Expression of RUNX3 protein in human gastric mucosa, intestinal metaplasia and carcinoma

Authors


  • Division of Organ Pathology, Department of Microbiology and Pathology, Faculty of Medicine (M. Osaki, K. Adachi, A. Takeda, Y. Inoue, H. Adachi, H. Ito), Division of Molecular Genetics and Biofunction, Department of Biomedical Science, Graduate School of Medicine (M. Osaki, M. Oshimura), and Division of Molecular Biology, Department of Molecular and Cellular Biology, Faculty of Medicine (M. Moriyama, C. Nakada, K. Sato), Tottori University, Yonago, Japan; Division of Molecular Pathology, Department of Immunology and Allergy, Faculty of Medicine, Oita University, Oita, Japan (M. Moriyama).

Mitsuhiko Osaki, PhD, Division of Organ Pathology, Department of Microbiology and Pathology, Faculty of Medicine, Tottori University, 86, Nishi-cho, Yonago 683–8503, Japan. Tel.: +81–859–34–8016; fax: +81–859–34–8273; e-mail: osamitsu@grape.med.tottori-u.ac.jp

Abstract

Background  Human runt-related transcription factor gene 3 (RUNX3) is considered as a possible candidate of tumour suppressor gene in human gastric carcinoma.

Materials and methods  To investigate the RUNX3 protein expression in human gastric mucosa and carcinoma, we generated a polyclonal antibody, AS251, which recognized amino acid sequences from 251 to 266 of human RUNX3. The AS251 antibody was immunoreactive with only RUNX3 protein, but not with RUNX1 and RUNX2. The AS251-antibody was available for Western blotting and immunohistochemistry using paraffin-embedded specimens.

Results  Western-blot analysis revealed that three (MKN-1, -7 and -45) of six human gastric carcinoma cell lines variably expressed RUNX3 protein, consistent with the expression pattern of RUNX3 mRNA reported previously by Li et al. (Cell 2002;109:113–24). Immunohistochemistry disclosed RUNX3 protein in most chief cells and a few gastrin-containing G cells in normal mucosa, but not in intestinal metaplasia and carcinoma cells.

Conclusions  These data suggest that RUNX3 may play a physiologic role in chief cells and G cells in gastric mucosa, and that suppression of RUNX3 expression in intestinal metaplasia and carcinoma of human stomach may be implicated in gastric carcinogenesis.

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