Development of a Microwave Resonator and Effects of Electric and Magnetic Fields on Cultured Cancer Cells

: Microwaves can both electrically and magnetically permeate a target substance ; however, the permeation can also be affected by the components and composition of the target substance. These factors complicate our understanding of how microwave irradiation affects living cells, thus limiting the therapeutic application of microwave irradiation, such as in cancer treatment. We previously investigated how microwave irradiation promotes cell death in cancer cells and now aim to evaluate the potential mechanisms underlying microwave-induced cell death. In this study, we investigated the mechanism underlying cell death in response to microwave heating. First, a microwave resonator that could precisely control microwave energy and separately generate an electric field and a magnetic field in a dish was developed. This system was employed to confirm whether it is the electric or the magnetic field in the microwave that affects the death of the human pancreatic carcinoma cell line, Panc-1. Cells were killed at the position where the electric field strength was at a maximum, suggesting that dielectric loss might affect cell death. Meanwhile, cell death was not induced at the position where the magnetic field strength was at a maximum, suggesting that the magnetic field might not affect cell death.