Abstract 817: Assessment and manipulation of DNA methylation in cancer cells using terahertz radiation

Abstract

Abstract Carcinogenesis is closely associated with abnormal regulation of gene expression, among which DNA methylation in one of the key epigenetic modifications. Therefore, several studies have been directed towards the evaluation of DNA methylation. Here, we aimed to experimentally observe the specific signal of methylated DNA in various blood cancer cell lines using terahertz (THz) radiation, which is presented as a resonance in the spectrum. THz radiations are electromagnetic waves having frequencies of 0.1−10 THz, which falls between those of infrared radiation and microwaves. Molecular low-energy motions in THz region, such as collective vibrations, torsion of molecular structures, and hydrogen bonds, is correlated with biological characteristics, i.e., vibrational modes of DNA, structural modes in proteins, cell membrane vibrations, or enzyme activity. These features are usually presented as a characteristic resonance of the modes in the THz spectrum. In our study, the degree of global DNA methylation was obtained by the quantification of the resonance around 1.7 THz, and the results were in good agreement with those obtained by enzyme-linked immunosorbent assay (ELISA). Further, DNA demethylation was performed using high-power THz radiation around the resonance frequency of 1.7 THz, which lead to a 10% to 72% decrease in the degree of DNA methylation as shown in Table 1. Thus, our data shows the feasibility of using THz radiation for the assessment and manipulation of DNA methylation. This is the first study wherein the sensing and manipulation of DNA methylation could be achieved using a non-contact and non-invasive optical technique. Use of THz radiation for the assessment of DNA methylation might be helpful for its rapid processing, while THz manipulation of DNA methylation can avoid the toxicity of chemical demethylating agents. We propose that THz radiation may be useful for the diagnosis of cancer and we expect that THz demethylation might find potential application in cancer therapy. Change of methylation status of blood cancer DNA using high-power THz radiation.SamplesNo ExposureHigh-power THz exxpsoureChange (%) THzChange (%) ELISATHzELISARatio1THzELISARatio2119.621.8510.6111.661.0611.0040.5742.70211.341.388.2210.201.198.5710.0513.77315.151.4310.596.240.738.5558.8148.95417.731.4712.063.510.447.9880.2070.07511.271.437.8810.001.367.3511.274.90STDEV1.58STDEV1.24THz, the amplitude of terahertz resonance; ELISA, optical density of Enzyme linked immunosorbent assay; STDEV, standard deviation1 THz/ELISA of no exposure2 THz/ELISA of high-power THz exposure Citation Format: Hee-Jin Yang, Hwayeong Cheon, Jin Ho Paik, Joo-Hiuk Son. Assessment and manipulation of DNA methylation in cancer cells using terahertz radiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 817.