Single-dose Irradiation Research Articles

Treatment of radiation-induced brain injury with bisdemethoxycurcumin.

Radiation therapy is considered the most effective non-surgical treatment for brain tumors. However, there are no available treatments for radiation-induced brain injury. Bisdemethoxycurcumin (BDMC) is a demethoxy derivative of curcumin that has anti-proliferative, anti-inflammatory, and anti-oxidant properties. To determine whether BDMC has the potential to treat radiation-induced brain injury, in this study, we established a rat model of radiation-induced brain injury by administering a single 30-Gy vertical dose of irradiation to the whole brain, followed by intraperitoneal injection of 500 μL of a 100 mg/kg BDMC solution every day for 5 successive weeks. Our results showed that BDMC increased the body weight of rats with radiation-induced brain injury, improved learning and memory, attenuated brain edema, inhibited astrocyte activation, and reduced oxidative stress. These findings suggest that BDMC protects against radiation-induced brain injury.

The injuries of spleen and intestinal immune system induced by 2-Gy 60Co γ-ray whole-body irradiation

Purpose The aim of the present study was to investigate the injuries of spleen and intestinal immune system induced by 2 Gy 60Co γ ray in mice. Materials and methods A total of 120 Balb/c mice were randomly divided into two groups: blank control (Ctrl) and model (IR). The IR mice were exposed to a single dose of total body irradiation (2 Gy, dose rate: 1 Gy/min) and sacrificed on 1st, 3rd, 7th, 14th and 21st day after irradiation. The indicators including general observations and body weight, the changes in peripheral hemogram, spleen index, histopathology examination and lymphocyte subsets of spleen. As well as the count and subsets of lymphocyte in gut-associated lymphoid tissue. Results Compared with the Ctrl group, the body weight, spleen index, peripheral blood cell and splenocyte amounts, intraepithelial lymphocytes number decreased significantly after exposure, accompanied by a notable decreased count of lymphocytes in Peyer’s patch and mesenteric lymph nodes. Moreover, ionizing radiation also broke the balance of CD4+/CD8+ and increased the Treg proportion in spleen, which then triggered immune imbalance and immunosuppression. In general, the spleen injuries occurred on 1st day after exposure, worse on 3rd day, and were relieved on 7th day. The intestinal immune injuries were observed on 1st day, and attenuated on 3rd day. On 21st day after exposure, the spleen volume and index have returned to normal, except for the distribution of lymphocyte subpopulations. Furthermore, all indicators of gut-associated lymphoid tissue, except for mesenteric lymph nodes lymphocyte count, had returned to normal levels on 21st day. Conclusion In conclusion, our data showed the injuries of spleen and intestinal immune system induced by 2 Gy 60Co γ ray whole-body irradiation. These findings may provide the bases for further radiation protection in the immunity.

Abstract 1718: Characterization of infiltrating immune cells after irradiation using 10x genomics single cell sequencing

Abstract Background: Radiation therapy is delivered to approximately 50% of all cancer patients. It has long been known that radiation causes not only DNA strand breaks, apoptosis, and necrosis, but also immunogenic modulation. Lately, there has been renewed interest in the potential of irradiation in colorectal cancer, not only as an adjuvant and palliative treatment, but also as an immune stimulant. Materials and Methods: CT26 murine colorectal carcinoma cells were subcutaneously implanted on the flank of BALB/c mice. Tumors were exposed to sham, single dose or fractionated radiotherapy regimens via a 300kV, 10mA X-ray with additional filtration to give a radiation quality of 2.3mm Cu half-value layer (HVL). Mice were anaesthetized, restrained and delivered a single uniform dose of radiation at a rate of 0.696Gy/min with the whole mouse being lead shielded except for a 1cm hole in the lead above the tumor site. Tumors were harvested at different timepoints post irradiation and dissociated into single cell suspensions. The tumor microenvironment and immune response within the tumors were analyzed with flow cytometry comparing the different treatment regimens. The individual CD45+ cell profile was investigated using 10x gene expression. 10x sequencing was demultiplexed using CellRanger and data analyzed using Seurat and ACTINN. Results: Following the initial cytotoxicity, flow cytometry showed a clear immune stimulatory effect of radiotherapy with immune cells infiltrating the irradiated tumors. The level of infiltration was dependent on the treatment scheduling. For single cell assessments, we observed approximately 8000 reads/cell and T-SNE cluster analysis using Seurat identified 16 clusters in control and treated samples. Identification of clusters by ACTINN demonstrated that CD8+ T-cells were increased 8-fold in irradiated samples whereas monocytes numbers decreased 3-fold. In irradiated tumors, the main population of CD8+ T-cells with increased numbers also expressed NKG7. Conclusion: These data provide evidence that radiotherapy can enhance immune cell trafficking to locally treated CT26 tumors. Furthermore, 10x genomics single cell sequencing revealed increased levels of cytotoxic T-cells expressing NKG7, a protein implicated in enhanced killing of extracellular targets. This response could prime the tumors such that they may be exploited by immune modulating drugs. Citation Format: Frida Ponthan, Valentina Ubertini, Gary Beale. Characterization of infiltrating immune cells after irradiation using 10x genomics single cell sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1718.

Abstract 6056: Activation of Sting in response to partial-tumor radiation exposure

Abstract Purpose: It has been shown that ionizing radiation can mediate antitumor immunity via the activation of the cytosolic DNA sensor cGAS/STING pathway. Therefore, the purpose of this study was to determine whether STING activation is involved in partial volume radiation therapy (RT). Materials/Methods: We investigated 67NR murine orthotopic breast tumors in Balb/c mice and LLC cells injected in the flank of C57Bl/6, cGAS, or STING KO mice. RT was delivered to 50% or 100% of the tumor volume using a 2X2 cm collimator on a microirradiator allowing precise irradiation. Tumors were collected at different time points post-RT and assessed for different measurements. Results: We previously showed that a single dose of radiation delivered to half of the tumor (50% RT) activated an anti-tumor immune response comparable to the response in a fully-irradiated tumor in the immunogenic 67NR murine breast carcinoma tumor model and in the less immunogenic and more radioresistant Lewis lung carcinoma (LLC) tumor model. We have also demonstrated that this immune response was due to the infiltration of CD8+ T cells along with an increased expression of ICAM adhesion molecules. Treatment with either anti-CD8 or anti-ICAM antibodies abrogated the hemi-RT response. Furthermore, a significant abscopal effect was observed after partial irradiation with a single dose of 10Gy in a bilateral 67NR tumors model. In this study, we tested whether the hemi-irradiation-mediated immune response involves the cGAS/STING canonical pathway, or a non-canonical activation of STING, in the 67NR or LLC tumor models. It has been reported that STING can be activated, independently of cGAS, via non-canonical activation of STING, involving ATM and TRAF6, among other factors. We found significant activation of the cGAS/STING pathway in the hemi-irradiated tumors as compared to control and to 100% exposed 67NR tumors. Interestingly, the increased expression of the cGAS/STING pathway was found in the hemi-irradiated tumor but, also in the non-irradiated part of this hemi-irradiated tumor. In the LLC model, a non-canonical activation of STING was involved. Using both cGAS and STING KO mice, we demonstrated that the partial exposure RT-mediated immune response is dependent on STING activation in the host while cGAS is dispensable. Conclusions: Upstream pathways responsible for STING activation are tumor type-specific. Identifying the upstream pathways responsible for STING activation in the partial RT-mediated immune response in different tumor types would improve this therapy and its potential combination with immune checkpoint blockade. Citation Format: Mickael Mathieu, Prerna R. Nepali, Sadna Budhu, Simon N. Powell, John Humm, Joseph Deasy, Adriana Haimovitz-Friedman. Activation of Sting in response to partial-tumor radiation exposure [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6056.

RONC-07. Fractionated radiotherapy is required to accurately mimic neurostructural late effects in preclinical models

Pediatric brain cancer patients treated with fractionated radiotherapy commonly develop long-term late side-effects including cognitive deficits. Many preclinical models of late effects have been developed that use a single, high dose of radiotherapy, which does not mimic the fractionated schedule children receive clinically. This study aimed to create a mouse model of late effects using clinically-relevant fractionated radiotherapy, and to measure the effects on the developing brain. Juvenile mice were treated at postnatal day 16 with a single dose of 8Gy whole brain radiation, or a mathematically-equivalent fractionated dose of 18Gy (9 x 2Gy daily fractions). Sham control mice received a CT scan, or 9 x sham CT scans. Mice were allowed to grow to young adulthood (63 days). Ex vivo anatomical MRI scans were performed along with diffusion tensor imaging (DTI) and histology. Mice receiving a single 8Gy radiation dose exhibited significantly decreased volumes in areas including the olfactory bulbs (-19%), hippocampus (-7%), corpus callosum (-9%) and motor cortex (-9%). In contrast, mice receiving fractionated radiotherapy showed fewer significantly decreased regions, although olfactory bulbs were reduced (-12%). Furthermore, doublecortin-positive cells were significantly reduced in the dentate gyrus indicating profound effects of radiotherapy on murine neural stem cells. Few radiotherapy-induced differences were observed by DTI, and immunohistochemistry revealed no changes in myelin basic protein, suggesting that white matter is minimally altered in mice. These results show that preclinical models exhibit treatment-induced late effects, and that commonly-used experimental approaches of single dose radiotherapy induce more neurological changes than an equivalent fractionated dose, thus may over-estimate radiotherapy-induced late effects. We have developed a clinically-relevant fractionated dosing protocol in mice, which replicates late effects experienced by children, and can be used to measure long-term effects of novel chemo/radiotherapy treatment combinations, ensuring children with brain cancer receive treatment both effective and safe treatment.

Comparison of Adhesion and Proliferation of Human Gingival Fibroblasts on Acellular Dermal Matrix with and without Low Level Diode Laser Irradiation, an in vitro Study.

Statement of the Problem: In recent years, regeneration of periodontal soft tissues in the reconstruction of periodontal defects and the finding of suitable membranes and graft materials for the placement of autogenous grafts have been of great interest in various studies. In this regard, the proliferation and adhesion of regenerative cells are two linchpins of the complete regenerative process.Purpose: This study aimed to evaluate the effects of low-level laser beams on the attachment and the proliferation of human gingival fibroblasts in the presence of acellular dermal matrix (ADM).Materials and Method: All the experiments were conducted compared to tissue culture plate in four groups as follows: (1) Fibroblast+ADM+laser, (2) Fibroblast+ADM+ no laser, (3) Fibroblast + laser radiation, and (4) Fibroblast+ no laser. In this experimental study, the primary attachment was evaluated by passing 8h from seeding of 5×105 gingival fibroblasts with or without a single dose (15.6 J/cm2) of laser radiation. Cell proliferation rate was also examined at 24, 48, and 72 hours after cell culture, following exposure to 5.2 J/cm2 of laser at each day of examination. Thereafter, fibroblasts were incubated under the normal culture condition (at 37°C, 5% CO2) in high glucose Dulbecco's Modified Eagle's medium (DMEM) medium supplemented with 10% fetal bovine serum, 1% glutamax, and 1% penicillin/streptomycin. Subsequently, the cellular viability was assessed on each time point using MTS calorimetric assay. The obtained data were statistically analyzed by applying ANOVA and Tukey tests.Results: There was a significant difference among the means of these four groups in terms of the proliferation of fibroblasts at 24, 48 and 72 hours (p< 0.001). Moreover, there was no significant difference among the means of two groups in terms of fibroblastic attachment in 8 hours (p< 0.2). The fibroblast group has shown the highest proliferation rate among all groups after laser radiation.Conclusion: It was indicated that the laser radiation increases the fibroblast cell proliferation. Accordingly, although this increase was higher in the fibroblast group alone compared to the fibroblasts cultured on acellular dermal matrix, the laser radiation did not significantly increase the attachment of fibroblast cells to acellular dermal matrix.

PO-1645 Treatment planning protocol in Single-Dose Radiation Therapy for prostate cancer

PO-1645 Treatment planning protocol in Single-Dose Radiation Therapy for prostate cancer

Exposure to 5 cGy 28Si Particles Induces Long-Term Microglial Activation in the Striatum and Subventricular Zone and Concomitant Neurogenic Suppression.

The proposed mission to Mars will expose astronauts to space radiation that is known to adversely affect cognition and tasks that rely on fine sensorimotor function. Space radiation has also been shown to affect the microglial and neurogenic responses in the central nervous system (CNS). We recently reported that a low dose of 5 cGy 600 MeV/n 28Si results in impaired cognition and skilled motor behavior in adult rats. Since these tasks rely at least in part on the proper functioning of the striatum, we examined striatal microglial cells in these same subjects. Using morphometric analysis, we found that 28Si exposure increased activated microglial cells in the striatum. The majority of these striatal Iba1+ microglia were ED1-, indicating that they were in an alternatively activated state, where microglia do not have phagocytic activity but may be releasing cytokines that could negatively impact neuronal function. In the other areas studied, Iba1+ microglial cells were increased in the subventricular zone (SVZ), but not in the dentate gyrus (DG). Additionally, we examined the relationship between the microglial response and neurogenesis. An analysis of new neurons in the DG revealed an increase in doublecortin-positive (DCX+) hilar ectopic granule cells (hEGC) which correlated with Iba1+ cells, suggesting that microglial cells contributed to this aberrant distribution which may adversely affect hippocampal function. Taken together, these results indicate that a single dose of 28Si radiation results in persistent cellular effects in the CNS that may impact astronauts both in the short and long-term following deep space missions.

Satellite Cells are Activated in a Rat Model of Radiation-Induced Muscle Fibrosis.

Radiation-induced muscle fibrosis is a long-term side effect of radiotherapy that significantly affects the quality of life and even reduces the survival of cancer patients. We have demonstrated that radiation induces satellite cell (SC) activation at the molecular level; however, cellular evidence in a rat model of radiation-induced muscle fibrosis was lacking. In this study, we evaluated SC activation in vivo and investigated whether radiation affects the proliferation and differentiation potential of SCs in vitro. For in vivo studies, Sprague-Dawley rats were randomly divided into six groups (n = 6 per group): non-irradiated controls, 90 Gy/1 week-, 90 Gy/2 weeks-, 90 Gy/4 weeks-, 90 Gy/12 weeks- and 90 Gy/24 weeks-postirradiation groups. Rats received a single dose of radiation in the left groin area and rectus femoris tissues were collected in the indicated weeks. Fibrosis, apoptosis, and autophagy were evaluated by Masson's trichrome staining, TUNEL staining, and electron microscopy, respectively. SC activation and central nuclear muscle fibers were evaluated by immunofluorescence staining and hematoxylin and eosin staining. IL-1β concentrations in serum and irradiated muscle tissue samples were determined by ELISA. For in vitro studies, SCs were isolated from rats with radiation-induced muscle fibrosis and their proliferation and differentiation were evaluated by immunofluorescence staining. In vivo, fibrosis increased over time postirradiation. Apoptosis and autophagy levels, IL-1β concentrations in serum and irradiated skin tissues, and the numbers of SCs and central nuclear muscle fibers were increased in the irradiated groups when compared with the control group. In vitro, cultured SCs from irradiated muscle were positive for the proliferation marker Pax7, and differentiated SCs were positive for the myogenic differentiation marker MyHC. This study provided cellular evidence of SC activation and proliferation in rats with radiation-induced muscle fibrosis.

Effects of a Single Dose of X-Ray Irradiation on MMP-9 Expression and Morphology of the Cerebellum Cortex of Adult Rats.

Although radiation is a strategy widely used to inhibit cancer progression, which includes those of the neck and head, there are still few experimental reports on radiation effects in the cerebellum,particularly on the morphology of its cortex layers and on the Matrix metalloproteinases' (MMPs') expression, which, recently, seems to be involved in the progression of some mental disorders. Therefore, in the present study, we evaluated the morphology of the cerebellum close to the expression of MMP-9 from 4 up to 60days after a 15-Gy X-ray single dose of X-ray irradiation had been applied to the heads of healthy adult male rats. The cerebellum of the control and irradiated groups was submitted for an analysis of cell Purkinje count, nuclear perimeter, and chromatin density using morphometric estimatives obtained from the Feulgen histochemistry reaction. In addition, immunolocalization and estimative for MMP-9 expression were determined in the cerebellar cortex on days 4, 9, 14, 25, and 60 after the irradiation procedure. Results demonstrated that irradiation produced a significant reduction in the total number of Purkinje cells and a reduction in their nuclear perimeter, along with an increase in chromatin condensation and visible nuclear fragmentation, which was also detected in the granular layer. MMP-9 expression was significantly increased on 4, 9, and 14days, being detected around the Purkinje cells and in parallel fibres at the molecular layer. We conclude that the effects of a single dose of 15-Gy X-ray irradiation in the cerebellum were an increase in MMP-9 expression in the first 2weeks after irradiation, especially surrounding the Purkinje cells and in the molecular layers, with morphological changes in the Purkinje cell and granular cell layers, suggesting a continuous cell loss throughout the days evaluated after irradiation.

Radiotherapy alters expression of molecular targets in prostate cancer in a fractionation- and time-dependent manner

The efficacy of molecular targeted therapy depends on expression and enzymatic activity of the target molecules. As radiotherapy modulates gene expression and protein phosphorylation dependent on dose and fractionation, we analyzed the long-term effects of irradiation on the post-radiation efficacy of molecular targeted drugs. We irradiated prostate cancer cells either with a single dose (SD) of 10 Gy x-ray or a multifractionated (MF) regimen with 10 fractions of 1 Gy. Whole genome arrays and reverse phase protein microarrays were used to determine gene expression and protein phosphorylation. Additionally, we evaluated radiation-induced pathway activation with the Ingenuity Pathway Analysis software. To measure cell survival and sensitivity to clinically used molecular targeted drugs, we performed colony formation assays. We found increased activation of several pathways regulating important cell functions such as cell migration and cell survival at 24 h after MF irradiation or at 2 months after SD irradiation. Further, cells which survived a SD of 10 Gy showed a long-term upregulation and increased activity of multiple molecular targets including AKT, IGF-1R, VEGFR2, or MET, while HDAC expression was decreased. In line with this, 10 Gy SD cells were more sensitive to target inhibition with Capivasertib or Ipatasertib (AKTi), BMS-754807 (IGF-1Ri), or Foretinib (VEGFR2/METi), but less sensitive to Panobinostat or Vorinostat (HDACi). In summary, understanding the molecular short- and long-term changes after irradiation can aid in optimizing the efficacy of multimodal radiation oncology in combination with post-irradiation molecularly-targeted drug treatment and improving the outcome of prostate cancer patients.

Gafchromic™ EBT3 Film Measurements of Dose Enhancement Effects by Metallic Nanoparticles for 192Ir Brachytherapy, Proton, Photon and Electron Radiotherapy

Interest in combining metallic nanoparticles, such as iron (SPIONs), gold (AuNPs) and bismuth oxide (BiONPs), with radiotherapy has increased due to the promising therapeutic advantages. While the underlying physical mechanisms of NP-enhanced radiotherapy have been extensively explored, only a few research works were motivated to quantify its contribution in an experimental dosimetry setting. This work aims to explore the feasibility of radiochromic films to measure the physical dose enhancement (DE) caused by the release of secondary electrons and photons during NP–radiotherapy interactions. A 10 mM each of SPIONs, AuNPs or BiONPs was loaded into zipper bags packed with GAFCHROMIC™ EBT3 films. The samples were exposed to a single radiation dose of 4.0 Gy with clinically relevant beams. Scanning was conducted using a flatbed scanner in red-component analysis for optimum sensitivity. Experimental dose enhancement factors (DEFExperimental) were then calculated using the ratio of absorbed doses (with/without NPs) converted from the films’ calibration curves. DEFExperimental for all NPs showed no significant physical DE beyond the uncertainty limits (p &gt; 0.05). These results suggest that SPIONs, AuNPs and BiONPs might potentially enhance the dose in these clinical beams. However, changes in NPs concentration, as well as dosimeter sensitivity, are important to produce observable impact.

Quercetin-3-Rutinoside alleviates radiation-induced lung inflammation and fibrosis via regulation of NF-κB/TGF-β1 signaling

BackgroundRadiation exposure to lungs during nuclear catastrophes or radiotherapy poses long-term side effects and can induce pulmonary injury sufficient for causing death. The strategies for preventing or reversing radiation-induced lung injuries have not been yet developed. Quercetin-3-Rutinoside (Q-3-R), a polyphenolic bioflavonoid, has shown multifaceted pharmacological applications due to its high antioxidant and anti-inflammatory properties. PurposeIn the current study, the potential of Q-3-R against radiation-induced lung pneumonitis/fibrosis and the possible underlying mechanism was investigated. Study designTo evaluate the effect of Q-3-R against lung damage, C57Bl/6 mice were administered with Q-3-R (10 mg/kg b.wt.) and irradiated with a single dose of gamma radiation (12 Gy) at thoracic region. Methods16 weeks after irradiation lung damage was seen by histopathological studies and staining for collagen deposition. Expression of Nuclear factor kappa-B (NF-κB), transforming growth factor-β1 (TGF-β1), Smad3, intercellular adhesion molecule 1 (ICAM-1), α-smooth muscle actin protein (α-SMA), Aquaporin 5 (AQP 5), Interleukins (IL-6, IL-18, IL-1β), tumor necrosis factor-α (TNF-α) and caspase-3 was evaluated by immunohistochemistry/western blot/Elisa. Reactive oxygen species (ROS)/ Nitric oxide (NO) scavenging potential of Q-3-R and inhibition of cell death in irradiated lungs were also assessed. ResultsMice showed signs of pneumonitis and fibrotic changes in lungs following radiation treatment. A dramatic increase in inflammatory cells and cytokines contributing to lung disease pathogenesis was observed. Furthermore, expression of NF-κB, TGF-β1, Smad3, ICAM-1, AQP5and α-SMA was found markedly up-regulated. However, pretreatment of Q-3-R significantly attenuated radiation-induced pneumonitis and fibrosis. Histological examination revealed less structural and fibrotic changes with down-regulation of AQP 5, ICAM-1, α-SMA and caspase-3 in Q-3-R pretreated irradiated groups. The formulation significantly relieved lung injury by suppressing inflammatory and pro-fibrotic cytokines such as IL-6, IL-18, IL-1β, TNF-α and TGF-β1 via inhibition of NF-κB. Q-3-R also curtailed radiation-induced ROS/NO generation and minimized DNA damage in the irradiated lungs. ConclusionThe findings from the current study clearly demonstrate that Q-3-R provides radioprotection to the lungs by regulating NF-κB/TGF-β1 signaling, scavenging free radicals, preventing perivascular infiltration and prolonged inflammatory cascade which could otherwise lead to chronic radiation fibrosis. Q-3-R can be proved as a potential therapeutic agent for alleviating radiation-induced lung injury in case of planned or unplanned radiation exposure scenario.

Hepatotoxicity and renal toxicity induced by radiation and the protective effect of quercetin in male albino rats

Purpose Although radiation is one of the basic methods commonly used in cancer treatment, it inevitably enters the field of treatment in healthy tissues and is adversely affected by the acute and chronic side effects of radiation. This study evaluated the possible protective effects of quercetin, an antioxidant agent, against liver and kidney damage in rats exposed to a whole-body single dose of radiation (10 Gy of gamma-ray). Materials and methods The study groups were formed as control, sham, quercetin, radiation, quercetin + radiation and radiation + quercetin using 60 male Wistar albino (200–250 g, 3 months old) rats, including 10 rats in each group. The gamma-ray provided by the Co60 teletherapy machine was given to the whole body as external irradiation. According to the groups, quercetin was administered to rats at 50 mg/kg/day via oral gavage before or after radiation administration. The rats were sacrificed the day after irradiation and the extracted tissue samples from all groups were compared histologically and immunohistochemically. DNA damage was determined by the neutral comet assay technique. Also, malondialdehyde (MDA) and glutathione peroxidase (GSH) were evaluated in liver and kidney tissues by the ELISA method. Results Histopathological changes were observed altered morphology of liver and kidney tissues in the radiation groups. Sinusoidal dilatations, vacuolization, and hepatic parenchyma necrosis in the liver, while in kidneys, glomerular shrinkage, widened Bowman’s space, tubular dilatation, and inflammation were evident. TNF-α, IL1-α, HIF1-α, and caspase 3 immunoreactivities in tissues were determined by immunohistochemistry. High caspase 3 positive cell number confirmed apoptosis, the comet parameters were decreased in the quercetin + radiation group. When compared to the control group, the exposure to radiation showed a marked elevation in MDA which was accompanied by high GSH. This damage was reduced in the quercetin + radiation group. Conclusions With the results obtained from the study; Quercetin is thought to have a protective potential against radiation-induced liver and kidney damage due to its radioprotective effect.

In vitro Scolicidal Efficacy of 5-Fluorouracil and Radiation Against Protoscoleces of Echinococcus granulosus Sensu Lato.

Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is a globally distributed zoonosis. CE treatment is difficult, but radiation and 5-fluorouracil (5-FU) can be effective. However, the combination of radiation and 5-FU has not been reported. This study evaluated the effect of combination of 5-FU and radiation on E. granulosus s.l. protoscoleces (PSCs). In this study, PSCs were collected from the liver of diseased sheep, and some were exposed to a single dose of 20 Gy 6-MV X-ray combined with (5 μg/mL or 10 μg/mL) 5-FU in vitro. Methylene blue staining was used to detect the viability of the PSCs. Transcription of EgHSP70 and Egp38 was measured by quantitative real-time PCR (qRT- PCR). A single dose of radiation killed 18% of the PSCs, and 5-FU showed weak parasiticidal efficacy on the first day of treatment. After 14 d, 5 μg and 10 μg/mL of 5-FU killed 40.20% and 50.02% of the PSCs, whereas 20 Gy of radiation killed 31.44%. The combination of 5-FU (10 μg/mL) with 20 Gy of radiation showed 77.55% killing efficacy. qRT-PCR showed that 5-FU inhibited Egp38 expression, whereas radiation increased its expression. EgHSP70 was highly expressed 14 days after radiation treatment. The data indicate that 5-FU has parasiticidal efficacy against the PSCs of E. granulosus s.l. The lethal efficacy of PSCs caused by a single dose of radiation exposure is related to the upregulated expression level of Egp38 and EgHSP70. The killing effect of 5-FU (10 μg/mL) with 20Gy of radiation was significantly better than that of single treatment group. This study provided a basis for the potential role of 5-FU combined with radiation in the treatment of CE.

Photosensitizer-loaded gold nanocages for immunogenic phototherapy of aggressive melanoma

Malignant melanoma remains the life-threatening form of skin cancer with high mortality and poor prognosis. Thus, an ideal melanoma therapeutic strategy is of immediate importance which can remove the primary tumor, as well as inhibit the metastasis and recurrence. Here, we report the fabrication of adjuvant monophosphoryl lipid A (MPLA) lipid bilayer-enveloped and photosensitizer indocyanine green (ICG)-loaded gold nanocages (MLI-AuNCs) for immunogenic phototherapy of aggressive melanoma. Hollow porous AuNCs are used as carriers to deliver MPLA and ICG, and protect ICG from photodegradation. Both AuNCs and ICG absorb near infrared (NIR) light and can be applied in controllable NIR-triggered photothermal and photodynamic combination therapy (PTT/PDT) of melanoma. MLI-AuNCs coated by thermosensitive lipid bilayer exhibit uniform size, good biocompatibility and bioavailability with prominent tumor accumulation, which further improve the PTT/PDT efficacy. MLI-AuNCs under NIR irradiation not only destroy the primary tumor by PTT/PDT, but also elicit robust antitumor immune response with melanoma associated antigens and MPLA released in situ. The released antigens and MPLA subsequently enhance the recruitment and maturation of dendritic cells, which further activate the effector T cells to inhibit metastases and recurrence of melanoma. This immunomodulatory-boosted PTT/PDT nanoplatform provides a new opportunity for highly aggressive melanoma treatment. Statement of significanceAn ideal tumor therapeutic strategy not only can remove the primary tumor, but also inhibit metastasis and recurrence. Here, we introduced a versatile nanoplatform MLI-AuNCs for immunogenic phototherapy of aggressive melanoma. Adjuvant MPLA and photosensitizer ICG can be protected and co-delivered to the tumors by thermosensitive lipid-enveloped AuNCs. MLI-AuNCs exhibited prominent tumor accumulation ability and produced the potent PTT/PDT effect to destroy the primary tumors with a single dose of NIR irradiation, as well as elicited the strong antitumor immunity to inhibit the metastasis and relapse. This study may provide a potential therapeutic vaccination strategy against advanced melanoma and other difficult-to-treat cancers.

Pulmonary Delivery of Theranostic Nanoclusters for Lung Cancer Ferroptosis with Enhanced Chemodynamic/Radiation Synergistic Therapy.

Inefficient tumor accumulation and penetration remain as the main challenges to therapy efficacy of lung cancer. Local delivery of smart nanoclusters can increase drug penetration and provide superior antitumor effects than systemic routes. Here, we report self-assembled pH-sensitive superparamagnetic iron oxide nanoclusters (SPIONCs) that enhance in situ ferroptosis and apoptosis with radiotherapy and chemodynamic therapy. After pulmonary delivery in orthotopic lung cancer, SPIONCs disintegrate into smaller nanoparticles and release more iron ions in an acidic microenvironment. Under single-dose X-ray irradiation, endogenous superoxide dismutase converts superoxide radicals produced by mitochondria to hydrogen peroxide, which in turn generates hydroxyl radicals by the Fenton reaction from iron ions accumulated inside the tumor. Finally, irradiation and iron ions enhance tumor lipid peroxidation and induce cell apoptosis and ferroptosis. Thus, rationally designed pulmonary delivered nanoclusters provide a promising strategy for noninvasive imaging of lung cancer and synergistic therapy.

Tumor radioresistance caused by radiation-induced changes of stem-like cell content and sub-lethal damage repair capability

Cancer stem-like cells (CSCs) within solid tumors exhibit radioresistance, leading to recurrence and distant metastasis after radiotherapy. To experimentally study the characteristics of CSCs, radioresistant cell lines were successfully established using fractionated X-ray irradiation. The fundamental characteristics of CSCs in vitro have been previously reported; however, the relationship between CSC and acquired radioresistance remains uncertain. To efficiently study this relationship, we performed both in vitro experiments and theoretical analysis using a cell-killing model. Four types of human oral squamous carcinoma cell lines, non-radioresistant cell lines (SAS and HSC2), and radioresistant cell lines (SAS-R and HSC2-R), were used to measure the surviving fraction after single-dose irradiation, split-dose irradiation, and multi-fractionated irradiation. The SAS-R and HSC2-R cell lines were more positive for one of the CSC marker aldehyde dehydrogenase activity than the corresponding non-radioresistant cell lines. The theoretical model analysis showed that changes in both the experimental-based ALDH (+) fractions and DNA repair efficiency of ALDH (−) fractions (i.e., sub-lethal damage repair) are required to reproduce the measured cell survival data of non-radioresistant and radioresistant cell lines. These results suggest that the enhanced cell recovery in SAS-R and HSC2-R is important when predicting tumor control probability in radiotherapy to require a long dose-delivery time; in other words, intensity-modulated radiation therapy is ideal. This work provides a precise understanding of the mechanism of radioresistance, which is induced after irradiation of cancer cells.

Bystander effects induced by the interaction between urothelial cancer cells andirradiated adipose tissue-derived stromal cells in urothelial carcinoma.

Cell-cell interactions between cancer cells and neighboring adipose tissue-derived stromal cells (ATSCs) are known to regulate the aggressiveness of cancer cells. In addition, the radiation-induced bystander effect is an important modulator of cancer cell kinetics. Radiation therapy is often given for urinary cancer, but the biological effects of the irradiated cancer stroma, including adipose tissue, on urothelial carcinoma (UC) remain unclear. We investigated the bystander effect of irradiated ATSCs on UC using a collagen gel culture method to replicate irradiated ATSC-cancer cell interactions after a single 12-Gy dose of irradiation. Proliferative activity, invasive capacity, protein expression and nuclear translocation of p53 binding protein-1 (53BP1) were analyzed. Irradiated ATSCs significantly inhibited the growth and promoted the apoptosis of UC cells in comparison to non-irradiated controls. The invasiveness of UC cells was increased by irradiated ATSCs, but not irradiated fibroblasts. Nuclear translocation of 53BP1 protein due to the bystander effect was confirmed in the irradiated group. Irradiated ATSCs regulated the expressions of the insulin receptor, insulin-like growth factor-1 and extracellular signal-regulated kinase-1/2 in UC. In conclusion, the bystander effect of irradiated ATSCs is a critical regulator of UC, and the actions differed depending on the type of mesenchymal cell involved. Our alternative culture model is a promising tool for further investigations into radiation therapy for many types of cancer.

Yiqi Jiedu herbal decoction attenuates the 2 Gy 60Co γ ray induced spleen injury by inhibiting apoptosis and modulating the immune balance

Ethnopharmacological RelevanceIrradiation-induced immunosuppression often occurs during radiotherapy in patients, which would increase the risk of opportunistic infections. Many Chinese herbal prescriptions or natural extracts have recently attracted increased radiation protection and therapy attention due to their low toxicity. Aim of the studyThe present study aimed to investigate the protective effects of Yiqi Jiedu (YQJD) decoction on spleen injury induced by 2 Gy 60Co γ ray in mice. Materials and methodsA total of 180 Balb/c mice were randomly divided into five groups: blank control (Ctrl), model (IR), positive drug (IRA), low-dose YQJD decoction (IRL), and high-dose YQJD decoction (IRH). After a ten-day intervention, mice were exposed to a single dose of total body irradiation (2 Gy) and sacrificed on the 1st, 3rd, and 7th day after irradiation. The indicators include general observations and body weight, changes in peripheral hemogram, index and histopathology examination of the spleen, distribution of lymphocyte subsets, cytokine levels, and apoptosis in the spleen. ResultsIn comparison to the Ctrl group, the body weight, spleen index, peripheral blood cell, and splenocyte quantities decreased significantly after exposure, accompanied by a notable increase of apoptosis in spleen cells. Moreover, ionizing radiation also broke the balance of CD4+/CD8+, Th1/Th2, and Th17/Treg, triggering immune imbalance and immunosuppression. The above injuries occurred on the 1st day after exposure, worsened on the 3rd, and were relieved on the 7th day. However, the pretreatment of YQJD decoction increased the spleen index, improved the spleen structure, and inhibited radiation-induced apoptosis after exposure. Additionally, YQJD decoction has shown its ability to promote immunological balance recovery following exposure by regulating CD4+/CD8+, Th1/Th2, and Th17/Treg ratios, which may minimize the risk of infection. In addition, the high-dose of YQJD decoction showed a better protective effect than the low-dose group. ConclusionThe protective effects of YQJD decoction on 2 Gy 60Coγray induced spleen injury were confirmed in this study. This mechanism may be related to inhibiting apoptosis and modulating immune balance. This exploration might provide new insights into the use of Chinese herbs on radioprotection of the immune system.