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MicroRNA-34a suppresses breast cancer cell proliferation and invasion by targeting Notch1

Xiaoping Rui1, Haibin Zhao2, Xianqiu Xiao1

  • 1Department of Thyroid Breast Surgery, Wuxi Taihu Hospital, Wuxi, Jiangsu 214044, P.R. China.

Experimental and Therapeutic Medicine
|December 14, 2018
PubMed

Insights

MicroRNA 34a (miR-34a) is downregulated in breast cancer and suppresses tumor progression. It inhibits cancer cell viability and invasion, partly by targeting Notch1.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • MicroRNAs (miRs) play crucial roles in tumor progression.
  • The specific function of miR-34a in breast cancer remains largely uncharacterized.

Purpose of the Study:

  • To investigate the expression and function of miR-34a in breast cancer.
  • To elucidate the molecular mechanism underlying miR-34a's role in breast cancer, focusing on its potential target, Notch1.

Main Methods:

  • Quantitative reverse transcription polymerase chain reaction (RT-qPCR) to measure miR-34a levels in breast cancer tissues.
  • Transfection of MCF-7 cells with miR-34a mimics or inhibitors to modulate its expression.
  • MTT assay, Transwell assay, and flow cytometry to assess cell viability, invasion, apoptosis, and cell cycle.
  • Western blotting to analyze protein levels.

Main Results:

  • miR-34a expression was significantly downregulated in human breast cancer tissues compared to adjacent normal tissues.
  • Notch1 was identified as a direct target of miR-34a.
  • Overexpression of miR-34a in MCF-7 cells reduced cell viability, induced apoptosis and G1 phase arrest, and inhibited invasion.
  • Downregulation of miR-34a led to opposite effects on cell behavior.

Conclusions:

  • miR-34a acts as a tumor suppressor in breast cancer by inhibiting cell proliferation and invasion.
  • The tumor-suppressive effects of miR-34a are, at least partly, mediated through the inhibition of its target, Notch1.
Keywords:
Notch1breast cancerinvasionmicroRNA-34aproliferation

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