Pulsed And Discontinuous Electromagnetic Field Exposure Decreases Temozolomide Resistance In Glioblastoma By Modulating The Expression Of O-6-Methylguanine-Dna Methyltransferase, Cyclin-D1, And P53

Background: Glioblastoma is a malignant and very aggressive brain tumor with a poor prognosis. Despite having chemotherapy concomitant with surgery and/or radiation therapy, the median survival of glioblastoma-affected people is less than 1 year. Temozolomide (TMZ) is a chemotherapy drug used today as the first line of glioblastoma treatment. Several studies have reported that resistance to TMZ due to overexpression of O-6-methylguanine-DNA methyltransferase (MGMT) is the main reason for treatment failure. Several studies described that pulsed-electromagnetic field (EMF) exposure could induce cell death and influence gene expression.Materials and Methods: In this study the authors assessed the effects of EMF (50 Hz, 70 G) on cytotoxicity, cell migration, gene expression, and protein levels in TMZ-treated T98 and A172 cell lines.Results: In this study, the authors show that treatment with a combination of TMZ and EMF enhanced cell death and decreased the migration potential of T98 and A172 cells. The authors also observed overexpression of the p53 gene and downregulation of cyclin-D1 protein in comparison to controls. In addition, T98 cells express MGMT protein following treatment, since A172 cells did not express MGMT.Conclusion: Their data indicate that EMF exposure improved the cytotoxicity of TMZ on T98 and A172 cells and could partially affect resistance to TMZ in T98 cells.