Human papillomavirus 45 (HPV45) is a high-risk type within the Alphapapillomavirus genus. It contains a circular double-stranded DNA genome enclosed in a non-enveloped icosahedral capsid. HPV45 infects epithelial cells of the anogenital tract via microabrasions and is categorized as carcinogenic because persistent infection can lead to cancer.
Virology & Oncogenic Potential
HPV45 belongs to the alpha 7 species group of high risk papillomaviruses identified by cancer agencies. Its genome encodes early proteins (E1–E7) for replication and cell cycle manipulation and late structural proteins (L1–L2). The oncoproteins E6 and E7 promote degradation of p53 and retinoblastoma family proteins, enabling uncontrolled cell proliferation. Infection begins when virions attach to heparan sulfate proteoglycans on keratinocytes in the cervical transformation zone. The virus replicates as an episome in basal cells and expresses early genes in differentiating epithelium; integration into the host genome with deregulated E6/E7 expression is a hallmark of malignant progression. HPV16 and HPV18 account for most HPV-related cancers, but additional types including 31, 33, 45, 52 and 58 collectively contribute to about 15 % of cervical cancers.
Clinical Significance and Prevention
Persistent HPV45 infection is associated with high-grade squamous intraepithelial lesions and cervical adenocarcinoma. It can also contribute to cancers of the vagina, vulva, penis and anus, though it is less prevalent than HPV16 or HPV18. Because HPV45 is oncogenic, women infected with this type may have a higher risk of developing cervical adenocarcinoma at a younger age. DNA-based screening assays detect high risk HPV types including HPV45, enabling early identification and follow‑up. Prophylactic vaccination is important: the nonavalent vaccine includes L1 virus-like particles from types 31, 33, 45, 52 and 58 in addition to 6, 11, 16 and 18. Vaccination before sexual debut and regular cervical screening with Pap and HPV testing remain central preventive strategies. HPV45 is a recognized high-risk papillomavirus whose persistence can lead to cervical and other anogenital cancers. Understanding its biology and employing screening and vaccination can reduce the burden of HPV45-related disease. Related Terms: HPV16, HPV18, Cervical cancer, E6 protein, Gardasil 9