Single-dose Irradiation Research Articles

The Influence of Different Irradiation Regimens on Inflammation and Vascularization in a Random-Pattern Flap Model.

Irradiation plays an important role in the oncological treatment of various tumor entities. The aim of the study was to investigate the influence of different irradiation regimens on random-pattern flaps at the molecular and histopathological levels. Twenty-five rats underwent harvesting of bilateral random-pattern fasciocutaneous flaps. The right flaps received irradiation, while the left flaps served as non-irradiated intraindividual controls. Five rats served as a non-irradiated control group. Four different irradiation regimens with give rats each were tested: 20 Gy postoperatively, 3 × 12 Gy postoperatively, 20 Gy preoperatively, and 3 × 12 Gy preoperatively. Two weeks after surgery, HE staining and immunohistochemical staining for CD68 and ERG, as well as PCR analysis to detect Interleukin 6, HIF-1α, and VEGF, were performed. A postoperative cumulative higher dose of irradiation appeared to result in an increase in necrosis, especially in the superficial layers of the flap compared to preoperative or single-stage irradiation. In addition, we observed increased expression of VEGF and HIF-1α in all irradiation groups. Even though no statistically significant differences were found between the different groups, there was a tendency for fractional postoperative irradiation with a higher total dose to have a more harmful effect compared to preoperative or single-dose irradiation.

7-Hydroxy-6-Methoxycoumarin 8-Glucoside (Fraxin) Confers Protection against Ionizing Radiation-Induced Intestinal Epithelial Cell Death Both In Vitro and In Vivo

The small intestine is highly sensitive to ionizing radiation. Radiation-induced intestinal injury (RIII) limits the therapeutic effect of tumor radiotherapy. However, there are currently few effective treatments available for the prevention or mitigation of RIII. Fraxin, structurally a derivative of a coumarin glucoside extracted from the herbal Cortex Qinpi, has the advantages of low toxicity and relatively low cost. Some studies have proven that Fraxin has anti-inflammatory and antibacterial effects. Our results show that Fraxin can not only promote the regeneration of intestinal stem cells and repair the intestinal structure caused by irradiation but also regulate the composition of gut microbiota and then play an immunomodulatory role through IL-22 signaling pathways, resulting in radioprotective effects. Human intestinal epithelial cells (HIECs) and intestinal organs were used as experimental models in vitro. The experimental group was irradiated with 6 Gy, detected by a cell counting kit, cell cloning, apoptosis, γ-H2AX and 8-OHdG IF. Male C57BL/6 mice aged 6-8 weeks were given a single dose of whole abdominal irradiation (WAI) at 13 Gy, detected by HE staining, IHC, IF and TUNEL methods, and survival and body weight changes were recorded, fecal samples and small intestinal tissue samples were collected 6 hours and 3 days after irradiation, and the gut microbiota was detected by 16S rRNA sequencing. Whole small intestinal tissue was analyzed by genomic transcript spectrum and RNA sequencing. Compared with vehicle treatment, Fraxin administration significantly improved the quality of life after WAI and maintained the body weight of mice. In addition, the crypt-villus architecture of the intestinal tracts in mice treated with Fraxin was well preserved, and the number of goblet cells, Lgr5+ intestinal stem cells (ISCs) and their daughter cells, Ki67+ proliferating cells increased significantly, reducing the structural damage caused by radiation. Meanwhile, Fraxin improved the expression of tight junction proteins such as E-cadherin and Claudin-3 after WAI, strikingly reduced the levels of FITC-dextran in serum, maintained the integrity of the intestinal barrier. In addition, we have confirmed that Fraxin can increase the cell viability of HIECs, reduce the 8OHdG fluorescence intensity induced by IR, and reduce γ H2AX lesions and apoptosis. Fraxin administration recovered the disorder of the structure of gut microbiota after irradiation and promoted the expression of probiotics, and KEGG pathway analysis suggested that it was related to immunity. Transcriptional sequencing showed that the IL-22 signaling pathway was significantly activated in the Fraxin treatment group, suggesting that Fraxin may have a protective effect on intestinal radiation through IL-22. In conclusion, Fraxin treatment attenuate RIII by modulating the composition of the gut microbiota and activate the IL-22 signaling pathway to reduce RIII.

Radiotherapy Shows Synergistic Anti-Tumor Efficacy with Treg Depletion by Reprogramming the Immune-Excluded Tumor Microenvironment

Tumor-infiltrating Treg cells (TITR) negatively regulates anti-tumor immune response and promotes tumor progression. Increased levels of TITR cells have been associated with poor prognosis in multiple cancer indications which led to the development of immunotherapies that target tumor Tregs. CCR8 antibody is one of the best-in-class therapies in clinical development for depleting TITR cells. It has demonstrated potent efficacy in tumors that are responsive to checkpoint inhibitors but failed in cold tumors that lack immune infiltration and activation. Radiotherapy (RT) has been shown to induce pro-inflammatory responses in tumors, but still failed to show consistent synergy with checkpoint inhibitors. Here we test the hypothesis that RT synergizes with Treg depletion to improve anti-tumor efficacy by reprogramming the immune-excluded tumor microenvironment. The CCR8 + RT combination therapy was tested in syngeneic mouse tumor models: 4T1 breast, LL2 lung, and B16F10 melanoma, all of which present a cold tumor phenotype. Tumor-bearing mice (n = 10 per group) received a single dose of focal irradiation by SARRP, 4 doses of anti-CCR8 depleting antibody or a combination of the two. Tumor size was measured 3 times per week, survival was monitored until day 42, and tumor metastasis was evaluated at endpoint by necropsy. Mouse tumors, spleens, draining lymph nodes, and blood were collected 1 day after the last dose of CCR8 therapy and analyzed by multi-color flow cytometry and RNA-sequencing for pharmacodynamics and mechanism studies. In the syngeneic mouse models, CCR8+RT combination therapy displayed significantly improved tumor growth inhibition, metastasis control, and prolonged survival compared with either treatment alone, without increase in toxicity. Flow cytometry showed reduced TITR population and increased infiltration and activation of CD8+ cytotoxic T cells in the tumors of CCR8 + RT treated mice. Increased activation of CD8+ T cells was also observed in the blood and draining lymph nodes in mice treated with the combination therapy. Moreover, transcriptomic analysis identified up-regulation of pathways associated with TNF-α and IFN-γ response in the combination-treated tumors, suggesting the creation of a pro-inflammatory tumor microenvironment. Interestingly, these changes were only induced by the combination therapy, but not either treatment alone. Immunotherapies targeting Treg/TITR cells have so far failed to show promise in clinical trials. Our data suggest that TITR depletion is not sufficient to treat tumors with minimal immune infiltration. Our animal data demonstrate that combining RT with CCR8 therapy significantly inhibited tumor growth and prevented metastasis by enriching the tumor microenvironment with pro-inflammatory cytokines and activated cytotoxic T cells. These findings have clinical relevance to apply TITR depletion therapy in combination with RT.

Effect of photobiomodulation on the behaviour of mesenchymal stem cells in three-dimensional cultures.

Photobiomodulation (PBM) has been proposed as a strategy to improve the regenerative capacity of human adipose-derived stem cells (hASCs). Yet, this effect has been proved in 2D culture conditions. To analyze the effect of different doses of laser irradiation (660nm) with different levels of energy (1J, 2J and 6J) on hASCs cultured at 2D and 3D conditions. We used gellan gum spongy-like hydrogels as a biomaterial to 3D culture hASCs. Different doses (1-7 daily irradiations) and energy levels (1-6J) of PBM were applied, and the metabolic activity, viability, proliferation, and release of ROS and IL-8 was evaluated up to 7days. In 3D, cell proliferation increased at high energy (6J) and after a single dose of irradiation, while in 2D, metabolic activity and proliferation was enhanced only after 3 doses and independently of the energy. More than 1 dose was needed to promote ROS secretion both in 2D and 3D culture conditions. Interestingly, a decrease of IL-8 secretion was detected only in 3D after 3-7 daily irradiations. Overall, hASCs response to PBM was not only dependent on the energy level and the number of applied stimuli, but also on the in vitro culture conditions.

Radioprotective Effects of Carvacrol and/or Thymol against Gamma Irradiation-Induced Acute Nephropathy: In Silico and In Vivo Evidence of the Involvement of Insulin-like Growth Factor-1 (IGF-1) and Calcitonin Gene-Related Peptide.

Radiotherapy (RT) is an effective curative cancer treatment. However, RT can seriously damage kidney tissues resulting in radiotherapy nephropathy (RN) where oxidative stress, inflammation, and apoptosis are among the common pathomechanisms. Carvacrol and thymol are known for their antioxidative, anti-inflammatory, and radioprotective activities. Therefore, this study investigated the nephroprotective potentials of carvacrol and/or thymol against gamma (γ) irradiation-induced nephrotoxicity in rats along with the nephroprotection mechanisms, particularly the involvement of insulin-like growth factor-1 (IGF-1) and calcitonin gene-related peptide (CGRP). Methods: Male rats were injected with carvacrol and/or thymol (80 and 50 mg/kg BW in the vehicle, respectively) for five days and exposed to a single dose of irradiation (6 Gy). Then, nephrotoxicity indices, oxidative stress, inflammatory, apoptotic biomarkers, and the histopathological examination were assessed. Also, IGF-1 and CGRP renal expressions were measured. Results: Carvacrol and/or thymol protected kidneys against γ-irradiation-induced acute RN which might be attributed to their antioxidative, anti-inflammatory, and antiapoptotic activities. Moreover, both reserved the γ -irradiation-induced downregulation of CGRP- TNF-α loop in acute RN that might be involved in the pathomechanisms of acute RN. Additionally, in Silico molecular docking simulation of carvacrol and thymol demonstrated promising fitting and binding with CGRP, IGF-1, TNF-α and NF-κB through the formation of hydrogen, hydrophobic and alkyl bonds with binding sites of target proteins which supports the reno-protective properties of carvacrol and thymol. Collectively, our findings open a new avenue for using carvacrol and/or thymol to improve the therapeutic index of γ-irradiation.

P02.20.B PLASMA MEMBRANE-ASSOCIATED 70 KDA HEAT SHOCK PROTEIN (HSP70) INVOLVED IN GLIOBLASTOMA CELLS INVASION AS A TARGET FOR TUMOR THERANOSTICS

Abstract BACKGROUND Heat shock proteins (HSPs) represent a large family of highly conserved proteins serving as molecular chaperones that play an important role in intracellular homeostasis. Apart from their intracellular localization, members of various HSPs families such as HSP70 have been reported to be expressed on the plasma membrane of malignant cells, including glioblastoma multiforme (GBM). However, the role of the membrane-bound protein Hsp70 has not yet been investigated in the pathophysiology of GBM. MATERIAL AND METHODS mHsp70 expression as related to GBM cell invasive potential was analyzed in biopsies obtained from neurooncological patients using CellVoyager CQ1 Benchtop High-Content Analysis System (Yokogawa) and inverted confocal microscopy (Leica Microsystems). Application of membrane-associated chaperone for targeted therapies was assessed in the intracranial human NCH644, NCH421k, and U87 GBM models in immunodeficient mice employing various chaperone inhibitors (i.e., JG-98, MKT-077, pifithrin-μ (PES)) as a monotherapy or in combination with a single dose of stereotactic irradiation (10Gy) (SARRP). RESULTS Live-cell imaging of the patient-derived biopsies demonstrated the increased cellular density of mHsp70+ GBM cells particularly in the tissue along the tumor-brain margin. Time-lapse evaluation of the tumor sample further proved the migration of mHsp70+ cells into the surrounding normal brain tissues. Subsequent high-powered multiplex immunofluorescence analysis (Akoya Biosystems) confirmed significantly increased single-cell infiltration of mHsp70+ tumor cells (also positively stained for Nestin, Oct4, and SOX2) in the normal brain tissues. When mHsp70 inhibitors were applied in GBM animal models as a monotherapy or in combination with radiotherapy dramatic inhibition of tumor progression (as shown by MRI) and increased animal survival were observed. CONCLUSION Expression of the mHsp70 on the plasma membrane of GBM cells corresponds to the highly invasive potential of the tumor cells in neuro-oncological patients. Administration of the HSP70 small molecular inhibitors significantly decreased the GBM growth and invasion thus prolonging the overall survival of tumor-bearing mice. Further development of mHsp70-targeted agents represents a promising approach in treatment of multiforme glioblastoma.

The effect of single-dose radiation on cell survival and growth hormone secretion by rat anterior pituitary cells

The effect of single-dose radiation on cell survival and growth hormone secretion by rat anterior pituitary cells

Transcriptomic and genomic effects of gamma-radiation exposure on strains of the black yeast Exophiala dermatitidis evolved to display increased ionizing radiation resistance.

Ionizing radiation poses a significant threat to living organisms and human health, given its destructive nature and widespread use in fields such as medicine and the potential for nuclear disasters. Melanized fungi exhibit remarkable survival capabilities, enduring doses up to 1,000-fold higher than mammals. Through adaptive laboratory evolution, we validated the protective role of constitutive upregulation of DNA repair genes in the black yeast Exophiala dermatitidis, enhancing survival after radiation exposure. Surprisingly, we found that evolved strains lacking melanin still achieved high levels of radioresistance. Our study unveiled the significance of robust activation and enhancement of redox homeostasis, as evidenced by the profound transcriptional changes and increased accumulation of mutations, in substantially improving ionizing radiation resistance in the absence of melanin. These findings underscore the delicate balance between DNA repair and redox homeostasis for an organism's ability to endure and recover from radiation exposure.

Enhancement of Radiation Therapy through Blockade of the Immune Checkpoint, V-domain Ig Suppressor of T Cell Activation (VISTA), in Melanoma and Adenocarcinoma Murine Models.

Radiation therapy (RT) has recently demonstrated promise at stimulating an enhanced immune response. The recent success of immunotherapies, such as checkpoint inhibitors, CART cells, and other immune modulators, affords new opportunities for combination with radiation. The aim of this study is to evaluate whether and to what extent blockade of VISTA, an immune checkpoint, can potentiate the tumor control ability of radiation therapy. Our study is novel in that it is the first comparison of two VISTA-blocking methods (antibody inhibition and genetic knockout) in combination with RT. VISTA was blocked either through genetic knockout (KO) or an inhibitory antibody and combined with RT in two syngeneic murine flank tumor models (B16 and MC38). Selected mRNA, immune cell infiltration, and tumor growth delay were used to assess the biological effects. When combined with a single 15Gy radiation dose, VISTA blockade via genetic knockout in the B16 model and via anti-VISTA antibodies in the MC38 model significantly improved survival compared to RT alone by an average of 5.5 days and 6.3 days, respectively (p < 0.05). The gene expression data suggest that the mechanism behind the enhanced tumor control is primarily a result of increased apoptosis and immune-mediated cytotoxicity. VISTA blockade significantly enhances the anti-tumor effect of a single dose of 15Gy radiation through increased expression and stimulation of cell-mediated apoptosis pathways. These results suggest that VISTA is a biologically relevant immune promoter that has the potential to enhance the efficacy of a large single radiation dose in a synergic manner.

Radiation induces long-term muscle fibrosis and promotes a fibrotic phenotype in fibro-adipogenic progenitors.

Radiation-induced muscle pathology, characterized by muscle atrophy and fibrotic tissue accumulation, is the most common debilitating late effect of therapeutic radiation exposure particularly in juvenile cancer survivors. In healthy muscle, fibro/adipogenic progenitors (FAPs) are required for muscle maintenance and regeneration, while in muscle pathology FAPs are precursors for exacerbated extracellular matrix deposition. However, the role of FAPs in radiation-induced muscle pathology has not previously been explored. Four-week-old Male CBA or C57Bl/6J mice received a single dose (16Gy) of irradiation (IR) to a single hindlimb with the shielded contralateral limb (CLTR) serving as a non-IR control. Mice were sacrificed 3, 7, 14 (acute IR response), and 56days post-IR (long-term IR response). Changes in skeletal muscle morphology, myofibre composition, muscle niche cellular dynamics, DNA damage, proliferation, mitochondrial respiration, and metabolism and changes in progenitor cell fate where assessed. Juvenile radiation exposure resulted in smaller myofibre cross-sectional area, particularly in type I and IIA myofibres (P<0.05) and reduced the proportion of type I myofibres (P<0.05). Skeletal muscle fibrosis (P<0.05) was evident at 56days post-IR. The IR-limb had fewer endothelial cells (P<0.05) and fibro-adipogenic progenitors (FAPs) (P<0.05) at 56days post-IR. Fewer muscle satellite (stem) cells were detected at 3 and 56days in the IR-limb (P<0.05). IR induced FAP senescence (P<0.05), increased their fibrogenic differentiation (P<0.01), and promoted their glycolytic metabolism. Further, IR altered the FAP secretome in a manner that impaired muscle satellite (stem) cell differentiation (P<0.05) and fusion (P<0.05). Our study suggests that following juvenile radiation exposure, FAPs contribute to long-term skeletal muscle atrophy and fibrosis. These findings provide rationale for investigating FAP-targeted therapies to ameliorate the negative late effects of radiation exposure in skeletal muscle.

Intratumor delivery of amino-modified graphene oxide as a multifunctional photothermal agent for efficient antitumor phototherapy

Due to the high selectivity and non-invasive property, phototherapy has attracted increasing attention in the treatment of cancer. Targeted delivery and retention of photoactive agents in tumor tissue is of great significance and importance for safe and efficient phototherapy. Herein, we report a multifunctional nanomaterial photothermal agent, namely amino-modified graphene oxide (AGO) for anti-oral cancer photothermal therapy (PTT). Compared to the parental graphene oxide (GO) which has a negative charge and weak photothermal effect, AGO possesses a positive charge (∼+50 mV) and the significantly enhanced photothermal effect. Positive charge allows AGO to efficiently interact with tumor cells and retain in tumor tissue after intratumor injection. The enhanced photothermal effect allows AGO to achieve the tunable and efficient PTT. In vitro results show that AGO (15 μg/mL) reduces the viability of HSC-3 cells (oral squamous cell carcinoma cell line) to 5% under near infrared (NIR) irradiation (temperature increased to 58.4 °C). In vivo antitumor study shows that intratumor delivery of AGO (200 μg/mouse) has no inhibition effects on tumor growth (454% of initial tumor size) without NIR. With a single dose of NIR irradiation, however, AGO significantly reduces the tumor size to 25% of initial size in 1 of 4 mice, and even induces the complete tumor ablation in 3 of 4 mice. Furthermore, the injected AGO falls off along with the scab after PTT. Our findings indicate that AGO is a potential nano-photothermal agent for tunable, convenient and efficient anticancer PTT.

Microwave Radiation Induced Human iPSC Derived Cardiomyo-cytes Injury

Electromagnetic waves are recognized as the third major source of pollution, which can damage to the heart. However, due to the limitation of human subjects in research, it is difficult to extrapolate the biological effects of electromagnetic waves directly from animals to humans. In this study, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were used to explore the effect of microwave radiation on human heart injury. Human iPSC-CMs were radiated with a single irradiation dose of 30W/Kg for 30 min. After radiation, the content of Reactive Oxygen Species (ROS) in hiPSC-CMs increased significantly, and the Mito-tracker and mitochondrial membrane potential decreased synchronously. Seahorse assay found that the mitochondrial functions in cardiomyocytes were weakened after being exposed irradiation. The electrophysiological functions of hiPSC-CMs were significantly abnormal, with increased proportions of late apoptosis and decreased proportions of viable cells. In addition, the secretion of 10 pro-inflammatory cytokines/chemokines was increased in hiPSC-CMs after radiation. An effector model of microwave irradiation-induced cardiac injury was established using hiPSC-CMs in this study. Based on the fully observation of the structure and functions of iPSC-CMs after radiation, it was speculated that mitochondrial damage might be the dominant cause of delayed intracellular energy transfer, which was synchronously manifested as abnormal electrophysiological functions. The findings of this study provide valuable data for the clinical transformation of basic experimental research, and the damage mechanism will be explored in the future in order to provide effective assistance to the occupational practitioners.

Early and Accurate Detection of Radiation-induced Heart Damage by Cardiodynamicsgram.

Cardiodynamicsgram (CDG) has emerged recently as a noninvasive spatiotemporal electrocardiographic method for subtle cardiac dynamics information analysis within electrocardiogram (ECG). This study explored the feasibility of CDG for detecting radiation-induced heart damage (RIHD) in a rat model. A single radiation dose of 40Gy was delivered to the cardiac apex of female Wistar rats. First, CDG was generated through dynamic modeling of ECG signals using the deterministic learning algorithm. Furthermore, CDG indexes were calculated using the wavelet transform and entropy. In this model, CDG entropy indexes decreased significantly after radiotherapy. The shape of CDG changed significantly after radiotherapy (irregular shape) compared with controls (regular shape). Macrophage and fibrosis in myocardium of rats increased significantly after radiotherapy. CDG changes after radiotherapy were significantly correlated with histopathological changes and occurred significantly earlier than histopathological changes. This study provides an experimental basis for the clinical application of CDG for the early detection of RIHD.

Using immunotherapy to enhance the response of a C3H mammary carcinoma to proton radiation

Background The benefit of combining immunotherapy with photon irradiation has been shown pre-clinically and clinically. This current pre-clinical study was designed to investigate the anti-tumour action of combining immunotherapy with protons. Materials and Methods Male CDF1 mice, with a C3H mammary carcinoma inoculated on the right rear foot, were locally irradiated with single radiation doses when tumours reached 200mm3. Radiation was delivered with an 83–107MeV pencil scanning proton beam in the centre of a 3 cm spread out Bragg peak. Following irradiation (day 0), mice were injected intraperitoneal with anti-CTLA-4, anti-PD-1, or anti-PD-L1 (10 mg/kg) twice weekly for two weeks. Endpoints were tumour growth time (TGT3; time to reach 3 times treatment volume) or local tumour control (percent of mice showing tumour control at 90 days). A Student’s T-test (tumour growth) or Chi-squared test (tumour control) were used for statistical analysis; significance levels of p < 0.05. Results Untreated tumours had a mean (± 1 S.E.) TGT3 of 4.6 days (± 0.4). None of the checkpoint inhibitors changed this TGT3. A linear increase in TGT3 was seen with increasing radiation doses (5–20 Gy), reaching 17.2 days (± 0.7) with 20 Gy. Anti-CTLA-4 had no effect on radiation doses up to 15 Gy, but significantly enhanced 20 Gy; the TGT3 being 23.0 days (± 1.3). Higher radiation doses (35–60 Gy) were investigated using a tumour control assay. Logit analysis of the dose response curve, resulted in a TCD50 value (radiation dose causing 50% tumour control; with 95% confidence intervals) of 48 Gy (44–53) for radiation only. This significantly decreased to 43 Gy (38–49) when mice were treated with anti-CTLA-4. Neither anti-PD-1 nor anti-PD-L1 significantly affected tumour control. Conclusion Checkpoint inhibitors enhanced the response of this C3H mammary carcinoma to proton irradiation. However, this enhancement depended on the checkpoint inhibitor and radiation dose.

Overcoming radioresistance with the hypoxia-activated prodrug CP-506: A pre-clinical study of local tumour control probability

Background and purposeTumour hypoxia is an established radioresistance factor. A novel hypoxia-activated prodrug CP-506 has been proven to selectively target hypoxic tumour cells and to cause anti-tumour activity. The current study investigates whether CP-506 improves outcome of radiotherapy in vivo. Materials and methodsMice bearing FaDu and UT-SCC-5 xenografts were randomized to receive 5 daily injections of CP-506/vehicle followed by single dose (SD) irradiation. In addition, CP-506 was combined once per week with fractionated irradiation (30 fractions/6 weeks). Animals were followed-up to score all recurrences. In parallel, tumours were harvested to evaluate pimonidazole hypoxia, DNA damage (γH2AX), expression of oxidoreductases. ResultsCP-506 treatment significantly increased local control rate after SD in FaDu, 62% vs. 27% (p = 0.024). In UT-SCC-5, this effect was not curative and only marginally significant. CP-506 induced significant DNA damage in FaDu (p = 0.009) but not in UT- SCC-5. Hypoxic volume (HV) was significantly smaller (p = 0.038) after pretreatment with CP-506 as compared to vehicle in FaDu but not in less responsive UT-SCC-5. Adding CP-506 to fractionated radiotherapy in FaDu did not result in significant benefit. ConclusionThe results support the use of CP-506 in combination with radiation in particular using hypofractionation schedules in hypoxic tumours. The magnitude of effect depends on the tumour model, therefore it is expected that applying appropriate patient stratification strategy will further enhance the benefit of CP-506 treatment for cancer patients. A phase I-IIA clinical trial of CP-506 in monotherapy or in combination with carboplatin or a checkpoint inhibitor has been approved (NCT04954599).

PTEN potentiation of oncolytic HSV therapy for glioblastoma

PTEN potentiation of oncolytic HSV therapy for glioblastoma

Deep TL: progress of a machine learning aided personal dose monitoring system.

Personal dosemeters using thermoluminescence detectors can provide information about the irradiation event beyond the pure dose estimation, which is valuable for improving radiation protection measures. In the presented study, the glow curves of the novel TL-DOS dosemeters developed by the Materialprüfungsamt NRW in cooperation with the TU Dortmund University are analysed using deep learning approaches to predict the irradiation date of a single-dose irradiation of 10mGy within a monitoring interval of 41d. In contrast of previous work, the glow curves are measured using the current routine read-out process by pre-heating the detectors before the read-out. The irradiation dates are predicted with an accuracy of 2-5d by the deep learning algorithm. Furthermore, the importance of the input features is evaluated using Shapley values to increase the interpretability of the neural network.

Multiomics analysis of adaptation to repeated DNA damage in prostate cancer cells

ABSTRACT DNA damage is frequently utilized as the basis for cancer therapies; however, resistance to DNA damage remains one of the biggest challenges for successful treatment outcomes. Critically, the molecular drivers behind resistance are poorly understood. To address this question, we created an isogenic model of prostate cancer exhibiting more aggressive characteristics to better understand the molecular signatures associated with resistance and metastasis. 22Rv1 cells were repeatedly exposed to DNA damage daily for 6 weeks, similar to patient treatment regimes. Using Illumina Methylation EPIC arrays and RNA-seq, we compared DNA methylation and transcriptional profiles between the parental 22Rv1 cell line and the lineage exposed to prolonged DNA damage. Here we show that repeated DNA damage drives the molecular evolution of cancer cells to a more aggressive phenotype and identify molecular candidates behind this process. Total DNA methylation was increased while RNA-seq demonstrated these cells had dysregulated expression of genes involved in metabolism and the unfolded protein response (UPR) with Asparagine synthetase (ASNS) identified as central to this process. Despite the limited overlap between RNA-seq and DNA methylation, oxoglutarate dehydrogenase-like (OGDHL) was identified as altered in both data sets. Utilising a second approach we profiled the proteome in 22Rv1 cells following a single dose of radiotherapy. This analysis also highlighted the UPR in response to DNA damage. Together, these analyses identified dysregulation of metabolism and the UPR and identified ASNS and OGDHL as candidates for resistance to DNA damage. This work provides critical insight into molecular changes which underpin treatment resistance and metastasis.

Resilience, aging, and response to radiation exposure (RARRE) in nonhuman primates: a resource review.

The Wake Forest nonhuman primate (NHP) Radiation Late Effects Cohort (RLEC) is a unique and irreplaceable population of aging NHP radiation survivors which serves the nation's need to understand the late effects of radiation exposure. Over the past 16years, Wake Forest has evaluated > 250 previously irradiated rhesus macaques (Macaca mulatta) that were exposed to single total body irradiation (IR) doses of 1.14-8.5Gy or to partial body exposures of up to 10Gy (5% bone marrow sparing) or 10.75Gy (whole thorax). Though primarily used to examine IR effects on disease-specific processes or to develop radiation countermeasures, this resource provides insights on resilience across physiologic systems and its relationship with biological aging. Exposure to IR has well documented deleterious effects on health, but the late effects of IR are highly variable. Some animals exhibit multimorbidity and accumulated health deficits, whereas others remain relatively resilient years after exposure to total body IR. This provides an opportunity to evaluate biological aging at the nexus of resilient/vulnerable responses to a stressor. Consideration of inter-individual differences in response to this stressor can inform individualized strategies to manage late effects of radiation exposure, and provide insight into mechanisms underlying systemic resilience and aging. The utility of this cohort for age-related research questions was summarized at the 2022 Trans-NIH Geroscience Interest Group's Workshop on Animal Models for Geroscience. We present a brief review of radiation injury and its relationship to aging and resilience in NHPs with a focus on the RLEC.

Lipo-MGN nanoparticle hypoxia attenuation-mediated single-dose radiotherapy- and pH/ROS-responsive T1 contrast magnetic resonance imaging in hepatocellular carcinoma

Tumor hypoxia is an important factor for developing resistance to radiation therapy (RT) and presents a bleak prognosis in cancer patients undergoing treatment for RT resistant hepatocellular carcinoma. Here, we present the synthesis of liposome-coated Mn3O4 (MGN) nanoparticles (Lipo-MGN) and investigation of their therapeutic potential with RT utilizing a HepG2 cancer model. According to in vitro research, Lipo-MGN effectively produced oxygen in the presence of H2O2 and significantly reduced the expression of HIF-1 in human HepG2 cells that were under hypoxic conditions. Lipo-MGN reversed the radio-resistance brought on by hypoxia and increased cell damage. When Lipo-MGN and RT were administered together in a HepG2 xenograft mice model, the tumor growth was delayed more than with RT alone. As determined by MR imaging, liposome-MGN also exhibited T1 contrast enhancement in tumor. According to these findings, Lipo-MGNs may increase the impact of RT by focusing tumor hypoxia. Hypoxic, radioresistant HepG2 cancer may be treated with Lipo-MGN in clinical studies.