Characterization of novel papillomavirus from free-ranging Antillean manatee Trichechus manatus manatus with genital papillomatosis.

The Antillean manatee Trichechus manatus manatus is an Endangered species living along the Atlantic coasts of the Americas from Florida (USA), throughout the Caribbean, to Brazil. In July 2020, a manatee with multiple wounds due to boat-inflicted trauma was rescued from the coast east of Cayo Mata, Salinas, Puerto Rico. This manatee had neutropenia, leukopenia, and monocytosis associated with immunosuppression and nutritional deficiency anemia, as well as bacteria and fungi within the lesions. The manatee had genital lesions which included papules and linear plaques, microscopically characterized by mucosal hyperplasia with cytopathic changes typical of papillomavirus infection. Superficial epithelial cells had strong nuclear immunolabeling when examined using a monoclonal antibody specific to papillomavirus. The sequencing data of PCR products with papillomavirus-specific degenerative primers indicated that these lesions contained a novel manatee papillomavirus (Trichechus manatus papillomavirus, TmPV). The genomic DNA was amplified using a rolling circle amplification, and fully sequenced to be 7586 bp (GenBank accession no. OK073977). Other TmPVs were previously isolated from Florida manatees T. manatus latirostris. This novel virus was designated TmPV type 5 (TmPV5) based on its genomic characterization and sequence comparison. The TmPV5 genome shared 50.7, 48.9, 69.4, and 62.1% similarities with TmPV1, TmPV2, TmPV3, and TmPV4, respectively. TmPV5 is classified in the genus Rhopapillomavirus together with other manatee papillomaviruses. After 2.5 mo of veterinary treatment and rehabilitation, the manatee recovered and was released. This is the first report of papillomatosis in a free-ranging Antillean manatee.

Human papillomavirus-positivity is associated with EREG down-regulation and promoter hypermethylation in head and neck squamous cell carcinoma.

BACKGROUND: Human papillomavirus (HPV) etiology has become evident in head and neck cancers (HNCs) and HPV positivity showed a strong association with its malignant progression. Since aberrant DNA methylation is known to drive carcinogenesis and progression in HNCs, we investigated to determine target gene(s) associated with this modification. METHODS: We characterized epigenetic changes in tumor-related genes (TRGs) that are known to be associated with HNC development and its progression. RESULTS: The expression levels of 42 candidate HNC-associated genes were analyzed. Of these, 7 TGRs (CHFR, RARß, GRB7, EREG, RUNX2, RUNX3, and SMG-1) showed decreased expressions in HPV-positive (+) HNC cells compared with HPV-negative (-) HNC cells. When gene expression levels were compared corresponding to the DNA methylation conditions, GRB7 and EREG showed significant differential expression between HPV+ and HPV- cells, which suggested these genes as primary targets of epigenetic regulation in HPV-induced carcinogenesis. Furthermore, treatment with a demethylation agent, 5-aza-2'-deoxycytidine (5-aza-dc), caused restoration of EREG expression and was associated with hypomethylation of its promoter in HPV+ cells, while no changes was noted in HPV- cells. EREG promoter hypermethylation in HPV+ cells was confirmed using methylation-specific PCR (MS-PCR). CONCLUSION: We conclude that EREG is the target of epigenetic regulation in HPV+ HNCs and its suppressed expression through promoter hypermethylation is associated with the development of HPV-associated HNCs.