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miR-34a suppresses mutagenesis by inducing apoptosis in human lymphoblastoid TK6 cells

Xinrong Chen1, Yongbin Zhang, Jian Yan

  • 1Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079, USA.

Mutation Research. Genetic Toxicology and Environmental Mutagenesis
|September 13, 2013
PubMed

Insights

MicroRNA 34a (miR-34a) suppresses X-ray induced mutations in human cells by promoting apoptosis. Modulating miR-34a levels affects mutation rates and cell death following radiation exposure.

Area of Science:

  • Molecular Biology
  • Radiation Biology
  • Genetics

Background:

  • MicroRNA 34a (miR-34a) is a tumor suppressor and a target of P53.
  • Previous studies showed X-rays increase miR-34a expression.
  • The role of miR-34a in radiation-induced mutagenesis was unclear.

Purpose of the Study:

  • To investigate the function of miR-34a in X-ray-induced mutations in human lymphoblast TK6 cells.
  • To determine if miR-34a modulates X-ray-induced apoptosis.

Main Methods:

  • TK6 cells were treated with miR-34a precursors or inhibitors.
  • Cells were exposed to X-rays.
  • Micronucleus frequency, mutant frequency (MF) at the Thymidine Kinase (TK) locus, and apoptosis were assessed.

Main Results:

  • miR-34a modulation did not affect X-ray-induced micronucleus frequency.
  • Over-expression of miR-34a reduced X-ray-induced MF in the TK locus.
  • Suppression of miR-34a increased background MF and inhibited apoptosis.
  • miR-34a over-expression promoted apoptosis.

Conclusions:

  • miR-34a acts as a negative regulator of mutagenesis.
  • The mechanism involves the modulation of apoptosis.
  • miR-34a plays a significant role in cellular response to radiation-induced DNA damage.
Keywords:
ApoptosisMutagenesismiR-34a

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