title: Immortalization of differentiated human keratinocytes by human papillomavirus (HPV) 16 DNA.
abstract: Human papillomavirus (HPV) 16 is strongly implicated as having an etiologic role in cervical carcinoma. Human basal keratinocytes have been used in most HPV transformation studies, and transformed cells have exhibited undifferentiated characteristics. However, tumor cells in cervical squamous cell carcinoma are differentiated to certain degrees. Therefore, we hypothesize that HPV may transform not only basal cells but also differentiated keratinocytes. Human keratinocytes isolated from neonatal foreskin were induced to differentiate by treatment with 2 mM Ca2+ for various times (24, 48, 72 and 96 h) and were transfected with HPV 16 DNA. After G418 selection and repeated subculture, HPV 16-transformed cells were derived from each group of the Ca(2+)-treated and untreated cells. HPV DNA was detected in the transformed cells by polymerase chain reaction (PCR). Southern analysis and two-dimensional gel results indicated that HPV 16 DNA had been integrated into the chromosomes. The HPV 16-transformed cells exhibited an indefinite lifespan and were not tumorigenic in nude mice. They also showed the morphology and expressed the markers of differentiated keratinocytes. This study showed that differentiated human keratinocytes could be immortalized by HPV 16, and this may be a better model for cervical carcinomas in humans.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston 77555-1019, USA.
authors.forename: W
authors.initials: W
authors.lastname: Zhou
authors.forename: S K
authors.initials: SK
authors.lastname: Tyring
authors.forename: M
authors.initials: M
authors.lastname: Brysk
authors.forename: T S
authors.initials: TS
authors.lastname: Chan
mesh_terms: D000818:Animals; D015415:Biomarkers; D002118:Calcium / Q000494:pharmacology; D002454:Cell Differentiation; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D004279:DNA, Viral / Q000235:genetics*; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000821:virology*; D051379:Mice; D008819:Mice, Nude; D008954:Models, Biological; D027383:Papillomaviridae / Q000235:genetics* / Q000472:pathogenicity*; D030361:Papillomavirus Infections / Q000209:etiology / Q000821:virology; D014162:Transfection; D014412:Tumor Virus Infections / Q000209:etiology / Q000821:virology; D002583:Uterine Cervical Neoplasms / Q000209:etiology / Q000821:virology
chemical_list: D015415:Biomarkers; D004279:DNA, Viral; D002118:Calcium