Abstract
β-Human papillomavirus (β-HPV) DNA is present in some cutaneous squamous cell carcinomas (cuSCCs), but no mechanism of carcinogenesis has been determined. We used ultra-high-throughput sequencing of the cancer transcriptome to assess whether papillomavirus transcripts are present in these cancers. In all, 67 cuSCC samples were assayed for β-HPV DNA by PCR, and viral loads were measured with type-specific quantitative PCR. A total of 31 SCCs were selected for whole transcriptome sequencing. Transcriptome libraries were prepared in parallel from the HPV18-positive HeLa cervical cancer cell line and HPV16-positive primary cervical and periungual SCCs. Of the tumors, 30% (20/67) were positive for β-HPV DNA, but there was no difference in β-HPV viral load between tumor and normal tissue (P=0.310). Immunosuppression and age were significantly associated with higher viral load (P=0.016 for immunosuppression; P=0.0004 for age). Transcriptome sequencing failed to identify papillomavirus expression in any of the skin tumors. In contrast, HPV16 and HPV18 mRNA transcripts were readily identified in primary cervical and periungual cancers and HeLa cells. These data demonstrate that papillomavirus mRNA expression is not a factor in the maintenance of cuSCCs.