1993 Fiscal Year Final Research Report Summary
Proliferation and differentiation of Gastric Mucosal Cells in Culture
| Project/Area Number |
04670430
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Gastroenterology
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| Research Institution | Osaka University |
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Principal Investigator |
NAGANO Koichi Osaka University Assistant Prof. First Dept. of Medicine, 医学部, 助手 (60237542)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHI Nobuhiko Osaka University Hospital, 医学部・付属病院, 医員
TSUJI Shingo Osaka University Hospital, 医学部・付属病院, 医員
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| Project Period (FY) |
1992 – 1993
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| Keywords | gastric mucosal cell / proliferation / differentiation / TGF-alpha / antisense Oligonucleotide / c-myc / gastric cancer / apoptosis |
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| Research Abstract |
PROLIFERATION AND DEFFERENTIATION OF GASTRC MUCOSAL CELL IN CULTURE
Rabbit gastric mucosal cells were isolated and fractionated by a centrifugal elutriator according to cell-size. Cell cycli analysis of these fractionated cells by flowcytometry demonstrated that 15-35% of cells are in S-phase and therefore gastric stem cells are widely distributed in various fractions. Effects of a variety of growth factors including TGFa, TGFb, ET-1 on these gastric mucosal cells were examined in this study.
Immunohistochemical localization of TGFa and epidermal growth factor receptor was performed using biopsy samples of human stomach. Both TGFa and EGFR immunoreactivity were co-localized in surface mucous epithelias cells, parietal cells, and gastric stem cells (PCNA-positive cells). In the regenerating gastric mucosa arround peptic uleer, TGFa immunoreactivity was co-localized with PCNA-positive cells at the basal portion of the regenerative glands. Thus, TGFa may support gastric mucosal cell proliferation in a autocrine or paracrine fashion. TGFa mRNA expression was also examined in biopsy samples of human stomach using RT-PCR method. It was demonstrated that TGFa mRNA expression in regenerating gastric mucosa is increased with gastric ulcer healing.
Overexpression of c-myc gene has been detected in a variety of tumors in the gastrointestinal tract. Antisense oligonneleotides to c-myc (18 mer and 27 mer) inhibited growth of MKN45 gastric cancer cells by 40-75% at concentrations of 0.1-10uM, while sense oligonucleotide did not. TUNEL (Nick-end labeling) method revealed that frequency of apoptotic cells is correlated with the degree of supression of tumor cell growth. These results suggests that antisense oligonucleotide to c-myc may be promising for the treatment of gastric cancer.
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