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Ultraviolet-B (UVB) radiation is a major physical factor that induces structural changes in human skin. The aim of this study was to determine whether the novel silent information regulator 1 (sirtuin 1 SIRT1) protein activator, penilumamide, exerted any protective effects against UVB-induced skin damage using human HaCaT keratinocytes as a model. Enzymatic assays were performed to determine the SIRT1-activating ability of penilumamide, which was compared with that of resveratrol, a potent natural product SIRT1 activator with antioxidant and anti-inflammatory properties. Penilumamide markedly activated SIRT1 enzyme activity compared to resveratrol. To further investigate the protective effect of penilumamide against UVB-induced cytotoxicity, HaCaT cells were pretreated with penilumamide (10 μM) for 24 hr followed by irradiation with UVB (40 mJ/cm 2 ). UVB (40 mJ/cm 2 ) irradiation significantly reduced cell viability in a time-dependent manner, whereas pretreatment with penilumamide blocked this effect. Further, penilumamide decreased the levels of intracellular reactive oxygen species (ROS) generated by UVB irradiation in HaCaT cells. Pretreatment with penilumamide also prevented UVB irradiation-induced changes in mitochondrial membrane potential (Δ Ψ m ). In addition, pretreatment with penilumamide significantly reduced the expression levels of pro-inflammatory cytokines, interleukin (IL)-6, IL-8, and IL-10 and phosphorylation of nuclear factor-kB (NF-kB). These results indicate that penilumamide protects HaCaT cells from UVB-induced inflammation. Taken together data demonstrate that penilumamide exerted protective effects against UVB-induced ROS generation in HaCaT cells. Therefore, penilumamide may be considered to be used as a new SIRT1 activator to protect human keratinocyte against UVB-induced damage.

Photothermal therapy, in which a laser is an effective tool, is a promising method for cancer treatment. Laser parameters, including power, irradiation time, type of laser radiation (continuous or chopped), and the concentration of the photothermal agent, can affect the efficiency of this method. Therefore, this study investigated and compared the effects of different laser parameters on the efficiency of photothermal treatment for cervical cancer, which is the fourth most prevalent cancer in women. In addition, we investigated the properties of graphene oxide (GO) synthesized as a photothermal agent under laser radiation, and its effectiveness in achieving the desired therapeutic temperature. This study examined and compared the effects of temperature, nanoparticle concentration, irradiation time, and laser power to understand their impact on heat transfer. The toxicity of graphene oxide at different concentrations in HeLa cancer cells was also evaluated. These results demonstrated low toxicity, particularly after 24 h, with approximately 10% toxicity. The study explored mortality under laser irradiation at various powers and time intervals using continuous and chopped beam irradiation. In addition, a model for temperature prediction using a regression tree was presented. Finally, the combined photothermal effects of graphene oxide and laser irradiation were investigated. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test results reveal significant effects, with a mortality rate of 90% in continuous radiation with a concentration of 0.3 mg/ml and 75% in chopped beam irradiation with concentrations of 0.3 and 0.4 mg/ml. A regression tree model was developed to predict temperature changes based on the GO concentration, laser power, and irradiation time, providing valuable insights for optimizing photothermal therapy parameters. Statistical analysis showed that the combined effect of graphene oxide with continuous laser irradiation was more effective than chopped-beam laser irradiation. However, the chopped-beam irradiation method is expected to cause less damage to surrounding tissues. These findings indicate that photothermal therapy with graphene oxide, chopped, and continuous laser irradiation can potently treat HeLa cancer cells and pave the way for further exploration of targeted cancer treatments., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Background: Electromagnetic radiation (EMR) from wireless technology and mobile phones, operates at various frequencies. The present study analyses the major impact of short-term exposure to 2.4 GHz frequency EMR, using the two model systems chick embryos and SH-SY5Y cell lines. We hypothesized that exposure to this frequency would induce oxidative stress and apoptosis in neurons., Methods and Results: Chick embryos were exposed continuously to 2.4 GHz EMR for 4 h each day over a 5-day period, and comparisons were made with a control group. At the end of the exposure, brain tissues were dissected for histopathological analysis, antioxidant assays, and reactive oxygen species (ROS) detection. Additionally, SH-SY5Y cells were exposed to 2.4 GHz EMR to assess cell viability, DNA damage, and apoptosis. Our results showed that exposure to 2.4 GHz EMR induces oxidative stress in both chick embryos and the SH-SY5Y cells, though no significant tissue-level impact was observed. In SH-SY5Y cells, ROS production increased after 4 h of exposure, accompanied by moderate DNA damage and early markers of apoptosis, such as upregulation of the Bax gene. Furthermore, we observed that antioxidants, such as NAC and Mito-TEMPO, helped mitigate the cytotoxic effects of EMR in both the study models., Conclusion: In conclusion, short-term exposure (4 h) to 2.4 GHz EMR induced moderate cellular and molecular changes, primarily oxidative stress. The oxidative stress was reduced by antioxidants, which suggests potential benefits in preventing EMR-induced cytotoxicity. Extended exposure to EMR beyond 4 h may pose adverse health risks to humans, endorsing further investigation., Competing Interests: Declarations. Ethical approval: Ethical approval is not applicable to this study (Short-term exposure of 2.4 GHz electromagnetic radiation on cellular ROS generation and apoptosis in SH-SY5Y cell line and impact on developing brain tissue). Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature B.V.)

Objective . Mathematical modeling can offer valuable insights into the behavior of biological systems upon treatment. Different mathematical models (empirical, semi-empirical, and mechanistic) have been designed to predict the efficacy of either hyperthermia (HT), radiotherapy (RT), or their combination. However, mathematical approaches capable of modeling cell survival from shared general principles for both mono-treatments alone and their co-application are rare. Moreover, some cell cultures show dose-dependent saturation in response to HT or RT, manifesting in survival curve flattenings. An advanced survival model must, therefore, appropriately reflect such behavior. Approach . We propose a mathematical approach to model the effect of both treatments based on the general principle of sublethal damage (SLD) accumulation for the induction of cell death and irreversible proliferation arrest. Our approach extends Jung's model on heat-induced cellular inactivation by incorporating dose-dependent recovery rates that delineate changes in SLD restoration. Main results . The resulting unified model (Umodel) accurately describes HT and RT survival outcomes, applies to simultaneous thermoradiotherapy modeling, and is particularly suited to reproduce survival curve flattening phenomena. We demonstrate the Umodel's robust performance (R2 0.95) based on numerous clonogenic cell survival data sets from the literature and our experimental studies. Significance . The proposed Umodel allows using a single unified mathematical function based on generalized principles of accumulation of SLD with implemented radiosensitization, regardless of the type of energy deposited and the mechanism of action. It can reproduce various patterns of clonogenic survival curves, including any flattening, thus encompassing the variability of cell reactions to therapy, thereby potentially better reflecting overall tumor responses. Our approach opens a range of options for further model developments and strategic therapy outcome predictions of sequential treatments applied in different orders and varying recovery intervals between them., (Creative Commons Attribution license.)

Introduction: Pancreatic cancer (PC) is one of the most aggressive and lethal malignancies, calling for enhanced research. Pancreatic ductal adenocarcinoma (PDAC) represents 70-80% of all cases and is known for its resistance to conventional therapies. Carbon-ion radiotherapy (CIRT) has emerged as a promising approach due to its ability to deliver highly localized doses and unique radiobiological properties compared to X-rays. In vitro radiobiology has relied on two-dimensional (2D) cell culture models so far; however, these are not sufficient to replicate the complexity of the in vivo tumor architecture. Three-dimensional (3D) models become a paradigm shift, surpassing the constraints of traditional models by accurately re-creating morphological, histological, and genetic characteristics as well as the interaction of tumour cells with the microenvironment. Materials and Methods: This study investigates the survival of pancreatic cancer cells in both 2D and spheroids, a 3D model, following photon, proton, and carbon-ion irradiation by means of clonogenic, MTT, spheroid growth, and vitality assays. Results: Our results demonstrate that carbon ions are more efficient in reducing cancer cell survival compared to photons and protons. In 2D cultures, carbon-ion irradiation reduced cell survival to approximately 15%, compared to 45% with photons and 30% with protons. In the 3D culture model, spheroid growth was similarly inhibited by carbon-ion irradiation; however, the overall survival rates were higher across all irradiation modalities compared to the 2D cultures. Carbon ions consistently showed the highest efficacy in reducing cell viability in both models. Conclusions: Our research highlights the pivotal role of 3D models in unraveling the complexities of pancreatic cancer radiobiology, offering new avenues for designing more effective and precise treatment protocols.

To enhance the treatment of tumors that are resistant to radio- and chemotherapy while minimizing the side effects of radiochemotherapy, researchers are continuously seeking new active compounds for use in combination with radiotherapy. Therefore, the aim of our study was to examine the cytotoxic and radiosensitizing effects of an extract from St. John's Wort ( Hypericum perforatum) , referred to as HP01, on human epithelial tumor cells in vitro. The growth of MCF-7 (breast carcinoma) and HT-29 (colon carcinoma) cells was examined under the influence of HP01. In combination with radiation, the effects of HP01 on cytotoxicity and long-term survival were assessed using a colony formation assay. The number of DNA double-strand breaks was analyzed using the γH2AX assay, while cell cycle distribution was examined via flow cytometry. A growth-inhibiting and cytotoxic effect was observed for both tumor cell lines starting at a concentration of 10 µg/mL HP01. Treatment with HP01 resulted in an inhibition of clonogenic survival of tumor cells after ionizing radiation (6 Gy). The number of DNA double-strand breaks (DSBs) in tumor cells increased with HP01 treatment, but the repair of radiation-induced DNA DSBs was not affected. Cell cycle analysis revealed that HP01, in addition to radiation, enhanced G2/M arrest in MCF-7 and HT-29 cells. Overall, HP01 not only showed a growth-inhibiting effect but also demonstrated a radiosensitizing effect on human tumor cells for the first time. We conclude that the HP01-induced G2/M accumulation of cells may be the main rationale for the drug-induced radiosensitivity. It is therefore a promising candidate for combined therapy in tumor diseases and warrants further investigation.

Low-level laser (LLL) therapy is a well-known noninvasive treatment that stimulates fibroblasts to improve wound healing. LLL can improve fibroblast proliferation and migration without causing toxicity. The present study aimed to evaluate the effects of two laser wavelengths at different irradiation times on canine fibroblasts. Fibroblasts were isolated from canine oral mucosa. After seeding for 24 hr, the fibroblasts were irradiated using the Erchonia ® EVL dual-diode laser at wavelengths of 405 nm (5 mW) and 640 nm (7.5 mW) with irradiation times of 120, 360, and 1,800 sec. The proliferating and viability cells were evaluated 24 hr after laser irradiation. Wound closure rates were calculated at 0, 24, and 48 hr after laser irradiation. Parameters, including proliferation cell, cell viability, and cell migration, tended to be higher in the 360-sec group (405 nm) and 120-sec group (640 nm) than in other groups. Our findings suggest that LLL therapy at wavelengths of 405 and 640 nm with an irradiation time of 120-360 sec (0.26-0.51 J/cm 2 ) can stimulate the proliferation and migration of canine fibroblasts. This finding may contribute to a better understanding of the beneficial role of LLL stimulation in canine wound healing.

The vast majority of breast cancer patients require radiotherapy but some of them will develop local recurrences and potentially metastases in the future. Recent data show that exosomal cargo is essential in these processes. Thus, we investigated the influence of ionising radiation on exosome properties and their ability to modify the sensitivity and biology of non-irradiated cells. Exosomes were isolated from breast cancer cell lines (MDA-MB-231, MCF7, and SKBR3) irradiated with 2 Gy (Exo 2 Gy) or no irradiation (Exo 0 Gy). Despite some differences in their molecular profiles, they did not affect cell viability, proliferation, cell cycle phase distribution, and radioresistance; however, both populations showed the ability to modify cell migration and invasion potential, as confirmed by the downregulation of β-catenin, which is responsible for maintaining the epithelial phenotype. Interestingly, exosomes from irradiated BCa cells were more actively deposited in the endothelial cells (EA.hy926). Furthermore, exosomes tend to lower the expression of CD31, which is responsible for maintaining intact vascularity. This preliminary study demonstrates the vital role of exosomes and their altered profile due to irradiation in the pathobiology of breast cancer.

Although static magnetic fields (SMFs) have been reported to induce only minimal biological effects, it has been proposed that they may alter the effects of other agents, such as ionizing radiation. We sham-exposed or exposed human SH-SY5Y neuroblastoma cells to 0.5-, 1.5-, 2.5-, or 3.5-mT SMFs for 24 h either before or after irradiation at 0, 0.4 or 2.0 Gy. After the exposures, cell cycle distribution (subG1 for apoptosis), reactive oxygen species (ROS) levels, caspase-3 activity, and clonogenic survival were assayed. Increase of G0/G1 and decrease of S phase cells was observed in samples exposed to a 3.5-mT SMF after irradiation. The same exposure schedule with a 1.5-mT SMF was associated with an increase of S phase cells, and an increase in ROS levels. Conversely, a decrease in ROS levels was observed in cells exposed to a 2.5-mT SMF before ionizing radiation. No cell cycle changes were observed with SMF exposures before irradiation. Caspase-3 activity or clonogenic survival was not affected by SMF exposures, irrespective of the exposure schedule. In conclusion, small changes in cell cycle distribution and ROS levels were observed in SH-SY5Y cells exposed to SMFs, with more prominent effects observed when SMF exposure was applied after irradiation. Our results suggest that SMF-induced effects show no linear dependency on magnetic flux density below 5 mT. Notably, SMF exposures did not significantly potentiate the effects of ionizing radiation but rather caused an independent additive effect. Bioelectromagnetics. 00:00-00, 2024., (© 2025 Bioelectromagnetics Society.)

Ultraviolet (UV) irradiation is a major factor contributing to skin photoaging, including the formation of reactive oxygen species (ROS), collagen breakdown, and overall skin damage. Insulin-like growth factor-I (IGF-1) is a polypeptide hormone that regulates dermal survival and collagen synthesis. Echinacoside (Ech), a natural phenylethanoid glycoside, is the most abundant active compound in Cistanches. However, its potential benefits for the skin and the underlying molecular mechanisms remain unclear. The objective of this research is to investigate the protective effect of Ech on human dermal fibroblast cells (HDFs) against UVB-induced skin photodamage. In this study, we demonstrated that Ech promotes IGF-1/IGF-1R/ERK-mediated collagen synthesis and IGF-1/IGF-1R/PI3K-mediated survival pathways, as well as induces IGF-1 secretion to counteract UVB-induced aging in HDFs. Furthermore, UVB-induced accumulation of SA-β-gal-positive cells, ROS, and impaired collagen synthesis were attenuated following Ech treatment. However, the protective effects of Ech were significantly diminished when IGF-1 and IGF-1R expression was silenced using small interfering RNA, indicating that Ech exerts its antiaging effects primarily by activating the IGF-1/IGF-1R signaling pathway. Our findings provide evidence of the antiaging effects of Ech on UVB-induced skin photodamage and suggest its potential development as a supplement in cosmetic dermal protective products., (© 2025 International Union of Biochemistry and Molecular Biology.)

The widespread use of wireless communication technologies has increased human exposure to radiofrequency electromagnetic fields (RF-EMFs). Considering the brain's close proximity to mobile phones and its entirely electrical transmission network, it emerges as the organ most profoundly impacted by the RF field. This study aims to investigate the potential effects of RF radiation on cell viability, apoptosis, and gene expressions in glioblastoma cells (U118-MG) at different exposure times (1, 24, and 48 h). To achieve this, we designed and implemented an in vitro RF exposure system operating at a frequency of 2.1 GHz, specifically for cell culture studies, with an average specific absorption rate (SAR) of 1.12 ± 0.18 W/kg determined through numerical dosimetry calculations. Results reveal a significant influence of a 48 h exposure to a 2.1 GHz RF field on U118-MG cell viability, gene expression, and the induction of caspase (CASP) dependent apoptosis. Notably, increased CASP3, CASP8, and CASP9 mRNA levels were observed after 24 and 48 h of RF treatment. However, only the 48 h RF exposure resulted in apoptotic cell death and a significant elevation in the BAX/BCL-2 ratio. This observed effect may be influenced by extended exposure durations surpassing the cell's doubling time. The increased BAX/BCL-2 ratio, which acts as a key switch for apoptosis, and the heterogeneous morphology of the astrocyte-derived U118-MG cell line may also play a role in this effect., (© 2025 Bioelectromagnetics Society.)

Laser-irradiation-assisted cell gene transfection is sterile and nontoxic, but the low transfection efficiency cannot meet the application requirements. To improve the efficiency, a temporal and spatial shaping method of a femtosecond laser is proposed. Using the time shaping method, we can segment the pulse into subpulses of varying energies and with a defined delay, thereby influencing the interaction between electrons and photons, ultimately enhancing transfection efficiency. The transfection efficiency is further improved by spatially shaping the laser pulse to extend the focusing beam's working distance and reduce the cell's sensitivity to the focal position. Through the characterization of the viability and transfection efficiency of HEK-293T cells, the method achieved efficient and active transfection, with a maximum transfection efficiency of 45.1% and a cell survival rate of 93.6%. This method provides key technical support for femtosecond laser transfection and promotes its further application in clinical practice., (© 2024 Wiley‐VCH GmbH.)

Diffuse intrinsic pontine gliomas (DIPG) are highly aggressive and treatment-resistant childhood primary brainstem tumors with a median survival of less than one year after diagnosis. The prevailing standard of care for DIPG, radiation therapy, does not prevent fatal disease progression, with most patients succumbing to this disease 3-8 months after completion of radiation therapy. This underscores the urgent need for novel combined-modality approaches for enhancing therapy responses. This study demonstrates that the cellular redox modulating drug, copper (II)-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM) dose-dependently (1-3 μM) decreased clonogenic cell survival in SU-DIPG50 and SU-DIPG36 cell lines during 6 h of exposure but had no significant effect on survival in normal human astrocytes (NHA). Additional significant (>90%) decreases in DIPG clonogenic survival were observed at 24 h of Cu-ATSM exposure. However, NHAs also began to show dose-dependent 10-70% survival decreases at this point. Notably, 3 μM Cu-ATSM for 6 h resulted in additive clonogenic cell killing of DIPG lines when combined with radiation, which was not seen in NHAs and was partially inhibited by the copper chelator, bathocuproinedisulfonic acid. Cu-ATSM toxicity in DIPG cells was also inhibited by overexpression of mitochondrial-targeted catalase. These results support the hypothesis that Cu-ATSM is selectively cytotoxic to DIPGs by a mechanism involving H2O2 generation and copper and being additively cytotoxic with ionizing radiation., (© 2025 by Radiation Research Society. All rights of reproduction in any form reserved.)

Purpose: A substantial proportion of children with high risk Neuroblastoma die within the first 5 years post-diagnosis despite the complex treatment applied. In the recent years, tumor environment has been revealed as key factor for cancer treatment efficacy. In this sense, non-tumorigenic Neural Crest progenitor cells from high risk patients, have been described as part of Neuroblastoma stroma, promoting tumor growth and contributing to mesenchyme formation. In this paper we wanted to study the radiobiological behavior of these cells (NB14t) and how they influence the growth of tumorigenic neuroblasts after radiotherapy., Materials and Methods: To achieve our aim, we employed a wide list of methods either using NB14t cells as well as commercial NB cells. We have analyzed viability, survival, cell cyle profiles and differentiation. In addition, cocultured experiments were performed to monitor the influence of stroma cells to tumorigenic neuroblasts., Results: We found that stromal progenitor cells showed an extraordinary radio-resistance either cultured in attached or suspension conditions. In good agreement, we found an enhanced repair of irradiation-induced DNA lesions as compared with commercial cell lines. In addition, according to our data these cells differentiate into a Cancer Associated Fibroblasts (CAFs)-like phenotype, hence contributing to the formation of mesenchymal stroma enhancing the growth of tumor cells after irradiation., Conclusion: Our data show that neural progenitor cells from high risk NB stroma are radio-resistant and promote cancer growth after irradiation. This paper can help to understand the complex cell relationships within a tumor that will determine patient prognosis after radiotherapy.

Background: The clinical advantages of light-emitting diode (LED) therapy in skin healing and its underlying mechanism remain subjects of ongoing debate., Objective: This study aims to explore the impact of LED therapy on normal skin keratinocytes (HaCaT) and in the repair of full-thickness dorsal wounds in Wistar rats., Methods: HaCaT cell viability (SRB assay) and migration (scratch assay) were assessed under LED therapy, comparing stress conditions (2.5% FBS) with sham irradiation and optimal conditions (10% FBS). In vivo, 50 rats with induced wounds were divided into Sham and LED (daily treatment) groups. Euthanasia occurred at 3, 5, 10, 14, and 21 days for clinical, morphological, oxidative stress (MDA, SOD, and GSH), and cytokine analyses (IL-1β, IL-10, TNF-α)., Results: LED therapy significantly enhanced keratinocytes viability compared to sham irradiation, with minimal impact on cell migration. Clinical benefits were prominent on day 10, influencing inflammation progression and resolution on days 3 and 10. Re-epithelization remained unaffected. Reduced MDA and increased GSH levels were observed throughout, while SOD levels varied temporally. Notably, on day 10, LED significantly decreased IL-1β, IL-10, and TNF-α., Study Limitations: Although translational, clinical trial confirmation of observed benefits is warranted., Conclusions: LED therapy expedites cutaneous healing in the experimental model, primarily modulating inflammation and enhancing antioxidant activity., Competing Interests: Conflicts of interest None declared., (Copyright © 2024 Sociedade Brasileira de Dermatologia. Published by Elsevier España, S.L.U. All rights reserved.)

Background: Radioresistance is a major clinical challenge in cancer treatment, as it reduces the effectiveness of radiation therapy (RT). While advances in radiation delivery have enabled the clinical use of high-dose hypofractionated RT, its impact on radioresistant tumors remains unclear. This study aimed to compare the effects of single high-dose RT with conventional fractionated RT on radioresistant breast cancer cells and explore the underlying mechanisms., Methods: Radioresistant cell lines were previously established by exposing SK-BR-3 and MCF-7 cells to 48 Gy and 70 Gy of radiation, respectively, in multiple fractions. We compared the effects of 2 Gy × 5 and 7 Gy × 1 fractions on these cells using clonogenic survival assays and western blot analysis. In vivo antitumor effects were assessed in SR tumor-bearing BALB/c mice irradiated with either 2 Gy × 5 or 7 Gy × 1 fractions., Results: 7 Gy x1 was more efficient at killing radioresistant breast cancer cells than 2 Gy x5. Furthermore, the 7 Gy x1 fraction produced higher levels of reactive oxygen species (ROS) and decreased the expression of radioresistance factors such as p-STAT3, ACSL4, FOXM1, RAD51, Bcl-xL, and survivin. Consistent with the in vitro studies, the 7 Gy × 1 fraction also showed superior antitumor effects in SR tumor-bearing BALB/c mice., Conclusions: Single high-dose RT offers superior advantages over conventional fractionated RT in regard to overcoming radioresistance, supporting its potential as a promising treatment for recurrent tumors.

It is thought that cells surviving ionizing radiation exposure repair DNA double-strand breaks (DSBs) and restore their genomes. However, the recent biochemical and genetic characterization of DSB repair pathways reveals that only homologous recombination (HR) can function in an error-free manner and that the non-homologous end joining (NHEJ) pathways canonical NHEJ (c-NHEJ), alternative end joining (alt-EJ), and single-strand annealing (SSA) are error-prone, and potentially leave behind genomic scars and altered genomes. The strong cell cycle restriction of HR to S/G2 phases and the unparalleled efficiency of c-NHEJ throughout the cell cycle, raise the intriguing question as to how far a surviving cell "reaches" after repairing the genome back to its pre-irradiation state. Indeed, there is evidence that the genomes of cells surviving radiation treatment harbor extensive genomic alterations. To directly investigate this possibility, we adopted next-generation sequencing (NGS) technologies and tested a normal human fibroblast cell line, 82-6 hTert, after exposure up to 6 Gy. Cells were irradiated and surviving colonies expanded and the cells frozen. Sequencing analysis using the Illumina sequencing platform and comparison with the unirradiated genome detected frequent genomic alterations in the six investigated radiation survivor clones, including translocations and large deletions. Translocations detected by this analysis and predicted to generate visible cytogenetic alterations were frequently (three out of five) confirmed using mFISH cytogenetic analysis. PCR analysis of selected deletions also confirmed seven of the ten examined. We conclude that cells surviving radiation exposure tolerate and pass to their progeny a wide spectrum of genomic alterations. This recognition needs to be integrated into the interpretation of biological results at all endpoints, as well as in the formulation of mathematical models of radiation action. NGS analysis of irradiated genomes promises to enhance molecular cytogenetics by increasing the spectrum of detectable genomic alterations and advance our understanding of key molecular radiobiological effects and the logic underpinning DSB repair. However, further developments in the technology will be required to harness its full potential., (© 2025 by Radiation Research Society. All rights of reproduction in any form reserved.)

Androgenetic alopecia (AGA) is a prevalent hair loss disorder and influenced by genetic, hormonal, and environmental factors. Minoxidil and finasteride have been widely used for treating AGA. However, the side effects associated with these drugs often lead to poor patient compliance. In contrast, photobiomodulation (PBM), due to its safety and non-invasiveness, holds promising prospects for use. Although the promoting effects of PBM on AGA have been reported, the mechanisms by which PBM affects dermal papilla cells (DPCs) remain largely unknown. Hence, this study explored the impacts of both continuous wave (CW) and pulsed wave (PW) PBM on DPCs, and revealed the underlying actions of light parameters in PBM. Orthogonal experiments were conducted to evaluate the effects of CW PBM on DPCs at varying irradiances and doses, indicating that irradiance was the crucial parameter, as well as cell viability and proliferation were maximized at 8 mW/cm 2 and 8 J/cm 2 . For PW PBM, response surface methodology was employed to determine the influences of duty cycles, frequencies, and doses. The findings highlighted frequency as a primary factor, with the optimum cell viability observed at peak irradiance 10 mW/cm 2 , duty cycle 80 %, 500 Hz, and 8.8 J/cm 2 . Notably, PBM could enhance cell viability, proliferation, and migration in DPCs by activating the Wnt/β-Catenin signaling and suppressing Transforming Growth Factor signaling, particularly when applied in pulsed mode. Overall, this study determined the key light parameters that influence PBM effectiveness, further identified the optimal light conditions, and preliminary revealed into the mechanisms of PBM in DPCs, highlighting that PW PBM may be a competitive therapeutic option for alleviating AGA in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: Photodynamic Therapy (PDT) is a therapeutic modality that combines the application of a photoactive compound (photosensitizer, PS) with low-power light to generate reactive oxygen species in the target tissue, resulting in cytotoxic damage and cell death, while sparing adjacent tissues. The objective of this study was to evaluate the phototoxicity of a cyanine dye with two chromophores (biscyanines, BCD) in systems with varying levels of cellular organization, and we used the Photogem® (a photosensitizer approved by the Brazilian ANVISA agency for clinical use in Photodynamic Therapy) as a positive control., Materials and Methods: The cytotoxicity of the compounds was assessed in vitro in 2D monolayers, 3D spheroid cultures, and artificial skin models. Four tumoral cell lines A375 (melanoma), HCB-541 (cutaneous squamous cell carcinoma), Vu120T and Vu147T (head and neck cancer), and two normal cell lines fibroblastic HFF-1 and keratinocyte HACAT were used in this study. Cell viability, migration, production of reactive oxygen species, expression of proteins linked to DNA damage and repair, internalization, and skin permeation of PS agents., Results: Light irradiation in the presence of the PS resulted in greater cytotoxic effects for BCD as compared to Photogem®, which was accompanied by an increase in the production of reactive oxygen species including H 2 O 2 , elevated levels of cleaved PARP, and a higher rate of phosphorylated H2AX protein. BCD demonstrated enhanced internalization and bioaccumulation in the spheroids and equivalent skin models., Conclusion: BCD, as a photosensitizer, showed higher cytotoxicity, with an increased ability to generate reactive oxygen species. This led to reduced cell viability, inhibited migration, and upregulated DNA damage-related proteins. Additionally, its enhanced cellular uptake improved skin barrier permeability, making BCD a strong candidate for in vivo Photodynamic Therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Branched-chain amino acids (BCAAs) facilitate cancer cell proliferation and survival. Stresses, including X-irradiation, increase BCAA uptake. However, the role of BCAA metabolism in cancer cell survival remains unclear. Therefore, this study aimed to elucidate the role of the BCAA catabolic pathway in cancer cell survival following X-irradiation. X-irradiation dose-dependently dephosphorylated branched-chain α-keto acid dehydrogenaseE1α (BCKDHA) suggesting the activation of the BCKDH complex, which catalyzes the rate-determining step of BCAA catabolism. We considered that activation of BCKDH promoted the BCAA catabolism, which resulted in cancer cell resistance to X-irradiation. Consistent with this notion, cells with BCKDHA knockdown exhibited increased radiosensitivity, which was associated with the increase in mitotic catastrophe and residual double-strand breaks by decreasing cellular ATP levels after X-irradiation. Our results suggest that BCKDHA dephosphorylation promotes BCAA catabolism, leading to cell survival by mitigating DNA damage after X-irradiation. Thus, BCAA catabolic pathway may be a target for radiation therapy., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: It is possible to combine theoretical models with Monte Carlo simulations to investigate the relationship between radiation-induced initial DNA damage and cell survival. Several combinations of models have been proposed in recent years, sparking interest in comparing their predictions in view of future clinical applications., Methods: Two in silico methods for calculating cell survival fractions were optimized for proton irradiation of the Chinese hamster V79 cell line, for LET values ranging from 3.40 and 100 keV/μm. These methods, based on different Monte Carlo codes and theoretical models, were benchmarked against published V79 cell survival data to identify the sources of discrepancies., Results: The predictive capacities of the methods were evaluated for several proton LET values using an external dataset. After recalibrating model parameters, multiple methods were assessed. This approach helped identify sources of variation, the main one being the simulated number of DSBs, which differed by a factor up to 3 between the two Monte Carlo codes. In this process a new method was defined, that, in all but one case, allows for a reduction in prediction error of up to 56%. Additionally, a freely available GUI for computing cell survival was refined, to facilitate further comparison of diverse theoretical models., Conclusion: The systematic comparison of two predictive chains, characterized by distinct applicability ranges and features, was conducted. Optimization and analysis of various combinations were undertaken to elucidate differences. Addressing and minimizing such discrepancies will be crucial for further enhancing the reliability of predictive models of cell survival, aiming for biologically informed treatment planning., Competing Interests: Declaration of competing interest The authors and their respective institutions declare no conflicts of interest., (Copyright © 2024 Associazione Italiana di Fisica Medica e Sanitaria. Published by Elsevier Ltd. All rights reserved.)

Objective . The present work shows the first extensive validation of the generalized stochastic microdosimetric model (GSM 2 ). This mechanistic and probabilistic model is trained and tested over cell survival experiments conducted with two cell lines (H460 and H1437), three different types of radiation (protons, helium, and carbon ions), spanning a very broad LET range from1 keVμm-1up to more than300 keVμm-1. Currently, the existing mechanistic radiation biophysical models show some limitations in describing cell killing without the addition of ad hoc corrections, especially in the high-LET regime, where the overkill effect is observed. Approach . The experimental irradiation conditions have been accurately reproduced with Monte Carlo simulations using the GEANT4-based TOPAS computational toolkit. We show the main and unique features of GSM2, i.e. how it can predict the biological response by considering the full information on the stochasticity of radiation through the microdosimetric spectrum, which is supposed to be the best descriptor of radiation quality. Main results . Well-matching results for different biological endpoints with the natural presence of the overkill effect fully display the predictive power of GSM 2 . Significance . This study shows the complete generality and flexibility of GSM 2 and its ability to successfully predict the cell survival probability from very different particle radiation fields. Consequently, we demonstrate the dependence of the relative biological effectiveness on the whole microdosimetric spectrum, which fully includes the stochasticity inherently given by radiation-matter interaction., (Creative Commons Attribution license.)

Background: Embryoid bodies (EBs) are three-dimensional (3D) multicellular cell aggregates that are derived from stem cell and play a pivotal role in regenerative medicine. They recapitulate many crucial aspects of the early stages of embryonic development and is the first step in the generation of various types of stem cells, including neuronal stem cells. Current methodologies for differentiating stem cells into neural embryoid bodies (NEBs) in vitro have advanced significantly, but they still have limitations which necessitate improvement. Photobiomodulation (PBM) a low powered light therapy is a non-invasive technique shown to promote stem cell proliferation and differentiation., Methods: This in vitro study elucidated the effects of photobiomodulation (PBM) on the differentiation of immortalized adipose-derived stem cells (iADSCs) into NEBs within a 3D cell culture environment. The study utilized PBM at wavelengths of 825 nm, 525 nm, and a combination of both, with fluences of 5 and 10 J/cm 2 . Morphology, viability, metabolic activity, and differentiation following PBM treatment was analysed., Results: The results revealed that the effects of photobiomodulation (PBM) are dose dependent. PBM, at 825 nm with a fluence of 10 J/cm 2 , significantly enhanced the size of neural embryoid bodies (NEBs), improved cell viability and proliferation, and reduced lactate dehydrogenase (LDH) levels, indicating minimal cell damage. Interestingly, the stem cell marker CD 44 was upregulated at 5 J/cm 2 in all treatment groups at 24 and 96 hpi, CD105 increased with 825 nm at 10 J/cm 2 at 24 hpi, which may be attributed to a heterogeneous cell population within the NEBs. Pax6 expression showed transient activation. Nestin was upregulated at 825 nm with 10 J/cm 2 at 96 hpi, suggesting a promotion of neural precursor populations. GFAP an intermediate filament protein was upregulated at 825 nm at 10 J/cm2 at both 24 and 96 hpi. SOX2, a pluripotency marker, was expressed at 5 J/cm 2 across all wavelengths. Neu N a neuronal nuclei marker was expressed at 5 J/cm 2 in all treatments at 24 hpi and over time the expression was observed in all treatment groups at 10 J/cm 2 ., Conclusion: In conclusion, the application of PBM at 825 nm with a fluence of 10 J/cm 2 during the differentiation of iADSCs into NEBs resulted in optimal differentiation. Notably, the neuronal marker Nestin was significantly upregulated, highlighting the potential of the PBM approach for enhancing neuronal differentiation its promising applications in regenerative medicine., Competing Interests: Declarations. Ethics approval and consent to participate: (1) Title of the approved project: Differentiation of ADMSCS into brain organoids using photobiomodulation for developmental and disease modeling and regeneration; (2) Name of the institutional approval committee or unit: University of Johannesburg Faculty of Health Sciences Research Ethics Committee; (3) Approval number: REC-1972–2023 (4) Date of approval: 21 April 2023. Consent for publication: NA. Competing interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024. The Author(s).)

Degenerative retinal diseases can lead to blindness if left untreated. At present, there are no curative therapies for retinal diseases. Therefore, effective treatment strategies for slowing the progression of retinal diseases and thus improving patients' life standards are urgently needed. The present study aimed to assess the effect of sinusoidal electromagnetic field (EMF) (50 Hz, 1.3 mT) treatment for 15 and 30 min on spontaneously arising retinal pigment epithelial cells (ARPE-19) and retinal ganglion cells (RGC-5) and its short-term post-treatment significance. Our study indicated the beneficial impact of EMF treatment on the proliferative and migratory capacity of the tested cells. ARPE-19 and RGC-5 cells exposed to an EMF exhibited elevated levels of HO-1, increased N6-methyladenosine (m 6 A) and N5-methylcytosine (m 5 C) status mediated by METTL3 and NSUN2, respectively, and changes in levels of DNA damage repair factors, which may contribute to the regenerative properties of ARPE-19 and RGC-5 cells. Overall, this analysis showed that EMF (sinusoidal, 50 Hz, 1.3 mT) treatment may serve as a potential therapeutic strategy for retinal diseases.

Liew and Mairani (2024 Phys. Med. Biol . 69 248001) commented on our previous reply to comments on our paper, 'Modeling for predicting survival fraction of cells after ultra-high dose rate irradiation'. We appreciate their comments on the choice of experimental data on DNA damage for cell survival and agree that the estimate of the dose-response curve on cell survival depends on the selection of DNA damage data. As an additional benchmark test, we compared the relative biological effectiveness (RBE) predicted using the recommended DNA damage data measured in normoxia with those reported in our original paper, and confirmed that the difference in RBE was less than 8%. Although our model allows for the estimation of cell survival and RBE under ultra-high dose rate (UHDR) irradiation, we highlight that a further accumulation of experimental data on DNA damage under UHDR irradiation is necessary for the further development of biophysical models concerning the mechanistical estimation of biological effects., (© 2024 Institute of Physics and Engineering in Medicine. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

We comment on the reply by Shiraishi et al to our comments regarding their recently published study 'Modeling for Predicting Survival Fraction of Cells after Ultra-High Dose Rate Irradiation'. While we appreciate the effort of the authors to consider our comments, we see ourselves compelled to add another short comment as we believe that some of our suggestions have been misrepresented. This may have resulted in a misguiding re-evaluation of the model., (© 2024 Institute of Physics and Engineering in Medicine. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Objective. To develop an empirical model to predict carbon ion (C-ion) relative biological effectiveness (RBE). Approach. We used published cell survival data comprising 360 cell line/energy combinations to characterize the linear energy transfer (LET) dependence of cell radiosensitivity parameters describing the dose required to achieve a given survival level, e.g. 5% (D 5% ), which are linearly correlated between photon and C-ion radiations. Based on the LET response of the metrics D 5% and D 37% , we constructed a model containing four free parameters that predicts cells' linear quadratic model (LQM) survival curve parameters for C-ions, α C and β C , from the reference LQM parameters for photons, α X and β X , for a given C-ion LET value. We fit our model's free parameters to the training dataset and assessed its accuracy via leave-one out cross-validation. We further compared our model to the local effect model (LEM) and the microdosimetric kinetic model (MKM) by comparing its predictions against published predictions made with those models for clinically relevant LET values in the range of 23-107 keV μ m -1 . Main Results. Our model predicted C-ion RBE within ±7%-15% depending on cell line and dose which was comparable to LEM and MKM for the same conditions. Significance. Our model offers comparable accuracy to the LEM or MKM but requires fewer input parameters and is less computationally expensive and whose implementation is so simple we provide it coded into a spreadsheet. Thus, our model can serve as a pragmatic alternative to these mechanistic models in cases where cell-specific input parameters cannot be obtained, the models cannot be implemented, or for which their computational efficiency is paramount., (Creative Commons Attribution license.)

This study aimed to assess the impact of nutritional conditions and irradiation parameters on the viability and proliferation of murine preosteoblasts. MC3T3-E1 cells were maintained under standard culture conditions (αMEM supplemented with 10% fetal bovine serum) or nutritional deficit conditions (αMEM without serum) and irradiated or not (control) with an InGaAlP diode laser at wavelengths of 660 nm (red) or 790 nm (infrared), with doses of 1, 4, or 6 J/cm², in a single dose in continuous mode. Cell viability and proliferation were assessed 24, 48, and 72 h after irradiation using the Alamar blue reduction assay. The cell cycle and events related to cell death were evaluated via propidium iodide (PI) staining and Annexin V/PI assays, respectively, through flow cytometry. The data revealed that in cells cultured with normal nutrition (10% FBS), there was no significant difference (p > 0.05) in cell viability or proliferation among the different irradiation protocols. In contrast, in the experiments conducted under nutritional deficiency, the infrared laser at a dose of 6 J/cm² significantly increased (p < 0.05) cell viability and proliferation compared with those of the control group at 72 h. The data were confirmed by cell cycle and cell death events (Annexin V/PI) assays. These results suggest that in vitro PBM yields more consistent biostimulatory effects on pre-osteoblasts subjected to nutritional deficiency, highlighting the need for attention to simulate these conditions in studies with laser therapy in in vitro bone disease models and in in vitro experiments using PBM for bone tissue engineering., Competing Interests: Declarations. Clinical trial number: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Breast cancer remains a global health challenge, prompting interest in the anticancer properties of other drugs, including chlorpromazine (CPZ). This study presents a novel approach in breast cancer treatment using laser irradiated CPZ. CPZ dissolved in distilled water, was exposed to 266 nm laser irradiation for varying durations, characterized by UV-Vis and FTIR spectroscopy, followed by drug-likeness and ADME-Tox predictions. In vitro assays evaluated the cytotoxicity and cellular effects on MCF-7 breast cancer cells, and compared with MCF-12 A healthy cell line. Laser irradiation altered CPZ molecular structure resulting in photoproducts with favourable drug-like properties and ADME-Tox profiles. In vitro evaluations demonstrate dose and irradiation time-dependent cytotoxicity against breast cancer cells, and reduced toxicity on healthy cell line. Significant alterations in F-actin organization, and excessive ROS generation were also proved, suggesting the potential of laser-modified CPZ for breast cancer therapy. This study introduces a novel approach to breast cancer treatment through laser irradiated CPZ, highlighting promising advancements in therapy and emphasizing the role of laser-generated compounds., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Cherenkov radiation is emitted during x-ray irradiation in a linear accelerator (LINAC). Cherenkov light contains many short wavelength components, including ultraviolet (UV) light, which is well-known for its bactericidal effects. A similar phenomenon is probable for human cancer cells. To assess the effect of Cherenkov light on cell death in x-ray irradiation, we employed simulations and UV cell survival data. We measured the survival rates of HeLa cells exposed to 254 nm (UVC) and 310 nm (UVB) light to determine the 50% lethal dose (LD50) required to kill 50% of the cells. For other wavelengths, we utilized literature values to establish the relationship between wavelength and LD50. Due to the broad range of the Cherenkov light spectrum, we need LD50 as a function of wavelength to estimate cell survival solely from Cherenkov light. A Monte Carlo simulation was used to calculate the fluence distribution of Cherenkov light in a 300 mm 3 phantom comprised of soft tissue, both with and without absorption of visible light. The latter scenario is considered to be most influenced by Cherenkov light. By combining the fluence distribution and the wavelength-LD50 relationship, we determined the distribution of the survival rate. Our findings indicate that, in the absence of absorption, a radiation dose of approximately 90 Gy or greater is necessary for Cherenkov light to have any effect. As a result, the impact of Cherenkov light on cell survival can be considered negligible for typical dose of 2 Gy., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Our previous study demonstrated that the linear quadratic model appeared to be not well-suited for high dose per fraction due to an observed increase in α/β ratio as the dose per fraction increased. To further validate this conclusion, we draw the cell survival curve to calculate the α/β ratio by the clone formation experiment and then convert the fractionated radiation dose into an equivalent single hypofractionated radiation dose comparing with that on the survival curve. Western Blot and laser confocal immunofluorescence were used to detect the expression of γ-H2AX and RAD51 after different fractionated modes of radiation. We constructed a murine xenograft model, and changes in transplanted tumor volume were used to evaluate the biological effects after different fractionated radiation. The results demonstrated that when fractionated radiation dose was converted into equivalent single hypofractionated radiation dose, the effectiveness of hypofractionated radiation was overestimated. If a larger α/β ratio was used, the discrepancy tended to become smaller. γ-H2AX was higher in 24 h after a single high dose radiation than the continuous expression of the DNA repair marker RAD51. This implies more irreparable damage in a single high dose radiation compared with fractionated radiation. In the murine xenograft model, the effectiveness of hypofractionated radiation was also overestimated, and additional fractions of irradiation may be required. The conclusion is that after single hypofractionated radiation, the irreparable damage in cells increased (α value increased) and some repairable sublethal damage (β value) was converted into irreparable damage (α value). When α value increased and β value decreased, the ratio increased., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Iodine has an anti-proliferative effect on cancer cells; however, its effects have not been explored adequately. The aim of this study was to evaluate the therapeutic potential of iodine and radioiodine by assessing their effects on the viability of various breast cancer cell lines: MCF7, SKBR3, and MDA-MB231. The viability of cells was measured in treated cells exposed to six doses of iodine (5, 10, 20, 40, 60, 80 µM) and two doses of radioiodine (3.7 × 10 4 and 3.7 × 10 5 Bq). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and modified clonogenic assays were used to assess cell viability. Exposure to 80 µM of iodine significantly reduced the viability of all cell types. The cells were then exposed to a 50% inhibitory concentration (IC 50 ) dose. When the cells were exposed to the IC 50 dose of iodine, the MCF7 cell viability was reduced by 42.6 ± 0.14% (IC 50 dose 12.88 µM), 40.2 ± 0.08% for SKBR3 (IC 50 dose 11.03 µM) and 47.0 ± 0.02% for MDA-MB231 (IC 50 dose 14.09 µM). All cells were also exposed to 3.7 × 10 4 Bq and 3.7 × 10 5 Bq radioiodine. Both doses significantly reduced the cell viability of MCF7 and SKBR3 cells compared to the unexposed control cells (all had p  < 0.05), while MDA-MB231 cell viability only reduced significantly after 3.7 × 10 5 Bq of radioiodine exposure compared to the unexposed control cells ( p  < 0.05). This study highlighted that iodine had a toxic effect on breast cancer cells, and radioiodine enhanced the toxicity to breast cancer cells. The types of cancer cells and doses of iodine and radioiodine influenced the effect. These findings suggest that iodine and radioiodine hold promise as therapeutic agents for breast cancer, similar to their established use in thyroid disease treatment. However, further in vivo studies are important to provide more evidence., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results., (© 2024 The Author(s).)

Background: Studies show that photobiomodulation therapy (PBMT) boosts cellular ATP production and cell growth and reduces inflammation. Additionally, mechanical tension affects gene expression, impacting cellular functions like proliferation and migration. Objective: We investigated the impact of PBMT on OCCM-30 cementoblast cells under tensile stress, focusing on cell survival, differentiation, and inflammatory responses, particularly relating to orthodontic tooth movement and root resorption. Methods: Cultured OCCM-30 cells under negative pressure received PBMT with a 10.6 μm wavelength in continuous mode at 1.0 W power for 3, 5, or 10 sec, corresponding to energy densities of 3, 5, or 10 J/cm 2 . We assessed cell viability with the Presto Blue assay and inflammatory markers Interleukin 6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) through western blots at 1, 12, 24 h, and 7 days post-irradiation. Results: PBMT improved cell viability over time while maintaining levels of inflammatory markers. alkaline phosphatase levels dropped initially but increased after 7 days, suggesting enhanced cementoblast differentiation. IL-6 levels rose gradually, with 3J and 5J treatments showing significantly higher levels than the control. iNOS levels spiked within the first 24 h, then declined by day 7. COX-2 levels consistently rose, with the 5J treatment showing greater increases. Conclusions: PBMT appears to support cementoblast survival and differentiation while managing inflammation, potentially aiding root repair during orthodontic treatments and reducing inflammatory root resorption.

The efficacy of radiation treatment (RT) of head and neck squamous cell carcinoma (HNSCC) is limited by radioresistance and the toxicity of FDA approved radiosensitizers. In extension to our previous research where we demonstrated that telaglenastat (CB839) increased efficacy of RT in in vitro and in vivo HNSCC models, here, we examine the radiosensitizing effects of telaglenastat in comparison to cisplatin's, as cisplatin is currently the standard of care for concurrent therapy. Combination of telaglenastat with RT reduced tumor volume in a HNSCC patient derived xenograft mouse model. The efficacy of telaglenastat with RT in reducing cell survival and increasing apoptosis was similar if not greater than that of cisplatin with RT in Cal27 and HN5 HNSCC cells. The addition of telaglenastat increased reactive oxygen species and reduced the antioxidant glutathione in both Cal27 and HN5 cells. Reverse Phase Protein Array analyses revealed alterations in cell death and DNA damage response proteins. This study provides the scientific underpinnings for the use of telaglenastat as a radiosensitizer in the treatment of HNSCC either as an alternative to cisplatin or in cisplatin-ineligible patients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

Aim: Retinal photochemical damage (RPD) plays a significant role in the development of various ocular diseases, with Caspase-1 being a key contributor. This study investigates the protective effects of Caspase-1 gene-mediated pyroptosis against RPD., Methods: Differentially expressed genes (DEGs) associated with RPD were identified through the analysis of two expression profiles from the GEO database. Correlation analysis was used to pinpoint pyroptosis-related genes (PRGs) linked to RPD. A Caspase-1 knockout 661 W cell line was generated via CRISPR-Cas9 gene editing, and single-cell colonies were screened and purified. Validation of knockout cells was performed through RT-qPCR, gene sequencing, and Western blot analysis. Comparative assays on cell proliferation, intracellular reactive oxygen species (ROS), and cytotoxicity were conducted between wild-type and Caspase-1 knockout cells under light exposure. Further RT-qPCR and Western blot experiments examined changes in the mRNA and protein levels of key pyroptosis pathway components., Results: Significant alterations in Caspase-1 expression were observed among PRGs. Homozygous Caspase-1 knockout cell lines were confirmed through RT-qPCR, genomic PCR product sequencing, and Western blot analysis. Compared to wild-type 661 W cells, Caspase-1 knockout cells exhibited higher viability and proliferation rates after 24 h of light exposure, alongside reduced LDH release. The expression of downstream pyroptosis factors at both the mRNA and protein levels was markedly decreased in the knockout group., Conclusion: CRISPR/Cas9-mediated Caspase-1 knockout enhanced the resistance of 661 W cells to photochemical damage, suggesting that Caspase-1 may serve as a potential therapeutic target for RPD-related diseases., Competing Interests: Declaration of competing interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Recently, the use of natural products as skin photoprotective agents has been in increasing demand. This study investigated the bioactivity of phycocyanin (PC) extracted from Spirulina sp. on human skin fibroblast cell line (CCD-966SK), specifically focusing on apoptosis, necrosis, anti-inflammatory effects, and enzymatic reactions., Methods: The first step of this study was cyanobacterial cell culture and the extraction and purification of PC. After that, CCD-966SK cell line was cultivated under normal and UV irradiation. The bioassays included the cytotoxicity measurement, cell viability assay, morphology determination, tumour necrosis factor-α and Interleukin 6 release assays, enzyme activity for superoxide dismutase and glutathione peroxidase as well as malondialdehyde content and the cell-free extract of cyanobacterial stains were assessed., Results: The cell viability results showed that as the concentration of the PC increased, the viability of CCD-966SK cell line was reduced, which suggested that the effect of PC on the growth of fibroblast cells was dose dependent. The morphological results indicated that presence of PC in the fibroblast cell culture medium led to a transformation in cell morphology from spindle-shaped to spherical. PC released anti-inflammatory IL-6 and TNF-a cytokines, indicating high inflammation resistance. Furthermore, the findings revealed that PC dramatically reduced the release of superoxide dismutase, glutathione peroxidase, and malondialdehyde from inflammatory cells, with the reduction being more apparent at increasing doses., Conclusions: In conclusion, the results indicated that PC inhibit the CCD-966SK cell line by membrane destructor, which led to the increase the leakage of cell constituent and increase enzymes activities.

Objective: Sonodynamic therapy (SDT) is an innovative, non-invasive approach to cancer treatment, by using low-intensity ultrasound to trigger the activation of sonosensitizers localized within cancerous cells. This current study aimed to explore the therapeutic efficacy of a new sonosensitizer, Sinoporphyrin Sodium (DVDMS), under ultrasound irradiation, against oral squamous cell carcinoma (OSCC)-derived SCC-154 cells, both in vitro and in vivo., Methods: Fluorescence spectra, cytotoxicity assessments, uptake mechanisms, and subcellular distributions of DVDMS within the SCC-154 cell line were detected. Additionally, the study comprehensively assessed the antitumor effect, oxidative stress responses, apoptosis, apoptosis-related proteins, autophagic processes, and ultrastructural changes in SCC-154 cells, both in vitro and in vivo, subsequent to treatment with low-intensity ultrasound (at 1.0 MHz, 1 W/cm 2 in vitro and 3 W/cm 2 in vivo) in conjunction with DVDMS also being examined., Results: The findings indicate that SCC-154 cells exhibit heightened sensitivity to DVDMS compared to SAS and HSC-3 cell lines. Within SCC-154 cells, DVDMS primarily localizes within the mitochondria and lysosomes. DVDMS-based SDT significantly increased the intracellular levels of reactive oxygen species (ROS), induced morphological changes such as mitochondrial swelling and formation of autolysosomes, and exhibited a notable dose-dependent reduction in cell viability in vitro. Also, DVDMS-SDT demonstrated significant inhibition of xenograft growth without discernible adverse effects. Mechanistically, DVDMS-SDT upregulated Bax expression while downregulating Bcl-2 expression, which led to the Bax/Bcl-2 ratio and induced autophagy., Conclusion: DVDMS-SDT triggers mitochondrial-dependent apoptosis in SCC-154 cells, unlike 5-ALA and protoporphyrin IX (PpIX). Also, the combination of DVDMS with ultrasound stimulation induces autophagy, with the onset of autophagic processes preceding apoptosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Electromagnetic fields create potential negative implications on biological systems, including modifications to DNA structure, nuclear condensation, cellular ion transport, and intracellular Ca 2+ accumulation. To explore these effects on cancer cells, we exposed prostate, glioblastoma and cervix cancer cell lines to electromagnetic fields of wireless and assessed its anti-proliferative effects. PC3, A172, and HeLa cancer cells were cultured and exposed to electromagnetic fields for 24, 48, and 72 h. We used the MTT assay to detect cell viability and proliferation, Annexin V staining to determine apoptotic cells, and confocal microscopy to measure apoptosis-mediated intracellular calcium signals. Additionally, we performed profiling for apoptosis-related miRNAs. The results indicated that the electromagnetic field triggers apoptosis in the glioblastoma cell line A172 by increasing level of miR-129-5p, a known tumor suppressor. In contrast, the cervix cancer cell line and the prostate cancer cell line remained largely unaffected. In summary, our investigation underscores that electromagnetic fields at a 2.4 GHz frequency may adversely affect certain cancer cell lines, notably triggering apoptosis in the glioblastoma cancer cell line., Competing Interests: Compliance with Ethical Standards Conflict of Interest The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Boron neutron capture therapy (BNCT) is a targeted radiotherapy that relies on the 10 B (n, α) 7 Li reaction, which produces secondary particles with high linear energy transfer (LET), leading to a high relative biological effectiveness (RBE) in tumors. The biological effectiveness of BNCT is influenced by factors such as boron distribution and concentration, necessitating improved methods for assessing its radiobiological effects and clarifying the sensitivity of the differences in different factors to the biological effects., Purpose: This paper introduces a method to evaluate the biological effects of BNCT using the cellular repair model. This method aims to overcome some of the limitations of current evaluation approaches. The primary goal is to provide guidance for clinical treatments and the development of boron drugs, as well as to investigate the impact of the synergistic effects of mixed radiation fields in BNCT on treatment outcomes., Methods: The approach involves three key steps: first, extending the radial energy deposition distribution of BNCT secondary particles using Geant4-DNA. This allows for the calculation of initial DNA double-strand breaks (DSBs) distributions for a given absorbed dose. Next, the obtained initial DSB distributions are used for DNA damage repair simulations to generate cell survival curves, then thereby quantifying RBE and compound biological effectiveness (CBE). The study also explores the synergistic effects of the mixed radiation fields in BNCT on assessing biological effects were also explored in depth., Results: The results showed that the RBE of boronophenylalanine (BPA) and sodium borocaptate (BSH) drugs at cell survival fraction 0.01 was 2.50 and 2.15, respectively. The CBE of the boron dose component was 3.60 and 0.73, respectively, and the RBE of the proton component was 3.21, demonstrating that BPA has a significantly higher biological impact than BSH due to superior cellular permeability. The proton dose significance in BNCT treatment is also underscored, necessitating consideration in both experimental and clinical contexts. The study demonstrates that synergistic effects between disparate radiation fields lead to increased misrepairs and enhanced biological impact. Additionally, the biological effect diminishes with rising boron concentration, emphasizing the need to account for intercellular DNA damage heterogeneity., Conclusions: This methodology offers valuable insights for the development of new boron compounds and precise assessment of bio-weighted doses in clinical settings and can be adapted to other therapeutic modalities., (© 2024 American Association of Physicists in Medicine.)

Sonoporation has long been known to disrupt intracellular signaling, yet the involved molecules and pathways have not been identified with clarity. In this study, we employed whole transcriptome shotgun sequencing (RNA-seq) to profile sonoporation-induced gene responses after membrane resealing has taken place. Sonoporation was achieved by microbubble-mediated ultrasound (MB-US) exposure in the form of 1 MHz ultrasound pulsing (0.50 MPa peak negative pressure, 10 % duty cycle, 30 s exposure period) in the presence of microbubbles (1:1 cell-to-bubble ratio). Using propidium iodide (PI) and calcein respectively as cell viability and cytoplasmic uptake labels, post-exposure flow cytometry was performed to identify three viable cell populations: 1) unsonoporated cells, 2) sonoporated cells with low uptake, and 3) sonoporated cells with high uptake. Fluorescence-activated cell sorting was then conducted to separate the different groups followed by RNA-seq analysis of the gene expressions in each group of cells. We found that sonoporated cells with low or high calcein uptake showed high similarity in the gene responses, including the activation of multiple heat shock protein (HSP) genes and immediate early response genes mediating apoptosis and transcriptional regulation. In contrast, unsonoporated cells exhibited a more extensive gene expression alteration that included the activation of more HSP genes and the upregulation of diverse apoptotic mediators. Four oxidative stress-related and three immune-related genes were also differentially expressed in unsonoporated cells. Our results provided new information for understanding the intracellular mobilization in response to sonoporation at the molecular level, including the identification of new molecules in the sonoporation-induced apoptosis regulatory network. Our data also shed light on the innovative therapeutic strategy which could potentially leverage the responses of viable unsonoporated cells as a synergistic effector in the microenvironment to favor tumor treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: The management of non-small cell lung cancer (NSCLC) often includes the use of radiotherapy, with individual outcomes being impacted by the tumor's response to this treatment modality. Cephalomannine (CPM), a taxane diterpenoid found in Taxus spp, has been found to have anti-tumor activity. This study was aim to the explore the role and mechanism by which CPM affects radiotherapy resistance in NSCLC., Methods: H460 cells were pretreated with different doses of CPM. H460 cells were transfected with β-catenin overexpression plasmids. The cell viability, colony-forming ability, migration ability, and sphere-forming ability and apoptosis of the cells were measured by using CCK-8, colony-forming, transwell, and sphere-forming assay and flow cytometry. Western blot assay was employed to detect the expression of β-catenin and BMP2., Results: The cell viability, proliferation, migration and sphere-forming ability of cells in the radiotherapy-resistant (RR) group were significantly higher than those in the radiotherapy-sensitivity (RS) group. Conversely, the apoptosis rate of cells in the RR group was lower than that in the RS group. However, after CPM pretreatment of RR group cells, the above phenomena were reversed in a CPM dose-dependent manner. Subsequently, pretreatment with CPM resulted in a decrease in the expression levels of β-catenin and BMP2 in the RR group. In addition, overexpression of β-catenin mitigated the inhibitory effects of CPM on radiotherapy-resistant NSCLC cells., Conclusion: CPM has the potential to decrease radiotherapy resistance in NSCLC cells by inhibiting the β-catenin-BMP2 signaling pathway, promoting apoptosis, and ultimately impeding cell growth., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Targeted radiotherapies with low-energy ions show interesting possibilities for the selective irradiation of tumor cells, a strategy particularly appropriate for the treatment of disseminated cancer. Two promising examples are boron neutron capture therapy (BNCT) and targeted radionuclide therapy with α $\alpha$ -particle emitters (TAT). The successful clinical translation of these radiotherapies requires the implementation of accurate radiation dosimetry approaches able to take into account the impact on treatments of the biological effectiveness of ions and the heterogeneity in the therapeutic agent distribution inside the tumor cells. To this end, biophysical models can be applied to translate the interactions of radiations with matter into biological endpoints, such as cell survival., Purpose: The NanOx model was initially developed for predicting the cell survival fractions resulting from irradiations with the high-energy ion beams encountered in hadrontherapy. We present in this work a new implementation of the model that extends its application to irradiations with low-energy ions, as the ones found in TAT and BNCT., Methods: The NanOx model was adapted to consider the energy loss of primary ions within the sensitive volume (i.e., the cell nucleus). Additional assumptions were introduced to simplify the practical implementation of the model and reduce computation time. In particular, for low-energy ions the narrow-track approximation allowed to neglect the energy deposited by secondary electrons outside the sensitive volume, increasing significantly the performance of simulations. Calculations were performed to compare the original hadrontherapy implementation of the NanOx model with the present one in terms of the inactivation cross sections of human salivary gland cells as a function of the kinetic energy of incident α $\alpha$ -particles., Results: The predictions of the previous and current versions of NanOx agreed for incident energies higher than 1 MeV/n. For lower energies, the new NanOx implementation predicted a decrease in the inactivation cross sections that depended on the length of the sensitive volume., Conclusions: We reported in this work an extension of the NanOx biophysical model to consider irradiations with low-energy ions, such as the ones found in TAT and BNCT. The excellent agreement observed at intermediate and high energies between the original hadrontherapy implementation and the present one showed that NanOx offers a consistent, self-integrated framework for describing the biological effects induced by ion irradiations. Future work will focus on the application of the latest version of NanOx to cases closer to the clinical setting., (© 2024 American Association of Physicists in Medicine.)

Introduction: Heart failure (HF) and type 2 diabetes mellitus (DM2) are global health problems that often lead to muscle atrophy. These conditions are associated with increased autophagy and apoptosis in the muscle cells, resulting in decreased muscle mass. Physical exercise associated with photobiomodulation (PBM) seems promising to attenuate the skeletal muscle changes caused by HF and DM2, due to its direct effects on mitochondria, which may result in an increase in antioxidant capacity. Objective: To verify the influence of physical exercise and the association with PBM on autophagy, apoptosis, and cell survival signaling pathways in myocytes from rats with HF and DM2. Materials and Methods: Male rats were assigned to one of four groups: control (CT), HF+DM (disease model), exercise+HF+DM (EX+HF+DM), and EX+HF+DM+PBM (EX+HF+DM+PBM). To induce DM2, we administered streptozotocin (STZ) (0.25 mL/kg, intraperitoneally). HF was induced by coronary ligation. One week post-induction, an 8-week aerobic exercise and PBM protocol was initiated. Western blot analysis was used to measure the expression of apoptosis-related proteins and autophagy. Results: The EX+HF+DM+PBM group showed a substantial increase in Nrf2, p -AKT, and LC3-I levels compared to the HF+DM group. Conclusions: These findings suggest that physical exercise combined with PBM can upregulate proteins that promote myocyte survival in rats with HF and DM2.

The skin is the largest organ in the body and the only one to come into contact with solar UV radiation (UVR). UVA (320-400 nm) is a significant contributor to UV-related skin damage. The UVA spectrum makes up over 95% of solar-UV energy reaching the earth's surface causing the majority of the visible signs of skin photoaging. Many consumer products also emit UVA, including nail dryers. There have been sporadic reports suggesting that these units may be contributing to skin cancer incidence. This notion was recently bolstered by a finding that nail dryer-irradiated mammalian skin cells develop a mutational signature consistent with UVA exposure. This report was surprising considering the comparatively low level of UVA to which the skin is exposed during nail treatments. In this research, we investigated how UVA-emitting devices caused cytotoxic/genotoxic impact after only low levels of UVA exposure. Our data showed that levels of UVA in the unit are highly variable and location dependent. We confirm previous reports that using prolonged exposure protocols could induce significant levels of DNA damage. It was also determined that UV-induced DNA damage only partially correlated with the level of UVA fluency. On investigation, we found that the unit had a rapid increase in internal temperature when in use. Exposing human cells to these elevated temperatures acted synergistically with UVA to magnify the cytotoxic and genotoxic impact of UV irradiation., Competing Interests: Declaration of Conflicting interestThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Dr Peter Sykora is the CSO and director of Amelia Technologies LLC. None of the entities involved in this research have any commercial interest now or in the future regarding UV-emitting nail devices.

Hepatocellular carcinoma (HCC) is a common cause of cancer‑related mortality and morbidity worldwide. While iodine‑125 ( 125 I) particle brachytherapy has been extensively used in the clinical treatment of various types of cancer, the precise mechanism underlying its effectiveness in treating HCC remains unclear. In the present study, MHCC‑97H cells were treated with 125 I, after which, cell viability and proliferation were assessed using Cell Counting Kit‑8, 5‑ethynyl‑2'‑deoxyuridine and colony formation assays, cell invasion and migration were evaluated using wound healing and Transwell assays, and cell apoptosis was determined using flow cytometry. Omics data were analyzed using Kyoto Encyclopedia of Genes and Genomes, Gene Ontology and STRING analyses to observe the key genes that exhibited significant changes at the transcriptional and protein levels in MHCC‑97H cells treated with 125 I particles. Finally, the expression levels of key genes (GPNMB, C4BPA, CTH, H1‑0 and MT2A) were verified through reverse transcription quantitative PCR. Following treatment with 125 I, the proliferation, invasion and migration of MHCC‑97H cells were inhibited, and apoptosis was enhanced. The results of omics data analysis indicated that the biological behavior of MHCC‑97H cells treated with 125 I was related to the expression levels of CTH and MT2A genes. These findings indicated that intervention with 125 I radiation particles may induce changes in gene expression, potentially influencing alterations in biological characteristics. In conclusion, these insights may shed light on the underlying mechanisms of 125 I radiation particle therapy in HCC and offer novel targets for HCC treatment.

Radiation-induced lung injury (RILI) is the damage to lung tissue caused by radiation. Epithelial-mesenchymal transition (EMT) and fibrogenesis in radiated lung epithelial cells play critical roles in RILI. Tripartite motif-containing (TRIM) family proteins have been shown to be involved in fibrotic diseases, but whether TRIM22 plays a role in RILI and relative underlying mechanism remain unexplored. Here, we reported a unique comprehensive analysis of the impact of TRIM22 on radiation-induced EMT and fibrogenesis in A549 and BEAS-2B cells. Cell viability and proliferation were measured by Cell-Counting Kit (CCK)-8 and colony formation assays. The interaction between TRIM22 and protein phosphatase magnesium-dependent 1 A (PPM1A) was validated using co-immunoprecipitation. A chromatin immunoprecipitation assay was used to verify the interaction between SMAD3 and TRIM22 promoter. Cell viability and proliferation were decreased by 8 Gy raddition. TRIM22 was elevated in a dose- and time-dependent manner after radiation, and its knockdown reduced EMT and fibrogenesis. TRIM22 could interact with PPM1A and promote its ubiquitination to activate the TGF-β1/Smad pathway. The overexpression of PPM1A abolished TRIM22-mediated EMT and fibrogenesis. Meanwhile, SMAD3 could bind to the TRIM22 promoter to elevate its expression. This study revealed a novel TRIM22/PPM1A/Smad3 signaling pathway that contributes to the raddition-induced EMT and fibrogenesis, which would provide novel targets and strategies for treating RILI., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In radiation tumor therapy, irradiation, on one hand, should cause cell death to the tumor. On the other hand, the surrounding non-tumor tissue should be maintained unaffected. Therefore, methods of local dose enhancements are highly interesting. Gold nanoparticles, which are preferentially uptaken by very-fast-proliferating tumor cells, may enhance damaging. However, the results in the literature obtained from cell culture and animal tissue experiments are very contradictory, i.e., only some experiments reveal increased cell killing but others do not. Thus, a better understanding of cellular mechanisms is required. Using the breast cancer cell model SkBr3, the effects of gold nanoparticles in combination with ionizing radiation on chromatin network organization were investigated by Single-Molecule Localization Microscopy (SMLM) and applications of mathematical topology calculations (e.g., Persistent Homology, Principal Component Analysis, etc.). The data reveal a dose and nanoparticle dependent re-organization of chromatin, although colony forming assays do not show a significant reduction of cell survival after the application of gold nanoparticles to the cells. In addition, the spatial organization of γH2AX clusters was elucidated, and characteristic changes were obtained depending on dose and gold nanoparticle application. The results indicate a complex response of ALU-related chromatin and heterochromatin organization correlating to ionizing radiation and gold nanoparticle incorporation. Such complex whole chromatin re-organization is usually associated with changes in genome function and supports the hypothesis that, with the application of gold nanoparticles, not only is DNA damage increasing but also the efficiency of DNA repair may be increased. The understanding of complex chromatin responses might help to improve the gold nanoparticle efficiency in radiation treatment.

Graphene oxide-mediated photothermal therapy using femtosecond lasers has recently shown promise in treating hepatocellular carcinoma. However, significant work remains to optimize irradiation parameters for specific nanoparticle types and cancer cells to improve nanomaterial-mediated photothermal anticancer therapy. This study investigated the photothermal potential of nGO and nGO-PEG nanoparticles (NPs) combined with femtosecond laser irradiation at 515 nm and 1030 nm wavelengths, with varying power (0.1 and 0.2 W/cm 2 ) and duration (5 and 10 min), to optimize photothermal therapy for hepatocellular carcinoma. Conversion efficiency of NPs, morphology and viability of HepG2 and normal MDCK cells after treatments were evaluated using an electronic thermometer, phase-contrast microscopy, and WST-1 assay. The results revealed that nGO-PEG NPs exhibited better photothermal efficiency than nGO, with 515 nm of irradiation inducing a temperature increase up to 19.1 °C compared to 4.7 °C with 1030 nm of light. Laser exposure to 515 nm significantly reduced HepG2 cell viability, with the most intense conditions (10 min at 0.2 W/cm 2 ) causing a decrease of up to 58.2% with nGO and 43.51% with nGO-PEG. Normal MDCK cells showed minimal impact or a slight viability increase, especially with nGO-PEG. Combined treatment with laser irradiation and NPs induced significant morphological changes in HepG2 cells, including cell detachment and apoptotic-like characteristics, particularly with 1030 nm of irradiation. MDCK cells exhibited minimal morphological changes, with some recovery observed under lower energy conditions. These findings suggest that low-energy lasers and engineered nanomaterials could provide a minimally invasive approach to photothermal cancer therapy with reduced side effects.

Reactive oxygen species (ROS) play a pivotal role in apoptosis. We reported that Blue Light (BL) induced oxidative stress in human retinal pigment epithelial (RPE) cells in vitro and increased drusen deposition and RPE cell apoptosis in human eyes. Here, we investigated the mechanisms underlying BL-induced damage to RPE cells. Cells were exposed to BL with or without the antioxidant N-acetylcysteine. Cells were analyzed for levels of ROS, proliferation, viability, and mitochondria membrane potential (ΔΨ M ) fluctuation. We performed proteomic analyses to search for differentially expressed proteins. ROS levels increased following RPE cell exposure to BL. While ROS production did not affect RPE cell proliferation, it was accompanied by decreased ΔΨ M and increased cell apoptosis due to the caspase cascade activation in a ROS-dependent manner. Proteomic analyses revealed that BL decreased the levels of ROS detoxifying enzymes in exposed cells. We conclude that BL-induced oxidative stress is cytotoxic to RPE cells. These findings bring new insights into the involvement of BL on RPE cell damage and its role in the progression of age-related macular degeneration. The use of antioxidants is an avenue to block or delay BL-mediated RPE cell apoptosis to counteract the disease progression.

Hypoxia-induced radioresistance limits therapeutic success in cancer. In addition, p53 mutations are widespread in tumors including non-small cell lung carcinomas (NSCLCs), and they might modify the radiation response of hypoxic tumor cells. We therefore analyzed the DNA damage and inflammatory response in chronically hypoxic (1% O 2 , 48 h) p53 null H358 NSCLC cells after X-ray exposure. We used the colony-forming ability assay to determine cell survival, γH2AX immunofluorescence microscopy to quantify DNA double-strand breaks (DSBs), flow cytometry of DAPI-stained cells to measure cell cycle distribution, ELISAs to quantify IL-6 and IL-8 secretion in cell culture supernatants, and RNA sequencing to determine gene expression. Chronic hypoxia increased the colony-forming ability and radioresistance of H358 cells. It did not affect the formation or resolution of X-ray-induced DSBs. It reduced the fraction of cells undergoing G2 arrest after X-ray exposure and delayed the onset of G2 arrest. Hypoxia led to an earlier enhancement in cytokines secretion rate after X-irradiation compared to normoxic controls. Gene expression changes were most pronounced after the combined exposure to hypoxia and X-rays and pertained to senescence and different cell death pathways. In conclusion, hypoxia-induced radioresistance is present despite the absence of functional p53. This resistance is related to differences in clonogenicity, cell cycle regulation, cytokine secretion, and gene expression under chronic hypoxia, but not to differences in DNA DSB repair kinetics.