Frequency-Dependent Demethylation of Cancer DNAs by High-Power Terahertz Radiation

Abstract

A high-power broadband terahertz (THz) system generating THz waves at the 10 mW level is developed to study the demethylation behavior of cancer DNAs by strong THz-field irradiation near the molecular resonant frequency of 1.6 THz. To systematically investigate the influence of the resonant radiation, metamaterial-based band-pass and notch filters are fabricated to selectively transmit or reject the frequency component around 1.6 THz from the generated broadband THz spectrum for treatment. Cancer DNA samples are irradiated with high-power THz waves, with and without the use of these filters, and methylation levels are subsequently measured through enzyme-linked immunosorbent assay (ELISA) technique. Using the 1.6 THz band-pass filter, high-power THz wave irradiation significantly reduces the methylation levels of cancer DNA by at least 19% after 30 min exposure, compared to untreated samples, yielding results similar to those without spectral filtering. In contrast, applying the 1.6 THz notch filter results in negligible changes in methylation levels, underscoring the role of the cancer DNAs’ molecular resonant frequency near 1.6 THz in the decrease of the global methylation. These results suggest that high-power THz waves can effectively modulate the methylation degree in cancer DNA, presenting a promising novel approach for anticancer therapies.