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Published on: August 12, 2018

p53-independent upregulation of miR-34a during oncogene-induced senescence represses MYC

N R Christoffersen1, R Shalgi, L B Frankel

  • 1Biotech Research & Innovation Centre, University of Copenhagen, Copenhagen, Denmark.

Cell Death and Differentiation
|August 22, 2009
PubMed

Insights

This study reveals that microRNA-34a (miR-34a) is upregulated during oncogene-induced senescence, independent of p53. It targets MYC, highlighting miR-34a's role as a tumor suppressor.

Area of Science:

  • Molecular Biology
  • Cellular Biology
  • Cancer Research

Background:

  • Aberrant oncogene activation triggers cellular senescence, a crucial tumor-suppressive mechanism.
  • MicroRNAs (miRNAs) are key regulators of gene expression implicated in various cellular processes, including senescence.

Purpose of the Study:

  • To identify miRNAs involved in oncogene-induced senescence.
  • To elucidate the regulatory mechanisms and targets of induced miRNAs during senescence.

Main Methods:

  • Expression profiling of miRNAs in human fibroblasts (TIG3) upon B-RAF activation.
  • Investigating the role of p53 and transcription factor ELK1 in miR-34a regulation.
  • Identifying downstream targets of miR-34a during senescence.

Main Results:

  • miR-34a and miR-146a were significantly induced during oncogene-induced senescence.
  • miR-34a upregulation was independent of p53 and mediated by ELK1.
  • miR-34a targets the proto-oncogene MYC, influencing cell cycle regulators.

Conclusions:

  • miR-34a acts as a tumor suppressor by targeting MYC during oncogene-induced senescence.
  • This highlights alternative regulatory pathways for miR-34a beyond the p53 pathway in cancer.
  • miR-34a plays a significant role in tumor suppression through cell cycle control.

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