Prognostic value of microRNA-9 and microRNA-155 expression in triple-negative breast cancer

Hum Pathol. 2017 Oct:68:69-78. doi: 10.1016/j.humpath.2017.08.026. Epub 2017 Sep 4.

Abstract

MicroRNAs (miRNAs) are involved in regulation of epithelial-mesenchymal transition (EMT) during breast cancer progression. The purpose of this study was to analyze the clinicopathologic significance of expression of EMT-related miRNAs, miR-9 and miR-155, in triple-negative breast cancers (TNBCs). We analyzed relative expression levels of miR-9 and miR-155 in 190 surgically resected TNBC specimens using quantitative real-time polymerase chain reaction. Then we analyzed the relationship between these miRNA expression levels and EMT marker expression (vimentin, smooth muscle actin [SMA], osteonectin, N-cadherin, E-cadherin, CD146, and ZEB1) assessed by immunohistochemistry. We also evaluated the prognostic significance of these miRNA expression levels. While miR-9 expression level showed a positive correlation with pT category, miR-155 expression level did not correlate with any clinicopathologic features of TNBCs. In relation to EMT phenotype, miR-9 expression was not associated with EMT marker expression except for SMA. However, miR-155 expression level correlated inversely with the expression of several EMT markers including SMA, osteonectin, and CD146. We observed that both miR-9 and miR-155 could be prognostic markers in TNBC in opposite ways; high level of miR-9 expression showed significant association with poor disease-free survival and distant metastasis-free survival (DMFS) in TNBC, while high level of miR-155 expression was associated with better DMFS. Our study suggests that expression levels of both miR-9 and miR-155 can serve as candidates for prognostic biomarkers in TNBCs.

Keywords: Epithelial-mesenchymal transition; Prognosis; Triple-negative breast cancer; miR-155; miR-9.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / analysis
  • Biomarkers, Tumor / genetics*
  • Disease Progression
  • Disease-Free Survival
  • Epithelial-Mesenchymal Transition
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Immunohistochemistry
  • Kaplan-Meier Estimate
  • MicroRNAs / genetics*
  • Middle Aged
  • Real-Time Polymerase Chain Reaction
  • Time Factors
  • Triple Negative Breast Neoplasms / chemistry
  • Triple Negative Breast Neoplasms / genetics*
  • Triple Negative Breast Neoplasms / pathology
  • Triple Negative Breast Neoplasms / therapy
  • Young Adult

Substances

  • Biomarkers, Tumor
  • MIRN155 microRNA, human
  • MIRN92 microRNA, human
  • MicroRNAs