title: Establishment and characterization of a human papillomavirus type 16-positive tonsillar carcinoma xenograft in BALB/c nude mice.
abstract: BACKGROUND
  Among head and neck cancers, human papillomavirus type 16 (HPV16) is associated with tonsillar carcinomas. Despite this, no HPV16-positive tonsillar cancer cell line has been established in nude mice.
  
  
  METHODS
  Fresh tonsillar carcinoma biopsies were obtained from 23 patients and implanted subcutaneously into nude mice (BALB/c, nu/nu).
  
  
  RESULTS
  After 7 months, one xenograft was established. The primary tumor harbored 2.7 copies (95% confidence interval = 2.4-2.9) of HPV16/cell and displayed 99.9% (7904/7906) nucleotide identity to HPV16 (EU118173.1). The xenograft showed increased methylation in two E2-binding sites of the HPV16 genome. Both episomal and integrated HPV16 were detected in the original tumor and in 14 xenografts from the second passage. From this passage, a viral load of 6.4 copies/cell (range = 4.6-9.6) and 3.7 (range = 1.0-5.5) E7-mRNA transcripts/HPV16-genome were detected.
  
  
  CONCLUSIONS
  This xenograft represents the first established HPV16-positive tonsillar tumor in nude mice and could provide an experimental system of HPV16-positive tonsillar cancers.
authors.affiliation: Department of Laboratory Medicine, Division of Medical Microbiology, Lund University and Skåne Regional and University Laboratories, Malmö, Sweden.|School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, Republic of South Africa.
authors.forename: Boitelo T
authors.initials: BT
authors.lastname: Letsolo
authors.affiliation: Department of Laboratory Medicine, Division of Medical Microbiology, Lund University and Skåne Regional and University Laboratories, Malmö, Sweden.
authors.forename: Helena
authors.initials: H
authors.lastname: Faust
authors.affiliation: Division of Oncology, Clinical Sciences, Lund University and Skåne University Hospital, Lund, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Ekblad
authors.affiliation: Division of Otorhinolaryngology/Head and Neck Surgery, Clinical Sciences, Lund University and University Hospital of Scania, Lund, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Wennerberg
authors.affiliation: Department of Laboratory Medicine, Division of Medical Microbiology, Lund University and Skåne Regional and University Laboratories, Malmö, Sweden.
authors.forename: Ola
authors.initials: O
authors.lastname: Forslund
mesh_terms: D000368:Aged; D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D064593:Heterografts / Q000821:virology*; D052162:Human papillomavirus 16 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D030361:Papillomavirus Infections / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014067:Tonsillar Neoplasms / Q000821:virology*; D019562:Viral Load
keywords: carcinoma; human papillomavirus type 16 (HPV16); nude mice; tonsil; xenograft