Radiofrequency Radiation and Cancer: A Review

Protective role of melatonin against radiation-induced disruptions in behavior rhythm of zebrafish (danio rerio)

Ionizing radiation, as an increasingly serious environmental pollutant, has aroused widespread public concern. Melatonin, as an indole heterocyclic compound, is known to have anti-inflammatory and antioxidant effects. However, few studies have considered the comprehensive impact of melatonin on radiation damage. In this study, we used zebrafish as experimental materials and employed methods such as acridine orange staining, enzyme-linked immunosorbent assay (ELISA), video tracking for automated behavior analysis, microscope imaging, and real-time fluorescence quantitative analysis. Zebrafish embryos at 2 h post-fertilization (hpf) were treated under four different experimental conditions to assess their growth, development, and metabolic consequences. Our findings indicate that 0.10 Gy gamma radiation significantly augments body length, eye area, spine width, and tail fin length in zebrafish, along with a marked increase in oxidative stress (P < 0.05). Moreover, it enhances cumulative swimming distance, time, and average speed, suggesting elevated activity levels. We observed circadian rhythm phase shifts, peak increases, and cycle shortening, accompanied by abnormal expression of genes pivotal to biological rhythms, exercise, melatonin synthesis, apoptosis/anti-apoptosis, and oxidation/antioxidant balance. The inclusion of melatonin (1 × 10-5 mol/L MLT) ameliorated these radiation-induced anomalies, while its independent effect on zebrafish was negligible. Melatonin can regulate oxidative stress responses, hinders apoptosis responses, and reprogramming the expression of rhythm-related genes in zebrafish embryos after reprogramming radiation stimulation. Overall, our research highlights melatonin's critical role in countering the biological damage inflicted by gamma radiation, proposing its potential as a therapeutic agent in radiation protection.

Abscopal effect: from a rare phenomenon to a new frontier in cancer therapy

Radiotherapy (RT) controls local lesions, meantime it has the capability to induce systemic response to inhibit distant, metastatic, non-radiated tumors, which is referred to as the "abscopal effect". It is widely recognized that radiotherapy can stimulate systemic immune response. This provides a compelling theoretical basis for the combination of immune therapy combined with radiotherapy(iRT). Indeed, this phenomenon has also been observed in clinical treatment, bringing significant clinical benefits to patients, and a series of basic studies are underway to amplify this effect. However, the molecular mechanisms of immune response induced by RT, determination of the optimal treatment regimen for iRT, and how to amplify the abscopal effect. In order to amplify and utilize this effect in clinical management, these key issues require to be well addressed; In this review, we comprehensively summarize the growing consensus and emphasize the emerging limitations of enhancing the abscopal effect with radiotherapy or immunotherapy. Finally, we discuss the prospects and barriers to the current clinical translational applications.

Radioactive Hydroxyapatite Microspheres Empower Sustainable In Situ Tumor Vaccination

Tumor in situ vaccination (ISV) strategies have emerged in clinical trials as promising approaches, involving the release of tumor antigens through local radiotherapy and intratumorally adjuvant injections. However, the current fabrication strategy for achieving a sustainable immune response to ISV remains a pressing challenge. In this study, we present an empowered sustainable ISV method for antitumor therapy using 177Lu-labeled manganese-doped mesoporous hydroxyapatite (177Lu/Mn-HAP) microspheres. The ISV enables the sustained utilization of tumor antigens, leading to the activation of dendritic cells and polarization of macrophages toward the M1 subtype. Consequently, it facilitates the generation of potent CD8+ T-cell responses, enhancing the antitumor effects of internal radiation in both primary and distant tumors. Importantly, this approach achieves complete remission in all tumor-bearing mice and stimulates immune memory to prevent tumor recurrence. Our study highlights a universal and safe ISV strategy capable of inducing potent tumor-specific and sustainable immune response.

Ultrasound-triggered with ROS-responsive SN38 nanoparticle for enhanced combination cancer immunotherapy

Controlled generation of cytotoxic reactive oxygen species (ROS) is essential in cancer therapy. Ultrasound (US)-triggered sonodynamic therapy (SDT) has shown considerable ability to trigger in situ ROS generation. Unfortunately, US therapy alone is insufficient to trigger an efficient anticancer response, owing to the induction of multiple immunosuppressive factors. It was identified that 7-ethyl-10-hydroxycamptothecin (SN38) could notably inhibit DNA topoisomerase I, induce DNA damage and boost robust anticancer immunity. However, limited by the low metabolic stability, poor bioavailability, and dose-limiting toxicity, the direct usage of SN38 is inadequate in immune motivation, which limits its clinical application. Hence, new strategies are needed to improve drug delivery efficiency to enhance DNA topoisomerase I inhibition and DNA damage and elicit a vigorous anticancer cancer immunity response. Considering US irradiation can efficiently generate large amounts of ROS under low-intensity irradiation, in this study, we aimed to design a polymeric, ROS-responsive SN38 nanoformulation for in vivo drug delivery. Upon the in-situ generation of ROS by US therapy, controlled on-demand release of SN38 occurred in tumor sites, which enhanced DNA damage, induced DC cell maturation, and boosted anticancer immunity. Our results demonstrated that a new strategy of involving the combination of a SN38 nanoformulation and US therapy could be used for cancer immunotherapy.

Galectin-9 is a target for the treatment of cancer: A patent review

Galectins, which correspond to a group of proteins capable of recognizing and reversibly binding to β-galactoside carbohydrates, have been the subject of innovation and development of technological products. Galectins play biological roles, such as cell proliferation and apoptosis, and some studies showed differences in the concentrations of galectins dispersed in serum of patients with cancer. For this reason, different studies have evaluated the biotechnological potential of these proteins as biomarkers for the prognosis and/or diagnosis of physiological disorders. Thus, this review discusses recent technological advancements in targeting galectins for the treatment of cancer and using galectins for cancer prognosis and diagnosis. Data mining was performed using the search descriptors "Galectin 9* and cancer*" and the ESPACENET and Cortellis Drug Discovery Intelligence (CDDI) databases. PRISMA guidelines were followed as a basis for literature review which aimed to conduct a systematic study of galectin-9 patents related to cancer prognosis, diagnosis and treatment. Results showed the importance of galectin-9 protein patents in furthering biomedical advancements in the global fight against cancer.

A Comprehensive Review of Small Interfering RNAs (siRNAs): Mechanism, Therapeutic Targets, and Delivery Strategies for Cancer Therapy

Small interfering RNA (siRNA) delivery by nanocarriers has been identified as a promising strategy in the study and treatment of cancer. Short nucleotide sequences are synthesized exogenously to create siRNA, which triggers RNA interference (RNAi) in cells and silences target gene expression in a sequence-specific way. As a nucleic acid-based medicine that has gained popularity recently, siRNA exhibits novel potential for the treatment of cancer. However, there are still many obstacles to overcome before clinical siRNA delivery devices can be developed. In this review, we discuss prospective targets for siRNA drug design, explain siRNA drug properties and benefits, and give an overview of the current clinical siRNA therapeutics for the treatment of cancer. Additionally, we introduce the siRNA chemical modifications and delivery systems that are clinically sophisticated and classify bioresponsive materials for siRNA release in a methodical manner. This review will serve as a reference for researchers in developing more precise and efficient targeted delivery systems, promoting ongoing advances in clinical applications.

BMI1 Silencing Liposomes Suppress Postradiotherapy Cancer Stemness against Radioresistant Hepatocellular Carcinoma

Radiotherapy causes DNA damage by direct ionization and indirect generation of reactive oxygen species (ROS) thereby destroying cancer cells. However, ionizing radiation (IR) unexpectedly elicits metastasis and invasion of cancer cells by inducing cancer stem cells' (CSCs) properties. As BMI1 is a crucial gene that causes radioresistance and an unfavorable prognosis of hepatocellular carcinoma (HCC), BMI1 inhibitor PTC-209 has been encapsulated in a ROS-responsive liposome (LP(PTC-209)) to be temporally and spatially delivered to radioresistant HCC tissue. The ROS generated during IR was not only considered to directly cause tumor cell death but also be used as a stimulator to trigger ROS-responsive drug release from LP(PTC-209). The PTC-209 released into resistant HCC tissue under radiotherapy further led to cancer stem cell (CSC) differentiation and then recovered radiosensitivity of HCC tumor. The suppression of the radioresistant performance of LP(PTC-209) has been proved on radiosensitive and radioresistant Hepa1-6 CSC tumor models, respectively. Our study clarified the relationship between radiotherapy and cancer stemness and provided insights to achieve complete suppression of radioresistant HCC tumor by inhibiting cancer stemness.

Ionizing radiation-induced mitophagy promotes ferroptosis by increasing intracellular free fatty acids

Ferroptosis is a type of cell death characterized by the accumulation of intracellular iron and an increase in hazardous lipid peroxides. Ferroptosis and autophagy are closely related. Ionizing radiation is a frequently used cancer therapy to kill malignancies. We found that ionizing radiation induces both ferroptosis and autophagy and that there is a form of mutualism between the two processes. Ionizing radiation also causes lipid droplets to form in proximity to damaged mitochondria, which, through the action of mitophagy, results in the degradation of the peridroplet mitochondria by lysosomes and the consequent release of free fatty acids and a significant increase in lipid peroxidation, thus promoting ferroptosis. Ionizing radiation has a stronger, fatal effect on cells with a high level of mitophagy, and this observation suggests a novel strategy for tumor treatment.

Inhibition of mitochondrial calcium uptake by Ru360 enhances the effect of 1800 MHz radio-frequency electromagnetic fields on DNA damage

Today, the existence of radio-frequency electromagnetic fields (RF-EMF) emitted from cell phones, wireless routers, base stations, and other sources are everywhere around our living environment, and the dose is increasing. RF-EMF have been reported to be cytotoxic and supposed to be a risk factor for various human diseases, thus, more attention is necessary. In recent years, interfere with mitochondrial calcium uptake by using mitochondrial calcium uniporter (MCU) inhibitor were suggested to be potential clinical treatment in mitochondrial calcium overload diseases, like neurodegeneration, ischemia/reperfusion injury, and cancer, but whether this approach increases the health risk of RF-EMF exposure are unknown. To address our concern, we did a preliminary study to determine whether inhibition of MCU will increase the genotoxicity of RF-EMF exposure in cells, and found that short-time (15 min) exposure to 1800 MHz RF-EMF induced significant DNA damage and cell apoptosis in mouse embryonic fibroblasts (MEFs) treated with Ruthenium 360 (Ru360), a specific inhibitor of MCU, but no significant effects on cell cycle, cell proliferation, or cell viability were observed. In conclusion, our results indicated that inhibiting MCU increases the genotoxicity of RF-EMF exposure, and more attention needs to be paid to the possible health impact of RF-EMF exposure under these treatments.

Multifaceted role of redox pattern in the tumor immune microenvironment regarding autophagy and apoptosis

The reversible oxidation-reduction homeostasis mechanism functions as a specific signal transduction system, eliciting related physiological responses. Disruptions to redox homeostasis can have negative consequences, including the potential for cancer development and progression, which are closely linked to a series of redox processes, such as adjustment of reactive oxygen species (ROS) levels and species, changes in antioxidant capacity, and differential effects of ROS on downstream cell fate and immune capacity. The tumor microenvironment (TME) exhibits a complex interplay between immunity and regulatory cell death, especially autophagy and apoptosis, which is crucially regulated by ROS. The present study aims to investigate the mechanism by which multi-source ROS affects apoptosis, autophagy, and the anti-tumor immune response in the TME and the mutual crosstalk between these three processes. Given the intricate role of ROS in controlling cell fate and immunity, we will further examine the relationship between traditional cancer therapy and ROS. It is worth noting that we will discuss some potential ROS-related treatment options for further future studies.

Targeting the p53 signaling pathway in cancers: Molecular mechanisms and clinical studies

Tumor suppressor p53 can transcriptionally activate downstream genes in response to stress, and then regulate the cell cycle, DNA repair, metabolism, angiogenesis, apoptosis, and other biological responses. p53 has seven functional domains and 12 splice isoforms, and different domains and subtypes play different roles. The activation and inactivation of p53 are finely regulated and are associated with phosphorylation/acetylation modification and ubiquitination modification, respectively. Abnormal activation of p53 is closely related to the occurrence and development of cancer. While targeted therapy of the p53 signaling pathway is still in its early stages and only a few drugs or treatments have entered clinical trials, the development of new drugs and ongoing clinical trials are expected to lead to the widespread use of p53 signaling-targeted therapy in cancer treatment in the future. TRIAP1 is a novel p53 downstream inhibitor of apoptosis. TRIAP1 is the homolog of yeast mitochondrial intermembrane protein MDM35, which can play a tumor-promoting role by blocking the mitochondria-dependent apoptosis pathway. This work provides a systematic overview of recent basic research and clinical progress in the p53 signaling pathway and proposes that TRIAP1 is an important therapeutic target downstream of p53 signaling.