Cooperation of genes in HPV16 E6/E7-dependent cervicovaginal carcinogenesis trackable by endoscopy and independent of exogenous estrogens or carcinogens

Carcinogenesis. 2020 Nov 13;41(11):1605-1615. doi: 10.1093/carcin/bgaa027.


Human papillomavirus (HPV) infection is necessary but insufficient for progression of epithelial cells from dysplasia to carcinoma-in situ (CIS) to invasive cancer. The combination of mutant cellular and viral oncogenes that regulate progression of cervical cancer (CC) remains unclear. Using combinations of HPV16 E6/E7 (E+), mutant Kras (mKras) (K+) and/or loss of Pten (P-/-), we generated autochthonous models of CC without exogenous estrogen, carcinogen or promoters. Furthermore, intravaginal instillation of adenoCre virus enabled focal activation of the oncogenes/inactivation of the tumor suppressor gene. In P+/+ mice, E6/E7 alone (P+/+E+K-) failed to cause premalignant changes, while mKras alone (P+/+E-K+) caused persistent mucosal abnormalities in about one-third of mice, but no cancers. To develop cancer, P+/+ mice needed both E6/E7 and mKras expression. Longitudinal endoscopies of P+/+E+K+ mice predicted carcinoma development by detection of mucosal lesions, found on an average of 23 weeks prior to death, unlike longitudinal quantitative PCRs of vaginal lavage samples from the same mice. Endoscopy revealed that individual mice differed widely in the time required for mucosal lesions to appear after adenoCre and in the time required for these lesions to progress to cancer. These cancers developed in the transition zone that extends, unlike in women, from the murine cervix to the distal vagina. The P-/-E+K+ genotype led to precipitous cancer development within a few weeks and E6/E7-independent cancer development occurred in the P-/-E-K+ genotype. In the P-/-E+K- genotype, mice only developed CIS. Thus, distinct combinations of viral and cellular oncogenes are involved in distinct steps in cervical carcinogenesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinogenesis
  • Carcinogens / toxicity*
  • Endoscopy / methods*
  • Estrogens / toxicity*
  • Female
  • Human papillomavirus 16 / isolation & purification
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mutation
  • Oncogene Proteins, Viral / metabolism*
  • PTEN Phosphohydrolase / physiology
  • Papillomavirus E7 Proteins / metabolism*
  • Papillomavirus Infections / complications
  • Papillomavirus Infections / virology
  • Proto-Oncogene Proteins p21(ras) / genetics
  • Repressor Proteins / metabolism*
  • Uterine Cervical Neoplasms / diagnostic imaging
  • Uterine Cervical Neoplasms / etiology
  • Uterine Cervical Neoplasms / metabolism
  • Uterine Cervical Neoplasms / pathology*
  • Vaginal Neoplasms / diagnostic imaging
  • Vaginal Neoplasms / etiology
  • Vaginal Neoplasms / metabolism
  • Vaginal Neoplasms / pathology*


  • Carcinogens
  • E6 protein, Human papillomavirus type 16
  • Estrogens
  • Oncogene Proteins, Viral
  • Papillomavirus E7 Proteins
  • Repressor Proteins
  • oncogene protein E7, Human papillomavirus type 16
  • PTEN Phosphohydrolase
  • Pten protein, mouse
  • Hras protein, mouse
  • Proto-Oncogene Proteins p21(ras)