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Low rate of apoptosis and overexpression of bcl‐2 in Epstein–Barr virus‐associated gastric carcinoma
Author(s) -
Kume T,
Oshima K,
Shinohara T,
Takeo H,
Yamashita Y,
Shirakusa T,
Kikuchi M
Publication year - 1999
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/j.1365-2559.1999.00686.x
Subject(s) - epstein–barr virus , immunostaining , apoptosis , immunohistochemistry , biology , virus , pathology , terminal deoxynucleotidyl transferase , carcinoma , programmed cell death , in situ hybridization , cancer research , tunel assay , immunology , medicine , gene expression , gene , biochemistry
Aims Epstein–Barr virus (EBV) has been demonstrated in about 10% of gastric carcinomas. However, the pathogenetic role of EBV in gastric carcinoma is uncertain. We compared the rate of apoptotic cell death, cell proliferation and the expression of apoptosis‐related proteins in gastric carcinomas with or without EBV. Methods and results Epstein–Barr virus was detected in 40 gastric carcinomas by EBV‐encoded small RNA‐1 in‐situ hybridization. Apoptotic cell death, MIB‐1, p53, bcl‐2 and bcl‐x were examined by the terminal deoxynucleotidyl‐mediated dUTP‐nick end labelling method and immunohistochemistry. We also included 40 age‐, sex‐ and disease stage‐matched EBV‐negative cases as a control. The number of apoptotic cells was significantly lower in EBV‐positive (20 ± 15.1/1000 cells) and bcl‐2‐positive (17 ± 12.9/1000 cells) tumours than in EBV‐negative (43 ± 37.1) and bcl‐2‐negative tumours (38 ± 32.1, P < 0.001, P < 0.001, respectively). bcl‐2 immunostaining was significantly higher in EBV‐positive tumours (24 cases) than in EBV‐negative tumours (12 cases, P < 0.05). There was no significant difference in bcl‐x and p53 expression between EBV‐positive and ‐negative tumours. The number of MIB‐1‐positive cells in EBV‐positive tumours (237 ± 161/1000) was significantly lower than in EBV‐negative tumours (480 ± 208/1000 cells, P < 0.001). Conclusions A low rate of apoptosis and high bcl‐2 expression were recognized in EBV‐positive gastric carcinomas, suggesting that bcl‐2 protein is the main inhibitor of apoptosis in EBV‐positive carcinomas. In addition, the low apoptotic and proliferative activities may reflect a low biological activity in EBV‐positive gastric carcinomas.