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ツゲ ヒデアキ
TSUGE HIDEAKI
津下 英明 所属 京都産業大学 生命科学部 先端生命科学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2010/06 |
| 形態種別 | 研究論文 |
| 標題 | Nucleolin as cell surface receptor for tumor necrosis factor-alpha inducing protein: a carcinogenic factor of Helicobacter pylori |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY |
| 出版社・発行元 | SPRINGER |
| 巻・号・頁 | 136(6),pp.911-921 |
| 著者・共著者 | Tatsuro Watanabe,Hideaki Tsuge,Takahito Imagawa,Daisuke Kise,Kazuya Hirano,Masatoshi Beppu,Atsushi Takahashi,Kensei Yamaguchi,Hirota Fujiki,Masami Suganuma |
| 概要 | Tumor necrosis factor-alpha inducing protein (Tip alpha) is a unique carcinogenic factor released from Helicobacter pylori (H. pylori). Tip alpha specifically binds to cells and is incorporated into cytosol and nucleus, where it strongly induces expression of TNF-alpha and chemokine genes mediated through NF-kappa B activation, resulting in tumor development. To elucidate mechanism of action of Tip alpha, we studied a binding protein of Tip alpha in gastric epithelial cells.
Tip alpha binding protein was found in cell lysates of mouse gastric cancer cell line MGT-40 by FLAG-pull down assay and identified to be cell surface nucleolin by flow cytometry using anti-nucleolin antibody. Incorporation of Tip alpha into the cells was determined by Western blotting and expression of TNF-alpha gene was quantified by RT-PCR. Nucleolin was co-precipitated with Tip alpha-FLAG, but not with del-Tip alpha-FLAG (an inactive mutant). After treatment with Tip alpha-FLAG, incorporated Tip alpha was co-immunoprecipitated with endogenous nucleolin using anti-nucleolin antibody. The direct binding of Tip alpha to recombinant His-tagged nucleolin fragment (284-710) was also confirmed. Although nucleolin is an abundant non-ribosomal protein of the nucleolus, we found that nucleolin is present on the cell surface of MGT-40 cells. Pretreatment with anti-nucleolin antibody enhanced Tip alpha-incorporation into the cells through nucleolin internalization. In addition, pretreatment with tunicamycin, an inhibitor of N-glycosylation, decreased the amounts of cell surface nucleolin and inhibited both internalization of Tip alpha and expression of TNF-alpha gene. All the results indicate that nucleolin acts as a receptor for Tip alpha and shuttles Tip alpha from cell surface to cytosol and nuclei. These findings provide a new mechanistic insight into gastric cancer development with Tip alpha. |
| DOI | 10.1007/s00432-009-0733-y |
| ISSN | 0171-5216/1432-1335 |