miR-146a and miR-638 in BRCA1-deficient triple negative breast cancer tumors, as potential biomarkers for improved overall survival

Cancer Biomark. 2016;16(1):99-107. doi: 10.3233/CBM-150545.

Abstract

Background: Mechanisms that lead to the reduced expression of BRCA1 in triple-negative breast cancer (TNBC) tumors are not fully understood. A possible cause is overexpression of miR-146a and miR-638, which regulate BRCA1 expression in other cancers.

Objective: To evaluate the expression of these microRNAs in relation to BRCA1 expression in TNBC tumors.

Methods: Expression of both microRNAs was assessed by real time qPCR using Taqman microRNA assays in TNBC tumors. Results were related to protein expression of BRCA1 and patient's survival.

Results: miR-146a and miR-638 were overexpressed in 36% and 59% of TNBC tumors, respectively. Overexpression was preeminent in BRCA1-deficient tumors and significantly associated to a better overall survival.

Conclusion: Both miRNAs are potential biomarkers for improved overall survival in patients with BRCA1-deficient TNBC tumors.

Keywords: BRCA1; breast cancer; miR-146a; miR-638; microRNA; triple negative breast cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • BRCA1 Protein / deficiency*
  • BRCA2 Protein / genetics
  • Biomarkers, Tumor*
  • Cell Line, Tumor
  • ErbB Receptors / genetics
  • Female
  • Gene Expression Regulation, Neoplastic
  • Germ-Line Mutation
  • Humans
  • MicroRNAs / genetics*
  • Middle Aged
  • Neoplasm Grading
  • Triple Negative Breast Neoplasms / diagnosis
  • Triple Negative Breast Neoplasms / genetics*
  • Triple Negative Breast Neoplasms / mortality*
  • Young Adult

Substances

  • BRCA1 Protein
  • BRCA2 Protein
  • Biomarkers, Tumor
  • MIRN146 microRNA, human
  • MIRN638 microRNA, human
  • MicroRNAs
  • ErbB Receptors