Rat Glioma Research Articles

ET-4 BASIC RESEARCH OF BORON NEUTRON CAPTURE THERAPY USING A NOVEL BORON COMPOUND TARGETED TO INTEGRIN

Abstract Background Boron neutron capture therapy (BNCT) is a particle radiation modality capable of selectively destroying tumor cells. The most commonly used boron compound for BNCT is boronphenylalanine (BPA). BPA is taken up into the tumor cell via the L-type aminoacid transporter (LAT-1). However, there are some BPA-refractory situations. Therefore, a novel boron compound is expected to improve the therapeutic performance of BNCT. We focused on integrinαvβ3, which is overexpressed in malignant gliomas as in many cancer cells, and have developed cRGD-MID-AC, a conjugate of cyclic RGD (cRGD), which selectively inhibited integrinαvβ3, and MID-AC, which we have already reported as effective on BNCT as BPA as a boron compound in F98 rat glioma models. We evaluated the efficacy of BNCT using this novel compound.Methods: F98 glioma cells were exposed to BPA, cRGD-MID-AC, and cRGD-MID for cellular uptake and neutron irradiation experiment. Intracellular boron concentrations and compound biological effectiveness (CBE) for each boron compound was calculated. After intravenous administration (i.v.) of cRGD-MID-AC or BPA, the biodistribution of boron compounds was measured and neutron irradiation experiment were performed in F98 rat glioma models. Results Intracellular boron concentrations of BPA and cRGD-MID-AC were increased gradually at all exposed time, and CBE for cRGD-MID-AC was comparable to that for BPA. In cRGD-MID-AC, the boron concentration in the tumor was the highest at 8 h after i.v. and tended to be retained longer at 24h. In vivo neutron irradiation experiment, long-term survival was observed only in the group irradiated 8 h after cRGD-MID-AC i.v.. These experiments suggest that cRGD-MID-AC has sufficient cell-killing effect and may be more effective in vivo. Conclusion cRGD-MID-AC has a tumor accumulation mechanism different from that of BPA, and could be an effective boron carrier in BNCT for malignant gliomas.

Fludioxonil, a phenylpyrrol pesticide, induces Cytoskeleton disruption, DNA damage and apoptosis via oxidative stress on rat glioma cells.

Pesticides products are widely used to increase food productivity and to decrease food-borne diseases. Fludioxonil is a worldwide used phenylpyrrol fungicide. This pesticide can induce serious effects on human health especially on nervous system. We assessed the role of oxidative stress in the toxicity of Fludioxonil and examined its apoptotic mechanism of action on rat neural cells (F98). We have shown that the increasing concentration of Fludioxonil reduces the percentage of living F98cells viability and increases the levels of reactive oxygen species and malondialdheydes. The reduction of cells proliferation was demonstrated with an accumulation in G2/M phase. The immunocytochemical analysis has shown that Fludioxonil induced the disruption of the cytoskeleton. DNA damage was also provoked in a concentration dependent manner as illustrated by the comet assay. The depolarization of the mitochondria and the positive Annexin V FITC-PI confirmed the apoptosis induced by this fungicide. Interestingly, the F98cells viability and ROS levels were restored with N-acetylcysteine pre-treatment. These results highlight the involvement of oxidative stress in the toxicity induced by this fungicide, and that free radicals generation plays a key role in the induction of apoptosis probably induced via the mitochondrial pathway.

Transmembrane water-efflux rate measured by magnetic resonance imaging as a biomarker of the expression of aquaporin-4 in gliomas.

The water-selective channel protein aquaporin-4 (AQP4) contributes to the migration and proliferation of gliomas, and to their resistance to therapy. Here we show, in glioma cell cultures, in subcutaneous and orthotopic gliomas in rats, and in glioma tumours in patients, that transmembrane water-efflux rate is a sensitive biomarker of AQP4 expression and can be measured via conventional dynamic-contrast-enhanced magnetic resonance imaging. Water-efflux rates correlated with stages of glioma proliferation as well as with changes in the heterogeneity of intra-tumoural and inter-tumoural AQP4 in rodent and human gliomas following treatment with temozolomide and with the AQP4 inhibitor TGN020. Regions with low water-efflux rates contained higher fractions of stem-like slow-cycling cells and therapy-resistant cells, suggesting that maps of water-efflux rates could be used to identify gliomas that are resistant to therapies.

EXTH-05. TOWARD 100% CLINICAL EFFICACY FOR TUMOR-TREATING FIELDS

Abstract In vitro and in animal models of various tumor cell types, empirical data suggest tumor-treating fields (TTFields) can attain 100% efficacy, with two pre-conditions: 1) Delivering sufficient electric field strength to the target tumor cells, and 2) Changing the direction of the imposed electric field such that intra-cellular structures at any angle with respect to the field see the required efficacious field strength. Requirement #2 reflects empirical findings as well as prevailing theories of TTFields’ mechanism of action, which center on mitosis disruption via energy imparted to polarizable intracellular structures aligned with the field. We tried various trial curve-fits to TTFields empirical dose-response curves. Quadratic formulae yield a close fit, resembling well-known radiotherapy linear-quadratic (LQ) curves and suggesting a connection between the mechanisms of the two treatment modalities: F98 (rat glioma): -16.3271x2 - 0.664019x+100 (R2=0.9995); MDA-MB-231 (human breast cancer): -9.64922x2 + 2.96348x + 100 (R2=0.9999); H1299 (human non-small cell lung carcinoma): -12.0515x2 - 1.58272x + 100 (R2=0.9993); B16 (mouse melanoma): -83.8066x2 + 47.4537x + 100 (R2=0.9954). We extrapolate these fits to predict the approximate required field strength seen at the target cells for 100% efficacy: F98: 2.45 V/cm; MDA-MB-231: 3.4 V/cm; H1299: 2.8 V/cm; B16: 1.4 V/cm. Alternatively, the LQ fits may not reflect the extrapolated high amplitude range for which data is lacking. Under two assumptions, 1) intracellular structures are randomly oriented in vivo, and 2) only two changes of TTFields direction are used, as is the current clinical practice, then extrapolating the dose-response curves predicts that infinite field strength is required for 100% efficacy, since some intracellular structures must be oriented at 90 degrees to the imposed field and the cosine of 90 degrees is zero. Adding a third TTFields direction, not necessarily orthogonal to the plane of the other two directions, can solve this problem.

TMIC-23. EXPLORING IBRUTINIB'S EFFECTS ON BLOOD-BRAIN BARRIER INTEGRITY AND GLIOMA PROGRESSION

Abstract BACKGROUND The blood-brain barrier (BBB), among malignant gliomas limits certain agents from impairing tumor growth. Thus, identifying agents that can transiently increase BBB permeability may prove useful in enhancing glioma treatment response. Previous ibrutinib studies showed it independently disrupted gut epithelial integrity and hampered glioma growth through BMX (bone marrow x-linked tyrosine kinase) inhibition. We propose BMX inhibition via ibrutinib disrupts BBB integrity while impairing glioma progression. METHODS To evaluate ibrutinib’s effect on brain endothelium, we evaluated electrical cell-cell impedance, junctional/cytoskeletal expression, downstream protein expression and functional ABC transporter activity; monitoring changes over time (0 to 8h) and at varied drug concentrations (1-10μM ibrutinib). Using rat glioma cells (S635) in vitro and in models, we examined cytotoxicity, apoptosis, model survival, and drug concentrations with ibrutinib alone or combined with poorly permeable Abcb1 substrate doxorubicin. RESULTS Ibrutinib dose-dependently decreased brain endothelial cell-cell impedance by 60% at 2h, without affecting cell viability. We observed decreased ZO-1 junctions, actin cytoskeletal rearrangement, and downstream pErk and pMek decreased expression optimally 2h (10μM ibrutinib). Dose-dependently ibrutinib inhibited Abcb1 efflux activity, further favoring a more permeable endothelium. Synergy with doxorubicin was seen in rat glioma cells treated with ibrutinib via increased apoptosis and cytotoxicity. However, while combined treatment resulted in decreased systemic doxorubicin concentrations, no differences in brain:plasma or tumor:plasma concentrations were evident. Combination therapy also did not increase rodent glioma model survival nor decrease tumor size. CONCLUSION Our results suggest that while ibrutinib induces brain endothelial permeability by junctional/cytoskeletal disruption and inhibition of Abcb1 efflux, no sustained effect can be seen in rodent glioma models in combination with a cytotoxic agent. Additional studies exploring similar agents that can enhance BBB permeability while slowing glioma growth are warranted, so as to improve upon current bleak malignant glioma treatment options.

TMIC-46. DISRUPTING TRICELLULAR TIGHT JUNCTIONS TO ENHANCE BLOOD-BRAIN-BARRIER PERMEABILITY IN GLIOMA MODELS

Abstract BACKGROUND The blood-brain-barrier (BBB) is predominantly regulated by brain endothelial cells held together by junctional proteins. The BBB poses a significant hinderance to CNS drug entry of effective chemotherapy agents. Previous BBB studies have shown that disruption of tricellular and/or bicellular tight junctional proteins transiently increased CNS drug permeability. OBJECTIVE To evaluate the effect of drug proteins angubindin-1, C-CPE, and C-CPEmt on tight junction proteins angulin-1, claudin-3, and claudin 5, respectively, aimed at transiently enhancing BBB permeability and decreasing glioma growth. METHODS We evaluated junctional disruption with drug proteins, angubindin-1 (600µg/mL), C-CPE (200µg/mL), and C-CPEmt (200µg/mL) on rat brain endothelium. Endothelial junctional integrity studies were assessed by immunoblotting and cell-cell electrical impedance assays. Treatment effects on rat malignant glioma (S635) was measured via migration and rat glioma models. RESULTS Overall, we observed a time-dependent effect of drug proteins on junctional expression and function. Immunoblotting demonstrated a significant decrease (p< 0.05) in angulin-1 expression 5-hours after angubindin-1 treatment, while claudin-3 and claudin-5 expression barely decreased between 2 and 24-hours after C-CPE and C-CPEmt treatment, respectively. Cell-cell integrity was disrupted by 73%, 52%, and 69% compared with control, 3-hours after angubindin-1, C-CPE, and C-CPEmt treatment, respectively. Studies assessing qualitative junctional expression changes after drug proteins are ongoing. Gliomas cells expressed high angulin-1, and interestingly, migration was 50% decreased with angubindin-1 treatment, yet no migration changes were evident with C-CPE or C-CPEmt treatment. Rat glioma model studies evaluating liposomal doxorubicin combined with angubindin-1 are currently being explored to display effects on CNS drug concentrations, cytotoxicity, junctional expression, and survival. DISCUSSION Transient disruption of BBB tricellular junctions was seen with angubindin-1 treatment. Additionally, cell migration was hindered in angulin-1 overexpressing gliomas. These findings are promising and demonstrate the need for more combinational therapies aimed at increasing BBB permeability while also impairing glioma progression.

Genotoxic damage and apoptosis in rat glioma (F98) cell line following exposure to bromuconazole

Bromuconazole, a fungicide from the triazole family, is widely used to protect the crop from various fungal contaminations to increase product quality and productivity. Although the massive use of bromuconazole poses a serious risk to human health, the exact mechanism of bromuconazole toxicity, especially on brain support cells, called glia cells, remains unclear so far. This study aimed to determine the mechanism of cytotoxicity and genotoxicity of bromuconazole via inspection of apoptotic death in rat glioma (F98) cells. We observed that bromuconazole treatment caused concentration-dependent cell death with an IC50 of 60 µM, and disruption of the cytoskeleton was observed via immunocytochemical analysis. Further, bromuconazole inhibits cell proliferation, it arrests the cell cycle in the G0/G1 phase and so inhibits DNA synthesis. Genotoxic analysis showed that bromuconazole exposition causes DNA fragmentation (comet assay) and nuclear condensation (DAPI staining). Apoptotic cell death was confirmed through: positive Annexin-V/FITC-PI dyes, p53 and Bax overexpression, Bcl2 repression, an increase in Bax/BCL-2 ratios of the mRNA, mitochondrial membrane depolarization, and an increase of caspase-3 activity. All these results demonstrate that bromuconazole exerts its cytotoxic and genotoxic effects through apoptotic cell death, which could implicate mitochondria.

MiR-134-5p/Stat3 Axis Modulates Proliferation and Migration of MSCs Co-Cultured with Glioma C6 Cells by Regulating Pvt1 Expression.

Mesenchymal stem cells (MSCs) are critical in regenerating tissues because they can differentiate into various tissue cells. MSCs interact closely with cells in the tissue microenvironment during the repair of damaged tissue. Although regarded as non-healing wounds, tumors can be treated by MSCs, which showed satisfactory treatment outcomes in previous reports. However, it is largely unknown whether the biological behaviors of MSCs would be affected by the tumor microenvironment. Exploring the truth of tumor microenvironmental cues driving MSCs tumor “wound” regeneration would provide a deeper understanding of the biological behavior of MSCs. Therefore, we mimicked the tumor microenvironment using co-cultured glioma C6 cells and rat MSCs, aiming to assess the proliferation and migration of MSCs and the associated effects of Stat3 in this process. The results showed that co-cultured MSCs significantly exhibited enhanced tumorigenic, migratory, and proliferative abilities. Both up-regulation of Stat3 and down-regulation of miR-134-5p were detected in co-cultured MSCs. Furthermore, miR-134-5p directly regulated Stat3 by binding to the sequence complementary to microRNA response elements in the 3′-UTR of its mRNA. Functional studies showed that both the migration and proliferation abilities of co-cultured MSCs were inhibited by miR-134-5p, whereas Stat3 gain-of-function treatment reversed these effects. In addition, Pvt1 was confirmed to be regulated by miR-134-5p through Stat3 and the suppression of Pvt1 reduced the migration and proliferation abilities of co-cultured MSCs. To sum up, these results demonstrate a suppressive role of miR-134-5p in tumor-environment-driven malignant transformation of rat MSCs through directly targeting Stat3, highlighting a crucial role of loss-of-function of miR-134-5p/Stat3 axis in the malignant transformation, providing a reference to the potential clinic use of MSCs.

Impact of PEGylated Liposomal Doxorubicin and Carboplatin Combination on Glioblastoma.

Glioblastoma is an incurable cancer with a 5-year survival chance of less than 5%. Chemotherapy is a therapeutic approach to treating the disease; however, due to the presence of the blood–brain barrier (BBB), the probability of success is low. To overcome this issue, nanoparticles are promising carriers for crossing the BBB and delivering drugs to the tumor. In this study, the anticancer efficacy of doxorubicin (DOX) and carboplatin (CB) loaded into polyethylene glycol (PEG)ylated liposome nanoparticles (PEG-Lip) and in treating brain cancer was evaluated in vitro and in vivo. The results demonstrated that PEG-Lip-DOX/CB with a size of 212 ± 10 nm was synthesized that could release the loaded drugs in a controlled manner, from which 56.3% of the loaded drugs were released after 52 h. In addition, PEG-Lip-DOX/CB could significantly increase the cytotoxicity effects of the drugs against rat glioma C6 cells (IC50: 8.7 and 12.9 µM for the drugs-loaded nanoparticles and DOX + CB, respectively). The in vivo results also demonstrated that PEGylated liposomes, compared to non-PEGylated liposomes (Lip) and DOX + CB, were more efficient in increasing the therapeutic effects and decreasing the side effects of the drugs, in which the survival times of the glioblastoma-bearing rats were 39, 35, and 30 days in the PEG-Lip-DOX/CB, Lip-DOX/CB, and DOX + CB receiver groups, respectively. In addition, the weight loss was found to be 8.7, 10.5, and 13%, respectively, in the groups. The results of the toxicity evaluation were also confirmed by histopathological studies. Overall, the results of this study demonstrated that the encapsulation of DOX and CB into PEG-Lip is a promising approach to improving the properties of DOX and CB in terms of their therapeutic effects and drug side effects for the treatment of glioblastoma.

Pelargonidin inhibits vascularization and metastasis of brain gliomas by blocking the PI3K/AKT/mTOR pathway

Pelargonidin has attracted much attention in many cancers. Whether the growth of glioma inhibited by pelargonidin is related to the PI3K/AKT/mTOR pathway is unknown. To examine this, we performed both in vivo and in vitro studies. Twenty-four hours after inoculation, C6 cells received various treatments: CCK8, transwell, flow cytometry, and Western blot were performed. The cell supernatant was collected in order to pretreat HUVEC cells, and tube formation assay was performed. An in situ glioma rat model was constructed and administrated treatment according to its group. After 14 days, the brains were obtained for TUNEL assay, immunohistochemical staining, and Western blot. In vitro studies demonstrated that pelargonidin inhibited the proliferation, migration, and invasion of C6 cells, and promoted apoptosis of C6 cells. Additionally, pelargonidin could inhibit tube formation of HUVECs. We also detected the proteins in the PI3K/AKT/mTOR pathway, and the results indicated that pelargonidin inhibited the phosphorylation of AKT, PI3K, and mTOR, and downregulated VEGF protein. In vivo glioma models were successfully built, and pelargonidin could increase the survival rate of rat, and pathological staining results indicated that pelargonidin increased TUNELpositive cells and decreased micro-vessel density (MVD) through PI3K/AKT/mTOR. Pelargonidin could reduce the relative expression of MMP2, MMP9, N-cadherin, and VEGF proteins, and inhibit the PI3K/AKT/ mTOR pathway. Pelargonidin inhibited the vascularization and metastasis of glioma by blocking the PI3K/ AKT/mTOR pathway.

Instructive electroactive electrospun silk fibroin-based biomaterials for peripheral nerve tissue engineering.

Aligned sub-micron fibres are an outstanding surface for orienting and promoting neurite outgrowth; therefore, attractive features to include in peripheral nerve tissue scaffolds. A new generation of peripheral nerve tissue scaffolds is under development incorporating electroactive materials and electrical regimes as instructive cues in order to facilitate fully functional regeneration. Herein, electroactive fibres composed of silk fibroin (SF) and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) were developed as a novel peripheral nerve tissue scaffold. Mats of SF with sub-micron fibre diameters of 190±50nm were fabricated by double layer electrospinning with thicknesses of ∼100μm (∼70-80μm random fibres and ∼20-30μm aligned fibres). Electrospun SF mats were modified with interpenetrating polymer networks (IPN) of PEDOT:PSS in various ratios of PSS/EDOT (α) and the polymerisation was assessed by hard X-ray photoelectron spectroscopy (HAXPES). The mechanical properties of electrospun SF and IPNs mats were characterised in the wet state tensile and the electrical properties were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The cytotoxicity and biocompatibility of the optimal IPNs (α=2.3 and 3.3) mats were ascertained via the growth and neurite extension of mouse neuroblastoma x rat glioma hybrid cells (NG108-15) for 7days. The longest neurite outgrowth of 300μm was observed in the parallel direction of fibre alignment on laminin-coated electrospun SF and IPN (α=2.3) mats which is the material with the lowest electron transfer resistance (Ret, ca. 330Ω). These electrically conductive composites with aligned sub-micron fibres exhibit promise for axon guidance and also have the potential to be combined with electrical stimulation treatment as a further step for the effective regeneration of nerves.

Determination of Antiproliferative Effects of Exopolysaccharides from Six Mushroom Species on Glioma Cells

Glial tumors are the largest and danger group of central nervous system tumors. The use of natural products now has been contemplated of exceptional value in the control of cancer. Mushrooms have been used for many centuries, not just as a food, but also to treat many illnesses. Therefore, we aimed to evaluate the effect of exopolysaccharides (EPS) obtained from six different edible mushrooms on the survival of glioma cells. In this study the effects of 0.4, 1, 2, 4 and 6 μg/mL doses of EPSs from six mushroom species Coprinus comatus, Fistulina hepatica, Panus neostrigosus, Laetiporus sulphureus, Polyporus squamosus, and Lenzites betulinus were investigated on the rat glioma cell line (C6) in two different periods by MTT assay. According to our results 0.4 and 1 μg/mL of EPSs from six mushroom species were not effective or less effective, but 2, 4 and 6 μg/mL doses killed glioma cells about 27 to 71 % for 24 hours, 35 to 78 % for 48 hours As a result, these mushroom EPSs showed different cytotoxicity to glioma cells time and dose-dependently. These findings can be suggested that the anti-tumor effects of EPSs can be potential use in clinical applications to treat glioma. Further studies are needed to understand these effects more clearly on glioma.

Rodent Brain Tumor Models for Studies Focusing on Boron Neutron Capture Therapy.

Rodent brain tumor models have been very useful in advancing the treatment of glioblastomas. This review focuses on the four most widely used rodent brain tumor models: the C6, 9L, and F98 rat gliomas, and the GL261 murine glioma. All of these have been used in studies relating to boron neutron capture therapy. The most important of these studies were those using the 9L gliosarcoma, which led to the clinical use of boronophenylalanine, and the F98 glioma, which has been used for the preclinical evaluation of new boron delivery agents and methods of optimizing their delivery.

The therapeutic effect of an autologous and allogenic mixed glioma cell lysate vaccine in a rat model.

Tumor immunotherapy has the advantages of high specificity, minimal damage to the patient's body, and a long-lasting anti-tumor effect. However, due to the existence of immune escape phenomenon, the effect of anti-tumor immunotherapy is still poor. Therefore, a cancer vaccine that reverses tumor-associated immunosuppression is a very promising approach for research and treatment. Vaccines were prepared using autologous and allogeneic tumor cells and their lysates to syngeneic tumor cell lysates as immunogens. The glioma cell proliferation, apoptosis and the secretion level of MCP-2, IFN-γ were detected to evaluate the efficacy of this treatment against glioma in vitro. In addition, a rat glioma model was established to investigate the anti-tumor effect in vivo, and evaluated its efficacy by observing the changes of CD4 + T cells, CD8 + T cells, NK cells, and the level of IL-2 and IL-10 in peripheral blood before and after treatment. The C6 + 9L glioma cell lysate vaccine (C6 + 9L-CL) not only inhibited the proliferation of glioma cells and promoted their apoptosis in vitro, but also significantly inhibited the tumor growth in vivo and improved the survival time of rats. In addition, the C6 + 9L-CL vaccine enhanced the anti-tumor immune response by promoting the secretion of T cell chemokines MCP-2, IFN-γ and IL-2, and by stimulating the proliferation of T cells and NK cells in peripheral blood and glioma tissues. Our findings demonstrate the inhibitory effect of molecular mimic vaccines on glioma and provided a theoretical basis for molecular mimic hybrid vaccines as a potential therapeutic approach.

Rose Bengal-Modified Upconverting Nanoparticles: Synthesis, Characterization, and Biological Evaluation.

High-quality upconverting NaYF4:Yb3+,Er3+ nanoparticles (UCNPs; 26 nm in diameter) based on lanthanides were synthesized by a high-temperature coprecipitation method. The particles were modified by bisphosphonate-terminated poly(ethylene glycol) (PEG) and Rose Bengal (RB) photosensitizer. The particles were thoroughly characterized using transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, FTIR, and X-ray photoelectron and upconversion luminescence spectroscopy in terms of morphology, hydrodynamic size, composition, and energy transfer to the photosensitizer. Moreover, the singlet oxygen generation from RB-containing UCNPs was investigated using 9,10-diphenylanthracene probe under 980 nm excitation. The cytotoxicity of UCNPs before and after conjugation with RB was evaluated on highly sensitive rat mesenchymal stem cells (rMSCs) and significant differences were found. Correspondingly, consi-derable variations in viability were revealed between the irradiated and non-irradiated rat glioma cell line (C6) exposed to RB-conjugated UCNPs. While the viability of rMSCs was not affected by the presence of UCNPs themselves, the cancer C6 cells were killed after the irradiation at 980 nm due to the reactive oxygen species (ROS) production, thus suggesting the potential of RB-conjugated PEG-modified UCNPs for applications in photodynamic therapy of cancer.

Exposure of aluminium to C6 glioma cells modulates molecular and functional neurotoxic markers.

The risk of aluminium exposure to humans is very high as it may get into the human body through excessive dietary contaminants, inhalation of fine particulate matter, or through parenteral routes as a vaccine adjuvant and so forth. The increased level of aluminium in brain tissue has been shown to be associated with several neurodegenerative and neurotoxic adverse effects, including AD. However, the exact mechanism of aluminium-induced neurotoxicity is still unclear. Therefore, our study aimed to investigate the mechanism of neurotoxic and neurodegenerative effects through in vitro exposure of aluminium in rat glioma C6 cell line. The findings of our study have indicated that aluminium chloride exposure may lead to alteration in acetylcholine levels, increased oxidative imbalanceand induction of molecular structural and functional markers of neuronal inflammation. This study also demonstrated that aluminium exposure may lead to the induction of caspase-3 along with apoptotic cell death and a significant increase in amyloid-beta and hyperphosphorylated tau levels in C6 cells. Thus, this study may provide a mechanistic understanding of the regulation of neuroinflammatory and neurodegenerative biomarkers due to aluminium exposure.

Exogenous 3-Iodothyronamine (T1AM) Can Affect Phosphorylation of Proteins Involved on Signal Transduction Pathways in In Vitro Models of Brain Cell Lines, but These Effects Are Not Strengthened by Its Catabolite, 3-Iodothyroacetic Acid (TA1).

T1AM, a derivative of thyroid hormones, and its major catabolite, TA1, produce effects on memory acquisition in rodents. In the present study, we compared the effects of exogenous T1AM and TA1 on protein belonging to signal transduction pathways, assuming that TA1 may strengthen T1AM’s effects in brain tissue. A hybrid line of cancer cells of mouse neuroblastoma and rat glioma (NG 108-15), as well as a human glioblastoma cell line (U-87 MG) were used. We first characterized the in vitro model by analyzing gene expression of proteins involved in the glutamatergic cascade and cellular uptake of T1AM and TA1. Then, cell viability, glucose consumption, and protein expression were assessed. Both cell lines expressed receptors implicated in glutamatergic pathway, namely Nmdar1, Glur2, and EphB2, but only U-87 MG cells expressed TAAR1. At pharmacological concentrations, T1AM was taken up and catabolized to TA1 and resulted in more cytotoxicity compared to TA1. The major effect, highlighted in both cell lines, albeit on different proteins involved in the glutamatergic signaling, was an increase in phosphorylation, exerted by T1AM but not reproduced by TA1. These findings indicate that, in our in vitro models, T1AM can affect proteins involved in the glutamatergic and other signaling pathways, but these effects are not strengthened by TA1.

Molecular Modeling Study of Novel Lancifolamide Bioactive Molecule as an Inhibitor of Acetylcholinesterase (AChE), Herpes Simplex Virus (HSV-1), and Anti-proliferative Proteins.

Combretaceae, an immense family involving species (500) or genera (20), originates in tropical and subtropical regions. This family has evinced medicinal values such as anti-leishmanial, cytotoxic, antibacterial, antidiabetic, antiprotozoal, and antifungal properties. Conocarpus lancifolius (C. lancifolius) methanol extract (CLM) was prepared, then compound isolation performed by open column chromatography, and compound structure was determined by spectroscopic techniques (13C NMR, IR spectroscopy, 1H-NMR, mass spectrometry UV-visible, and 2D correlation techniques). Molecular docking studies of ligand were performed on transcriptional regulators 4EY7 and 2GV9 to observe possible interactions. Phytochemical screening revealed the presence of secondary metabolites including steroids, cardiac glycosides, saponins, anthraquinones, and flavonoids. The isolated compound was distinguished as lancifolamide (LFD). It showed cytotoxic activity against human breast cancer, murine lymphocytic leukemia, and normal cells, human embryonic kidney cells, and rat glioma cells with IC50 values of 0.72 µg/mL, 2.01 µg/mL, 1.55 µg/mL, and 2.40 µg/mL, respectively. Although no cytotoxic activity was noticed against human colon cancer and human lung cancer, LFD showed 24.04% inhibition against BChE and 60.30% inhibition against AChE and is therefore beneficial for Alzheimer’s disease (AD). AChE and LFD interact mechanistically in a way that is optimum for neurodegenerative disorders, according to molecular docking studies. Methanol and dichloromethane extract of C. lancifolius and LFD shows antibacterial and antifungal activity against antibiotic resistance Bacillus subtilis, Streptococcus mutans, Brevibacillus laterosporus, Salmonella Typhi, Candida albicans, and Cryptococcus neoformans, respectively. LFD shows antiviral activity against HSV-1 with 26% inhibition IP. The outcomes of this study support the use of LFD for cognitive disorders and highlight its underlying mechanism, targeting AChE, DNA-POL, NF-KB, and TNF-α, etc., for the first time.

The Effects of Methanol Extracts of Hyssopus officinalis on Model of Induced Glioblastoma Multiforme (GBM) in Rats.

Given the complexity of pathophysiological processes of brain tumors, ineffective therapies, and high mortality rate, new therapeutic options with less toxicity are necessary. Hyssopus officinalis (hyssop) is an aromatic plant with important biological activities. The aim of this study is to assess the anti-cancer effect of hyssop extract on damages of glioblastoma multiforme. In this study, total flavonoids, phenolic content, and quantification of phenolic compound of hyssop extracts were analyzed. In vitro antioxidant properties of hyssop extract were also examined. In addition, cell viability, apoptosis, and cell cycle were evaluated in C6 glioma cell culture. In vivo, the rats were divided randomly into four main groups: intact, control, vehicle, and treatment groups. 1 × 106 C6 rat glioma cells were implanted into the right caudate nucleus of the rat's brain. The treatment group received the methanol extract of hyssop (100mg/kg) for 7days. Evolution of locomotor activity, tumor volume, survival rate, activities of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)), vascular endothelial growth factor (VEGF) expression, TUNEL-positive cells, p53 and p21 mRNA expression, and histological alterations were performed. The results showed that the methanol extract of hyssop increased the apoptosis and reduced the cell division of C6 glioma cells in cell culture. Moreover, methanol extract decreased the tumor volume and prolonged survival. Also, the activity of SOD and CAT enzymes was reduced in tumor tissue and enhanced in surrounding tissue. TUNEL-positive cells were increased in methanol extract of hyssop group. The expression of p53 and p21 mRNA was upregulated in the treatment group. Moreover, the histological analysis indicated a considerable decrease in invasion of tumor cells and inflammation in the hyssop-treated rats. According to the achieved results, it can be stated that hyssop has sufficient potential to inhibit damage of brain tumors, at least in part, by affecting the oxidative stress and cell proliferation pathways.

Comparable Long-Term Tumor Control for Hypofractionated FLASH Versus Conventional Radiation Therapy in an Immunocompetent Rat Glioma Model

PurposeTo ensure a clinical translation of FLASH radiation therapy (FLASH-RT) for a specific tumor type, studies on tumor control and toxicity within the same biological system are needed. In this study, our objective was to evaluate tumor control and toxicity for hypofractionated FLASH-RT and conventional radiation therapy (CONV-RT) in an immunocompetent rat glioma model. Methods and MaterialsFisher 344 rats (N = 68) were inoculated subcutaneously with NS1 glioma cells and randomized into groups (n = 9-10 per group). CONV-RT (∼8 Gy/min) or FLASH-RT (70-90 Gy/s) was administered in 3 fractions of either 8 Gy, 12.5 Gy, or 15 Gy using a 10-MeV electron beam. The maximum tumor diameter was measured weekly, and overall survival was determined until day 100. Long-term tumor control was defined as no evident tumor on day 100. Animals were evaluated for acute dermal side effects at 2 to 5 weeks after completed RT and for late dermal side effects at 3 months after initiation of treatment. ResultsSurvival was significantly increased in all irradiated groups compared with control animals (P < .001). In general, irradiated tumors started to shrink at 1 week post–completed RT. In 40% (23 of 58) of the irradiated animals, long-term tumor control was achieved. Radiation-induced skin toxic effects were mild and consisted of hair loss, erythema, and dry desquamation. No severe toxic effect was observed. There was no significant difference between FLASH-RT and CONV-RT in overall survival, acute side effects, or late side effects for any of the dose levels. ConclusionsThis study shows that hypofractionated FLASH-RT results in long-term tumor control rates similar to those of CONV-RT for the treatment of large subcutaneous glioblastomas in immunocompetent rats. Neither treatment technique induced severe skin toxic effects. Consequently, no significant difference in toxicity could be resolved, suggesting that higher doses may be required to detect a FLASH sparing of skin.