ABSTRACT
BACKGROUND: Epstein-Barr virus associated gastric lymphoepithelioma-like carcinoma (LELC) is characterized by the intensive infiltration of lymphoid cells, the presence of EBV, and the better prognosis over typical adenocarcinoma. Thus, it was assumable that viral latent proteins may be responsible for the recruitment of a certain T cell repertoire to EBV-associated gastric carcinoma. METHODS: To examine above possibility, EBV gene expression in gastric carcinoma tissues and usage of TCR among the tumor infiltrating lymphocytes were analyzed. RESULTS: EBV specific DNA and EBERs RNA were detected in 4 out of 30 patients. RT-PCR analysis revealed that all 4 of EBV-positive tumor tissues expressed EBNA1 mRNA and BARTs and LMP2a was detected only one sample out of 4. However, the EBNA2 and LMP-1 transcripts were not detected in these tissues. CD8+ T cells were the predominant population of infiltrating lymphocytes in the EBV-positive gastric carcinoma. According to spectra type analysis of infiltrating T cells, 10 predominant bands were detected by TCR Vbeta CDR3 specific RT-PCR from 4 EBV-positive tumor tissues. Sequence analysis of these bands revealed oligoclonal expansion of T cells. CONCLUSION: These findings suggest that clonally expanded T cells in vivo might be a population of cytotoxic T cells reactive to EBV-associated gastric carcinoma.
Subject(s)
Humans , Adenocarcinoma , DNA , Gene Expression , Herpesvirus 4, Human , Lymphocytes , Lymphocytes, Tumor-Infiltrating , Prognosis , Proteins , RNA , RNA, Messenger , Sequence Analysis , T-LymphocytesABSTRACT
PURPOSE: To report on the incidence of EBVaGC and its associated clinical and pathological characteristics. METHODS: Between Nov. 1998 and Mar. 2000, 183 gastric cancers were resected, and the histology and lymphocytes infiltration reviewed. The EBVaGC was determined by EBER ISH, along with the clinical characteristics, such as sex distribution, tumor location, ABO blood group, status of H. pylori and postop survival. RESULTS: Out of 183 gastric adenocarcinomas 10 were EBVaGCs (5.5%), 7/129 males and 3/54 females. The incidences of EBVaGC, according to the WHO histology, were 7.1% (4/56) for tub. po, 9.3% (4/43) tub. mo, 4.1% (2/48) tub. well, 0/11 muc., 0/3 pap. and 0/22 sig. types. The incidences of EGVaGC, in relation to the severity of lymphocytic infiltration of tumor, were 0% (0/141) for Less- than-minimal, 21% (8/38) for Moderate and 50% (2/4) for Severe infiltration of the lymphocytes (P=0.000). The incidences of EGVaGC, according to the location of gastric cancer, were 26.3% (5/19), 7.3% (3/41) and 1.8% (2/110) for the upper, middle and lower stomach, respectively (P= 0.000). The incidences of EBVaGC were 3.1% (3/96) for stages I-II and 8% (7/87) for stages III-IV. The blood type distributions of the EBVaGCs, by the ABO blood group system were 3 A type, 6 B type, no O type and 1 AB type compared with 42.8% (74), 27.1% (47), 19.6% (34) and 10.5% (18) of A, B, O and AB with the 173 non EBVaGC P=0.079). The H. pylori status was positive in 9/10 EBVaGC, and in 157/163 (96.3%) of the non-EBVaGC. The survivals of the EBVaGC and non EBVaGC were 80 and 61.4% (105/171), rspectively. CONCLUSION: The incidence of EBVaGC was 5.5%. There was no difference in the sex ratio with EBV ( )ve gastric cancer. Six out of the 10 EBVaGC were ABO blood group B.