=75%) beta-catenin accumulation than those with membranous (3/15=20%) localization (nuclear vs. membranous, P<0.02). In the former cases it was considered that cyclin D1 was induced with beta-catenin activation; in the latter, a direct or indirect pathway for cyclin D1 accumulation bypassing Wnt pathway might be involved. Cyclin D1 was also found to be accumulated in gastric glands within normal-looking mucosa, these perhaps representing preneoplastic lesions for cancers with membranous beta-catenin accumulation.
authors.affiliation: Division of Oncological Pathology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Takasu
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Ushijima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamashita
authors.forename: Naotaka
authors.initials: N
authors.lastname: Ogasawara
authors.forename: Hisayo
authors.initials: H
authors.lastname: Ban
authors.forename: Tokuma
authors.initials: T
authors.lastname: Yanai
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Masegi
authors.forename: Masae
authors.initials: M
authors.lastname: Tatematsu
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D056741:Cyclin D; D016213:Cyclins / Q000378:metabolism*; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000633:toxicity*; D051381:Rats; D011912:Rats, Inbred ACI; D013274:Stomach Neoplasms / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D051176:beta Catenin / Q000378:metabolism
chemical_list: D002273:Carcinogens; C495268:Ctnnb1 protein, rat; D056741:Cyclin D; D016213:Cyclins; D051176:beta Catenin; D008769:Methylnitronitrosoguanidine