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Subcellular localization of ATBF1 regulates MUC5AC transcription in gastric cancer
Author(s) -
Mori Yoshinori,
Kataoka Hiromi,
Miura Yutaka,
Kawaguchi Makoto,
Kubota Eiji,
Ogasawara Naotaka,
Oshima Tadayuki,
Tanida Satoshi,
Sasaki Makoto,
Ohara Hirotaka,
Mizoshita Tsutomu,
Tatematsu Masae,
Asai Kiyofumi,
Joh Takashi
Publication year - 2007
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.22654
Subject(s) - transcription factor , chromatin immunoprecipitation , homeotic gene , biology , mucin , promoter , immunohistochemistry , subcellular localization , cancer cell , microbiology and biotechnology , transcription (linguistics) , cancer research , gene expression , cancer , gene , immunology , biochemistry , genetics , cytoplasm , linguistics , philosophy
Human gastric epithelium has a unique mucin gene expression pattern, which becomes markedly altered in gastrointestinal disorder. This alteration in mucin expression, including the mucin MUC5AC, may be related to the development and prognosis of gastric cancers, and MUC5AC‐positive gastric cancer has been reported to be poor prognosis. However, the molecular mechanism of MUC5AC transcriptional regulation has not been fully elucidated. AT motif‐binding factor 1 (ATBF1) is a homeotic transcriptional regulatory factor recently identified as a tumor suppressor gene, and its subcellular localization suggests a link to cell proliferation and differentiation. We investigated the mechanism of MUC5AC transcriptional regulation by ATBF1. In 123 gastric cancer lesions, ATBF1 expressed in the nucleus significantly suppressed MUC5AC expression, as determined by immunohistochemistry. In addition, analysis of the MUC5AC promoter region revealed an AT motif‐like element. This element was found to be essential for ATBF1 suppression of MUC5AC promoter activity as shown in a dual luciferase‐reporter assay. Over‐expressed ATBF1 also significantly suppressed endogenous MUC5AC protein expression in gastric cancer cells. Chromatin immunoprecipitation demonstrated that ATBF1 binds to the AT motif‐like element in the MUC5AC promoter. These results indicate that ATBF1 in the nucleus negatively regulates the MUC5AC gene in gastric cancer by binding to an AT motif‐like element in the MUC5AC promoter. © 2007 Wiley‐Liss, Inc.