Changes in miR-21, -138, -141, -135 expression and apoptosis/necrosis levels in HCT116 colon cancer cells under 50 Hz ELF-EMF exposure at 0.4 and 0.8 mT

In this study, we investigated the effect of extremely low-frequency electromagnetic fields (ELF-EMF) on colorectal cancer cells. HCT116 colorectal carcinoma cells were exposed to an electromagnetic field under various conditions encompassing three variables: time (9 and 18 hours), field intensity (0.4 and 0.8 milliTesla), and continuity (continuous and discontinuous), resulting in eight distinct irradiated groups alongside control groups (untreated cancer cells). The levels of apoptosis and necrosis in the different groups were measured and compared using flow cytometry. Furthermore, changes in the expression of miR-21, miR-141, miR-135, and miR-138 were evaluated using RT-qPCR, with the results indicating a significant alteration in the expression of these microRNAs under exposure to electromagnetic fields. Considering previous studies on the effects of these microRNA expressions in cancer cells and our study's findings, the observed expression changes under our applied irradiation conditions - specifically, the downregulation of miR-135 and miR-21, and the upregulation of miR-141-suggested a positive role in controlling and suppressing tumor growth and cancer cells. Conversely, the downregulation of miR-138 appeared to be a negative factor. Additionally, flow cytometry results demonstrated an increase in the rates of apoptosis and necrosis under the employed electromagnetic fields.