Papillomavirus type 16 oncogenes downregulate expression of interferon-responsive genes and upregulate proliferation-associated and NF-kappaB-responsive genes in cervical keratinocytes.
Infection with high-risk human papillomaviruses (HPV) is a major risk factor for development of cervical cancer. Expression of the HPV E6 and E7 oncoproteins increases in differentiating keratinocytes, resulting in inactivation of the p53 and retinoblastoma proteins, two important transcriptional regulators. We used cDNA microarrays to examine global alterations in gene expression in differentiating cervical keratinocytes after infection with retroviruses encoding HPV type 16 (HPV-16) E6 and E7. Expression of 80 cellular genes (approximately 4% of the genes on the array) was altered reproducibly by E6 and/or E7. Cluster analysis classified these genes into three functional groups: (i) interferon (IFN)-responsive genes, (ii) genes stimulated by NF-kappaB, and (iii) genes regulated in cell cycle progression and DNA synthesis. HPV-16 E6 or a dominant negative p53 protein downregulated multiple IFN-responsive genes. E6 decreased expression of IFN-alpha and -beta, downregulated nuclear STAT-1 protein, and decreased binding of STAT-1 to the IFN-stimulated response element. E7 alone was less effective; however, coexpression of E6 and E7 downregulated IFN-responsive genes more efficiently than E6. The HPV-16 E6 protein also stimulated expression of multiple genes known to be inducible by NF-kappaB and AP-1. E6 enhanced expression of functional components of the NF-kappaB signal pathway, including p50, NIK, and TRAF-interacting protein, and increased binding to NF-kappaB and AP-1 DNA consensus binding sites. Secretion of interleukin-8, RANTES, macrophage inflammatory protein 1alpha, and 10-kappaDa IFN-gamma-inducible protein were increased in differentiating keratinocytes by E6. Thus, high-level expression of the HPV-16 E6 protein in differentiating keratinocytes directly alters expression of genes that influence host resistance to infection and immune function.
Nees
M
M
Laboratory of Cellular Carcinogenesis and Tumor Promotion, National Cancer Institute, Bethesda, Maryland, USA.
Geoghegan
J M
JM
Hyman
T
T
Frank
S
S
Miller
L
L
Woodworth
C D
CD
D002453:Cell Cycle; D002455:Cell Division; D002478:Cells, Cultured; D002584:Cervix Uteri / Q000166:cytology; D016207:Cytokines / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D015870:Gene Expression; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology; D016898:Interferon-alpha / Q000235:genetics / Q000494:pharmacology; D016899:Interferon-beta / Q000235:genetics / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000378:metabolism*; D009857:Oncogenes; D027383:Papillomaviridae / Q000235:genetics / Q000378:metabolism*; D050725:Papillomavirus E7 Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D020218:Response Elements; D050794:STAT1 Transcription Factor; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D016207:Cytokines; D004268:DNA-Binding Proteins; C068651:E6 protein, Human papillomavirus type 16; D007370:Interferon Type I; D016898:Interferon-alpha; D016328:NF-kappa B; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D015534:Trans-Activators; D018808:Transcription Factor AP-1; D014157:Transcription Factors; C059731:oncogene protein E7, Human papillomavirus type 16; D016899:Interferon-beta; D007371:Interferon-gamma; D004247:DNA