Detection of Epstein–Barr Virusand JC Polyomavirus in Gastric Cancer Tissue by Quantitative Real Time PCR

Abstract

Background: Epstein–Barr virus (EBV) is a ubiquitous virus and it is the first virus recognized as
carcinogen, gastric cancer is one of its suspected oncogenic potentials. Also in the last few years, a role of JC
polyomavirus (JCV) is suspected in gastric carcinoma. This study is carried out to determine the frequency
of EBV and JCV in gastric cancer tissues.
Subjects and Method: A case-control study included 40 gastric cancer tissue samples which were
categorized as intestinal- or diffuse-type, and 20 gastric tissue samples which were histologically proven
normal or mild gastritis cases taken from patients suspected to have gastritis or peptic ulcer.All these tissues
were subjected for DNA extraction and real time PCR for quantification of EBV and JCV DNA copies in
these tissues.
Results: Among these 40 gastric cancer tissues (15%), 6 out of 40 were EBV DNA positive, and 5 out of
these 6 tissues were of diffuse type, poorly differentiated, and with lymphocytic infiltration. While none of
the control tissues was positive for viral DNA, p=0.023. Moreover, 25% (10/40) of gastric cancers were
positive for JCV DNA,80% (8/10) of them were of intestinal type, and only 10% (2/20) were JCV positive
among the control group with significantly higher mean viral load in cancerous tissues (P=0.028), none of
the tissues had both viruses.
Conclusion: EBV could be considered one of the important risk factors for the development of gastric
cancer, especially of diffused, poorly differentiated, and lymphocytic type looking like EBV-associated
nasopharyngeal carcinoma. And JCV could be regarded another risk factor for the development of intestinaltype gastric carcinoma, and there is no association between these two viruses.