1. Identification of Stem Cells in the Epithelium of the Stomach Corpus and Antrum of Mice.
- Author
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Matsuo J, Kimura S, Yamamura A, Koh CP, Hossain MZ, Heng DL, Kohu K, Voon DC, Hiai H, Unno M, So JB, Zhu F, Srivastava S, Teh M, Yeoh KG, Osato M, and Ito Y
- Subjects
- Animals, Carcinogenesis, Cell Differentiation, Cell Lineage, Cell Proliferation, Core Binding Factor Alpha 2 Subunit metabolism, Gene Expression, Green Fluorescent Proteins genetics, Humans, Ki-67 Antigen metabolism, Metaplasia metabolism, Mice, Mice, Inbred C57BL, Mice, Transgenic, Mucin 5AC metabolism, Pyloric Antrum metabolism, Tissue Culture Techniques, Core Binding Factor Alpha 2 Subunit genetics, Enhancer Elements, Genetic genetics, Gastric Mucosa metabolism, Gastric Mucosa pathology, Pyloric Antrum pathology, RNA, Messenger metabolism, Stem Cells metabolism, Stem Cells pathology, Stomach Neoplasms genetics, Stomach Neoplasms pathology
- Abstract
Background & Aims: Little is known about the mechanisms of gastric carcinogenesis, partly because it has been a challenge to identify characterize gastric stem cells. Runx genes regulate development and their products are transcription factors associated with cancer development. A Runx1 enhancer element, eR1, is a marker of hematopoietic stem cells. We studied expression from eR1 in the stomach and the roles of gastric stem cells in gastric carcinogenesis in transgenic mice., Methods: We used in situ hybridization and immunofluorescence analyses to study expression of Runx1 in gastric tissues from C57BL/6 (control) mice. We then created mice that expressed enhanced green fluorescent protein (EGFP) or CreERT2 under the control of eR1 (eR1-CreERT2;Rosa-Lox-Stop-Lox [LSL]-tdTomato, eR1-CreERT2;Rosa-LSL-EYFP mice). Gastric tissues were collected and lineage-tracing experiments were performed. Gastric organoids were cultured from eR1-CreERT2(5-2);Rosa-LSL-tdTomato mice and immunofluorescence analyses were performed. We investigated the effects of expressing oncogenic mutations in stem cells under control of eR1 using eR1-CreERT2;LSL-KrasG12D/+ mice; gastric tissues were collected and analyzed by histology and immunofluorescence., Results: Most proliferation occurred in the isthmus; 86% of proliferating cells were RUNX1-positive and 76% were MUC5AC-positive. In eR1-EGFP mice, EGFP signals were detected mainly in the upper part of the gastric unit, and 83% of EGFP-positive cells were located in the isthmus/pit region. We found that eR1 marked undifferentiated stem cells in the isthmus and a smaller number of terminally differentiated chief cells at the base. eR1 also marked cells in the pyloric gland in the antrum. Lineage-tracing experiments demonstrated that stem cells in the isthmus and antrum continuously gave rise to mature cells to maintain the gastric unit. eR1-positive cells in the isthmus and pyloric gland generated organoid cultures in vitro. In eR1-CreERT2;LSL-Kras G12D/+ mice, MUC5AC-positive cells rapidly differentiated from stem cells in the isthmus, resulting in distinct metaplastic lesions similar to that observed in human gastric atrophy., Conclusions: Using lineage-tracing experiments in mice, we found that a Runx1 enhancer element, eR1, promotes its expression in the isthmus stem cells of stomach corpus as well as pyloric gland in the antrum. We were able to use eR1 to express oncogenic mutations in gastric stem cells, proving a new model for studies of gastric carcinogenesis., (Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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