The expression of miR-21 and miR-143 is deregulated by the HPV16 E7 oncoprotein and 17β-estradiol

Int J Oncol. 2016 Aug;49(2):549-58. doi: 10.3892/ijo.2016.3575. Epub 2016 Jun 9.

Abstract

MicroRNAs (miRNAs) are a class of non-coding RNAs that negatively regulate their target mRNAs at a posttranscriptional level, thereby affecting crucial processes in cancer development. However, little is known about the molecular events that control expression of miRNAs in cervical cancer (CC). HPV16 E7 oncoprotein in conjunction with estrogen are sufficient to produce high grade cervical dysplasia and invasive cervical malignancies in a mouse model. In the present study, we determined the potential role that the E7 oncoprotein and 17β-estradiol (E2) play in the deregulation of miR-21 and miR-143 expression levels by these two risk factors. We found that, while the expression of miR-21 was upregulated and the expression of miR-143 was downregulated by the HPV16 E7 oncoprotein in vivo, and in vitro and that E2 treatment is also implicated in the deregulation of these important miRNAs in vivo. Sustained upregulation of miR-21 resulted in suppression of PTEN expression, and repression of miR-143 increased the mRNA and protein levels from Bcl-2. These results suggested that HPV type 16 E7 oncoprotein and E2 play an important role in regulating miR-21 and miR-143 expression. We have observed similar results in CC patients containing HPV16 sequences, suggesting that these miRNAs could serve as diagnostic biomarkers in CC. The present study highlights the roles of miRNAs in cervical tissue and implicates these important molecules in cervical carcinogenesis.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cervix Uteri / drug effects
  • Cervix Uteri / metabolism
  • Cervix Uteri / physiology*
  • Cervix Uteri / virology
  • Estradiol / pharmacology*
  • Female
  • Gene Expression Regulation
  • Humans
  • Mice
  • Mice, Transgenic
  • MicroRNAs / biosynthesis*
  • MicroRNAs / genetics
  • PTEN Phosphohydrolase / biosynthesis
  • PTEN Phosphohydrolase / genetics
  • Papillomavirus E7 Proteins / administration & dosage*
  • Papillomavirus E7 Proteins / genetics
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Transfection
  • Uterine Cervical Neoplasms / genetics
  • Uterine Cervical Neoplasms / metabolism
  • Uterine Cervical Neoplasms / virology

Substances

  • MIRN143 microRNA, human
  • MIRN21 microRNA, human
  • MicroRNAs
  • Papillomavirus E7 Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • oncogene protein E7, Human papillomavirus type 16
  • Estradiol
  • PTEN Phosphohydrolase
  • PTEN protein, human