Up-regulation of miR-144 and miR-375 in the human gastric cancer cell line following the exposure to extremely low-frequency electromagnetic fields

Abstract

Purpose Recently, therapeutic effects of extremely low-frequency electromagnetic field (ELF-EMF), as complementary and alternative medicine, used in the oncology field to control disease symptoms and life quality improvement. Micro RNAs (miRs) expression changes in response to ELF-EMFs were detected in some research projects. MiRs are responsible for the post-transcriptional regulation of gene expression in the cell. This study aimed to evaluate the expression changes of miR-144 and miR-375 in the human gastric adenocarcinoma cell line (AGS) under the exposure of ELF-EMF. Materials and methods After 24 h pre-incubation, AGS cells were exposed to 50 Hz ELF-EMF with a magnetic flux density of 0.2 and 2 mT for 18 h, continuously and discontinuously (1.5h on/1.5h off). A separate sham exposure group was used for each exposure condition. Cell viability was evaluated by MTT assay. Changes of miR-144 expression levels in AGS cells immediately after exposure and 18 and 36 h after the exposure cut off was calculated by QRT-PCR. Results The cell viability of AGS cells was decreased under the exposure of 0.2 and 2 mT EMFs when compared to the control. Up-regulation of miR-144 and miR-375 were observed in AGS cells under the exposure of continuous and discontinuous magnetic flux densities of 0.2 and 2 mT. The results indicated that the miR levels were significantly decreased 18 and 36 h after finishing the exposure, but not reached the normal range. Conclusions The results of this investigation indicated that weak and moderate intermittent 50 Hz ELF-EMFs can induce changes in miRNA expression. Given the role of miR-144 in cell proliferation and tumor suppressor role of miR-375 in cancer cells, overexpression of these two miRs under the exposure of ELF-EMF could be effective in growth inhibition and controlling gastric cancer cells. Changes in gene expression are largely reversible after the magnetic field is cut off. Biographical note: Fatemeh Aalami Zavareh, is an MSc student at the Department of Cellular and Molecular Biology, Faculty of Advanced Sciences and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Soheila Abdi (Corresponding Author), MSc, Ph.D. of Atomic Physics, is Assistant Professor at Department of Physics, Safadasht Branch, Islamic Azad University, Tehran, Iran. Maliheh Entezari, MSc, Ph.D. of Cell Developmental is Associate Professor at Farhikhtegan Medical Convergence, Science Research Center, Farhikhtegan Hospital, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.