Study of the effects of 0.15 terahertz radiation on genome integrity of adult fibroblasts

Terahertz Irradiation Promotes Angiogenesis in vitro by Enhancing Permeability of the Voltage-Gated Calcium Channel

Terahertz (THz) waves, positioned between microwave and infrared in the electromagnetic spectrum, have promising applications in medical imaging and biomedicine. In this study, terahertz irradiation at 2.52 THz (100 mW/cm2) did not alter the proliferation of human umbilical vein endothelial cells (HUVECs), but significantly enhanced their angiogenic capacity. This enhancement was accompanied by increased levels of angiogenesis-related proteins such as VEGF in the culture supernatant. ATAC sequencing and RNA sequencing revealed a significant increase in the expression of cytoskeleton-associated genes, including PDXP and SH3BP1, post-irradiation. Additionally, intracellular calcium concentration, closely linked to angiogenesis, markedly increased following terahertz exposure. However, diltiazem significantly mitigated the enhanced angiogenic capacity induced by terahertz irradiation. In conclusion, terahertz irradiation promotes angiogenesis in HUVECs, partly by activating the VEGF signaling pathway through increased calcium fluxes.

Research Advances in Terahertz Technology for Skin Detection

Background: With the continuous development of Terahertz technology and its high sensitivity to water, Terahertz technology has been widely applied in various research areas within the field of biomedicine, such as research onskin wounds and burns, demonstrating numerous advantages and potential. Objective: The aim of this study is to summarize and conclude the current research status of Terahertz radiation in skin wounds, burns, and melanoma. Additionally, it seeks toreveal the development status of Terahertz in skin wound models and analyze the short comings of Terahertz in detecting such models at the present stage. Methods: We retrieved relevant literature published from the inception of the Web of Science and CNKI databases up to 2024. The search terms included "THz," "Terahertz," "skin," "wound," "burn," and "melanoma." High-quality articles were included after rigorous screening. Results and Conclusions: This review explores the progress of terahertz radiation technology in the treatment and diagnosis of skin wounds and other related diseases. The results of its interaction with skin tissues provide valuable insights for future research. Terahertz radiation imaging has proven to be effective in assessing burn severity, capturing changes in edema, measuring exudates in dressings, assisting in burn grading and detection, and quantifying wound changes over time. Terahertz technology offers significant advantages in trauma assessment, which has accelerated its development and adoption in this field. (4) However, fs-THz radiation has been found to have the potential drawback of affecting wound healing. This finding necessitates careful consideration before application, and further research is warranted to explore its role in burn assessment and other medical applications.

Transcriptomic Analysis of Blood Collagen-Induced Arthritis Mice Exposed to 0.1 THz Reveals Inhibition of Genes and Pathways Involved in Rheumatoid Arthritis

Inflammation plays an essential role in the phases of rheumatoid arthritis (RA) as the joints secrete a range of molecules that modulate the inflammatory process. While therapies based on physical properties have shown effectiveness in a range of animal experimental models, the understanding of their biological mechanisms remains unclear. The aim of this study was to investigate the immunomodulatory effects of a 0.1 terahertz (THz) wave in rheumatoid arthritis in an attempt to dissect the molecular pathways implicated. The collagen-induced rheumatoid arthritis (CIA) model joint mice were irradiated daily for 30 min over a period of 2 weeks with continuous 0.1 terahertz waves. High-throughput bulk RNA sequencing of the murine blood was performed to analyze and characterize the differences in gene expression changes between the control (Ctrl), CIA (RA), and CIA exposed to THz. Differentially expressed genes, canonical pathway analysis, gene set enrichment, and protein-protein interaction were further run on the selected DEGs. We found that terahertz exposure downregulated gene ontologies representing the "TGF-β signaling pathway", "apoptosis", "activation of T cell receptor signaling pathway", and "non-canonical NF-κB signal transduction". These observations were further confirmed by a decreased level in the expression of transcription factors Nfib and Nfatc3, and an increased level of Lsp1. In addition, the expression of Mmp8 was significantly restored. These results indicate that THz ultimately attenuates the inflammatory response of hemocytes through the T cell and NF-κB pathway, and these changes are reverberated in the blood transcriptome. In this first report of transcriptome sequencing in a model of rheumatoid arthritis exposed to terahertz waves, the downregulated DEGs were associated with anti-inflammatory effects.

Genotoxicity of radiofrequency electromagnetic fields on mammalian cells in vitro: A systematic review with narrative synthesis

BACKGROUND

Over the last decades, great concern has been raised about possible adverse effects to human health due to exposures to radiofrequency electromagnetic fields (RF-EMF, 100 kHz - 300 GHz) emitted by wireless communication technologies. In 2011 the International Agency for Research on Cancer classified RF-EMF as possibly carcinogenic to humans, highlighting that the evidence was weak and far from conclusive. Updated systematic reviews of the scientific literature on this topic are lacking, especially for mechanistic studies.

OBJECTIVES

To perform a systematic review of the scientific literature on genotoxic effects induced by RF-EMF in in vitro experimental models. The overall aim is to assess the confidence and level of evidence of the induced effects in mammalian cell cultures.

METHODS

Full details regarding the eligibility criteria, information sources, and methods developed to assess risk of bias in the included study, are reported in our published protocol (Romeo et al. 2021). The databases NCBI PubMed, Web of Science, and EMF-Portal were used as information sources (last searched on 31st December 2022). In developing the systematic review, we followed the guidelines provided by the National Toxicology Program-Office of Health Assessment and Translation (NTP-OHAT), adapted to the evaluation of in vitro studies. A narrative synthesis of the body of evidence was performed by tabulating data classified according to meaningful groups (endpoints) and sub-groups (exposure parameters). This report, abstract included, conforms to the PRISMA 2020 (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines.

RESULTS

Out of 7750 unique records identified, 159 articles were eligible for inclusion. From the extracted data, we identified 1111 experiments (defined as independent specific combinations of diverse biological and electromagnetic parameters). The large majority (80%) of experiments reviewed did not show statistically significant genotoxic effects of RF-EMF exposures, and most "positive" studies were rated as of moderate to low quality, with negative ratings in the key bias domains. A qualitative evidence appraisal was conducted at the endpoint level, and then integrated across endpoints.

DISCUSSION

To the best of our knowledge, this is the first systematic review of the scientific literature on genotoxic effects in mammalian cell cultures in relation to RF-EMF exposure, which confirms and strengthens conclusions from previous syntheses of this specific topic thanks to the use of transparently reported methods, pre-defined inclusion criteria, and formal assessment of susceptibility to bias. Limitations of the evidence included the frequent reporting of findings in graphical display only, and the large heterogeneity of experimental data, which precluded a meta-analysis.

CONCLUSIONS

In the assessment restricted to studies reporting a significant effect of the exposure on the outcome, we reached an overall assessment of "low" confidence in the evidence that RF-EMF induce genotoxic effects in mammalian cells. However, 80% of experiments reviewed showed no effect of RF exposure on the large majority of endpoints, especially the irreversible ones, independently of the exposure features, level, and duration (moderate evidence of no effect). Therefore, we conclude that the analysis of the papers included in this review, although only qualitative, suggests that RF exposure does not increase the occurrence of genotoxic effects in vitro.

FRAMEWORK AND FUNDING

This systematic review addresses one of the evidence streams considered in a larger systematic review of the scientific literature on the potential carcinogenicity of RF-EMF, performed by scientists from several Italian public research agencies. The project is supported by the Italian Workers' Compensation Authority (INAIL) in the framework of the CRA with the Istituto Superiore di Sanità "BRiC 2018/06 - Scientific evidence on the carcinogenicity of electromagnetic fields".

Doxorubicin-Induced Cardiac Senescence Is Alleviated Following Treatment with Combined Polyphenols and Micronutrients through Enhancement in Mitophagy

Oxidative stress and impaired mitophagy are the hallmarks of cardiomyocyte senescence. Specifically, a decrease in mitophagic flux leads to the accumulation of damaged mitochondria and the development of senescence through increased ROS and other mediators. In this study, we describe the preventive role of A5+, a mix of polyphenols and other micronutrients, in doxorubicin (DOXO)-induced senescence of H9C2 cells. Specifically, H9C2 cells exposed to DOXO showed an increase in the protein expression proteins of senescence-associated genes, p21 and p16, and a decrease in the telomere binding factors TRF1 and TRF2, indicative of senescence induction. Nevertheless, A5+ pre-treatment attenuated the senescent-like cell phenotype, as evidenced by inhibition of all senescent markers and a decrease in SA-β-gal staining in DOXO-treated H9C2 cells. Importantly, A5+ restored the LC3 II/LC3 I ratio, Parkin and BNIP3 expression, therefore rescuing mitophagy, and decreased ROS production. Further, A5+ pre-treatment determined a ripolarization of the mitochondrial membrane and improved basal respiration. A5+-mediated protective effects might be related to its ability to activate mitochondrial SIRT3 in synergy with other micronutrients, but in contrast with SIRT4 activation. Accordingly, SIRT4 knockdown in H9C2 cells further increased MnSOD activity, enhanced mitophagy, and reduced ROS generation following A5+ pre-treatment and DOXO exposure compared to WT cells. Indeed, we demonstrated that A5+ protects H9C2 cells from DOXO-induced senescence, establishing a new specific role for A5+ in controlling mitochondrial quality control by restoring SIRT3 activity and mitophagy, which provided a molecular basis for the development of therapeutic strategies against cardiomyocyte senescence.

Studying the genotoxic effects of high intensity terahertz radiation on fibroblasts and CNS tumor cells

The data is obtained on the effect of high-intensity pulses of terahertz (THz) radiation with a broad spectrum (0.2-3 THz) on cell cultures. We have evaluated the threshold exposure parameters of THz radiation causing genotoxic effects in fibroblasts. Phosphorylation of histone H2AX at Ser 139 (γH2AX) was chosen as a marker for genotoxicity and a quantitative estimation of γH2AX foci number in fibroblasts was performed after cell irradiation with THz pulses for 30 min. No genotoxic effects of THz radiation were observed in fibroblasts unless peak intensity and electric field strength exceeded 21 GW cm-2 and 2.8 MV cm-1 , respectively. In tumor cell lines (neuroblastoma (SK-N-BE (2)) and glioblastoma (U87)), exposure to THz pulses with peak intensity of 21 GW cm-2 for 30 min caused no morphological changes as well as no statistically significant increase in histone phosphorylation foci number.

Inhibition of Cancer Cell Migration and Glycolysis by Terahertz Wave Modulation via Altered Chromatin Accessibility

Metastasis and metabolic disorders contribute to most cancer deaths and are potential drug targets in cancer treatment. However, corresponding drugs inevitably induce myeloid suppression and gastrointestinal toxicity. Here, we report a nonpharmaceutical and noninvasive electromagnetic intervention technique that exhibited long-term inhibition of cancer cells. Firstly, we revealed that optical radiation at the specific wavelength of 3.6  μm (i.e., 83 THz) significantly increased binding affinity between DNA and histone via molecular dynamics simulations, providing a theoretical possibility for THz modulation- (THM-) based cancer cell intervention. Subsequent cell functional assays demonstrated that low-power 3.6  μm THz wave could successfully inhibit cancer cell migration by 50% and reduce glycolysis by 60%. Then, mRNA sequencing and assays for transposase-accessible chromatin using sequencing (ATAC-seq) indicated that low-power THM at 3.6  μm suppressed the genes associated with glycolysis and migration by reducing the chromatin accessibility of certain gene loci. Furthermore, THM at 3.6  μm on HCT-116 cancer cells reduced the liver metastasis by 60% in a metastatic xenograft mouse model by splenic injection, successfully validated the inhibition of cancer cell migration by THM in vivo. Together, this work provides a new paradigm for electromagnetic irradiation-induced epigenetic changes and represents a theoretical basis for possible innovative therapeutic applications of THM as the future of cancer treatments.

A Comparative Study on the Viability of Normal and Cancerous Cells upon Irradiation with a Steady Beam of THz Rays

Terahertz (THz) electromagnetic radiation is commonly used in astronomy, security screening, imaging, and biomedicine, among other applications. Such approach has raised the question of the influence of THz irradiation on biological objects, especially the human body. However, the results obtained to date are quite controversial. Therefore, we performed a comparative study on the viability of normal cells and cancer cells upon irradiation with a steady beam of THz rays. We used human peripheral blood mononuclear cells and cancer cell lines. Primary human mononuclear blood cells (monocytes, and B-, and T-cells) showed an increased death rate, determined by cell counting and fluorescence microscopy, upon 0.14 THz irradiation. The effect of THz radiation was different among malignant cells of B- and T-cell origin (Ramos and Jurkat cells) and epithelial cancer cells (MCF7 and LNCaP). This was demonstrated by cell counting and by the alamarBlue assay. In conclusion, THz radiation can result in the death of human primary and malignant cells. However, the mechanism of this phenomenon is largely unknown. Hence, more work should be done to shed some light on the mechanism of action of THz irradiation in living organisms to enhance technologic developments.

Transcriptome profiling of guinea pig skin exposed to a high-power terahertz source

Terahertz (THz) radiation has a wide range of applications including use in medicine. However, effects of high‐power THz radiation have not been clearly elucidated. We used a 2.52 THz self‐made optically pumped gas THz laser, the low‐ and high‐energy group, to irradiate the backs of Hartley guinea pigs. RNA‐sequencing was done to explore global transcriptional responses in the irradiated skin. Gene Ontology analysis revealed that differentially expressed genes (DEGs) between the unexposed and low‐energy exposed groups were associated with skin development, skin barrier establishment, and multicellular organismal water homeostasis or water loss regulation via the skin. On the other hand, comparison between the unexposed and high‐energy exposed groups showed that the DEGs mediated monocarboxylic acid metabolism, blood vessel morphogenesis, establishment of skin barrier, blood vessel development, or angiogenesis. Our analyses demonstrate the potential effects of high‐power THz source on the skin and sets the basis for further studies on the safety and application of the high‐power THz in dermatology.

Effects of high intensity non-ionizing terahertz radiation on human skin fibroblasts

For the first time, the data have been obtained on the effects of high-intensity terahertz (THz) radiation (with the intensity of 30 GW/cm2, electric field strength of 3.5 MV/cm) on human skin fibroblasts. A quantitative estimation of the number of histone Н2АХ foci of phosphorylation was performed. The number of foci per cell was studied depending on the irradiation time, as well as on the THz pulse energy. The performed studies have shown that the appearance of the foci is not related to either the oxidative stress (the cells preserve their morphology, cytoskeleton structure, and the reactive oxygen species content does not exceed the control values), or the thermal effect of THz radiation. The prolonged irradiation of fibroblasts also did not result in a decrease of their proliferative index.

Cellular effects of terahertz waves

SIGNIFICANCE

An increasing interest in the area of biological effects at exposure of tissues and cells to the terahertz (THz) radiation is driven by a rapid progress in THz biophotonics, observed during the past decades. Despite the attractiveness of THz technology for medical diagnosis and therapy, there is still quite limited knowledge about safe limits of THz exposure. Different modes of THz exposure of tissues and cells, including continuous-wave versus pulsed radiation, various powers, and number and duration of exposure cycles, ought to be systematically studied.

AIM

We provide an overview of recent research results in the area of biological effects at exposure of tissues and cells to THz waves.

APPROACH

We start with a brief overview of general features of the THz-wave-tissue interactions, as well as modern THz emitters, with an emphasis on those that are reliable for studying the biological effects of THz waves. Then, we consider three levels of biological system organization, at which the exposure effects are considered: (i) solutions of biological molecules; (ii) cultures of cells, individual cells, and cell structures; and (iii) entire organs or organisms; special attention is devoted to the cellular level. We distinguish thermal and nonthermal mechanisms of THz-wave-cell interactions and discuss a problem of adequate estimation of the THz biological effects' specificity. The problem of experimental data reproducibility, caused by rareness of the THz experimental setups and an absence of unitary protocols, is also considered.

RESULTS

The summarized data demonstrate the current stage of the research activity and knowledge about the THz exposure on living objects.

CONCLUSIONS

This review helps the biomedical optics community to summarize up-to-date knowledge in the area of cell exposure to THz radiation, and paves the ways for the development of THz safety standards and THz therapeutic applications.

Fluorescent bacterial biosensor E. coli/pTdcR-TurboYFP sensitive to terahertz radiation

A fluorescent biosensor E. coli/pTdcR-TurboYFP sensitive to terahertz (THz) radiation was developed via transformation of Escherichia coli (E. coli) cells with plasmid, in which the promotor of the tdcR gene controls the expression of yellow fluorescent protein TurboYFP. The biosensor was exposed to THz radiation in various vessels and nutrient media. The threshold and dynamics of fluorescence were found to depend on irradiation conditions. Heat shock or chemical stress yielded the absence of fluorescence induction. The biosensor is applicable to studying influence of THz radiation on the activity of tdcR promotor that is involved in the transport and metabolism of threonine and serine in E. coli.

Terahertz radiation and the skin: a review

SIGNIFICANCE

Terahertz (THz) radiation has demonstrated a great potential in biomedical applications over the past three decades, mainly due to its non-invasive and label-free nature. Among all biological specimens, skin tissue is an optimal sample for the application of THz-based methods because it allows for overcoming some intrinsic limitations of the technique, such as a small penetration depth (0.1 to 0.3 mm for the skin, on average).

AIM

We summarize the modern research results achieved when THz technology was applied to the skin, considering applications in both imaging/detection and treatment/modulation of the skin constituents.

APPROACH

We perform a review of literature and analyze the recent research achievements in THz applications for skin diagnosis and investigation.

RESULTS

The reviewed results demonstrate the possibilities of THz spectroscopy and imaging, both pulsed and continuous, for diagnosis of skin melanoma and non-melanoma cancer, dysplasia, scars, and diabetic condition, mainly based on the analysis of THz optical properties. The possibility of modulating cell activity and treatment of various diseases by THz-wave exposure is shown as well.

CONCLUSIONS

The rapid development of THz technologies and the obtained research results for skin tissue highlight the potential of THz waves as a research and therapeutic instrument. The perspectives on the use of THz radiation are related to both non-invasive diagnostics and stimulation and control of different processes in a living skin tissue for regeneration and cancer treatment.

Study on the effects of terahertz radiation on gene networks of Escherichia coli by means of fluorescent biosensors

Three novel fluorescent biosensors sensitive to terahertz (THz) radiation were developed via transformation of Escherichia coli (E. coli) cells with plasmids, in which a promotor of genes matA, safA, or chbB controls the expression of a fluorescent protein. The biosensors were exposed to THz radiation from two sources: a high-intensity pulsed short-wave free electron laser and a low-intensity continuous long-wave IMPATT-diode-based device. The threshold and dynamics of fluorescence were found to depend on radiation parameters and exposure time. Heat shock or chemical stress yielded the absence of fluorescence induction. The biosensors are evaluated to be suitable for studying influence of THz radiation on the activity of gene networks related with considered gene promoters.

Effective demethylation of melanoma cells using terahertz radiation

Terahertz (THz) demethylation is a photomedical technique applied to dissociate methyl-DNA bonds and reduce global DNA methylation using resonant THz radiation. We evaluated the performance of THz demethylation and investigated the DNA damage caused by THz irradiation. The demethylation rate in M-293T DNA increased linearly with the irradiation power up to 48%. The degree of demethylation increased with exposure to THz radiation, saturating after 10 min. Although THz demethylation occurred globally, most of the demethylation occurred within the partial genes in the CpG islands. Subsequently, we performed THz demethylation of melanoma cells. The degree of methylation in the melanoma cell pellets decreased by approximately 10-15%, inducing ∼5-8 abasic sites per 10⁵ bp; this was considerably less than the damaged DNA irradiated by the high-power infrared laser beam used for generating THz pulses. These results provide initial data for THz demethylation and demonstrate the applicability of this technique in advanced cancer cell research. THz demethylation has the potential to develop into a therapeutic procedure for cancer, similar to that involving chemical demethylating agents.

Detection and manipulation of methylation in blood cancer DNA using terahertz radiation

DNA methylation is a pivotal epigenetic modification of DNA that regulates gene expression. Abnormal regulation of gene expression is closely related to carcinogenesis, which is why the assessment of DNA methylation is a key factor in cancer research. Terahertz radiation may play an important role in active demethylation for cancer therapy because the characteristic frequency of the methylated DNA exists in the terahertz region. Here, we present a novel technique for the detection and manipulation of DNA methylation using terahertz radiation in blood cancer cell lines. We observed the degree of DNA methylation in blood cancer at the characteristic resonance of approximately 1.7 THz using terahertz time-domain spectroscopy. The terahertz results were cross-checked with global DNA methylation quantification using an enzyme-linked immunosorbent assay. We also achieved the demethylation of cancer DNA using high-power terahertz radiation at the 1.7-THz resonance. The demethylation degrees ranged from 10% to 70%, depending on the type of cancer cell line. Our results show the detection of DNA methylation based on the terahertz molecular resonance and the manipulation of global DNA methylation using high-power terahertz radiation. Terahertz radiation may have potential applications as an epigenetic inhibitor in cancer treatment, by virtue of its ability to induce DNA demethylation, similarly to decitabine.