MicroRNA-449b-5p suppresses the growth and invasion of breast cancer cells via inhibiting CREPT-mediated Wnt/β-catenin signaling

Chem Biol Interact. 2019 Apr 1;302:74-82. doi: 10.1016/j.cbi.2019.02.004. Epub 2019 Feb 7.


Accumulating evidence has suggested that microRNA-449b-5p (miR-449b-5p) plays an important role in the development and progression of multiple cancers. However, little is known about the role of miR-449b-5p in breast cancer. In this study, we aimed to investigate the expression level, biological function and underlying mechanism of miR-449b-5p in breast cancer. Our results showed that miR-449b-5p expression was frequently down-regulated in breast cancer cell lines and tissues. The overexpression of miR-449b-5p significantly inhibited growth and invasion, and induced the cell cycle arrest of breast cancer cells. In contrast, the inhibition of miR-449b-5p showed the opposite effect. Interestingly, bioinformatic analysis predicted that cell cycle-related and expression-elevated protein in tumor (CREPT), an important oncogene in breast cancer, was a potential target gene of miR-449b-5p. The overexpression of miR-449b-5p decreased CREPT expression while miR-449b-5p inhibition promoted CREPT expression in breast cancer cells. Restoration of CREPT expression in miR-449b-5p mimics transfected cells partially reversed the suppressive effect of miR-449b-5p on breast cancer cell growth and invasion. Notably, our results showed that miR-449b-5p overexpression decreased the expression of β-catenin and suppressed the activation of Wnt/β-catenin/TCF-4 signaling via targeting CREPT. In addition, blocking Wnt/β-catenin partially reversed the promotion effect of miR-449b-5p inhibition on breast cancer cell growth and invasion. Overall, these results reveal a tumor suppressive role of miR-449b-5p that restricts the growth and invasion of breast cancer cells through targeting CREPT and inhibiting CREPT-mediated activation of Wnt/β-catenin signaling. Our study suggests that the miR-449b-5p/CREPT/Wnt/β-catenin axis may play an important role in the pathogenesis of breast cancer and miR-449-5p may serve as a potential therapeutic target for breast cancer.

Keywords: Breast cancer; CREPT; Wnt/β-catenin; miR-449–5p.

MeSH terms

  • 3' Untranslated Regions
  • Antagomirs / metabolism
  • Binding Sites
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Female
  • Humans
  • MCF-7 Cells
  • MicroRNAs / antagonists & inhibitors
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Neoplasm Proteins / chemistry
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Transcription Factor 4 / metabolism
  • Wnt Proteins / metabolism
  • Wnt Signaling Pathway*
  • beta Catenin / metabolism


  • 3' Untranslated Regions
  • Antagomirs
  • Cell Cycle Proteins
  • MIRN449 microRNA, human
  • MicroRNAs
  • Neoplasm Proteins
  • RPRD1B protein, human
  • Transcription Factor 4
  • Wnt Proteins
  • beta Catenin