Human papillomavirus type 16 in head and neck carcinogenesis.
The aetiology of squamous cell carcinomas of the head and neck (HNSCC) is multifactorial. Oncogenic human papillomaviruses (HPVs), a causative agent in uterine cervical cancer, have also been repeatedly detected in HNSCC, especially in squamous cell carcinomas of tonsils. Approximately half the HPV DNA-positive HNSCC contain detectable E6/E7 transcripts with wild-type p53, reduced pRb and overexpressed p16 in the tumours. HPV-16 is the predominant type and exists in episomal, integrated, or mixed forms. Tonsillar carcinomas have a remarkably higher viral load than carcinomas at other sites of the head and neck region. HPV-16 DNA has also been detected in tumour-free tonsils. Infection by oncogenic HPVs is a necessary but not a sufficient cause of cancers. Studies on the molecular mechanisms underlying HPV-associated carcinogenesis are difficult, because HPV is not easy to propagate in vitro. HPV-immortalised human tonsillar epithelial cell lines may provide an in vitro model to study co-factors for the HPV-associated tonsillar cancers and to test the effects of anti-viral and anti-tumour agents.
Chen
Renwei
R
Department of Virology, Haartman Institute, University of Helsinki, Finland. Renwei.chen@helsinki.fi
Aaltonen
Leena-Maija
LM
Vaheri
Antti
A
D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000821:virology*; D019942:Genes, p16 / Q000502:physiology; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000821:virology*; D052162:Human papillomavirus 16 / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis / Q000235:genetics; D014066:Palatine Tonsil / Q000821:virology; D050725:Papillomavirus E7 Proteins; D030361:Papillomavirus Infections / Q000150:complications*; D012333:RNA, Messenger / Q000235:genetics; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics
C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16