Human Papillomaviruses (HPVs) are small double-stranded DNA viruses that infect the cutaneous or mucosal epithelium. The high-risk genital HPVs are associated with squamous intraepithelial lesions of the anogenital region that can progress to cancer. Cervical cancer is the third leading cause of cancer death in women worldwide, yet there are no specific therapeutic treatments for HPV-associated malignancies. Development of specific antisense oligonucleotides as antiviral agents is an alternative therapeutic strategy. We utilized the organotypic raft culture system which recapitulates the entire HPV life cycle, including the production of infectious virions. We studied the effect of the ORI-1001 antisense phosphorothioate oligonucleotide designed against the E1 mRNA translation start site of low-risk HPV6 and HPV11, and tested it against high-risk HPV31b and HPV16 vegetative replication and oncogene promoter activity. ORI-1001 significantly inhibited HPV31b genome amplification. In contrast, HPV16 genome amplification was unaffected. In addition, ORI-1001 significantly downregulated transcriptional activity from a HPV31b p99 early promoter luciferase reporter construct, and inhibited E1 and E6E7 transcript expression from the wild-type genome. Our results support the idea that the antisense activity of OR-1001 can target HPV31b functional activities in the differentiation dependent life cycle of this virus. Our results predict that binding stability between antisense oligonucleotides with partial homology to HPV genes may mediate targeting of multiple HPV types. Our studies also highlight the utility of the raft culture system in defining the parameters for testing antisense oligonucleotides against HPV.
