Identification of host transcriptional networks showing concentration-dependent regulation by HPV16 E6 and E7 proteins in basal cervical squamous epithelial cells

Sci Rep. 2016 Jul 26:6:29832. doi: 10.1038/srep29832.

Abstract

Development of cervical squamous cell carcinoma requires increased expression of the major high-risk human-papillomavirus (HPV) oncogenes E6 and E7 in basal cervical epithelial cells. We used a systems biology approach to identify host transcriptional networks in such cells and study the concentration-dependent changes produced by HPV16-E6 and -E7 oncoproteins. We investigated sample sets derived from the W12 model of cervical neoplastic progression, for which high quality phenotype/genotype data were available. We defined a gene co-expression matrix containing a small number of highly-connected hub nodes that controlled large numbers of downstream genes (regulons), indicating the scale-free nature of host gene co-expression in W12. We identified a small number of 'master regulators' for which downstream effector genes were significantly associated with protein levels of HPV16 E6 (n = 7) or HPV16 E7 (n = 5). We validated our data by depleting E6/E7 in relevant cells and by functional analysis of selected genes in vitro. We conclude that the network of transcriptional interactions in HPV16-infected basal-type cervical epithelium is regulated in a concentration-dependent manner by E6/E7, via a limited number of central master-regulators. These effects are likely to be significant in cervical carcinogenesis, where there is competitive selection of cells with elevated expression of virus oncoproteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cervix Uteri / metabolism*
  • Cervix Uteri / pathology
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology
  • Female
  • Gene Regulatory Networks*
  • Human papillomavirus 16 / genetics
  • Human papillomavirus 16 / metabolism*
  • Humans
  • Models, Biological*
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / metabolism*
  • Papillomavirus E7 Proteins / genetics
  • Papillomavirus E7 Proteins / metabolism*
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Uterine Cervical Neoplasms / genetics
  • Uterine Cervical Neoplasms / metabolism*
  • Uterine Cervical Neoplasms / pathology

Substances

  • E6 protein, Human papillomavirus type 16
  • Oncogene Proteins, Viral
  • Papillomavirus E7 Proteins
  • Repressor Proteins
  • oncogene protein E7, Human papillomavirus type 16