miR-200c is aberrantly expressed in leiomyomas in an ethnic-dependent manner and targets ZEBs, VEGFA, TIMP2, and FBLN5

Endocr Relat Cancer. 2012 Jul 22;19(4):541-56. doi: 10.1530/ERC-12-0007. Print 2012 Aug.

Abstract

MicroRNA-200c (miR-200c) through repression of specific target genes has been associated with cellular transition, tumorigenesis, and tissue fibrosis. We explored the expression and functional aspects of miR-200c in genesis of leiomyomas (LYO), benign uterine tumors with fibrotic characteristic. Using LYO and matched myometrium (MYO; n=76) from untreated and from patients exposed to hormonal therapies (GNRH agonist (GNRHa), Depo-Provera, and oral contraceptives), we found that miR-200c was expressed at significantly lower levels (P<0.05) in LYO as compared with MYO. These levels were lower in LYO from African Americans as compared with Caucasians, patients experiencing abnormal uterine bleeding and those exposed to GNRHa therapy. Gain-of-function of miR-200c in isolated leiomyoma smooth muscle cells (LSMCs), myometrial smooth muscle cells (MSMCs), and leiomyosarcoma cell line (SKLM-S1) repressed ZEB1/ZEB2 mRNAs and proteins, with concurrent increase in E-cadherin (CDH1) and reduction in vimentin expression, phenotypic alteration, and inhibition of MSMC and LSMC proliferations. We further validated TIMP2, FBLN5, and VEGFA as direct targets of miR-200c through interaction with their respective 3' UTRs, and other genes as determined by microarray analysis. At tissue levels, LYO expressed lower levels of TIMP2 and FBLN5 mRNAs but increased protein expressions, which to some extent altered due to hormonal exposure. Given the regulatory functions of ZEBs, VEGFA, FBLN5, and TIMP2 on cellular activities that promote cellular transition, angiogenesis, and matrix remodeling, we concluded that altered expression of miR-200c may have a significant impact on the outcome of LYO growth, maintenance of their mesenchymal and fibrotic characteristics, and possibly their associated symptoms.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Case-Control Studies
  • Ethnicity / genetics
  • Extracellular Matrix Proteins / genetics
  • Extracellular Matrix Proteins / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Humans
  • Leiomyoma / ethnology*
  • Leiomyoma / genetics*
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • MicroRNAs / physiology
  • Middle Aged
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Tissue Inhibitor of Metalloproteinase-2 / genetics
  • Tissue Inhibitor of Metalloproteinase-2 / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Uterine Neoplasms / ethnology*
  • Uterine Neoplasms / genetics*
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / metabolism
  • Young Adult
  • Zinc Finger E-box Binding Homeobox 2
  • Zinc Finger E-box-Binding Homeobox 1

Substances

  • Extracellular Matrix Proteins
  • FBLN5 protein, human
  • Homeodomain Proteins
  • MIRN200 microRNA, human
  • MicroRNAs
  • Repressor Proteins
  • TIMP2 protein, human
  • Transcription Factors
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • ZEB1 protein, human
  • ZEB2 protein, human
  • Zinc Finger E-box Binding Homeobox 2
  • Zinc Finger E-box-Binding Homeobox 1
  • Tissue Inhibitor of Metalloproteinase-2