Detection of novel papillomaviruslike sequences in paraffin-embedded specimens of invasive and in situ squamous cell carcinomas from cats

Objective-To detect and partially characterize papillomavirus (PV) DNA in squamous cell carcinoma (SCC) tumor specimens from cats. Sample Population-54 formalin-fixed paraffin-embedded skin biopsy specimens were examined. Specimens originated from Bowenoid in situ SCC (BISC; n = 21), invasive SCC (22), and skin affected by miscellaneous nonneoplastic conditions (11). Procedures-Samples from each tissue block underwent DNA extraction after deparaffinization, and PCB assays were performed. Two sets of primers derived from PV E1 were used. The first set of primers was designed for the narrow-range PCR assay and was able to generate amplification products of feline PV (FePV), canine oral PV, or closely related PVs. The second set of primers was selected for the broad-range PCR assay because of its ability to amplify DNA from 64 human PVs. Sequence analysis of each amplified DNA was performed. Results-1 of the 21 specimens of BISC was positive for PV DNA on the basis of narrow-range PCR assay results, whereas all the other specimens (BISC, invasive SCC, and controls) had negative results for PV DNA. In contrast, 5 of 21 BISC specimens and 4 of 22 invasive SCC specimens were positive for PV DNA on the basis of broad-range PCR assay results. Sequence analysis revealed that only 1 specimen was infected by a virus closely related to classic FePV In the 8 other specimens positive for PV DNA, DNA of unknown PVs was uncovered. Conclusions and Clinical Relevance-Bowenoid in situ SCC and invasive SCC of cats may be associated with PVs of genetic diversity.