The effect of extremely low frequency electromagnetic fields following on upregulation of miR-21 and miR-29 in gastric cancer cell line

Abstract

Aim: Extremely low frequency electromagnetic fields affect miRNAs expression in cancer cell. In this study, electromagnetic fields exposed to low frequency were used to compare miR-21 and miR-29 expressions in a gastric cancer cell line.

Background: It has been recently suggested that the low frequency electromagnetic fields probably function as a treatment for cancers.

Methods: A cultured cell line of gastric cancer was exposed to an electromagnetic radiation system. The cell line was assigned to 4 groups under continuous and discontinuous radiations of 0.25 and 2.5 ml Tesla field strength. Then, the groups were compared with a non-radiation control group. Later, RNA extraction and cDNA synthesis were prepared for miR-21 and miR-29. Real Time PCR method was used to determine how expressions of these two microRNAs differ. Finally, the results were statistically analyzed.

Results: The percentage of cell viability in the electromagnetic field radiation experienced a significant decrease compared to that of the control group. In addition, expression of miRNA-21 and miRNA-29 had a significant increase as the strength of the electromagnetic field radiations was on an upward trend. Similarly, the percentage of cell viability saw a significant decline in the upregulation of miRNA-21 and miRNA-29 regardless of radiation types.

Conclusion: Findings of this study showed the therapeutic effect of low frequency electromagnetic fields on the gastric cancer cell line. They also indicated that novel biomarkers (miRNA-21 and miRNA-29) could be proposed as potential treatments of gastric cancer, but the results are required to be well established by future studies.

Keywords: Electromagnetic field; Gastric cancer cell line; expression; miR-21; miR-29.

Figure 1

Effects of 10 Hz ELF-EMFs Exposure on the Viability of Gastric Cancer Cell Line (A: Continuous radiation, B: Discontinuous radiation)

Figure 2

ELF-MFs Exposure changes miR-21 (A) and miR-29 (B) Expression in Tumor Cells. (A1, B1: Continuous radiation and A2, B2: Discontinuous radiation).

Figure 3

Correlation between the expression of miR-21 and miR-29 levels after exposure to ELF-EMFs. (R=0.807, p value <0.001)

Figure 4

Associations between miR-21 expression and Cell viability after being exposed to ELF-EMFs. (A: Continuous radiation (R= -0.918, p value <0.001), B: Discontinuous radiation (R= -0.889, p value <0.001))

Figure 5

Associations between miR-29 expression and Cell viability after being exposed to ELF-EMFs. (A: Continuous radiation (R= -0.828, p value <0.001), B: Discontinuous radiation (R= -0.800, p value <0.001))

Figure 6

miR-21 (A) and miR-29 (B) target genes in regulatory pathways