Arsenic trioxide inhibits cell growth and motility via up-regulation of let-7a in breast cancer cells

Cell Cycle. 2017;16(24):2396-2403. doi: 10.1080/15384101.2017.1387699. Epub 2017 Nov 20.


Arsenic trioxide (ATO) has been reported to exert its anti-cancer activities in human cancers. However, the molecular mechanism of ATO-triggered anti-tumor activity has not been fully elucidated. Recently, multiple studies demonstrated that ATO could regulate miRNAs in human cancers. Therefore, in this study, we investigated whether ATO regulated let-7a in breast cancer cells. We found that ATO upregulated let-7a level in breast cancer cells. We also found that up-regulation of let-7a inhibited cell growth and induced apoptosis and retarded cell migration and invasion. We also observed that up-regulation of let-7a enhanced cell growth inhibition and invasion suppression induced by ATO treatment. Our findings suggest that ATO suppressed cell growth, stimulated apoptosis, and retarded cell invasion partly via upregulation of let-7a in breast cancer cells. Our study provides a new anti-tumor mechanism of ATO treatment in breast cancer.

Keywords: Arsenic trioxide; Let-7a; apoptosis; breast cancer; cell growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Arsenic Trioxide / pharmacology*
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / genetics
  • Cell Line, Tumor
  • Cell Movement / drug effects*
  • Cell Proliferation / drug effects*
  • Female
  • Humans
  • MCF-7 Cells
  • MicroRNAs / genetics*
  • Neoplasm Invasiveness / genetics
  • Neoplasm Invasiveness / prevention & control
  • Up-Regulation / drug effects*


  • MicroRNAs
  • mirnlet7 microRNA, human
  • Arsenic Trioxide