2.4 GHz Electromagnetic Field Influences the Response of the Circadian Oscillator in the Colorectal Cancer Cell Line DLD1 to miR-34a-Mediated Regulation

Int J Mol Sci. 2022 Oct 30;23(21):13210. doi: 10.3390/ijms232113210.


Radiofrequency electromagnetic fields (RF-EMF) exert pleiotropic effects on biological processes including circadian rhythms. miR-34a is a small non-coding RNA whose expression is modulated by RF-EMF and has the capacity to regulate clock gene expression. However, interference between RF-EMF and miR-34a-mediated regulation of the circadian oscillator has not yet been elucidated. Therefore, the present study was designed to reveal if 24 h exposure to 2.4 GHz RF-EMF influences miR-34a-induced changes in clock gene expression, migration and proliferation in colorectal cancer cell line DLD1. The effect of up- or downregulation of miR-34a on DLD1 cells was evaluated using real-time PCR, the scratch assay test and the MTS test. Administration of miR-34a decreased the expression of per2, bmal1, sirtuin1 and survivin and inhibited proliferation and migration of DLD1 cells. When miR-34a-transfected DLD1 cells were exposed to 2.4 GHz RF-EMF, an increase in cry1 mRNA expression was observed. The inhibitory effect of miR-34a on per2 and survivin was weakened and abolished, respectively. The effect of miR-34a on proliferation and migration was eliminated by RF-EMF exposure. In conclusion, RF-EMF strongly influenced regulation mediated by the tumour suppressor miR-34a on the peripheral circadian oscillator in DLD1 cells.

Keywords: birc5; bmal1; clock; cry; per; sirtuin1; survivin.

MeSH terms

  • CLOCK Proteins* / genetics
  • CLOCK Proteins* / metabolism
  • Cell Line, Tumor
  • Cell Proliferation
  • Circadian Clocks / genetics
  • Circadian Clocks / physiology
  • Colorectal Neoplasms / genetics
  • Electromagnetic Fields*
  • Humans
  • MicroRNAs* / genetics
  • MicroRNAs* / metabolism
  • Survivin / genetics


  • MicroRNAs
  • Survivin
  • CLOCK Proteins
  • MIRN34 microRNA, human