Exp Mol Med.  2018 Feb;50(2):e449. 10.1038/emm.2017.281.

Inhibition of TNFα-interacting protein α (Tipα)-associated gastric carcinogenesis by BTG2(/TIS21) via downregulating cytoplasmic nucleolin expression

Affiliations
  • 1Division of Medical Sciences, Graduate School of Ajou University, Gyeonggi-do, Republic of Korea. iklim@ajou.ac.kr
  • 2Department of Biochemistry and Molecular Biology, Ajou University, School of Medicine, Gyeonggi-do, Republic of Korea.
  • 3Graduate School of Science and Engineering, Saitama University, Saitama, Japan.
  • 4Department of Pathology, Chung-Ang University College of Medicine, Seoul, Republic of Korea.
  • 5Department of Clinical Laboratory of Medicine, Faculty of Medicine, Saga University, Saga, Japan.
  • 6Saitama Cardiovascular and Respiratory Center, Saitama, Japan.
  • 7Department of Pathology, Soonchunhyang Cheonan hospital, Soonchunhyang University, College of Medicine, Cheonan, Republic of Korea.

Abstract

To understand the regulation of Helicobacter pylori (H. pylori)-associated gastric carcinogenesis, we examined the effect of B-cell translocation gene 2 (BTG2) expression on the biological activity of Tipα, an oncoprotein secreted from H. pylori. BTG2, the human ortholog of mouse TIS21 (BTG2(/TIS21)), has been reported to be a primary response gene that is transiently expressed in response to various stimulations. Here, we report that BTG2 is constitutively expressed in the mucous epithelium and parietal cells of the gastric gland in the stomach. Expression was increased in the mucous epithelium following H. pylori infection in contrast to its loss in human gastric adenocarcinoma. Indeed, adenoviral transduction of BTG2(/TIS21) significantly inhibited Tipα activity in MKN-1 and MGT-40, human and mouse gastric cancer cells, respectively, thereby downregulating tumor necrosis factor-α (TNFα) expression and Erk1/2 phosphorylation by reducing expression of nucleolin, a Tipα receptor. Chromatin immunoprecipitation proved that BTG2(/TIS21) inhibited Sp1 expression and its binding to the promoter of the nucleolin gene. In addition, BTG2(/TIS21) expression significantly reduced membrane-localized nucleolin expression in cancer cells, and the loss of BTG2(/TIS21) expression induced cytoplasmic nucleolin availability in gastric cancer tissues, as evidenced by immunoblotting and immunohistochemistry. Higher expression of BTG2 and lower expression of nucleolin were accompanied with better overall survival of poorly differentiated gastric cancer patients. This is the first report showing that BTG2(/TIS21) inhibits nucleolin expression via Sp1 binding, which might be associated with the inhibition of H. pylori-induced carcinogenesis. We suggest that BTG2(/TIS21) is a potential inhibitor of nucleolin in the cytoplasm, leading to inhibition of carcinogenesis after H. pylori infection.


MeSH Terms

Adenocarcinoma
Animals
B-Lymphocytes
Carcinogenesis*
Chromatin Immunoprecipitation
Cytoplasm*
Epithelium
Gastric Mucosa
Helicobacter pylori
Humans
Immunoblotting
Immunohistochemistry
Mice
Necrosis
Phosphorylation
Rabeprazole
Stomach
Stomach Neoplasms
Full Text Links
  • EMM
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr