Detection and quantification of Epstein-Barr virus, cytomegalovirus, and human herpesvirus-6 in stomach frozen tissue of chronic gastritis and gastric cancer patients.

Abstract

Human herpes viruses (HHVs) are among the most common infectious agents detected in the gastrointestinal tract that might be involved in oncogenesis and other gastrointestinal disorders. Although the link between the Epstein-Barr virus (EBV) and gastric cancer (GC) has been established, the role of the viruses in various stomach diseases remains unknown. The frequencies and viral copy number of EBV, cytomegalovirus (CMV), and human herpesvirus 6 (HHV-6) among 50 gastric cancer tumors and 105 chronic gastritis tissues were measured by quantitative real-time PCR. In the tumor specimens and the adjacent normal tissues EBV was found in 60% and 30.9%, CMV in 14% and 4.7%, and HHV-6 in 18%, and 14.2%, respectively. The detection rate of EBV and CMV was found to be significantly higher in tumor tissues relative to the adjacent normal tissues. Also, in chronic gastritis, the frequency of EBV, CMV, and HHV-6 was 19%, 12.3%, and 15.2%, respectively, compared with 16.4%, 1.1%, and 8.2% in their corresponding normal tissues. Here, the CMV frequency was found to be significantly higher in gastritis tissues relative to the adjacent normal tissues. Furthermore, viral load in both gastric cancer and gastritis groups was higher in either tumor or gastritis lesion compared with matched adjacent normal tissue. This study showed a clear association between gastric cancer with both EBV and CMV. Meanwhile, analyses revealed a strong association between the EBV, CMV, and HHV-6 viral loads with gastritis (P = 0.0026, P < 0.0001, and P = 0.0405, respectively). Our results suggest that these three viruses might contribute to the induction and development the gastritis and gastric cancer.