Relationship between Epstein-Barr virus-encoded RNA expression, apoptosis and lymphocytic infiltration in gastric carcinoma with lymphoid-rich stroma.
OBJECTIVE
To investigate the association of apoptosis with apoptotic proteins and Epstein-Barr virus (EBV) expression in gastric carcinoma with lymphoid-rich stroma (GCLRS) in order to clarify the relationship between lymphocytic infiltration, EBV expression and apoptosis in gastric carcinoma.


METHODS
We performed immunohistochemical stains for bcl-2, bax and in situ hybridization for EBV-encoded RNA and the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling technique using the 24 cases of GCLRS and 23 cases of gastric carcinoma with lymphoid-poor stroma (GCLPS) out of 1,635 cases of gastric carcinoma.


RESULTS
The prevalence of GCLRS was 1.47% (24/1,635). The prevalence of EBV involvement in GCLRS (79%, 19/24) was significantly higher than in GCLPS (8.7%, 2/23). Apoptosis was revealed in all cases and there was no statistical difference between GCLRS and GCLPS. Immunohistochemical expression for bcl-2 was revealed only in the cytoplasm of lymphocytes in all cases, but bax showed distinct expression in the cytoplasm of neoplastic cells in all cases. There was a significant correlation between bax expression and the apoptotic index (p <0.05). Lymphocytic infiltration was significantly correlated with the expression of EBV (p <0.05) but not with survival rate and apoptosis. Most of the GCLRS cases were rated as low clinical stage (stage IA or B) and seemed to have a good prognosis.


CONCLUSIONS
These results support the hypothesis that EBV infection plays an important role in the tumorigenesis of GCLRS, which has a better prognosis than usual gastric adenocarcinoma although there was no significant difference in the apoptotic index between GCLRS and GCLPS.
Department of Pathology, Wonju College of Medicine, Yonsei University, Wonju, Korea.
Mee-Yon
MY
Cho
Tae Heon
TH
Kim
Sang Yeop
SY
Yi
Woo Hee
WH
Jung
Kwang Hwa
KH
Park
D000230:Adenocarcinoma / Q000473:pathology / Q000821:virology*; D017209:Apoptosis; D016022:Case-Control Studies; D020031:Epstein-Barr Virus Infections / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D007723:Korea / Q000453:epidemiology; D016246:Lymphocytes, Tumor-Infiltrating / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012367:RNA, Viral / Q000032:analysis*; D013194:Staining and Labeling; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology / Q000821:virology*
D019253:Proto-Oncogene Proteins c-bcl-2; D012367:RNA, Viral