title: Increased apoptosis associated with depressed type of early intestinal gastric cancer.
abstract: Early gastric cancer can be macroscopically classified into elevated and depressed types. To clarify the relationship between macroscopic appearance of early gastric cancer and apoptosis or cell proliferation, formalin-fixed paraffin-embedded tissue specimens of 44 intestinal-type early gastric cancers were investigated by the TUNEL method and immunohistochemical techniques. Diffuse type was excluded in this study. When tissue sections of gastric cancer were vertically classified into the 3 compartments of luminar, intermediate and basal, the apoptosis index (%) was significantly higher in the basal compartment of depressed type (1.76 +/- 2.04, mean +/- SD) than in the basal compartment of elevated type (0.63 +/- 0.81, P = 0.01). In depressed type, the apoptosis index (%) was significantly higher in the basal compartment than in the luminar compartment (0.76 +/- 0.85, P = 0.03). Apoptosis-inducing protein, Bax, was expressed more in each of the compartments of depressed type than in those of elevated type, while there were no significant differences in expression of anti-apoptotic protein, Bcl-2, between the two types. Moreover, the apoptosis index (%) of Bax-positive gastric cancer was significantly higher in the basal compartment (P = 0.03), compared to that of Bax-negative gastric cancer, while there were no significant differences in apoptosis index (%) in any compartment between Bcl-2-positive and Bcl-2-negative gastric cancers. There were no significant differences in Ki-67 expression, either between the two types, or among the compartments of depressed type. These results indicate that increased apoptosis with excessive expression of Bax in the basal compartment is involved in the morphogenesis of the depressed type in intestinal-type early gastric cancer.
authors.affiliation: First Department of Medicine, Hokkaido University School of Medicine, Kita-ku, Sapporo 060-8638. manabu-masutani@hokkaido.med.or.jp
authors.forename: M
authors.initials: M
authors.lastname: Masutani
authors.forename: J
authors.initials: J
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Matsuda
authors.forename: A
authors.initials: A
authors.lastname: Dochin
authors.forename: K
authors.initials: K
authors.lastname: Sadaoka
authors.forename: A
authors.initials: A
authors.lastname: Nomura
authors.forename: K
authors.initials: K
authors.lastname: Ohira
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Yamazaki
authors.forename: H
authors.initials: H
authors.lastname: Dosaka-Akita
authors.forename: M
authors.initials: M
authors.lastname: Nishimura
authors.forename: Y
authors.initials: Y
authors.lastname: Kawakami
mesh_terms: D000368:Aged; D017209:Apoptosis; D002455:Cell Division; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D008875:Middle Aged; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051028:bcl-2-Associated X Protein
chemical_list: C494826:BAX protein, human; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein