title: Virus transcript levels and cell growth rates after naturally occurring HPV16 integration events in basal cervical keratinocytes.
abstract: Cervical carcinogenesis is characterized by a clonal selection process in which the high-risk human papillomavirus (HRHPV) genome usually changes from the extra-chromosomal (episomal) state seen in productive infections to DNA that is integrated into host chromosomes. However, it is not clear whether all HRHPV integration events provide cells with a selective growth advantage compared with the episome-containing cells from which they originate. It is also unclear whether selection of cells containing a particular integrant from a mixed population simply reflects the highest levels of virus oncogene expression or has additional determinants. These early events in cervical carcinogenesis cannot readily be addressed by cross-sectional studies of clinical samples. We used the W12 model system to generate a panel of cervical squamous cell clones that were derived from an identical background under non-competitive conditions and differed only by the genomic site of HPV16 integration. Compared with the 'baseline' episome-containing cells from which they were isolated, only 9/17 clones (53%) showed significantly greater growth rates and only 7/17 (41%) showed significantly greater expression of the major virus oncogenes E7/E6. There were significant variations in levels of HPV16 transcription per DNA template, changes that were associated with histone modifications in the integrated virus chromatin. Cell growth rates showed only weak and non-significant associations with protein and mRNA levels for E7, E6, and the mean E7/E6 values. We conclude that HPV16 integration in basal cervical cells does not necessarily lead to increased levels of virus oncogenes, or to a competitive growth advantage, when compared with the initiating episome-containing cells.
authors.affiliation: Department of Pathology, University of Cambridge, UK.
authors.forename: Cinzia G
authors.initials: CG
authors.lastname: Scarpini
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Groves
authors.forename: Mark R
authors.initials: MR
authors.lastname: Pett
authors.forename: Dawn
authors.initials: D
authors.lastname: Ward
authors.forename: Nicholas
authors.initials: N
authors.lastname: Coleman
mesh_terms: D002460:Cell Line; D049109:Cell Proliferation; D048430:Cell Shape; D002472:Cell Transformation, Viral; D002584:Cervix Uteri / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D042002:Chromatin Assembly and Disassembly; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis; D005260:Female; D018628:Gene Dosage; D015967:Gene Expression Regulation, Viral; D005838:Genotype; D052162:Human papillomavirus 16 / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis* / Q000235:genetics; D050725:Papillomavirus E7 Proteins / Q000096:biosynthesis / Q000235:genetics; D030361:Papillomavirus Infections / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000821:virology*; D010641:Phenotype; D012333:RNA, Messenger / Q000096:biosynthesis*; D012367:RNA, Viral / Q000096:biosynthesis*; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics; D013997:Time Factors; D015854:Up-Regulation; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000821:virology; D016662:Virus Integration; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16
keywords: E6/E7; human papillomavirus; integration; selection
references.citation: Cancer Res. 2004 Feb 15;64(4):1359-68
references.pmid: 14973079
references.citation: J Med Virol. 2009 Jul;81(7):1276-82
references.pmid: 19475620
references.citation: Cell Res. 2011 Mar;21(3):381-95
references.pmid: 21321607
references.citation: J Virol. 2004 Oct;78(20):11172-86
references.pmid: 15452237
references.citation: N Engl J Med. 2003 Feb 6;348(6):518-27
references.pmid: 12571259
references.citation: Int J Cancer. 1997 Nov 4;73(3):339-44
references.pmid: 9359479
references.citation: EMBO J. 2007 Apr 18;26(8):2180-91
references.pmid: 17396148
references.citation: Virol J. 2013 May 21;10:159
references.pmid: 23693071
references.citation: Int J Cancer. 2004 Mar 20;109(2):157-62
references.pmid: 14750163
references.citation: J Clin Oncol. 2003 Dec 1;21(23):4306-13
references.pmid: 14645419
references.citation: Cancer Res. 2010 May 15;70(10):4081-91
references.pmid: 20442284
references.citation: Cancer Genet Cytogenet. 2005 Apr 1;158(1):27-34
references.pmid: 15771901
references.citation: Proc Natl Acad Sci U S A. 2006 Mar 7;103(10):3822-7
references.pmid: 16505361
references.citation: Oncogene. 2008 Mar 6;27(11):1610-7
references.pmid: 17828299
references.citation: J Virol. 1995 May;69(5):2989-97
references.pmid: 7707525
references.citation: Hum Pathol. 1992 Feb;23(2):117-28
references.pmid: 1310950
references.citation: Genome Biol. 2002 Jun 18;3(7):RESEARCH0034
references.pmid: 12184808
references.citation: Cancer Res. 2002 Dec 1;62(23):6959-65
references.pmid: 12460913
references.citation: J Virol. 1987 Apr;61(4):962-71
references.pmid: 3029430
references.citation: Cancer Res. 2000 Nov 1;60(21):5916-21
references.pmid: 11085503
references.citation: J Gen Virol. 2009 Oct;90(Pt 10):2364-2374
references.pmid: 19515830
references.citation: Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):3159-63
references.pmid: 1313584
references.citation: Am J Pathol. 1993 Aug;143(2):355-67
references.pmid: 8102029
references.citation: Cancer Res. 1999 Dec 15;59(24):6132-6
references.pmid: 10626803
references.citation: J Virol. 1991 May;65(5):2254-60
references.pmid: 1850010
references.citation: J Pathol. 2010 Jul;221(3):320-30
references.pmid: 20527025
references.citation: J Natl Cancer Inst. 1996 Mar 20;88(6):355-8
references.pmid: 8609644
references.citation: J Gen Virol. 1985 Jul;66 ( Pt 7):1515-22
references.pmid: 2991428
references.citation: Virology. 1992 Jul;189(1):132-40
references.pmid: 1318602
references.citation: Cancer Res. 2004 Jun 1;64(11):3878-84
references.pmid: 15172997
references.citation: PLoS One. 2013 Jun 18;8(6):e66693
references.pmid: 23824673
references.citation: J Pathol. 2007 Sep;213(1):27-34
references.pmid: 17642065
references.citation: Nat Rev Cancer. 2003 Mar;3(3):217-26
references.pmid: 12612656
references.citation: Annu Rev Genet. 2007;41:169-92
references.pmid: 17608616
references.citation: Virology. 2013 Oct;445(1-2):205-12
references.pmid: 23953230
references.citation: Br J Cancer. 1990 Jul;62(1):8-13
references.pmid: 2390488
references.citation: Nucleic Acids Res. 2001 May 1;29(9):e45
references.pmid: 11328886
references.citation: J Virol. 2012 Jun;86(11):6358-64
references.pmid: 22457518
references.citation: Carcinogenesis. 2006 Nov;27(11):2341-53
references.pmid: 16973673
references.citation: Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1654-8
references.pmid: 7878034
references.citation: Obstet Gynecol. 1993 Sep;82(3):465
references.pmid: 7689193
references.citation: J Pathol. 2006 Jan;208(2):152-64
references.pmid: 16362994
references.citation: Int J Cancer. 1989 Apr 15;43(4):672-6
references.pmid: 2467886
references.citation: J Pathol. 1999 Sep;189(1):12-9
references.pmid: 10451482
references.citation: J Virol. 2003 Oct;77(19):10186-201
references.pmid: 12970404
references.citation: J Pathol. 2007 Aug;212(4):356-67
references.pmid: 17573670
references.citation: Cancer Res. 2008 Oct 15;68(20):8249-59
references.pmid: 18922896
references.citation: PLoS Pathog. 2009 Apr;5(4):e1000397
references.pmid: 19390600