Suppression of Prostate Cancer Cell Growth by Mid-Infrared Rays

Experiments using rubber/resin foam (RB) have already shown that far-infrared rays suppress the proliferation of cancer cells. We will report as a follow up to these findings. When RB was used, the temperature of the culture solution increased by about 0.4°C. This time, with a focus on this temperature rise, a new heating plate was manufactured, and culture experiments were conducted without using RB. It was determined that the suppression of growth was because of heat transfer, not due to the special action of RB. The distribution of heat was calculated using Planck’s formula, and it was speculated that mid-infrared rays around 4.8 µm are involved in the inhibition of cancer cell proliferation. Furthermore, irradiation with a 4.8 µm mid-infrared free electron laser confirmed that the ratio of α-helix to β-sheet changed, providing corroborative evidence for growth suppression.