ABSTRACT
<p><b>BACKGROUND</b>To study the difference in gene expression between the EBV associated gastric carcinoma (EBVaGC) tissues. To explore the mechanism of gastric carcinoma pathogenesis initiated by EBV.</p><p><b>METHODS</b>In situ hybridization was used to study the frequencies of EBV small RNA expression in 155 cases of gastric carcinoma tissues. The expression levels of P53 protein and P21WAF1 protein were detected by immunohistochemistry in all gastric carcinoma tissues.</p><p><b>RESULTS</b>The expression of EBV small RNA was positive in 10 out of 155 cases (6.45%). The expression of P53 protein was weakly positive in 4 of the 10 cases. The expression level of P53 protein in EBVaGC was much lower than that in EBVnGC and was weakly positive in 30 of 145 cases with EBVnGC). P21WAF1 expression was detected in 7 of 10 cases with EBVaGC, but in 55 out of 145 cases with EBVaGC, P21WAF1 expression in EBVaGC was much higher than that in EBVnGC.</p><p><b>CONCLUSION</b>There seems existing a special mechanism of pathogenesis in EBVaGC. In which P53 gene mutation may not play an important role.</p>