Search Results (483)

Background: Reconstructive defect coverage after irradiation remains a challenge in reconstructive surgery, as ionizing radiation leads to tissue ischemia and fibrosis. Therefore, the application of adipose-derived stem cells (ASCs) might be a therapeutic strategy for improving flap survival. Nevertheless, the influence of irradiation on ASCs remains unclear. This study examines the effect of irradiation on 3D-printed ASCs. Methods: ASCs were 3D-cultured. The constructs were irradiated with 2 Gy and 5 Gy; one group treated with 0 Gy served as the non-irradiated control group. Cell viability was measured via a WST-8 assay, a live/dead assay and fluorescence microscopy 24 h, 48 h and 72 h after irradiation. Furthermore, qPCR analysis was performed to detect the expression of HIF-1α, p53 and IL-6 at the same timepoints. Results: Cell survival was high after 24 h. Expression of HIF1α after 24 h was 1.5 times significantly higher in the 2 Gy group compared with the 0 Gy group. The expression of other genes was not significantly affected by irradiation. Measurement of the metabolic activity and survival of the ASCs did not show differences between the different groups at all timepoints. Conclusions: 3D-cultured adipose-derived stem cells maintain high viability after moderate irradiation, suggesting radioresistance. Full article

Since 2014, a model of the individual response to ionizing radiation (IR), based on the radiation-induced nucleoshuttling of the ATM protein kinase (RIANS), has been developed by our lab: after irradiation, ATM dimers monomerize in cytoplasm and diffuse into the nucleus to trigger both recognition and repair of DNA double-strand breaks (DSB), the key-damage of IR response. Moderate radiosensitivity is generally caused by heterozygous mutations of ATM substrates (called X-proteins) that are over-expressed in cytoplasm and form complexes with ATM monomers, which reduces and/or delays the RIANS and DSB recognition. Here, we asked whether molecules, rather than X-proteins, can also influence RIANS. Caffeine was chosen as a potential “X-molecule” candidate. After incubation of cells with caffeine, cutaneous fibroblasts from an apparently healthy radioresistant donor, a patient suffering from Alzheimer’s disease (AD) and another suffering from neurofibromatosis type 1 (NF1) were exposed to X-rays. The functionality of ATM-dependent DSB repair and signaling was evaluated. We report here that caffeine molecule interaction with ATM leads to the inhibition of DSB recognition. This effect is significant in radioresistant cells. Conversely, in the AD and NF1 cells, the DSB recognition is already so low that caffeine does not provide any additional molecular effect. Full article

Antisense genes (usually suffixed by -AS) represent a class of long non-coding RNAs (lncRNAs) transcribed from the opposite strand of annotated human genes or exon(s). A total of ~2236 human antisense genes exist in the human genome. Their genomic locations with respect to the corresponding sense genes, their dysregulated expression patterns in cancer specimens, and clinical associations with patient outcomes reveal their potential importance in clinical settings. As of today, there lacks a comprehensive review of HNC-associated antisense genes/transcripts to help move forward the antisense field for genetic biomarker development or future drug research. In total, 2.3% (52/2236 antisense genes) of all known human antisense genes have been investigated in head and neck cancer (HNC). Thus, we perform a comprehensive review of the genomic aberrations (mutations, copy number changes, RNA-expression dysregulation, and single nucleotide polymorphisms) associated with HNC patient prognosis, disease progression, cancer cell signaling, drug sensitivity, and radio-resistance. Four antisense genes, namely HOXA10-AS, LEF1-AS1, MSC-AS1, and ZEB2-AS1, have been clinically cross-validated and have consistently demonstrated to be associated with patient outcomes in multiple independent cohorts by different research teams, with clear evidence for the prioritization of clinical biomarker development in HNC. Single nucleotide polymorphisms (SNPs) of antisense genes with evidence for HNC risk or outcomes should be further validated in different ethnic groups, for potential global HNC applications. Full article

Colorectal cancer (CRC) incidence is a significant cancer globally, and radiotherapy resistance is a serious problem. Cucurbitacin D (CBD), extracted from many plants such as the tubers of Trichosanthes kirilowii and the fruits of Ecballium elaterium (squirting cucumber), has various therapeutic effects, such as anti-cancer, -inflammation, -diabetes, and -viral infection effects. Since reports have indicated that CBD exhibits effective anti-cancer activity across various cancer types, our hypothesis is that CBD will overcome radioresistance in CRC radiotherapy. In the present study, we identified that CBD, a triterpenoid compound isolated from Trichosanthes kirilowii and Ecballium elaterium, has an anti-cancer and anti-inflammatory effect in vivo and in vitro. In LPS-induced murine models, CBD suppresses LPS-mediated cytokines, including TNFα, IL-6, IL-1β, and COX-2. In CRC xenograft mouse models, CBD treatment results in significantly smaller tumor volumes than the control. In HCT116 and HT29 cells, CBD treatment suppresses cell viability and increases LDH cytotoxicity and caspase-3 activity and cleavage. However, combined treatment of CBD and Z-VAD-FMK inhibits caspase-dependent apoptosis and cell death. Since CBD induces intracellular calcium (Ca²⁺) and reactive oxygen species (ROS) generation, it mediates ER stress-induced apoptotic cell death through the PERK-ATF4-CHOP axis. Moreover, ER stress inducer thapsigargin (TG) mediates synergistic apoptotic cell death in CBD-treated HCT116 and HT29 cells. However, PERK or CHOP knockdown suppresses ER stress-mediated apoptosis in CBD-treated HCT116 and HT29 cells. CBD treatment induces oxidative stress through the NADPH Oxidase 4 (NOX4) and also increases ROS generation. However, NOX4 knockdown and ROS inhibitor NAC or DPI block ER stress-induced apoptotic cell death by inhibiting the suppression of cell viability and the elevation of caspase-3 activity, LDH cytotoxicity, and intracellular ROS activity in CBD-mediated HCT116 and HT29 cells. We established radioresistant CRC models (HCT116R and HT29R); subsequently, radiation (2 Gy) in combination with CBD treatment overcame radioresistance via the modulation of the epithelial–mesenchymal transition (EMT) phenomenon, including the increase in N-cadherin and vimentin and the reduction in E-cadherin. Thus, these results show that CBD may be a new powerful therapeutic approach for CRC radiotherapy. Full article

Background: Lung cancer (LC) is a leading cause of cancer mortality worldwide. While radiotherapy (RT) has been a lasting cornerstone of LC management, there are concerns due to tumor radioresistance and unintended damage to surrounding healthy tissue. Ferroptosis is a recently described mechanism of programmed cell death which has potential to serve as a complementary adjunct to facilitate RT-based LC treatment. Objectives: This review is a comprehensive overview of ferroptosis in the broader context of synergism with RT for LC. Summary: Ferroptosis is essentially driven by intracellular iron overload, which drives the formation of reactive oxygen species, ultimately resulting in membrane instability and cell death. LC lines have been shown to exhibit a heterogeneous mix of pro- and anti-ferroptotic changes. RT shows promise as a potential ferroptosis inducer, especially when complemented with pharmacologic agents such as erastin. Conclusions: Ferroptosis represents a promising modern adjunct to a traditional therapeutic strategy. Future work should focus on rigorous dosage standards to avoid unintended toxicity, repurposing of currently available drugs into ferroptosis inducers, and establishment of safety protocols to begin the pathway towards clinical studies. Full article

Patient-derived organoids (PDOs) preserve patient genotypes and 3D architecture, offering a useful platform to investigate mechanisms of radioresistance and test radiosensitizers. We outline an end-to-end workflow—model establishment, multi-omics profiling, pharmacologic screening, and in vivo confirmation—and spotlight immune-competent, vascularized, and organ-on-chip formats. PDOs reveal actionable mechanisms across DNA damage response, hypoxia–metabolic and immune remodeling, and radiation-induced senescence, enabling rational radiosensitizer selection. Paired tumor–normal organoids concurrently gauge efficacy and normal tissue toxicity, refining the therapeutic index. Remaining gaps (incomplete microenvironment, fractionation modeling, and standardization) are being addressed via reporting standards and co-clinical studies, positioning PDOs to support precision radiotherapy. Full article

Epigenetics encompasses heritable but reversible modifications of gene expression that occur without changes in the DNA sequence and involve mechanisms such as DNA and RNA methylation and histone modifications. These mechanisms modulate chromatin architecture, genome stability, and cellular responses to environmental stressors, and their dysregulation contributes to oncogenesis and cancer progression. In parallel, radiotherapy remains a cornerstone of cancer treatment; furthermore, ionizing radiation induces epigenetic modifications alongside direct DNA double-strand breaks and oxidative damage. Radiation-induced epigenetic changes, including global or locus-specific DNA methylation shifts (e.g., genes promoter CpG islets), histone acetylation and methylation imbalances, are increasingly recognized as key contributors to molecular radioresistance. These adaptive responses may enhance tumor cell survival, affect therapeutic efficacy, and promote metastasis. Understanding the interplay between radiation exposure and epigenetic remodeling opens new perspectives for precision oncology and diagnostics. Epigenetic biomarkers hold potential for predicting treatment response and prognosis, while epigenetic modifiers may sensitize tumors to radiation. This review summarizes current evidence on radiation-induced epigenetic mechanisms and evaluates their diagnostic, prognostic, and therapeutic implications in cancer management. Full article

Nasopharyngeal carcinoma (NPC) is a head and neck malignancy strongly associated with Epstein–Barr virus (EBV) infection and characterized by high radiosensitivity but frequent therapy resistance. Despite advances in radiotherapy, chemotherapy, and immunotherapy, relapse and metastasis remain major challenges, underscoring the need for novel therapeutic approaches. This review aims to provide an integrated overview of the molecular mechanisms governing ferroptosis in NPC and to clarify how these pathways contribute to therapy resistance while revealing potential therapeutic vulnerabilities. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a promising target in NPC. Core regulators include the system xCT–GSH–GPX4 antioxidant axis, iron metabolism, and lipid remodeling enzymes such as ACSL4, with epigenetic modifiers (METTL3, IGF2BP2, HOXA9) and EBV-driven signaling further shaping ferroptosis responses. EBV-driven oncogenic programs substantially reshape ferroptosis sensitivity in NPC by activating the Nrf2/Keap1 antioxidant axis, stabilizing SLC7A11 and GPX4, and modulating iron and redox metabolism. These viral mechanisms suppress ferroptotic stress and contribute to both radioresistance and chemoresistance. Suppression of ferroptosis underlies both radioresistance and chemoresistance, whereas restoration of ferroptosis re-sensitizes tumors to treatment. Natural compounds including solasodine, berberine, cucurbitacin B, and celastrol-curcumin combinations, as well as pharmacologic modulators such as HO-1 inhibitors and GPX4 antagonists, have shown ferroptosis-inducing effects in preclinical models, although their translational potential remains to be clarified. Nanotechnology-based platforms (e.g., Bi₂Se₃ nanosheet hydrogels) further enhance efficacy and reduce toxicity by enabling controlled drug delivery. Biomarker discovery, encompassing ferroptosis-related gene signatures, epigenetic regulators, immune infiltration patterns, EBV DNA load, and on-treatment redox metabolites, provides a foundation for patient stratification. Integration of ferroptosis modulation with radiotherapy, chemotherapy, and immunotherapy represents a compelling strategy to overcome therapy resistance. In synthesizing these findings, this review highlights both the mechanistic basis and the translational promise of ferroptosis modulation as a strategy to overcome treatment resistance in NPC. Future directions include biomarker validation, optimization of drug delivery, early-phase clinical trial development, and multidisciplinary collaboration to balance ferroptosis induction in tumors while protecting normal tissues. Collectively, ferroptosis is emerging as both a vulnerability and a therapeutic opportunity for improving outcomes in NPC. Full article

Survivin (BIRC5) plays a key role in inhibiting apoptosis and is highly expressed in many cancers, including gliomas and breast cancer, where it contributes to tumor progression, therapeutic resistance and poor patient outcomes. With a dual function in promoting cell proliferation and survival, coupled with its potential immunogenicity, survivin is a compelling therapeutic target for cancer; yet, it has no FDA-approved agents to date. Here, we review key findings from preclinical models that emphasize how survivin contributes to chemoresistance and radioresistance; summarize the clinical landscape of survivin-targeted strategies, highlighting both the successes and limitations of these approaches; and outline next steps to optimize survivin-targeted therapies, including the need to integrate biomarker-focused patient selection and the potential for combination therapies. These insights establish survivin as a key driver of cancer progression and a promising target for future therapeutic development. Full article

Introduction: Current treatments for patients with stage III non-small-cell lung cancer (NSCLC) are not sufficiently personalized, resulting in suboptimal outcomes and high mortality rates. The Developing Circulating and Imaging Biomarkers Towards Personalized Radiotherapy in Lung Cancer (VIGILANCE) study employs innovative health technologies to collect a range of clinical data and features. This includes longitudinal analyses of cell-free and circulating tumor DNA from blood samples and radiomic features extracted from standard-of-care imaging. Additionally, patient-reported outcome measures will be collected to capture patients’ symptoms and quality of life. This will provide invaluable insight into the patient experience during and after radiotherapy. We aim to evaluate whether the data, including patient-reported outcomes, can serve as biomarkers to refine treatment strategies, improve post-treatment follow-up and provide patients with realistic outcome predictions. Key endpoints include the following: (1) assessing whether baseline ctDNA status and its early on-treatment dynamics can identify patients with radioresistant disease who could benefit from treatment intensification; (2) determining whether post-radiotherapy ctDNA clearance can predict benefit from consolidation durvalumab, potentially sparing ctDNA-negative patients from unnecessary immunotherapy; and (3) developing integrated models combining novel ctDNA and radiomic biomarkers to distinguish between radiation fibrosis and tumor recurrence and to predict survival. We adopt a pragmatic approach by recruiting patients receiving standard-of-care treatments in a real-world setting. In addition, most of the clinical data is already routinely collected in our center, except for the blood tests for cell-free and circulating tumor DNA analysis. Methods and analysis: This is a single-center, prospective, exploratory, longitudinal, follow-up study, recruiting patients with stage III NSCLC undergoing standard-of-care curative-intent radiotherapy (with or without systemic therapy). Data collection spans from baseline to during radiotherapy and is extended up to 1 year following radiotherapy. The longitudinal analysis aims to describe and characterize dynamic changes in the collected features and assess their utility as prognostic and response biomarkers. Trial registration number: NCT06086574. Full article

Galactic cosmic ray (GCR) radiation is a major barrier to human space exploration beyond Earth’s magnetic field protection. Mesenchymal stem cells (MSCs) are found in all organs and play a critical role in repair and regeneration of tissue. We engineered bone marrow-derived MSCs and evaluated their response to ionizing radiation exposure. Epidermal growth factor receptor (EGFR) expression by certain types of cancers has been shown to induce radioresistance. In this study, we tested the feasibility of transfecting MSCs to overexpress EGFR (eMSC-EGFR) and their capacity to tolerate and recover from X-ray exposure. Quantitative real-time PCR (qRT-PCR) and immunoblotting results confirmed the efficient transfection of EGFR into MSCs and EGFR protein production. eMSC-EGFR maintained characteristics of human MSCs as outlined by the International Society for Cell & Gene Therapy. Then, engineered MSCs were exposed to various dose rates of X-ray (1–20 Gy) to assess the potential radioprotective role of EGFR overexpression in MSCs. Post-irradiation analysis included evaluation of morphology, cell proliferation, viability, tumorigenic potential, and DNA damage. eMSC-EGFR showed signs of radioresistance compared to naïve MSCs when assessing relative proliferation one week following exposure to 1–8 Gy X-rays, and significantly lower DNA damage content 24 h after exposure to 4 Gy. We establish for the first time the efficient generation of EGFR overexpressing MSCs as a model for enhancing the human body to tolerate and recover from moderate dose radiation injury in long-term manned space travel. Full article

Background: Cervical cancer remains a major global health burden, and treatment failure due to radioresistance and secondary drug resistance severely limits clinical outcomes. Enhancer of zeste homolog 2 (EZH2) is a key epigenetic regulator implicated in tumor progression. This study aimed to determine whether EZH2-mediated PTEN silencing drives afatinib resistance via AKT activation in radiation-resistant cervical cancer cells. Methods: A radioresistant cervical cancer cell line (HeLaR) was established following cumulative irradiation (70 Gy). Cell viability, clonogenic survival, methylation-specific PCR (MSP), chromatin immunoprecipitation (ChIP), and Western blot analyses were conducted. EZH2 (Dznep; tazemetostat), PI3K, and AKT inhibitors were tested in combination with afatinib. A xenograft mouse model was used for in vivo validation. Results: HeLaR cells exhibited upregulation of EZH2 and H3K27me3, downregulation of PTEN, and sustained AKT activation. EZH2 inhibition restored PTEN expression, attenuated AKT phosphorylation, and re-sensitized cells to afatinib. MSP and ChIP confirmed EZH2-mediated PTEN promoter silencing. PI3K inhibition reproduced these effects, whereas ERK inhibition had minimal impact. In xenograft models, combined treatment with Dznep and afatinib significantly suppressed tumor growth compared to single agents. Conclusions: EZH2-driven PTEN suppression promotes AKT-dependent afatinib resistance in radiation-resistant cervical cancer. Targeting the EZH2–PTEN–AKT axis may provide a potential therapeutic approach to mitigate combined radioresistance and chemoresistance in recurrent cervical cancer, although further preclinical and clinical validation is required. Full article

Carnosic acid (CA) is a phenolic diterpene with high antioxidant activity that supports its radioprotective capacity. This study aims to determine whether the radiosensitizing effect of CA established in B16F10 melanoma cells also occurs in other melanin-producing cells. Cell survival analysis, apoptosis, intracellular glutathione levels, and cell cycle progression were evaluated by comparing radiosensitive cells (PNT2) with radioresistant melanin-producing cells (MELAN A, SK-MEL-1, and B16F10). In PNT2 cells, CA exhibited radioprotective capacity, with 100% cell survival after exposure to 20 Gy of X-rays (p < 0.001), decreasing apoptosis (p < 0.001) and increasing the GSH/GSSG ratio (p < 0.01), without significant modification in cell cycle progression. However, CA administration to irradiated cells failed to exert radioprotection in MELAN A and SK-MEL-1 cells, and even doubled cell death in B16F10 cells (p < 0.001). Specifically, CA did not alter apoptosis or prevent the decrease in GSH/GSSG ratio in MELAN A and SK-MEL-1 cells, while it intensified radiation-induced cell cycle disruptions in all melanin-producing cells. All of these led to a loss of radioprotective capacity in the melanin-producing cells (MELAN A and SK-MEL-1) and even induced a radiosensitizing effect in B16F10 cells. Understanding the mechanisms of action of substances such as CA could promote new applications that protect healthy cells and exclusively damage neoplastic cells when both are present within the same irradiated volume in cancer patients requiring radiotherapy. Full article

Background/Objectives: The lack of canonical biomarkers and strategies to target radioresistance contribute to poor patient outcomes in triple-negative breast cancer (TNBC). Identifying and targeting novel radioresistance genes will benefit in enhancing radiotherapy response and treatment outcomes in TNBC patients. Methods: A genome-wide CRISPR screen was performed to identify radioresistance genes in the TNBC cell line. An in vitro clonogenic assay was used to assess the antiproliferative effects of Artemis knockout or pharmacologic inhibition of Artemis, either alone or in combination with RT. Tumor doubling time and animal survival were assessed using an in vivo xenograft model. RNA-seq analysis was performed to identify genes and pathways deregulated under Artemis knockout conditions, both alone and in combination with RT. Cellular senescence was evaluated using a β-galactosidase assay. Results: Our CRISPR screen identified Artemis as a top hit in RT-treated TNBC cells, whose depletion led to radiosensitization in TNBC. Artemis knockout significantly reduced cell proliferation and enhanced the antiproliferative effects of RT in vitro. Compared to mice-bearing control MDA-MB-231 xenografts, Artemis knockout exhibited prolonged survival that was further enhanced with RT. Bulk RNA-sequencing indicated that the antiproliferative and radiosensitization effects of Artemis depletion were mediated by the activation of cellular senescence which was confirmed with a β-galactosidase assay. Conclusions: Taken together, our results highlight the critical role of Artemis in TNBC cell proliferation and response to radiation. Our findings identify Artemis as a potential biomarker indicative of sensitivity to radiation and a putative target that could be inhibited to enhance the efficacy of RT in TNBC. Full article

Radiotherapy employs high-energy X-rays to precisely target tumor tissues while minimizing damage to the surrounding healthy structures. Although its clinical efficacy is well established, the immunomodulatory effects of ionizing radiation remain complex and context-dependent. This study investigated the biological effects of radiotherapeutic doses on immune cells by evaluating lymphocyte viability, phenotypic profiles, and cytokine expression levels. Peripheral blood mononuclear cells (PBMCs) were isolated from six healthy donors and irradiated with 0, 2, or 6 Gy using a 6 MV linear accelerator (LINAC). Dose validation with an ionization chamber demonstrated strong agreement between estimated and measured values (intraclass correlation coefficient = 1, 95% CI). Immune subsets, including T cells (CD3+), helper T cells (CD3+CD4+), cytotoxic T cells (CD3+CD8+), regulatory T cells (CD3+CD4+Foxp3+), and natural killer (CD3-CD56+) cells, along with intracellular cytokines interleukin-12 (IL-12) and interferon-gamma (IFN-γ), were analyzed via flow cytometry at multiple time points. The results showed a significant, dose-dependent decline in overall lymphocyte viability (p < 0.01) compared to control. Cytotoxic T cells were the most radiosensitive, followed by helper and regulatory T cells, while NK cells were the most radioresistant. IL-12 expression initially increased post-irradiation, while IFN-γ levels remained variable. These findings demonstrate that radiation induces distinct alterations in immune phenotypes and cytokine profiles, which may shape the immune response. Immune profiling following irradiation may therefore provide valuable insights for optimizing combination strategies that integrate radiotherapy and immunotherapy in cancer treatment. Full article