Our discovery of human papillomavirus type 47 (HPV47) in benign lesions from a patient suffering from
epidermodysplasia verruciformis prompted us to examine whether the
viral DNA also resided in malignant lesions from the same patient. By using newly devised protocols for amplifying a group of
epidermodysplasia verruciformis-associated HPV DNAs by PCR and differentially identifying them by reverse-phase dot blot hybridization, we demonstrated that HPV47
DNA, but not other HPV DNAs of the group, was abundant (about 10(3) copies per diploid amount of cell
DNA) in DNAs prepared from three
carcinomas. Using
DNA from one of these
carcinomas, we also confirmed that
DNA of HPV5, HPV14, or HPV21, detected in significant amounts in DNAs from benign lesions from the patient, were present only in negligible amounts or not at all. The results suggest the involvement of HPV47
DNA in
tumorigenesis. Furthermore, we demonstrated by the Southern technique that most, if not all, of the HPV47
DNA consists of either a unit (or a nongrossly deleted unit) length of the viral genome carrying no (or no gross) internal rearrangements or tandem repeats. This and other results obtained by this technique indicated that a considerable amount of the
viral DNA resides as a circular monomer a unit length of the viral genome in
carcinoma cells, while the remainder reside as
catenanes, concatemers, or both. The concatemers were considered more likely to be replicated without integration into cellular
DNA than to be integrated, because no bands for the corresponding fragments including integration sites were detected by treatment with restriction
enzymes that would have produced such fragments.