| Objective EBV has been found in most cases of rare gastric lymphoepithelioma-like carcinoma and a small but significant proportion of common gastric adenocarcinoma. EBV DNA could be detected in about 7~10% gastric adenocarcinomas. However, the pathogenetic role of EBV in gastric carcinoma is uncertain. In order to explore the potential pathogenic role of proliferating cell nuclear antigen (PCNA) and c-myc protein in the oncogenic pathway, we detected the expression of PCNA and c-myc in EBV-associated gastric carcinoma(EBVaGC), compared some EBV-encoded proteins in EBVaGC and clinicopathological data matched EBV-negative gastric carcinoma (EBVnGC).Methods The expression of PCNA and c-myc protein were tested by immunohistochemistry in 13 EBVaGCs and 45 EBVnGCs.The expression of related genes of EBV (nuclear antigen EBNA1 and EBNA2 genes, latent membrane protein LMP1 gene, and early genes BARF1 and BHRF1 ) was tested by RT-PCR and Southern blotting.Results ①PCNA LI of EBVaGC, EBVnGC and the corresponding adjacent tissues were 49.3768±12.1832 , 14.839±7.1847 , 35.613±8.3831 and 24.2735±10.1332, respectively. The PCNA LI had a significant difference between EBVaGC and EBVnGC tissues (t=4.686, P<0.0l) , the difference between EBVaGC and corresponding adjacent tissues was also significant (t=8.805, P<0.01) .②The expression of c-myc protein was detectded in 33 of 58 (55.39%) gastric carcinomas and in 21 (36.21%) of 58 adjacent tissues. There was significant difference between the two groups(x~2=4.989 , p<0.05).The expression of c-myc protein was detectded in 8 of 13(61.54%) EBVaGCs and in 25 of 45 (55.56%)EBVnGCs. The difference between the two groups was not significant (x~2=0.147 , p>0.05) . ③EBNA1 mRNA was detected in all of 13 EBVaGCs, while both EBNA2 and LMP1 mRNA were not detected in 13 cases. Of the 13 EBV-positive samples, 6 exhibited BARF1 transcripts and 2 exhibited BHRF1 transcripts. 5 out of the 6 BARF1 positive samples samples were c-myc... |
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