Sequences homologous to two separate transforming regions of herpes simplex virus DNA are linked in two genital tumors

Ten human genital invasive squamous cell carcinomas and five human premalignant tissues were analyzed for the presence of selected sets of herpes simplex virus 2 (HSV-2) DNA sequences. Two vulvar tumors and one vulvar dysplastic tissue were found to contain DNA sequences homologous to the BglII O fragment (coordinates 0.38-0.42) and the BglII N fragment (coordinates 0.58-0.63) of HSV-2 DNA. These two fragments overlap the subsets of HSV-1 and HSV-2 DNA sequences (respectively) shown previously to transform cells in culture. Sequences homologous to an additional HSV-2 DNA probe (BglII G) were not detected in the same tumors. Surprisingly, in each of the two positive vulvar tumors, the BglII N and BglII O sequences appeared to be linked, whereas in the standard HSV-2 genome the two fragments are separated by approximately 26 kb. This finding suggested that the two sets of sequences may have rearranged prior to or following the association of the HSV DNA sequences with the tumor cells. The same set of 10 tumors were analyzed for the presence of sequences complementary to human papillomavirus 16 (HPV16) DNA. The HPV16 DNA probe hybridized to three of six cervical tumors, whereas no hybridization was detected with the two vulvar tumors which contained the HSV DNA sequences