title: Human papillomavirus type 16 DNA from a vulvar carcinoma in situ is present as head-to-tail dimeric episomes with a deletion in the non-coding region.
abstract: A number of genital cancer biopsy samples were screened for the presence of human papillomavirus type 16 (HPV-16) DNA sequences. One of these samples (a vulvar carcinoma in situ) was found to contain more than 100 copies of HPV-16 DNA sequences per cell. Using this tumour DNA, a genomic library was constructed in bacteriophage lambda and the library was screened for recombinant phage containing HPV-16 sequences. Five recombinant phage clones were isolated and their DNA was analysed by restriction endonuclease digestion and blot hybridization. All five recombinants contained two copies of the HPV-16 genome present in a head-to-tail arrangement. The data are consistent with the presence of HPV-16 sequences in the tumour DNA arranged as genomic dimers in a circular episomal configuration. The HPV-16 genomes contained a deletion within the non-coding region, a region which includes the viral origin of DNA replication and transcriptional control sequences. Possible consequences of this deletion for viral replication and transcription are discussed.
mesh_terms: D001483:Base Sequence; D002278:Carcinoma in Situ / Q000032:analysis* / Q000382:microbiology; D004273:DNA, Neoplasm / Q000032:analysis*; D004274:DNA, Recombinant / Q000032:analysis; D004279:DNA, Viral / Q000032:analysis* / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D006801:Humans; D027383:Papillomaviridae / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D010957:Plasmids; D014779:Virus Replication; D014846:Vulvar Neoplasms / Q000032:analysis* / Q000382:microbiology
chemical_list: D004273:DNA, Neoplasm; D004274:DNA, Recombinant; D004279:DNA, Viral