title: AID, p53 and MLH1 expression in early gastric neoplasms and the correlation with the background mucosa.
abstract: A number of tumor-associated genes have been associated with gastric cancer development. The present study evaluated differences in tumor-associated protein expression and phenotype among early gastric neoplasms, and correlated these data with those of the background mucosa. The expression of activation-induced cytidine deaminase (AID), p53 and MLH1 in 151 early gastric neoplasms [22 gastric adenomas, 92 intramucosal carcinomas (MCs), and 37 submucosal carcinomas (SMCs)] was examined immunohistochemically and compared with that of the corresponding background mucosal condition. The cellular phenotypes of the neoplasms and the corresponding background intestinal metaplasia were also determined. Aberrant AID, p53 and MLH1 expression was detected in 36.4, 0 and 0% of the adenomas, in 35.9, 32.6 and 16.3% of the MCs, and in 56.8, 62.2 and 21.6% of the SMCs, respectively. The frequency of aberrant AID and p53 expression in the SMCs was significantly increased compared with that in the MCs (AID, P<0.05; p53, P<0.01). Aberrant AID expression was significantly associated with p53 overexpression in the SMCs (P<0.01), but not in the adenomas or MCs. In addition, AID expression was associated with the severity of mononuclear cell activity in the non-cancerous mucosa adjacent to the tumor (P<0.05), particularly in the SMC cases. The percentage of MCs (34.8%) and SMCs (24.3%) that were of the gastric phenotype was higher compared with the percentage of adenomas (18.2%). These results indicated that p53 and MLH1 expression and a gastric phenotype may be important for carcinogenesis, and that chronic inflammation and AID and p53 expression are associated with submucosal progression.
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Kawata
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yashima
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Sohei
authors.initials: S
authors.lastname: Yamamoto
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takeda
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hayashi
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Matsumoto
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kawaguchi
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Harada
authors.affiliation: Division of Medicine and Clinical Science, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8504, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Murawaki
keywords: AID; endoscopic resection; gastric cancer; p53; phenotype