Epstein-Barr virus activating principle in husbands' semen of cervical cancer patients

A short-term in vitro assay for detecting tumor promoter activity has been cultivated utilizing the induction of Epstein-Barr virus early antigen (EBV-EA) in EBV genome-carrying human lymphoblastoid cell line (Raji cell) system. By using this system, we found that some of human semen samples possessed a marked capacity to induce EBV-EA, suggesting possible tumor promotor activity of semen. In the present study, 60 semen samples obtained from husbands of cervical cancer patients and 90 control samples were incubated with Raji cells for 48 h, and EBV-EA-expressing cells detected by indirect immunofluorescence were counted. The percentages of EBV-EA-positive cells treated with semen of cervical cancer patients' husbands (8.17 +/- 5.43%) were significantly higher than those of controls (5.23 +/- 5.91%). Since most of EBV-EA expressing effect on Raji cells show overlapping with tumor promotor activities, our present results implies the circumstantial association of seminal EBV-EA inducing activity with occurrence of human cervical cancer.