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Cancer is a global concern worldwide. Prostate cancer has high prevalence and mortality rates among men. Photodynamic therapy (PDT) is an alternative treatment that is promising and effective with fewer side-effects than conventional therapies. However, some factors may limit its efficacy. For this, PDT can be combined with other modalities such as photobiomodulation (PBM) which is commonly used for increased cell proliferation/differentiation and wound healing. In this study, PBM pre-treatment at 655 nm of wavelength with 1, 3, and 5 J/cm 2 energy densities was applied to prostate cancer cells to investigate its role in indocyanine green (ICG)-mediated PDT applications. Following PBM treatment, various analyses were assessed including cell viability, cellular uptake of ICG, ATP production, nitric oxide release, reactive oxygen species generation, and the changes in mitochondrial membrane potential. Increased cell death was observed with the PBM pre-treatment at 1 and 3 J/cm 2 energy densities depending on ICG incubation time. Intracellular ROS generation and nitric oxide release by PBM had a significant impact on anticancer PDT action. An enhanced anticancer PDT effect was obtained with the PBM pre-treatment which may become a valuable modality to increase the sensitivity of the cancerous cells to PDT applications., Competing Interests: Declarations Conflict of interest The authors have no competing interest to declare that is relevant to the content of this article. Ethical approval This study does not involve any study with human participants or animals performed by any of the authors. Consent for publication All authors agreed with the content and all gave explicit consent to submit the manuscript for publication., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Thermal neutrons generated in the body during proton beam therapy (PBT) can be used to cause boron neutron capture reactions and have recently been proposed as neutron capture enhanced PBT (NCEPBT). However, the cell killing effect of NCEPBT remains underexplored. Here, we show an increase in the cell killing effect of NCEPBT. Using Monte Carlo simulations, we showed that neutrons generated by proton beam irradiation are uniformly spread on tissue culture plates. Human salivary gland tumor cell line (HSG), human osteosarcoma cell line (MG63), human tongue squamous cell carcinoma cell line (SAS), and human malignant melanoma cell line (G-361) were irradiated with X-rays, proton beams, and proton beams with 10 B-enriched boronophenylalanine (boron concentration of 20 and 80 ppm). The relative biological effectiveness (RBE) values of proton beams alone, proton beams with 20 ppm boron, and proton beams with 80 ppm boron for HSG, MG63, SAS, and G-361 were 1.02, 1.07, and 1.23; 1.01, 1.08, and 1.44; 1.05, 1.09, and 1.46; and 1.04, 1.13, and 1.63, respectively. NCEPBT with high boron concentration showed high RBE and a high sensitizing effect. Our results confirm an increase in the cell killing effect of NCEPBT, should aid in its clinical use, and warrant its further investigation., Competing Interests: Declarations Competing interests Boronophenylalanine used in this study was provided by Stella Pharma Corporation (Japan). Tatsuya Ohno received research funding from Hitachi. All other authors declare no conflict of interest., (© 2024. The Author(s).)

In recent years, concerns have escalated regarding eye health problems arising from Light-emitting diode (LED), which emits high-energy blue light (BL), potentially causing corneal epithelial dysfunctions (CEpD). Nevertheless, the mechanisms underlying this damage remain poorly comprehended. This study endeavors to explore the specific mechanisms through which BL exposure induces CEpD. The study carried out diverse assays and treatments to investigate the toxicological effects of BL exposure. 48 hours (h) of 440 nm of BL exposure decreased the migration of human corneal epithelial cells (hCEpCs) while augmenting reactive oxygen species (ROS) production and apoptosis. RNA-Sequencing and bioinformatic analysis indicated that cellular oxidation and reduction equilibrium, wound healing, the positive regulation of the apoptotic process, and the Phosphoinositide 3-kinase (PI3K)/AKT pathway were significantly influenced by BL exposure. Treatment with N-acetylcysteine (NAC), a ROS scavenger, restored cell viability and AKT/S6 kinase (S6K) activation, suggesting the involvement of ROS in BL-induced damage. NAC also reversed BL-induced apoptosis and migration. Blocking AKT/S6K replicated detrimental effects, while pre-treatment with SC79 (SC), an AKT activator, alleviated the changes caused by BL exposure in hCEpCs. Furthermore, in mice, the combination of AKT inhibition and BL exposure led to CEpD. However, treatment with SC and NAC restored CEpD caused by BL exposure. These results imply that the regulation of the ROS/PI3K/AKT/S6K axis is implicated in BL-induced CEpD. Collectively, this study offers insights into the molecular mechanisms of BL-induced CEpD and proposes targeting the ROS/PI3K/AKT/S6K cascade as a potential therapeutic approach. The findings contribute to ocular health knowledge and establish the basis for developing interventions to safeguard the cornea from the detrimental effects of excessive BL exposure., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ye Shen reports financial support was provided by National Natural Science Foundation of China. Xiawei Wang reports financial support was provided by Traditional Chinese innovative talent support program. If there are other authors, they 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 Authors. Published by Elsevier Inc. All rights reserved.)

Senescence-like growth arrest (SLGA), which is a radiation-induced cell death pathway, is induced in immortalized normal human epithelial cell (hTERT-RPE1) by the daily fractionated X-irradiation with 1.5 Gy within 30 times. We here demonstrate that pre-treatment induces acquired radioresistance (ARR) that can survive from the lethal fractionated radiation. The parent cells were daily fractionated with 1.5 Gy for 5 d and then incubated for 7 d without fractionated radiation. After this, the daily fractionated radiation with 1.5 Gy was restarted. A small population of surviving cells appeared after 30 times of the daily fractionated radiation was completed and they were continuously growing up to 120 times of the daily fractionated radiation (RPE1-1.5Fr). We confirmed a higher basal expression level of p53, which functions in the activation of the SLGA pathway but fails to further accumulate after 1.5 Gy of single irradiation in RPE1-1.5Fr. It is the first report to induce ARR phenotype for fractionated radiation in normal human cells., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: The radiation sensitivity of tumor cells is a critical determinant of their therapeutic response to radiotherapy. Histone deacetylase 6 (HDAC6), beyond its known role in modulating tubulin acetylation and influencing cell motility, is also involved in the DNA damage response, potentially enhancing tumor cell radiosensitivity. Targeted HDAC6 inhibitors have shown substantial promise in preclinical studies aimed at increasing radiosensitivity and inhibiting cellular migration., Methods: A new HDAC inhibitor, named OXHA, was designed by substituting the phenyl cap of SAHA with an N,5-diphenyloxazole-2-carboxamide group. The inhibitory activity of OXHA was evaluated via in vitro enzymatic assays. Its effects on tumor cell migration and radiosensitization potential were assessed using scratch wound healing assays, micronucleus formation, and clonogenic survival assays., Result: Enzymatic assays confirmed OXHA's selective inhibition of HDAC6. Compared to SAHA, OXHA significantly increased α-tubulin acetylation while minimally impacting histone H3 acetylation, indicating a high selectivity for HDAC6. In combination with X-ray irradiation, OXHA markedly impaired wound healing in A549 and HepG2 cells, enhanced micronucleus formation, and reduced clonogenic survival across multiple tumor lines., Conclusion: OXHA exhibits potent and selective HDAC6 inhibition, effectively impeding tumor cell migration and enhancing radiosensitivity across multiple cell lines. These findings suggest that OXHA has strong potential as a therapeutic strategy to improve radiotherapy efficacy., Competing Interests: Declarations Conflict of interest The authors declare no competing interests. Ethical approval It is not applicable. Consent to participate It is not applicable. Consent for publication It is not applicable., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Introduction: Radioprotectors help to protect the body or at least minimize the negative consequences of radiation exposure. The present study aimed to assess the radioprotective potential of Helianthus tuberosus L. polysaccharide (HTLP) in vitality and micronuclei tests. To assess the cytotoxic effects of HTLP, both vitality and MTT reductase assays were conducted., Materials and Methods: RAW 264.7 cells viability was assessed 24 h after adding 200 μg/ml HTLP solution by staining cell cultures with propidium iodide and bis-benzimide to detect the nuclei of dead cells and the total number of cells in culture. To assess cell viability via cellular metabolic activity MTT test was used. In this work outbred 24-30 g 5-months old SHK mice have been used. Irradiation was provided with proton beams with an energy of 660 MeV at a dose rate of 80 Gy with doses 1.5 Gy for micronuclei test and 8.5 Gy for survival test. Whole body X-ray irradiation was conducted using the RUT-15 therapeutic X-ray unit with doses of 1.5 Gy for MN test and 6.5 Gy for survival. The HTLP sterile solution in dose 100 μg/animal was injected into the tail vein 15 min before X-ray or proton irradiation., Results and Conclusion: s: Vitality test showed no significant differences between the control group and cells treated with 200 μl of 200 μg/ml HTLP solution, though a greater variability was noted. In contrast, the MTT assay indicated enhanced cell viability in the HTLP-treated cells. HTLP does not exert any toxic effects in cell culture. Moreover, results of MTT reductase assay shows, that HTLP may enhance the cells' metabolic activity. Animals pre-treated with HTLP displayed a significant reduction in micronuclei formation, showing five times fewer micronuclei in bone marrow cells compared to the non-treated group. This comparison highlights HTLP's potential protective effect against radiation-induced chromosomal damage. HTLP treatment demonstrates a significant reduction in hazard compared to the control, indicating its protective effects against irradiation. Thus, it can be concluded that the use of HTLP increases the likelihood of animal survival under the ionizing effects of X-rays and protons. The survival analysis reveals that the HTLP-treated groups exhibit a higher survival rate compared to both the control and Cysteamine-treated groups, suggesting a significant protective effect of HTLP against irradiation, regardless of the type of irradiation (proton or X-ray) with p < 0.0001., 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 Inc. All rights reserved.)

This study evaluates the safety and potential benefits of PBM on pancreatic beta cells and islets. PBM was applied to insulin-secreting cell lines (MIN6) and rat pancreatic islets using a 670 nm light source, continuous output, with a power density of 2.8 mW/cm², from 5 s to several 24 h. Measure of cell viability, insulin secretion, mitochondrial function, ATP content, and cellular respiration were assessed. Additionally, a diabetic rat model is used for islet transplantation (pre-conditioning with PBM or not) experiments. Short and long-term PBM exposure did not affect beta cell islets viability, insulin secretion nor ATP content. While short-term PBM (2 h) increases superoxide ion content, this was not observed for long exposure (24 h). Mitochondrial respirations were slightly decreased after PBM. In the islet transplantation model, both pre-illuminated and non-illuminated islets improved metabolic control in diabetic rats with a safety profile regarding the post-transplantation period. In summary, for the first time, long-term PBM exhibited safety in terms of cell viability, insulin secretion, energetic profiles in vitro, and post-transplantation period in vivo. Further investigation is warranted to explore PBM's protective effects under conditions of stress, aiding in the development of innovative approaches for cellular therapy., (© 2024. The Author(s).)

Radiotherapy combined with a radiosensitizer represents an important treatment for head and neck squamous cell carcinoma (HNSCC). Only a few chemotherapy agents are currently approved as radiosensitizers for targeted therapy. Oral squamous cell carcinoma is one of the deadliest cancers, with approximately ~500,000 new diagnosed cases and 145,000 deaths worldwide per year. The incidence of new cases continues to increase in developing countries. This study aimed to investigate the effect of Croton tonkinensis and Curcuma longa on cell viability in OSCC cells. The HNSCC cell line OML1 and its radiation-resistant clone OML1-R were used. The anticancer effect and the mechanism of action of Croton tonkinensis and Curcuma longa in OSCC cells were analyzed by using cell viability assays, Western blot analysis, and Tranwell migration assays. The results showed that Croton tonkinensis concentration-dependently reduced the viability of OML1 and OML1-R (radioresistant) cells by downregulating the levels of AKT/mTOR mediators, such as p110α, p85, pAKT (ser473), p-mTOR (ser2448), and p-S6 Ribosomal (ser235/236). We found that cotreatment of OML1 and OML1R cells with either zVAD-FMK (apoptosis inhibitor), Ferrostatin-1 (Fer-1, a ferroptosis inhibitor), or chloroquine (CQ, an autophagy inhibitor) markedly reduced cell death. These results demonstrate that Croton tonkinensis exhibits anti-proliferation activity and highlight the therapeutic potential of small-molecule inhibitors against PI3K/mTOR signaling for radiosensitization in HNC treatment.

Background/aim: Natural compounds such as propolis have gained wide popularity in the last decades. While its antibacterial, antiviral, and antifungal properties are well known, the anticancer properties of propolis are just beginning to be appreciated. Herein, we comparatively investigate the cytotoxic and radiosensitizing potential of four different ethanolic propolis extracts originating from three different countries (Germany, Ireland, South Africa) in human lung cancer cell models., Materials and Methods: Liquid chromatography-mass spectrometry (LC-MS/MS) was applied to characterize the four different propolis extracts. Cytotoxicity and radiation survival were determined by 3D matrix-based clonogenic assays and autophagy was examined by western blotting., Results: We found cytotoxicity in a propolis type-, time- and cell model- dependent manner. In the four ethanolic propolis extracts, Coumaric acid, Caffeic acid phenethyl ester, Pinocembrin and Chrysin presented the major compounds identified. Examining the induction of autophagy using the marker LC3B and autophagy inhibition with chloroquine suggested autophagy to be part of the survival mechanisms upon propolis treatment in a cell model-dependent manner. Combining propolis with X-ray irradiation showed the radiosensitizing potential of propolis in human lung cancer cell models, which clearly presented in a manner dependent on the incubation time of propolis and the cell model treated., Conclusion: Propolis treatment showed cytotoxic and radiosensitizing effects of propolis on human lung cancer cells. Since these effects differ greatly between the four propolis extracts studied and originating from different regions, further studies are urgently needed to differentiate propolis species and their anticancer properties in more detail., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Exposure to artificial blue light, one of the most energetic forms of visible light, can increase oxidative stress in retinal cells, potentially enhancing the risk of macular degeneration. Retinal pigment epithelial (RPE) cells play a crucial role in this process; the loss of RPE cells is the primary pathway through which retinal degeneration occurs. In RPE cells, Kelch-like ECH-associated protein 1 (KEAP1) is located in both the nucleus and cytosol, where it binds to nuclear factor erythroid 2-related factor 2 (NRF2) and p62 (sequestosome-1), respectively. Blue light exposure activates the NRF2-heme oxygenase 1 (HMOX1) axis through both canonical and noncanonical p62 pathways thereby reducing oxidative damage, and initiates autophagy, which helps remove damaged proteins. These protective responses may support the survival of RPE cells. However, extended exposure to blue light drastically decreases the viability of RPE cells. This exposure diminishes the ability of KEAP1 to bind to p62 and reduces the level of KEAP1. Inhibition of autophagy does not prevent KEAP1 degradation, the NRF2-HMOX1 axis, or blue-light-induced cytotoxicity. However, proteasome inhibitor along with a transient increase in the amount of KEAP1 in RPE cells, partially restores the p62-KEAP1 complex and reduces blue-light-induced cytotoxicity. In vivo studies confirmed the downregulation of KEAP1 in damaged RPE cells. Mice subjected to periodic blue light exposure exhibited significant atrophy in the outer retina, particularly in the peripheral areas. Additionally, there was a significant decrease in c-wave electroretinography and pupillary light reflex, indicating functional impairments in both visual and nonvisual physiological processes. These data underscore the essential role of KEAP1 in managing oxidative defense and autophagy pathways triggered by blue light exposure in RPE cells., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The prognosis of osteosarcoma has not been improved for decades. As radioresistance is one of the major reasons, effective radiotherapy sensitization drugs need to be discovered. HOS and K7M2 osteosarcoma cell lines were treated with disulfiram (DSF) and radiation to assess cell viability, proliferation, migration ability, apoptosis level, ROS and Ca2+ level, and cell cycle in vitro. A HOS-derived subcutaneous tumor mouse model was constructed to evaluate tumor growth after DSF combined with radiation, and the Tunel assay and immunohistochemistry of Ki67 were conducted. Western blot was used to evaluate the protein expression level. The IC50 and working concentration of DSF in osteosarcoma cell lines were ascertained. When combined with radiation, DSF effectively suppressed cell viability, proliferation, and migration, while enhancing apoptosis in osteosarcoma cells. The cell cycle postirradiation exhibited a downward shift in the G1 phase, but the addition of DSF counteracted this trend. The combination of DSF and radiation exhibited inhibitory effects on tumor growth in vivo, which was corroborated by Ki67 staining and Tunel assay. Western blot analysis revealed that DSF upregulated the expression of P53, P21, CDKN2C, BAX, and cleaved Caspase-3 while downregulating BCL2, CDK4/6, and CyclinD1 after irradiation. Our results document that DSF exerts its radiosensitization effects in vivo and in vitro, and is a valuable radiosensitizing drug option for osteosarcoma. The radiosensitization effect is mainly achieved by activating the apoptotic pathway and promoting cell cycle arrest induced by P53/P21 and CDKN2C after irradiation., (© 2024 by Radiation Research Society. All rights of reproduction in any form reserved.)

The nucleotide excision repair (NER) system removes UV photoproducts from genomic DNA and is controlled by the circadian clock. Given that small-molecule compounds have been developed to target various clock proteins, we examined whether the cryptochrome inhibitor KS15 and REV-ERB antagonist SR8278 could modulate keratinocyte responses to UV radiation in vitro. We observed that though SR8278 promoted cell viability in UVB-irradiated cells, it had little effect on NER or on the expression of the clock-regulated NER factor XPA. Rather, we found that both KS15 and SR8278 absorb light within the UV spectrum to limit initial UV photoproduct formation in DNA. Moreover, SR8278 promoted UVB viability even in cells in which the core circadian clock protein BMAL1 was disrupted, which indicates that SR8278 is likely acting via other REV-ERB transcriptional targets. We further observed that SR8278 sensitized keratinocytes to light sources containing primarily UVA wavelengths of light likely due to the generation of toxic reactive oxygen species. Though other studies have demonstrated beneficial effects of SR8278 in other model systems, our results here suggest that SR8278 has limited utility for UV photoprotection in the skin and will likely cause phototoxicity in humans or mammals exposed to solar radiation., (© 2024 The Authors. Photochemistry and Photobiology published by Wiley Periodicals LLC on behalf of American Society for Photobiology.)

Background and Purpose: Radiotherapy (RT) is an integral treatment part for patients with head and neck squamous cell carcinoma (HNSCC), but radioresistance remains a major issue. Here, we use MitoTam, a mitochondrially targeted analogue of tamoxifen, which we aim to stimulate ferroptotic cell death with, and sensitize radioresistant cells to RT., Materials and Methods: We assessed viability, reactive oxygen species (ROS) production, disruption of mitochondrial membrane potential, and lipid peroxidation in radiosensitive (UT-SCC-40) and radioresistant (UT-SCC-5) HNSCC cells following MitoTam treatment. To assess ferroptosis specificity, we used the ferroptosis inhibitor ferrostatin-1 (fer-1). Also, total antioxidant capacity and sensitivity to tert-butyl hydroperoxide were evaluated to assess ROS-responses. 53BP1 staining was used to assess radiosensitivity after MitoTam treatment., Results: Our data revealed increased ROS, cell death, disruption of mitochondrial membrane potential, and lipid peroxidation following MitoTam treatment in both cell lines. Adverse effects of MitoTam on cell death, membrane potential and lipid peroxidation were prevented by fer-1, indicating induction of ferroptosis. Radioresistant HNSCC cells were less sensitive to the effects of MitoTam due to intrinsic higher antioxidant capacity. MitoTam treatment prior to RT led to superadditive residual DNA damage expressed by 53BP1 foci compared to RT or MitoTam alone., Conclusion: MitoTam induced ferroptosis in HNSCC cells, which could be used to overcome the elevated antioxidant capacity of radioresistant cells and sensitize such cells to RT. Treatment with MitoTam followed by RT could therefore present a promising effective therapy of radioresistant cancers., Statement of Significance: Radiotherapy is applied in the treatment of a majority of cancer patients. Radioresistance due to elevated antioxidant levels can be overcome by promoting ferroptotic cell death combining ROS-inducing drug MitoTam with radiotherapy., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [J.N., J.S. and L.W. own part of MitoTam intellectual property]., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Triple-negative breast cancer (TNBC) represents the most aggressive subtype of breast cancer and is frequently resistant to therapy, ultimately resulting in treatment failure. Clinical trials have demonstrated the potential of sensitizing radiation therapy (RT)-resistant TNBC through the combination of chemotherapy and RT. This study sought to explore the potential of CD151 as a therapy response marker in the co-treatment strategy involving ionizing radiation (IR) and the repurposed antiviral drug 2-Thio-6-azauridine (TAU) for sensitizing RT-resistant TNBC (TNBC/RR)., Methods: The investigation encompassed a variety of assessments, including viability using MTT and LDH assays, cell proliferation through BrdU incorporation and clonogenic assays, cell cycle analysis via flow cytometry, cell migration using wound scratch and Boyden chamber invasion assays, DNA damage assessment through γH2AX analysis, apoptosis evaluation through acridine-orange and ethidium bromide double staining assays, as well as caspase 3 activity measurement using a colorimetric assay. CD151 expression was examined through ELISA, flow cytometry and RT-qPCR., Results: The results showed a significant reduction in TNBC/RR cell viability following co-treatment. Moreover, the co-treatment reduced cell migration, induced apoptosis, downregulated CD151 expression, and increased caspase 3 activity in TNBC/RR cells. Additionally, CD151 was predicted to serve as a therapy response marker for co-treatment with TAU and IR., Conclusion: These findings suggest the potential of combination treatment with IR and TAU as a promising strategy to overcome RT resistance in TNBC. Furthermore, CD151 emerges as a valuable therapy response marker for chemoradiotherapy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The prevalence of male infertility has become a significant clinical concern worldwide, with a noticeable upward trend in recent times. The rates of fertilization and subsequent development of embryos are dependent on many parameters associated with the quality and viability of sperm. Photobiomodulation (PBM) is a promising approach with a great potential for translational applications in the treatment of spermatozoa exhibiting low quality and motility. In this study, a comprehensive analysis of the existing literature, specifically examining the mechanisms of action of PBM has been presented. Our objective was to enhance knowledge in the field of laser light therapy in order to promote the usage of irradiation in clinical settings in a more effective way. Within the realm of reproductive science, the utilization of PBM has been employed to enhance the metabolic processes, motility, and viability of spermatozoa. This is attributed to its advantageous effects on mitochondria, resulting in the activation of the mitochondrial respiratory chain and subsequent synthesis of ATP. This therapeutic approach can be highly advantageous in circumventing the reliance on chemical substances within the culture medium for spermatozoa while also facilitating the viability and motility of spermatozoa, particularly in circumstances involving thawing or samples with significant immotility., (© 2024 American Society for Photobiology.)

Treating lung and prostate cancer cells is a major health problem that may be solved through the interactions of laser beams with nanoparticles. In the paper, Au-H 2 Ti 3 O 7 nanotubes (NTs) are proposed as a treatment agent and the interactions of different laser beams with the nanostructure are considered to solve the mentioned health problem. Also, the NTs are employed to treat the cancers in dark conditions. The results are motivating because Au-H 2 Ti 3 O 7 NPs do not affect healthy cells, while they strongly affect cancer cells, and the viability percentage of LNCap cells reaches 16% for incubation times of 48 h. Furthermore, treating LNCap cells using the irradiated Au-H 2 Ti 3 O 7 NTs by NIR beam at 808 nm has no cytotoxicity, while cytotoxicity of 92% is obtained using an irradiation laser beam at 532 nm. Also, applying the laser beam at 635 nm to the NTs leads to a cytotoxicity of ∼53% in lung cancer (A549 cells). In total, the Au-H 2 Ti 3 O 7 NTs have a selective effect on cancer cells and greatly reduce the viability in the given dark and irradiation conditions, leading to the introduction of them as a promising agent for the non-invasive treatment of prostate cancer and a moderate candidate for lung cancer therapy., (© 2024. The Author(s).)

Background: The present study aimed to investigate the effects of infrared diode laser irradiation on the proliferation and differentiation capacity of periodontal ligament stem cells (hPDLSCs), which are optimal cell sources for periodontal regeneration., Methods: hPDLSCs were isolated and characterized by flow cytometric analysis of mesenchymal stem cell markers, and their trilineage differentiation capacity was tested. hPDLSCs were then cultured and irradiated with infrared diode laser (970 nm) at a power of 200 mW and a fluence of 4 J/cm 2 for 3 s. MTT assay was performed to assess cellular proliferation. Cell cycle analysis was performed, and the impact of infrared diode laser irradiation on the stemness and osteogenic differentiation potential of hPDLSCs was evaluated via RT‒PCR., Results: Infrared diode laser application enhanced the stemness, viability, proliferation, and differentiation of PDLSCs. Stem cell markers (OCT4, SOX2, and NANOG) were significantly upregulated in hPDLSCs exposed to laser irradiation. There was significant overexpression of RUNX2, ALP, OPN, and OCN on day 14 after laser application., Conclusions: These findings provide valuable insights into the specific applications of infrared diode lasers to effectively regenerate periodontal tissues. The results can aid in the development of precise clinical protocols aimed at enhancing osseointegration and promoting tissue regeneration. Ultimately, the combination of infrared diode laser with hPDLSCs is promising for stimulating periodontal regeneration., (© 2024. The Author(s).)

Objective . We propose a criterion of biological effectiveness of nonuniform hypoxia-targeted dose distributions in heterogeneous hypoxic tumors based on equivalent uniform aerobic dose (EUAD). We demonstrate the utility of this criterion by applying it to the model problems in radiotherapy for tumors with different levels of oxygen enhancement ratio (OER) and different degrees of dose nonuniformity. Approach . The EUAD is defined as the uniform dose that, under well-oxygenated conditions, produces equal integrated survival of clonogenic cells in radiotherapy for heterogeneous hypoxic tumors with a non-uniform dose distribution. We define the dose nonuniformity effectiveness (DNE) in heterogeneous tumors as the ratio of the EUAD( D N ) for a non-uniform distribution D N and the reference EUAD( D U ) for the uniform dose distribution D U with equal integral tumor dose. The DNE concept is illustrated in a radiotherapy model problem for non-small cell lung cancer treated with hypoxia targeted dose escalation. A two-level cell population tumor model was used to consider the hypoxic and oxygenated tumor cells. Results . Theoretical analysis of the DNE shows that the entire region of the OER can be separated in two regions by a threshold OER th : (1) OER > OER th where DNE > 1 indicating higher effectiveness of nonuniform dose distributions and (2) OER < OER th where DNE < 1 indicating higher effectiveness of uniform dose distributions. Our simulations show that the value of the threshold OER th in radiotherapy with conventional fractionation is significant in the range of about 1.2-1.6 depending on selected radiotherapy parameters. In general, the OER th increases with reoxygenation rate, relative hypoxic volume and dose escalation factor. The threshold value of OER th is smaller of about 1.1 for hypofractionated radiotherapy. Significance . The analysis of dose distributions using the DNE shows that the uniform dose distributions may improve biological cell killing effect in heterogeneous tumors with intermediate oxygen levels compared to targeted nonuniform dose distribution., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

To overcome chondrosarcoma's (CHS) high chemo- and radioresistance, we used polyethylene glycol-encapsulated iron oxide nanoparticles (IONPs) for the controlled delivery of the chemotherapeutic doxorubicin (IONP DOX ) to amplify the cytotoxicity of proton radiation therapy. Human 2D CHS SW1353 cells were treated with protons (linear energy transfer (LET): 1.6 and 12.6 keV/µm) with and without IONP DOX . Cell survival was assayed using a clonogenic test, and genotoxicity was tested through the formation of micronuclei (MN) and γH2AX foci, respectively. Morphology together with spectral fingerprints of nuclei were measured using enhanced dark-field microscopy (EDFM) assembled with a hyperspectral imaging (HI) module and an axial scanning fluorescence module, as well as scanning electron microscopy (SEM) coupled with energy-dispersive X-Ray spectroscopy (EDX). Cell survival was also determined in 3D SW3153 spheroids following treatment with low-LET protons with/without the IONP DOX compound. IONP DOX increased radiosensitivity following proton irradiation at both LETs in correlation with DNA damage expressed as MN or γH2AX. The IONP DOX -low-LET proton combination caused a more lethal effect compared to IONP DOX -high-LET protons. CHS cell biological alterations were reflected by the modifications in the hyperspectral images and spectral profiles, emphasizing new possible spectroscopic markers of cancer therapy effects. Our findings show that the proposed treatment combination has the potential to improve the management of CHS., Competing Interests: The authors declare no conflicts of interest.

Introduction: Radiobiological studies at low dose rates allow us to improve our knowledge of the mechanisms by which radiation exerts its effects on biological systems following chronic exposures. Moreover, these studies can complement available epidemiological data on the biological effects of low doses and dose rates of ionizing radiation. Very few studies have simultaneously compared the biological effects of low- and high-LET radiations at the same dose rate for chronic irradiation., Methods: We compared, for the first time in the same experiment, the effects of chronic (dose rates as low as ~18 and 5 mGy/h) and acute irradiations on clonogenicity and micronucleus formation in AG1522 normal human skin fibroblasts in the confluent state exposed to doses of low- and high-LET radiation (gamma rays and alpha particles) to investigate any differences due to the different radiation quality and different dose rate (in the dose range 0.006-0.9 Gy for alpha particles and 0.4-2.3 Gy for gamma rays)., Results: As expected, alpha particles were more effective than gamma rays at inducing cytogenetic damage and reduced clonogenic cell survival. For gamma rays, the cytogenetic damage and the reduction of clonogenic cell survival were greater when the dose was delivered acutely instead of chronically. Instead, for the alpha particles, at the same dose, we found equal cytogenetic damage and reduction of clonogenic cell survival for both chronic and acute exposure (except for the highest doses of 0.4 and 0.9 Gy, where cytogenetic damage is greater at a low dose rate)., Conclusion: The results of this study may have an impact on space and terrestrial radioprotection of humans at low doses and low dose rates, on biodosimetry, and on the use of ionizing radiation in medicine. These results also provide insights into understanding damage induction and cell reaction mechanisms following chronic exposure (at dose rates as low as 18 and 5 mGy/h) to low- and high-LET radiation., 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., (Copyright © 2024 Anello and Esposito.)

This study assessed the impact of low-level laser irradiation on the viability and proliferation of human periodontal ligament stem cells (hPDLSCs) cultivated on polylactic acid (PLA) scaffolds. hPDLSCs were obtained, characterized, and grown on the surface of PLA films produced via the solvent casting technique. The study involved two groups: the control group, which was not exposed to radiation, and the laser group, which was irradiated with a diode laser (InGaAIP) with a power of 30 mW, a wavelength of 660 nm, and a single dose of 1 J/cm² emitted continuously. Cell viability was assessed 24 and 48 hours after irradiation using the Alamar blue and Live/Dead assays. Flow cytometry was used to assess cell cycle events, and scanning electron microscopy (SEM) was used to evaluate the interaction between cells and the biomaterial. The results revealed a statistically significant increase in cell metabolic activity in the laser group compared with the control group at 24 hours (p <0.05) and 48 hours (p <0.001), as indicated by the Alamar blue assay. The Live/Dead assay also revealed a greater density of viable cells in the laser group. The cell cycle analysis revealed a significant increase in the number of cells in the proliferative phase (G2/M) in the laser group compared with the control group (p <0.001). The SEM images demonstrated that the irradiated group had a greater concentration of cells while still maintaining their cell shape and projections. This study demonstrated that photobiomodulation can increase the viability and proliferation of periodontal stem cells cultured on PLA scaffolds, suggesting the potential of this protocol for future studies on periodontal tissue engineering., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Rationale: 212 Pb, a promising in vivo alpha - particle generator of 212 Bi, has aroused much interest as a therapeutic radionuclide. For the development of targeted alpha therapy (TAT), it is important to determine the contribution of targeted effects in irradiated cells, and also of non-targeted effects in non-irradiated bystander cells. Currently, the critical roles of mitochondrial transfer in cellular crosstalk have garnered significant attention. However, the specific involvement of damaged mitochondrial transfer in orchestrating this alpha-particle radiation-induced bystander effect (RIBE) needs to be further explored. Methods: A novel alpha-emitting radiopharmaceutical, 212 Pb-hydrogel nanoparticles (HNPs), was synthesized and subsequently evaluated its theranostics effects. The impact of irradiated cell-conditioned media (ICCM), collected at different times post- 212 Bi irradiation, on bystander cancer cells regarding cell viability was also investigated. Additionally, damaged mitochondria were isolated and cultured with non-irradiated bystander cells to assess their role. Results: 212 Pb-HNPs exhibited efficient therapeutic antitumor effects in vitro , including increased GSH depletion, ROS accumulation, and mitochondrial damage in irradiated tumor cells. In vivo studies demonstrated its imaging potential through SPECT/CT, and RNA sequencing results indicated activation of oxidative stress-related pathways in irradiated tumors. Additionally, ICCM influenced the viability of non-irradiated bystander cells, suggesting a radiation-induced bystander effect by the alpha-particle 212 Bi. Interestingly, damaged mitochondria isolated from ICCM were observed to enter co-cultured non-irradiated bystander cells. Further experiments confirmed that the transfer of damaged mitochondria results in the death of non-irradiated bystander cells. Conclusion: The present study highlights the theranostic potential of the alpha-particle generator 212 Pb and, more importantly, elucidates the role of damaged mitochondrial transfer in alpha-particle RIBE. These findings provide a novel theoretical mechanism for the antitumor effects of alpha-particles and expand the clinical application prospects of TAT., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The influence of UV radiation on skin discoloration, skin aging and the development of skin cancer is widely known. As a part of this study, the effect of extracts from three varieties of Cornus mas L. ( C. mas L.) on skin cells exposed to UVA radiation was assessed. The analyses were performed on both normal and cancer skin cells. For this purpose, the potential photoprotective effects of the obtained extracts (aqueous and ethanolic) was assessed by performing two cytotoxicity tests (Alamar blue and Neutral red). Additionally, the antioxidant capacity was compared using three different assays. The 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCFDA) probe was used to evaluate the intracellular level of free radicals in cells exposed to the simultaneous action of UVA radiation and dogwood extracts. Additionally, the ability to inhibit excessive pigmentation was determined by assessing the inhibition of melanin formation and tyrosinase activity. The obtained results confirmed the strong antioxidant properties of dogwood extracts and their photoprotective effect on normal skin cells. The ability to inhibit the viability of melanoma cells was also observed. Additionally, a reduction in oxidative stress in skin cells exposed to UVA radiation and a strong inhibition of melanin formation and tyrosinase activity have been demonstrated. This study shows that dogwood extract could be a valuable cosmetic raw material that can play both a photoprotective and antihyperpigmentation role in cosmetic preparations.

Adipose-derived mesenchymal stem cells (ADMSCs) possess the ability to transform into various cell types, including neurons. It has been proposed that the optimization of this transformation can be achieved by using photobiomodulation (PBM). The objective of this laboratory-based investigation was to induce the transformation of immortalized ADMSCs (iADMSCs) into neurons with chemical triggers and then evaluate the supportive effects of PBM at two different wavelengths, 525 nm and 825 nm, each administered at a dose of 5 J/cm 2 , as well as the combined application of these wavelengths. The results revealed that the treated cells retained their stem cell characteristics, although the cells exposed to the green laser exhibited a reduction in the CD44 marker. Furthermore, early, and late neuronal markers were identified using flow cytometry analysis. The biochemical analysis included the assessment of cell morphology, viability, cell proliferation, potential cytotoxicity, and the generation of reactive oxygen species (ROS). The findings of this study indicate that PBM does not harm the differentiation process and may even enhance it, but it necessitates a longer incubation period in the induction medium. These research findings contribute to the validation of stem cell technology for potential applications in in vivo, pre-clinical, and clinical research environments., (© 2024. The Author(s).)

Cold atmospheric plasma (CAP) has been extensively utilized in medical treatment, particularly in cancer therapy. However, the underlying mechanism of CAP in skin cancer treatment remains elusive. In this study, we established a skin cancer model using CAP treatment in vitro . Also, we established the Xenograft experiment model in vivo . The results demonstrated that treatment with CAP induced ferroptosis, resulting in a significant reduction in the viability, migration, and invasive capacities of A431 squamous cell carcinoma, a type of skin cancer. Mechanistically, the significant production of reactive oxygen species (ROS) by CAP induces DNA damage, which then activates Ataxia-telangiectasia mutated (ATM) and p53 through acetylation, while simultaneously suppressing the expression of Solute Carrier Family 7 Member 11 (SLC7A11). Consequently, this cascade led to the down-regulation of intracellular Glutathione peroxidase 4 (GPX4), ultimately resulting in ferroptosis. CAP exhibits a favorable impact on skin cancer treatment, suggesting its potential medical application in skin cancer therapy., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Hair loss is a prevalent issue worldwide, which, though not life-threatening, can result in psychological problems, low self-esteem, and social anxiety. Previous studies have shown that ultraviolet radiation can have negative effects on hair follicle cells, leading to hair loss, while the impact of blue light on hair and hair follicle has largely been overlooked. This study aimed to examine the effects of blue light on hair follicle stem cells (HFSCs) and primary dermal papilla cells (DPCs), which are essential components of hair follicles. Human HFSCs and primary DPCs were exposed to blue light (457 nm) at various intensities (1, 4, 8, and 16 mW/cm 2 ) for 3 days. Subsequently, cell viability, cell proliferation, and intracellular reactive oxygen species (ROS) were assessed. The results showed that blue light (457 nm) significantly reduced the cell viability and proliferation of HFSCs and DPCs in vitro, with the inhibition being intensity-dependent. Additionally, blue light triggered the overproduction of ROS in the DPCs. While the exact mechanisms by which blue light affects hair follicle cells remain unclear, these findings suggest that blue light could impede the growth of these cells. This insight may offer a new approach to protecting hair by avoiding exposure to high-intensity blue light., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Chrysin is a natural flavonoid with anti-cancer effects. Despite its beneficial effects, little information is available regarding its immunogenic cell death (ICD) properties. In this work, we hypothesized that chrysin can potentiate radiotherapy(RT)-induced immunogenicity in melanoma cell line (B16-F10). We examined the effects of chrysin alone and in combination with radiation on ICD induction in B16-F10 cells. Cell viability was assessed using an MTT assay. Cell apoptosis and calreticulin (CRT) exposure were determined using flow cytometry. Western blotting and ELISA assay were employed to examine changes in protein expression. Combination therapy exhibited a synergistic effect, with an optimum combination index of 0.66. The synergistic anti-cancer effect correlated with increased cell apoptosis in cancer cells. Compared to the untreated control, chrysin alone and in combination with RT induced higher levels of DAMPs, such as CRT, HSP70, HMGB1, and ATP. The protein expression of p-STAT3/STAT3 and PD-L1 was reduced in B16-F10 cells exposed to chrysin alone and in combination with RT. Conditioned media from B16-F10 cells exposed to mono-and combination treatments elicited IL-12 secretion in dendritic cells (DCs), inducing a Th1 response. Our findings revealed that chrysin could induce ICD and intensify the RT-induced immunogenicity., (© 2024. The Author(s).)

Objective. Relative biological effectiveness (RBE) differs between radiation qualities. However, an RBE of 1.0 has been established for photons regardless of the wide range of photon energies used clinically, the lack of reproducibility in radiobiological studies, and outdated reference energies used in the experimental literature. Moreover, due to intrinsic radiosensitivity, different cancer types have different responses to radiation. This study aimed to characterize the RBE of clinically relevant high and low photon energies in vitro for three human cancer cell lines: HCT116 (colon), HeLa (cervix), and PC3 (prostate). Approach. Experiments were conducted following dosimetry protocols provided by the American Association of Physicists in Medicine. Cells were irradiated with 6 MV x-rays, an 192 Ir brachytherapy source, 225 kVp and 50 kVp x-rays. Cell survival post-irradiation was assessed using the clonogenic assay. Survival fractions were fitted using the linear quadratic model, and survival curves were generated for RBE calculations. Main results. Cell killing was more efficient with decreasing photon energy. Using 225 kVp x-rays as the reference, the HCT116 RBE SF0.1 for 6 MV x-rays, 192 Ir, and 50 kVp x-rays were 0.89 ± 0.03, 0.95 ± 0.03, and 1.24 ± 0.04; the HeLa RBE SF0.1 were 0.95 ± 0.04, 0.97 ± 0.05, and 1.09 ± 0.03, and the PC3 RBE SF0.1 were 0.84 ± 0.01, 0.84 ± 0.01, and 1.13 ± 0.02, respectively. HeLa and PC3 cells had varying radiosensitivity when irradiated with 225 and 50 kVp x-rays. Significance. This difference supports the notion that RBE may not be 1.0 for all photons through experimental investigations that employed precise dosimetry. It highlights that different cancer types may not have identical responses to the same irradiation quality. Additionally, the RBE of clinically relevant photons was updated to the reference energy of 225 kVp x-rays., (Creative Commons Attribution license.)

Objective: To evaluate the lymphocyte apoptotic impact of yellow laser light in vitro., Methods: The experimental study was conducted from November 2021 to April 2022 at the Postgraduate Medical Physics Laboratory, Mustansiriyah University, Baghdad, Iraq, and comprised blood samples from healthy volunteers. The samples were subjected to 1:1 dilution in isotonic phosphate buffered saline, and each sample was divided into two equal aliquots; one for irradiation, and other as control.The percentage of apoptotic lymphocyte was estimated before and after radiation exposure with low-level laser 589nm at 30J/cm², 50J/cm² and 70J/cm² energy intensities. Post-exposure evaluation was done immediately, and 1 and 2 hours after radiation on the viability of normal human cells. The vitality of the cells was determined using the trypan blue exclusion test. Data was analysed using SPSS 24., Results: There were 26 healthy volunteers (16 male, 10 females) with an age range of (20-40) years. After the exposure, the percentage of lymphocytes that apoptose increased significantly when cells were irradiated at 70J/cm2 immediately compared to the controls (p≤ 0.05), but there was no significant differences with the 30J/cm² dose. After 1 and 2 hours, a significant reduction in the proportion of apoptotic lymphocytes was observed (p<0.05)., Conclusions: Yellow low-level laser showed a noticeable protective effect on lymphocytes by decreasing the percentage of dead cells.

Objective: To assess how laser light affects blood lymphocyte viability in vitro., Methods: The comparative study was conducted from November 2021 to April 2022 at the Department of Medical Physics, Mustansiriyah University, Baghdad, Iraq, and comprised blood samples collected from healthy adults with no medical history of major illnesses or history of taking medications for major diseases.Low-level laser 589nm and 532nm was used at 30 J/cm², 50 J/cm² and 70J/cm² energy intensities and three different post-exposure time; immediately, 1h and 2h after radiation exposure. The viability of normal human lymphocytic cells of the blood was noted. Data was analysed using SPSS 24., Results: The blood samples were drawn from 6 adult male voluteers. The percentage of cells that showed apoptosis post-exposure to 589nm laser was significantly lower than that following exposure to 532nm laser (p<0.05). However, the proportion of apoptotic cells was significantly higher following irradiation with 532nm at varying doses than after irradiation with 589nm (p<0.05)., Conclusions: A low-level laser could promote and prevent apoptosis in human peripheral blood cells in a dose- and time-dependent manner.

In mice, intestinal tuft cells have been described as a long-lived, postmitotic cell type. Two distinct subsets have been identified: tuft-1 and tuft-2 (ref. 1 ). By combining analysis of primary human intestinal resection material and intestinal organoids, we identify four distinct human tuft cell states, two of which overlap with their murine counterparts. We show that tuft cell development depends on the presence of Wnt ligands, and that tuft cell numbers rapidly increase on interleukin-4 (IL-4) and IL-13 exposure, as reported previously in mice 2-4 . This occurs through proliferation of pre-existing tuft cells, rather than through increased de novo generation from stem cells. Indeed, proliferative tuft cells occur in vivo both in fetal and in adult human intestine. Single mature proliferating tuft cells can form organoids that contain all intestinal epithelial cell types. Unlike stem and progenitor cells, human tuft cells survive irradiation damage and retain the ability to generate all other epithelial cell types. Accordingly, organoids engineered to lack tuft cells fail to recover from radiation-induced damage. Thus, tuft cells represent a damage-induced reserve intestinal stem cell pool in humans., (© 2024. The Author(s).)

Background/aim: The purpose of this study was to evaluate whether the sparing effect on cell survival is observed under normoxia., Materials and Methods: A superconducting spiral sector-type azimuthally varying field (AVF) cyclotron produced 230 MeV proton beams at 250 Gy/s as ultra-high dose rate (uHDR) and 1 Gy/s as normal dose rate (NDR) to irradiate tumor and normal cell lines (HSGc-c5 and HDF up to 24 Gy at the center of spread-out Bragg peak (SOBP). The Advanced Markus chamber and Gafchromic film were used to measure the examined absolute dose and field sizes. Colony formation assay and immunofluorescence staining were conducted to evaluate the sparing effect., Results: A homogeneous field was achieved at the center of the SOBP for both uHDR and NDR scanned proton beams, and dose reproducibility and linearity were adequate for experiments. There were significant differences in cell surviving fractions of HSGc-C5 and HDF cells irradiated at uHDRs compared to NDRs at 20 Gy and 24 Gy. Increasing γ-H2AX foci were observed for both cell lines at NDR., Conclusion: The sparing effect on cell survival was first observed under normoxic conditions for tumor and normal cells with doses exceeding 20 Gy, using proton irradiation at 250 Gy/s extracted from a superconducting AVF cyclotron. This study marks a significant milestone in advancing our understanding of the underlying mechanism behind the sparing effect., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Alzheimer's disease, a prevalent neurodegenerative condition primarily affecting older adults, remains incurable. Its principle pathological hallmark is the accelerated accumulation of amyloid β (Aβ) protein. This study investigates the potential of photobiomodulation using near infrared light to counteract Aβ 1-42 -induced synaptic degeneration and neurotoxicity. We focused on the effect of 808 nm near-infrared laser diode (LD) on Aβ 1-42 cytotoxicity in primary cultured cortical neurons. We assessed cell survival using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, observing substantial benefits from LD irradiation with a power of 10 mW and a dose of 30 J. Cells exposed to Aβ 1-42 exhibited morphological changes indicative of synaptic damage and a significant decrease in the number of postsynaptic density protein-95 (PSD-95) contacts, which were significantly improved with near-infrared LD therapy. Furthermore, this therapy reduced Aβ and phosphorylated tau (P-tau) protein accumulation. Additionally, near-infrared LD irradiation substantially lessened the Aβ 1-42 -induced rise in glial fibrillary acid protein (GFAP) and ionized calcium-binding adaptor molecule 1 (IBA1) in astrocytes and microglia. Remarkably, near-infrared LD irradiation effectively inhibited phosphorylation of key proteins involved in Aβ 1-42 -induced necroptosis, namely Receptor-interacting protein kinase-3 (RIP3) and Mixed Lineage Kinase domain-Like protein (MLKL). Our findings suggest that near-infrared LD treatment significantly reduces neurodegeneration by reducing glial overactivation and neuronal necroptosis triggered by Aβ 1-42 . Thus, near-infrared LD treatment emerges as a promising approach for slowing or treating Alzheimer's disease, offering new avenues in its management., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Photobiomodulation therapy, as an emerging treatment modality, has been widely used in dentistry. However, reports on blue light therapy for oral cancer are scarce. This study investigated the effects of 457 and 475 nm LED irradiation on SCC-25 cells and explored the potential mechanisms underlying the impact of blue light. Both wavelengths were found to inhibit cell viability, induce oxidative stress, and cause cell cycle arrest without leading to cell death. Notably, the inhibitory effect of 457 nm blue light on cell proliferation was more sustained. Transcriptome sequencing was performed to explore the underlying mechanisms, revealing that blue light induced endoplasmic reticulum stress in SCC-25 cells, with 457 nm light showing a more pronounced effect. Moreover, 457 nm blue light upregulated the expression of the aryl hydrocarbon receptor pathway, indicating potential therapeutic prospects for the combined use of blue light and pharmacological agents., (© 2024 Wiley‐VCH GmbH.)

Preclinical data have shown that 161 Tb-labeled peptides targeting the somatostatin receptor are therapeutically more effective for peptide receptor radionuclide therapy than are their 177 Lu-labeled counterparts. To further substantiate this enhanced therapeutic effect, we performed cellular dosimetry to quantify the absorbed dose to the cell nucleus and compared dose-response curves to evaluate differences in relative biological effectiveness in vitro. Methods: CA20948 cell survival was assessed after treatment with [ 161 Tb]Tb- and [ 177 Lu]Lu-DOTATATE (agonist) and with [ 161 Tb]Tb- and [ 177 Lu]Lu-DOTA-LM3 (antagonist) via a clonogenic assay. Cell binding, internalization, and dissociation assays were performed up to 7 d to acquire time-integrated activity coefficients. Separate S values for each type of particle emission (Auger/internal conversion [IC] electrons and β - particles) were computed via Monte Carlo simulations, while considering spheric cells. Once the absorbed dose to the cell nucleus was calculated, survival curves were fitted to the appropriate linear or linear-quadratic model and corresponding relative biological effectiveness was evaluated. Results: Although the radiopeptide uptake was independent of the radionuclide, [ 161 Tb]Tb-DOTATATE and [ 161 Tb]Tb-DOTA-LM3 delivered a 3.6 and 3.8 times higher dose to the nucleus, respectively, than their 177 Lu-labeled counterparts on saturated receptor binding. This increased nucleus-absorbed dose was mainly due to the additional emission of IC and not Auger electrons by 161 Tb. When activity concentrations were considered, both [ 161 Tb]Tb-DOTATATE and [ 161 Tb]Tb-DOTA-LM3 showed a lower survival fraction than did labeling with 177 Lu. When the absorbed dose to the nucleus was considered, no significant difference could be observed between the dose-response curves for [ 161 Tb]Tb- and [ 177 Lu]Lu-DOTATATE. [ 161 Tb]Tb-DOTA-LM3 showed a linear-quadratic dose response, whereas [ 161 Tb]Tb-DOTATATE showed only a linear dose response within the observed dose range, suggesting additional cell membrane damage by Auger electrons. Conclusion: The IC, rather than Auger, electrons emitted by 161 Tb resulted in a higher absorbed dose to the cell nucleus and lower clonogenic survival for [ 161 Tb]Tb-DOTATATE and [ 161 Tb]Tb-DOTA-LM3 than for the 177 Lu-labeled analogs. In contrast, [ 161 Tb]Tb-DOTATATE showed no higher dose response than [ 177 Lu]Lu-DOTATATE, whereas for [ 161 Tb]Tb-DOTA-LM3 an additional quadratic response was observed. Because of this quadratic response, potentially caused by cell membrane damage, [ 161 Tb]Tb-DOTA-LM3 is a more effective radiopeptide than [ 161 Tb]Tb-DOTATATE for labeling with 161 Tb., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Radiotherapy is a common therapeutic strategy for various solid tumors, with vascular endothelial injury being a common side effect. The study aimed to examine the effect of long non-coding RNA PVT1 on radiation-induced vascular endothelial cell injury, and explore the possible underlying mechanism. Human umbilical vein endothelial cells (HUVECs) were exposed to different doses of X ray to mimic radiation. LncRNA and miRNA levels were detected via qRT-PCR. Interaction between lncRNA and miRNAs was determined through dual-luciferase reporter assay. Statistical processing was conducted using student's t test between two groups and one-way ANOVA among multiple groups, and P < 0.05 means a significant difference. GO and KEGG were performed for the function and pathway enrichment analysis. LncRNA PVT1 elevated along with the increase of radiation dose in HUVECs. Poorly expressed lncRNA PVT1 promotes cell viability and inhibits oxidative stress. PVT1 serves as a competitive endogenous RNA (ceRNA) of miR-9-5p. miR-9-5p inhibitor inverted the influence of PVT1 knockdown on radiation-stimulated cell apoptosis and oxidative stress in HUVECs. KEGG analysis identified significant enrichment of the MAPK signaling pathway among overlapping target genes of miR-9-5p. LncRNA PVT1 knockdown alleviated radiation-induced vascular endothelial injury via sponging miR-9-5p. The underlying mechanism might be probably MAPK signaling-related., (© 2024 by Radiation Research Society. All rights of reproduction in any form reserved.)

To increase the therapeutic efficacy of nanoparticle (NP)-assisted photothermal therapy (PTT) and allow for a transition toward the clinical setting, it is pivotal to characterize the thermal effect induced in cancer cells and correlate it with the cell biological response, namely cell viability and cell death pathways. This study quantitatively evaluated the effects of gold nanorod (GNR)-assisted near-infrared (NIR) PTT on two different cancer cell lines, the 4T1 triple-negative breast cancer cells and the Pan02 pancreatic cancer cells. The interaction between nanomaterials and biological matrices was investigated in terms of GNR internalization and effect on cell viability at different GNR concentrations. GNR-mediated PTT was executed on both cell lines, at the same treatment settings to allow a straightforward comparison, and real-time monitored through thermographic imaging. A thermal analysis based on various parameters (i.e., maximum absolute temperature, maximum temperature change, temperature variation profile, area under the time-temperature change curve, effective thermal enhancement (ETE), and time constants) was performed to evaluate the treatment thermal outcome. While GNR treatment and NIR laser irradiation alone did not cause cell toxicity in the selected settings, their combination induced a significant reduction of cell viability in both cell lines. At the optimal experimental condition (i.e., 6 μg/mL of GNRs and 4.5 W/cm 2 laser power density), GNR-assisted PTT reduced the cell viability of 4T1 and Pan02 cells by 94% and 87% and it was associated with maximum temperature changes of 25 °C and 29 °C (i.e., ∼1.8-fold increase compared to the laser-only condition), maximum absolute temperatures of 55 °C and 54 °C, and ETE values of 78% and 81%, for 4T1 and Pan02 cells, correspondingly. Also, the increase in the GNR concentration led to a decrease in the time constants, denoting faster heating kinetics upon irradiation. Furthermore, the thermal analysis parameters were correlated with the extent of cell death. Twelve hours after NIR exposure, GNR-assisted PTT was found to mainly trigger secondary apoptosis in both cell lines. The proposed study provides relevant insights into the relationship between temperature history and biological responses in the context of PTT. The findings contribute to the development of a universal methodology for evaluating thermal sensitivity upon NP-assisted PTT on different cell types and lay the groundwork for future translational studies., 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 Authors. Published by Elsevier B.V. All rights reserved.)

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.

Background: Magnetic hyperthermia (MHT) has emerged as a promising therapeutic approach in the field of radiation oncology due to its superior precision in controlling temperature and managing the heating area compared to conventional hyperthermia. Recent studies have proposed solutions to address clinical safety concerns associated with MHT, which arise from the use of highly concentrated magnetic nanoparticles and the strong magnetic field needed to induce hyperthermic effects. Despite these efforts, challenges remain in quantifying therapeutic outcomes and developing treatment plan systems for combining MHT with radiation therapy (RT)., Purpose: This study aims to quantitatively measure the therapeutic effect, including radiation dose enhancement (RDE) in the magnetic hyperthermia-radiation combined therapy (MHRT), using the equivalent radiation dose (EQD) estimation method., Methods: To conduct EQD estimation for MHRT, we compared the therapeutic effects between the conventional hyperthermia-radiation combined therapy (HTRT) and MHRT in human prostate cancer cell lines, PC3 and LNCaP. We adopted a clonogenic assay to validate RDE and the radiosensitizing effect induced by MHT. The data on survival fractions were analyzed using both the linear-quadradic model and Arrhenius model to estimate the biological parameters describing RDE and radiosensitizing effect of MHRT for both cell lines through maximum likelihood estimation. Based on these parameters, a new survival fraction model was suggested for EQD estimation of MHRT., Results: The newly designed model describing the MHRT effect, effectively captures the variations in thermal and radiation dose for both cell lines (R 2  > 0.95), and its suitability was confirmed through the normality test of residuals. This model appropriately describes the survival fractions up to 10 Gy for PC3 cells and 8 Gy for LNCaP cells under RT-only conditions. Furthermore, using the newly defined parameter r, the RDE effect was calculated as 29% in PC3 cells and 23% in LNCaP cells. EQD MHRT calculated through this model was 9.47 Gy for PC3 and 4.71 Gy for LNCaP when given 2 Gy and MHT for 30 min. Compared to EQD HTRT , EQD MHRT showed a 26% increase for PC3 and a 20% increase for LNCaP., Conclusions: The proposed model effectively describes the changes of the survival fraction induced by MHRT in both cell lines and adequately represents actual data values through residual analysis. Newly suggested parameter r for RDE effect shows potential for quantitative comparisons between HTRT and MHRT, and optimizing therapeutic outcomes in MHRT for prostate cancer., (© 2024 American Association of Physicists in Medicine.)

Objective. The energy deposition of photons and protons differs. It depends on the position in the proton Bragg peak (BP) and the linear energy transfer (LET) leading to a variable relative biological effectiveness (RBE). Here, we investigate LET dependent alterations on metabolic viability and proliferation of sarcoma and endothelium cell lines following proton irradiation in comparison to photon exposure. Approach. Using a multi-step range shifter, each column of a 96-well plate was positioned in a different depth along four BP curves with increasing intensities. The high-throughput experimental setup covers dose, LET, and RBE changes seen in a treatment field. Photon irradiation was performed to calculate the RBE along the BP curve. Two biological information out of one experiment were extracted allowing a correlation between metabolic viability and proliferation of the cells. Main results. The metabolic viability and cellular proliferation were column-wise altered showing a depth-dose profile. Endothelium cell viability recovers within 96 h post BP irradiation while sarcoma cell viability remains reduced. Highest RBE values were observed at the BP distal fall-off regarding proliferation of the sarcoma and endothelial cells. Significance. The high-throughput experimental setup introduced here (I) covers dose, LET, and RBE changes seen in a treatment field, (II) measures short-term effects within 48 h to 96 h post irradiation, and (III) can additionally be transferred to various cell types without time consuming experimental adaptations. Traditionally, RBE values are calculated from clonogenic cell survival. Measured RBE profiles strongly depend on physical characteristics such as dose and LET and biological characteristics for example cell type and time point. Metabolic viability and proliferation proofed to be in a similar effect range compared to clonogenic survival results. Based on limited data of combined irradiation with doxorubicin, future experiments will test combined treatment with systemic therapies applied in clinics e.g. cyclin-dependent inhibitors., (Creative Commons Attribution license.)

X-ray therapy aims to eliminate tumours while minimizing side effects. Intense mucositis is sometimes induced when irradiating the oral cavity with a dental metal crown (DMC). However, the underlying mechanisms of such inducing radiosensitization by DMC remain uncertain. This study explored the radiosensitizing mechanisms around DMCs in an interdisciplinary approach with cell experiments and Monte Carlo simulation with the PHITS code. Clonogenic survival and nuclear 53BP1 foci of a cell line derived from cervical cancer cells (HeLa cells) were measured post-irradiation with therapeutic X-rays near high-Z materials such as Pb or Au plates, and the experimental sensitizer enhancement ratio (SER) was obtained. Meanwhile, the dose enhancement ratio (DER) and relative biological effectiveness for DNA damage yields were calculated using the PHITS code, by considering the corresponding experimental condition. The experiments show the experimental SER values for cell survival and 53BP1 foci near metals are 1.2-1.4, which agrees well with the calculated DER values. These suggest that the radiosensitizing effects near metal are predominantly attributed to the dose increase. In addition, as a preclinical evaluation, the spatial distributions of DER near DMC are calculated using Computed Tomography Digital Imaging and Communications in Medicine (CT-DICOM) data and a simple tooth model. As a result, the DER values evaluated using the CT-DICOM data were lower than those from a simple tooth model. These findings highlight the challenge of evaluating radiosensitizing effects near DMCs using Digital Imaging and Communications in Medicine (DICOM) images due to volume-averaging effects and emphasize the need for a high-resolution (<1 mm) dose assessment method unaffected by these effects., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology.)

Breast cancer remains a significant global health challenge, spurring ongoing investigations into innovative treatment approaches. Low-level laser therapy (LLLT) has emerged as a promising non-invasive therapeutic avenue of interest. This research delves into the impact of LLLT on the cytotoxicity of the MCF-7 breast cancer cell line, employing lasers emitting various wavelengths. The objective is to assess whether diverse LLLT wavelengths elicit disparate cytotoxic responses, shedding light on LLLT's potential as a targeted breast cancer treatment. MCF-7 cell cultures were subjected to lasers of varying wavelengths, including blue (473 nm), red (660 nm), and near-infrared (780 nm). Each wavelength was delivered at four different power levels: 10, 25, 45, and 65 mW, with exposure durations of 60, 300, 600, and 900 s. Cellular responses, encompassing factors such as cell viability, and cytotoxicity were assessed using WST-1 assays technique. Statistical analysis was performed to discern the wavelength-specific impacts of low-level laser therapy (LLLT) on MCF-7 cells. The study revealed that the blue laser had the least noticeable adverse impact on MCF-7 breast cancer cell lines, leading to the highest cell survival rate of 107.62% after 24 h. The most severe toxicity occurred when the laser was used at 45 mW for 900 s, resulting in cell viability ranging from 81.85% to 107.62%. As for cell viability after exposure to the red laser, the mildest harmful effect was observed at 45 mW power for 60 s, resulting in a cell survival rate of 147.62%. Conversely, the most significant toxic response occurred at 10 mW power for 60 s, resulting in a cell viability of 91.56%. In contrast, when employing infrared laser irradiation, the least substantial cytotoxic effect on MCF-7 cells was observed at 10 mW power for 600 s, resulting in the highest cell viability of 109.37% after 24 h. The most pronounced cytotoxic effect was observed by infrared laser (780 nm) at 25 mW power for 900 s, leading to the lowest viability of 32.53%., (© 2024. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.)

Objective: Radioactive intestinal injury is a common complication during radiotherapy of tumors. The aim of this study is to observe the effect of ionizing radiation on short-term changes in intestinal bile acids and to investigate the radioprotective effect of bile acids on intestinal cells., Methods: A rat model of small intestinal injury was constructed by exposing the abdomen of the rats to daily irradiation at 2 Gy for 4 d in succession. The bile acids were quantified using metabolomics analysis. IEC-6 cells, a small intestinal epithelial cell line, were divided into a dimethyl sulfoxide (DMSO) control group receiving DMSO and 0 Gy irradiation, a glycoursodeoxycholic acid (GUDCA) experimental group receiving GUDCA and 0 Gy irradiation, a DMSO irradiation group receiving DMSO and 10 Gy irradiation, and a GUDCA irradiation group receiving GUDCA and 10 Gy irradiation. Cell viability and cytotoxicity was assessed by CCK-8 assay test. The apoptosis rate of cells was determined by flow cytometry. The colony formation rate and the radiosensitivity of the cells were determined by colony formation assay on solid media. The expression levels of proteins associated with cell death were determined using Western blot., Results: After exposure to irradiation, the small intestine tissues of the rats showed typical radioactive intestinal injury. In addition, various bile acids showed fluctuation before and after irradiation. Among the bile acids, GUDCA increased significantly at 3 d after irradiation, but returned to the pre-irradiation level at 7 d after irradiation. Compared with the control group, after GUDCA treatment at 20 μmol/L for 24 h, the cell viability rate after irradiation was significantly higher than that of the DMSO group ( P <0.05); the expression levels of the proteins, including PARP, caspase-3, RIP, and GSDMD, were significantly lower than those in the control group ( P <0.05). After GUDCA treatment at 20 μmol/L for 24 h and 48 h, the cell apoptosis rate of the cells after irradiation was lower than that of the DMSO group ( P <0.05). Compared with the DMSO control group, the colony formation ability of the GUDCA experimental group was stronger than that of the DMSO group after irradiation at 0, 2, 4, and 6 Gy ( P <0.05). D 0 , or the mean lethal dose, of the GUDCA group was 6.374, while that of the DMSO group was 4.572. Compared with the DMSO control group, the D 0 value of the GUDCA treatment group increased, and the sensitization enhancement ratio (SER) was 0.717., Conclusion: After exposing the abdomen of rats to irradiation, the intestinal bile acid metabolism of the rats will change significantly, and GUDCA can produce radioprotective effects on intestinal cells to a certain extent., Competing Interests: 利益冲突　本文作者张舒羽是本刊编委会编委。该文在编辑评审过程中所有流程严格按照期刊政策进行，且未经其本人经手处理。除此之外，所有作者声明不存在利益冲突。, (© 2024《四川大学学报（医学版）》编辑部 版权所有Copyright ©2024 Editorial Office of Journal of Sichuan University (Medical Sciences).)

This work aims to develop and validate a framework for the multiscale simulation of the biological response to ionizing radiation in a population of cells forming a tissue. We present TOPAS-Tissue, a framework to allow coupling two Monte Carlo (MC) codes: TOPAS with the TOPAS-nBio extension, capable of handling the track-structure simulation and subsequent chemistry, and CompuCell3D, an agent-based model simulator for biological and environmental behavior of a population of cells. We verified the implementation by simulating the experimental conditions for a clonogenic survival assay of a 2-D PC-3 cell culture model (10 cells in 10,000 µm 2 ) irradiated by MV X-rays at several absorbed dose values from 0-8 Gy. The simulation considered cell growth and division, irradiation, DSB induction, DNA repair, and cellular response. The survival was obtained by counting the number of colonies, defined as a surviving primary (or seeded) cell with progeny, at 2.7 simulated days after irradiation. DNA repair was simulated with an MC implementation of the two-lesion kinetic model and the cell response with a p53 protein-pulse model. The simulated survival curve followed the theoretical linear-quadratic response with dose. The fitted coefficients α = 0.280 ± 0.025/Gy and β = 0.042 ± 0.006/Gy 2 agreed with published experimental data within two standard deviations. TOPAS-Tissue extends previous works by simulating in an end-to-end way the effects of radiation in a cell population, from irradiation and DNA damage leading to the cell fate. In conclusion, TOPAS-Tissue offers an extensible all-in-one simulation framework that successfully couples Compucell3D and TOPAS for multiscale simulation of the biological response to radiation.

The present study aimed to compare the effect of photobiomodulation with different energy densities on the angiogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and stem cells from human exfoliated deciduous teeth (SHED). Photobiomodulation therapy with a 660 nm diode laser (2.4 J/cm 2 and 3.9 J/cm 2 ) on two consecutive days post-culture was applied to two types of stem cells (hPDLSCs and SHED). The Quantitative Real-time Polymerase Chain Reaction (RT-qPCR) test was undertaken to investigate Vascular Endothelial Growth Factor-A (VEGF-A) and Angiopoietin I (ANG-I) genes on days 1, 3, 5, 7, and 10 after the first session of laser application. The 4',6-diamidino-2-phenylindole (DAPI) staining and Methyl Thiazolyl Tetrazolium (MTT) test were conducted on days 1, 3, and 5 after the first session of laser application, to assess the cell viability. The Two-way ANOVA with Tukey post hoc test was used to analyze the outcomes of the MTT and RT-qPCR tests. The results of the MTT and DAPI convergently illustrated that the groups receiving photobiomodulation with 2.4 J/cm 2 had higher cell viability compared to 3.9 J/cm 2 . All experimental groups showed an upregulation of VEGF-A and ANG-I gene expression from day 1 to 5, followed by a downregulation from day 5 to 10. The groups with cultured hPDLSCs and SHED receiving photobiomodulation using 2.4 J/cm 2 had the most amounts of VEGF-A and ANG-I gene expression on day 5, respectively. In conclusion, the 660 nm mediated photobiomodulation therapy of cultured SHED and hPDLSCs with 2.4 J/cm 2 energy density may be associated with higher angiogenic differentiation (the expression of VEGF-A and ANG-I) as well as higher cell viability compared to the photobiomodulation therapy with 3.9 J/cm 2 ., (© 2024. The Author(s).)

Background: Ionizing radiation (IR), including radiotherapy, can exert lasting harm on living organisms. While liposaccharide (LPS) offers resistance to radiation damage, it also induces toxic responses. Thankfully, an LPS analogue called N-formylmethionine-leucyl-phenylalanine (fMLP) holds the potential to mitigate this toxicity, offering hope for radiation protection., Methods: Survival of C57BL/6 mice exposed to IR after administration with fMLP/LPS/WR-2721 or saline was recorded. Cell viability and apoptosis assay of bone marrow (BMC), spleen and small intestinal epithelial (HIECs) cells were tested by Cell Counting Kit-8 (CCK-8) and flow cytometry assay. Tissue damage was evaluated by Hematoxilin and Eosin (H&E), Ki-67, and TUNEL staining. RNA sequencing was performed to reveal potential mechanisms of fMLP-mediated radiation protection. Flow cytometry and western blot were performed to verify the radiation protection mechanism of fMLP on the cell cycle., Results: The survival rates of C57BL/6 mice exposed to ionizing radiation after administering fMLP increased. fMLP demonstrated low toxicity in vitro and in vivo, maintaining cell viability and mitigating radiation-induced apoptosis. Moreover, it protected against tissue damage in the hematopoietic and intestinal system. RNA sequencing shed light on fMLP's potential mechanism, suggesting its role in modulating innate immunity and cell cycling. This was evidenced by its ability to reverse radiation-induced G2/M phase arrests in HIECs., Conclusion: fMLP serves as a promising radioprotective agent, preserving cells and radiosensitive tissues from IR. Through its influence on the cell cycle, particularly reversing radiation-induced arrest in G2/M phases, fMLP offers protection against IR's detrimental effects., (© 2024. The Author(s).)

Esophageal adenocarcinoma (EAC) is a subtype of esophageal cancer that is difficult to treat, with overall poor survival and frequent recurrence despite curative-intent treatment strategies. There is limited understanding of EAC resistance mechanisms to chemotherapy or radiation. We have found that the AMP-activated protein kinase (AMPK) can serve a pro-survival function in EAC cells in response to cytotoxic treatments. Treatment with the IL-6 inhibitor tocilizumab, which previously has been shown to inhibit EAC organoid growth, resulted in the activation of AMPK in the OE33 EAC cell line, which was accompanied by a decrease in MTORC1 signaling and an increase in oxidative mitochondrial metabolism, both known downstream effects of AMPK activation to promote cell survival under conditions of metabolic stress. This increase in oxidative metabolism was abrogated in cells with a genetic knockdown of AMPK expression. Furthermore, we found that AMPK was activated in OE33 cells following treatment with cisplatin or ionizing radiation. Treatment with the AMPK inhibitor Compound C or genetic knockdown of AMPK expression enhanced cell death in a synergistic manner with chemotherapeutics or ionizing radiation. These findings were recapitulated in human patient-derived EAC organoids, suggesting that AMPK may be a common pro-survival mechanism to confer treatment resistance in EAC and may serve as a novel target to enhance the efficacy of current and future treatment strategies.

This study aimed to compare the effects of photobiomodulation therapy (PBMT) with 660 and 980 nm diode lasers on differentiation of periodontal ligament mesenchymal stem cells (PDLMSCs). In this in vitro, experimental study, PDLMSCs were obtained from the Iranian Genetic Bank and cultured in osteogenic medium. They were then subjected to irradiation of 660 and 980 nm diode lasers, and their viability was assessed after one, two, and three irradiation cycles using the methyl thiazolyl tetrazolium (MTT) assay. The cells also underwent DAPI staining, cell apoptosis assay by using the Annexin V/PI, Alizarin Red staining, and real-time polymerase chain reaction (PCR) for assessment of the expression of osteogenic genes. Data were analyzed by two-way ANOVA. The two laser groups had no significant difference in cell apoptosis according to the results of DAPI staining. Both laser groups showed higher cell viability in the MTT assay at 4 and 6 days compared with the control group. Annexin V/PI results showed higher cell viability in both laser groups at 4 days compared with the control group. Rate of early and late apoptosis was lower in both laser groups than the control group at 4 days. Necrosis had a lower frequency in 980 nm laser group than the control group on day 6. Alizarin Red staining showed higher cell differentiation in both laser groups after 3 irradiation cycles than the control group. The highest expression of osteopontin (OPN), osteocalcin (OCN), and Runt-related transcription factor 2 (RUNX2) was noted in 660 nm laser group with 3 irradiation cycles at 14 days, compared with the control group. PBMT with 660 and 980 nm diode lasers decreased apoptosis and significantly increased PDLMSC differentiation after 3 irradiation cycles., (© 2024. The Author(s).)

Background and Purpose: The linear-quadratic (LQ) model has been pivotal for evaluating the effects of radiation on cells, but it is primarily characterized by linear responses, which has exhibited limitations when applied to lymphocyte data. The present research aims to address these limitations and to explore an alternative model extended from the conventional LQ model., Materials and Methods: Literature providing lymphocyte counts from assays investigating apoptosis and survival after in vitro irradiation was selected. To address the nonlinearity in lymphocyte responses to radiation, we developed a saturation model characterized by a negative exponential relationship between radiation dose and cellular response. We compared the performance of this saturation model against that of conventional models, including the LQ model and its variants (linear model LM and linear-quadratic-cubic model LQC), as well as the repair-misrepair (RMR) model. The models were evaluated based on prediction-residual plots, residual standard errors, and the Akaike information criterion (AIC). We applied the saturation model to two additional datasets: (1) a dataset from the existing literature that assessed stimulated and unstimulated human lymphocytes exposed to gamma irradiation in vitro and (2) a novel dataset involving T lymphocytes from rodent spleens after exposure to various radiation types (X-rays and protons)., Results: The literature (n = 15 out of 2342) showed that lymphocyte apoptosis varies with dose, time and experimental conditions. The saturation model had a lower AIC of 718 compared to the LM, LQ, LQC and RMR models (AIC of 728, 720, 720 and 734, respectively). The saturation model had a lower residual error and more consistent error distribution. Integrating time as a covariate, the saturation model also had a better AIC for demonstrating time-dependent variations in lymphocyte responses after irradiation. For datasets involving unstimulated lymphocytes before irradiation, the saturation model provided a more accurate fit than did the LM, LQ, and RMR models. In these cases, the fit of the saturation model was comparable to that of the LQC model but offered an advantage when extrapolating to higher doses, where the LQC model might underestimate survival. For stimulated lymphocytes, which are radioresistant, all the models approximated the LM. Both the LQ and saturation models indicated greater radiosensitivity to protons in vitro., Conclusion: The new "saturation model" performed better than the LQ model in quantifying lymphocyte apoptosis and survival, estimating time dependency and assessing the role of radiation modalities or lymphocyte stimulation. Further experiments are warranted to experimentally explore the validity of the saturation model as a promising alternative in the clinical setting., 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.)

Oral squamous cell carcinoma (OSCC) constitutes over 90% of oral cancers, known for its aggressiveness and poor prognosis. Photodynamic therapy (PDT) has emerged as a promising adjuvant therapy and is linked to immunogenic cell death, activating innate and adaptive anti-tumor responses. Natural Killer (NK) cells, key players in malignant cell elimination, have not been extensively studied in PDT. This study evaluates whether PDT increases OSCC cell lines' susceptibility to NK cell cytotoxicity. PDT, using 5-aminolevulinic acid (5-ALA) and LED irradiation, was applied to Ca1 and Luc4 cell lines. Results showed a dose-dependent viability decrease post-PDT. Gene expression analysis revealed upregulation of NK cell-activating ligands (ULBP1-4, MICA/B) and decreased MHC class I expression in Ca1, suggesting increased NK cell susceptibility. Enhanced NK cell cytotoxicity was confirmed in Ca1 but not in Luc4 cells. These findings indicate that PDT may enhance NK cell-mediated cytotoxicity in OSCC, offering potential for improved treatment strategies., (© 2024 Wiley‐VCH GmbH.)