Decreased miR-124-3p Expression Prompted Breast Cancer Cell Progression Mainly by Targeting Beclin-1

Clin Lab. 2016;62(6):1139-45. doi: 10.7754/clin.lab.2015.151111.


Background: Recent findings have revealed that abnormal expression of microRNAs (miRNA, miR) contributes to the malignancies of various cancers. Here, we report a novel miRNA that regulates the expression of Beclin-1 in breast cancer cells.

Methods: The expression of miR-124-3p and Beclin-1 was identified in breast cancer tissues and breast cancer cell lines. To explore whether Beclin-1 was the target gene of miR-124-3p, luciferase reporter assay was applied. MIR-124-3p was overexpressed or inhibited with the corresponding mimics or inhibitors. The expression of autophagy-related proteins including Beclin-1 and LC3II were explored by western blot and quantitative real-time PCR.

Results: We first demonstrated that miR-124-3p was decreased in breast cancer tissues and breast cancer cells lines. Furthermore, we validated that miR-124-3p could negatively regulate the expression of Beclin-1. Increased miR-124-3p significantly decreased the expression of Beclin-1 and LC3I. Further study showed that overexpres- sion of miR-124-3p could partially reverse 4-hydroxytamoxifen (4-OHT)-induced autophagy in breast cancer cells.

Conclusions: Decreased miR-124-3p expression prompted breast cancer cell progression mainly by enhancing the expression of autophagy related protein, Beclin-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis Regulatory Proteins / genetics
  • Apoptosis Regulatory Proteins / metabolism*
  • Autophagy* / drug effects
  • Beclin-1
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • Cell Survival / drug effects
  • Down-Regulation
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • MCF-7 Cells
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Selective Estrogen Receptor Modulators / pharmacology
  • Signal Transduction
  • Tamoxifen / analogs & derivatives
  • Tamoxifen / pharmacology
  • Transfection


  • Apoptosis Regulatory Proteins
  • BECN1 protein, human
  • Beclin-1
  • MIRN124 microRNA, human
  • Membrane Proteins
  • MicroRNAs
  • Selective Estrogen Receptor Modulators
  • Tamoxifen
  • afimoxifene