🦠 Human Papillomavirus Type 16 (HPV16)
Human papillomavirus type 16 (HPV16) is a high-risk oncogenic strain of the human papillomavirus (HPV) family, with a strong tropism for squamous epithelial cells and a well-established role in the development of several human cancers.
Clinical significance:
HPV16 is the most carcinogenic HPV subtype.
It is responsible for approximately:
50–60% of cervical squamous cell carcinomas,
85–90% of HPV-positive oropharyngeal cancers,
and a substantial proportion of anal, vulvar, vaginal, and penile cancers.
Oncogenic mechanism:
HPV16 encodes the E6 and E7 oncoproteins, which respectively inactivate tumor suppressor proteins p53 and Rb, leading to cellular immortalization, genomic instability, and malignant transformation.
Transmission:
Primarily through sexual contact.
Persistent infection with high-risk types such as HPV16 is the key factor for oncogenesis.
Detection:
Identified by PCR-based HPV genotyping, in situ hybridization, or immunohistochemistry (e.g., p16 overexpression as a surrogate marker).
Prevention:
Highly effective vaccines (e.g., bivalent, quadrivalent, and nonavalent) include coverage for HPV16 and can prevent associated malignancies when administered prior to exposure.