Extremely Low-Frequency Electromagnetic Field Altered PPARγ and CCL2 Levels and Suppressed CD44⁺/CD24⁻ Breast Cancer Cells Characteristics

Extremely low-frequency electromagnetic fields (ELF-EMFs) (1–300 Hz) have been found to have practical applications in biological research. A case in point is the effect of ELF-EMF on the regulation of cell fate. In this study, we investigated the correlation between ELF-EMF stimulation of PPARγ to the stemness, tumorigenicity, and invasiveness of breast cancer stem cells in vitro. The CD44⁺/CD24⁻ subpopulation of the breast CSCs was isolated from the MDA-MB-231 breast cancer cell line. The CSCs were then exposed to ELF-EMF and further assays were carried out. ELF-EMF increased the expression of PPARγ and other critical proteins leading to cell cycle arrest and reduced stemness as evidenced by decreased expression of stemness genes and reduced proliferation rate in ELF-EMF-exposed CSCs compared to that in nonexposed CSCs. There was a decrease in the tumor-forming and invasion ability of CSCs that were exposed to ELF-EMFs.