miR-145-5p Suppresses Breast Cancer Progression by Inhibiting SOX2

J Surg Res. 2019 Apr;236:278-287. doi: 10.1016/j.jss.2018.11.030. Epub 2018 Dec 27.


Background: In this study, we aimed to investigate the expression and clinical significance of miR-145-5p and its tumor-suppressive effect in breast cancer patients.

Methods: We used luciferase reporter assay, real-time quantitative reverse transcription polymerase chain reaction and Western blot to identify sex-determining region Y-box2 (SOX2) as the target gene of miR-145-5p. Their expression levels in breast cancer tissues (n = 122) were detected by real-time quantitative polymerase chain reaction. We also applied 3-(4,5-dimethyl- 2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and flow cytometry to reveal the effect of miR-145-5p on proliferation in breast cancer.

Results: miR-145-5p expression is downregulated in breast cancer tissues and negatively correlated with SOX2 expression. Decreased miR-145-5p expression was significantly associated with larger tumor size, distal metastasis, higher Ki67 expression level, and shorter overall survival. miR-145-5p inhibits breast cancer cell proliferation via targeting SOX2, and multivariate regression showed that both miR-145-5p and SOX2 were unfavorable prognostic factors.

Conclusions: miR-145-5p played a suppressive role in the proliferation of breast cancer cells by targeting SOX2, and miR-145-5p is a putative biomarker for risk assessment in patients with breast cancer.

Keywords: Biomarker; Breast cancer; Prognostic; SOX2; miR-145-5p.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Breast / pathology
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / mortality
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Disease Progression
  • Down-Regulation
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • MicroRNAs / metabolism*
  • Middle Aged
  • Prognosis
  • SOXB1 Transcription Factors / genetics*
  • Young Adult


  • Biomarkers, Tumor
  • MIRN145 microRNA, human
  • MicroRNAs
  • SOX2 protein, human
  • SOXB1 Transcription Factors