Methylation and expression of miRNAs in precancerous lesions and cervical cancer with HPV16 infection

Oncol Rep. 2016 Apr;35(4):2297-305. doi: 10.3892/or.2016.4583. Epub 2016 Jan 21.

Abstract

Abnormal expression and promoter methylation of microRNAs (miRNAs) are common events during cervical carcinogenesis. Worldwide, infection by types 18 and 16 of human papillomaviruses (HPVs) is considered the major risk factor for cervical cancer development. It has been reported that expression of the miRNAs can be deregulated by specific HPV genotypes. In this study we analyzed the promoter methylation of 22 miRNAs and the expression of three miRNAs in 10 non-squamous intraepithelial lesions (Non-SIL) without HPV16 infection, and 7 Non-SIL, 16 low-grade SIL (LSIL) and 16 cervical cancer samples, all with HPV16 infection. The methylation status was determined using Human Cancer miRNA EpiTect Methyl II Signature PCR Array® and the expression of miR-124, miR-218 and miR-193b was determined by qRT-PCR using individual TaqMan assays. Comparisons of groups defined were performed using the Fisher exact test for categorical variables and Mann-Whitney test for continuous variables. A p-value of <0.05 was considered statistically significant. The methylation levels of miR-124-2, miR-218-1, miR-218-2 and miR-34b/c promoters were significantly higher in cervical cancer than in LSIL samples. The methylation levels of miR-193b promoter were significantly lower in cervical cancer than in LSIL samples. The expression of miR-124 and miR-218 was significantly lower in cervical cancer than in LSIL samples. The expression of miR-193b was significantly higher in cervical cancer than in LSIL and Non-SIL samples. Our results suggest that the abnormal promoter methylation and expression of miR-124, miR-218 and miR-193b are common events during cervical carcinogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • DNA Methylation*
  • Female
  • Gene Expression Profiling / methods*
  • Gene Expression Regulation, Neoplastic
  • Human papillomavirus 16 / pathogenicity
  • Humans
  • MicroRNAs / genetics*
  • Middle Aged
  • Oligonucleotide Array Sequence Analysis / methods*
  • Papillomavirus Infections / genetics*
  • Promoter Regions, Genetic
  • Uterine Cervical Dysplasia / genetics*
  • Uterine Cervical Neoplasms / genetics*
  • Young Adult

Substances

  • MIRN124 microRNA, human
  • MIRN193 microRNA, human
  • MIRN218 microRNA, human
  • MicroRNAs