C6 Cells Research Articles

The effects of cell displacement on DNA damages in targeted radiation therapy using Geant4-DNA

Charged particle radiation can, directly and indirectly, affect cells by breaking DNA strands. This effect includes DNA single-strand breaks (SSB) and DNA double-strand breaks (DSB), which may cause cell death and mitotic failure. Thus, using short-range charged particles such as Auger electrons (AEs) not only leads to the destruction of the target cell but also prevents the nearby healthy cells from exposing to ionizing radiation. In this study, two spherical cells (C and C2) and their cell nucleus, both made of liquid water, were modeled. An atomic DNA model constructed in the Geant4-DNA Monte Carlo (MC) simulation toolkit was placed inside the nucleus of the C and C2 cells. The number of direct and indirect SSB, DSB, and hybrid DSB (HDSB), caused by some of the most widely-used Auger electron-emitting (AEE) radionuclides, including 99mTc, 111In, 123I, 125I, and 201Tl, distributed within different compartments of the C cell, was calculated in the C and C2 cells, considering the distance between the surface of the two cells ranges from 0 to 5 μm. The present work aimed to investigate the biological effects of AEE radionuclides and their potential for cancer treatment through targeted radiation therapy. The results indicate the impact of 201Tl > 125I > 123I > 111In > 99mTc on DNA damage when the target is C (first spherical cell). On the other hand, for C2 at distances of 0 to 5 μm, the impact of 99mTc > 123I > 111In > 201Tl > 125I on DNA damage is observed.

Fingolimod Inhibits C6 Rat Glioma Proliferation and Migration, Induces Sub-G1 Cell Cycle Arrest, Mitochondrial and Extrinsic Apoptosis InVitro and Reduces Tumour Growth InVivo.

Glioblastoma multiforme (GBM), the most prevalent brain tumour, is universally fatal. GBM cells exhibit cell cycle disruption and treatment resistance, remarking an urgent need for newer treatments. Fingolimod, a sphingosine-1-phosphate receptor modulator, has been reported to have anti-cancer effects. This study investigated the therapeutic potentials of fingolimod in rat C6 cells and pursued the involved mechanism(s). Cell survival, proliferation, migration, and morphology of fingolimod-treated C6 cells were evaluated using MTT, soft-agar colony formation, wound-healing, and Giemsa staining assays. Apoptosis was investigated through acridine orange/ethidium bromide (AO/EB) and annexin V staining, and flow cytometry analysed the cell cycle. Quantitative reverse transcription PCR and western blotting were used to evaluate gene and protein expressions. An intracranial C6 rat model validated the anti-tumour effect of fingolimod. Fingolimod significantly reduced the survival and colonies of the C6 cells and delayed their gap closure. Cell shrinkage coupled with AO/EB and PI staining of the fingolimod-treated cells indicated apoptosis, subsequently confirmed by measuring the expression levels of the candidate genes involved in apoptosis and cell cycle, such as Bax/Bcl2, P53, Cytochrome C and Caspases 9/3, Fas, Fadd, Tnfrsf1a, Cdkn1a, and Ccnd1, at RNA and protein levels, indicating both extrinsic and mitochondrial apoptosis and cell cycle arrest at sub-G1 phase in fingolimod-treated cells. Furthermore, treating rats bearing intracranial C6 tumours with fingolimod led to significant suppression of intracranial tumour growth. Based on our findings, cell cycle arrest and apoptosis contribute to fingolimod antitumor effects.

Ultrasound-triggered drug release and cytotoxicity of microbubbles with diverse drug attributes

Ultrasound (US)-triggered cavitation of drug-loaded microbubbles (MBs) represents a promising approach for targeted drug delivery, with substantial benefits attainable through precise control over drug release dosage and form. This study investigates Camptothecin-loaded MBs (CPT-MBs) and Doxorubicin-loaded MBs (DOX-MBs), focusing on how properties such as hydrophilicity, hydrophobicity, and charged functional groups affect their interaction with the lipid surfaces of MBs, thereby influencing the fundamental characteristics and acoustic properties of the drug-loaded MBs. In comparison to DOX-MBs, CPT-MBs showed larger MB size (2.2 ± 0.3 and 1.4 ± 0.1 μm, respectively), a 2-fold increase in drug loading, and an 18 % reduction in leakage after 2 h at 37℃. Under 1 MHz US with a 100 ms pulse repetition interval (PRI), 1000 cycles, 5-minute duration, and 550 kPa acoustic pressure, CPT-MBs undergo inertial cavitation, while DOX-MBs undergo stable cavitation. Drug particles released from these MBs under US-induced cavitation were analyzed using dynamic light scattering, NanoSight, cryo-electron microscopy, and density gradient ultracentrifugation. Results showed that CPT-MBs mainly release free CPT, while DOX-MBs release multilayered DOX-lipid aggregates. The cytotoxicity to C6 cells induced by US-triggered cavitation of these two types of MBs also differed. DOX-lipid aggregates delayed initial uptake, leading to less pronounced short-term (2 h) effects compared to the rapid release of free CPT from CPT-MBs. These findings underscore the need to optimize drug delivery strategies by fine-tuning MB composition and US parameters to control drug release kinetics and achieve the best tumoricidal outcomes.

Mechanism and Effects of Multiscale Pulsed Electromagnetic Fields on Rat Glioma Cells

Pulsed electromagnetic field (PMF) treatment based on the dielectric difference between cancer cells and normal cells is a recently discovered novel cancer treatment. However, the mechanism behind PMF irradiation of cancer cells is not clear, and the relationship between the biological effect of cancer cells and PMF irradiation parameters is difficult to predict, leading to difficulties in its application in cancer therapy. In this paper, we designed nanosecond and microsecond PMFs for rat glioma cells (C6) considering different parameters— frequency, rise rate d<i>B</i>/d<i>t</i>, intensity <i>B</i>, action integral Σ<i>B</i>Δ<i>t</i>, and energy action integral Σ<i>B</i><sup>2</sup>Δ<i>t</i>—to accurately describe PMFs. The results point to a statistically significant window effect and cumulative effect of PMFs on cancer cell viability. In particular, the results of nanosecond PMFs showed that low-frequency and low-intensity electromagnetic fields are more likely to inhibit the proliferation of C6 cells. At a frequency of 1 Hz, C6 cell viability was inhibited by about 10%–15%. Furthermore, when the intensity was 0.353 mT, nanosecond PMFs showed an inhibitory effect, except at 10 Hz. The effective inhibition values of the magnetic field parameters d<i>B</i>/d<i>t</i> (T/s), <i>Bt</i> (mT·s), and <i>B</i><sup>2</sup><i>t</i> (mT<sup>2</sup>·s) after microsecond PMFs were [4.14 × 10<sup>3</sup>, 5.65 × 10<sup>4</sup>], [1.18 × 10<sup>-2</sup>, 4.51 × 10<sup>-2</sup>], and [1.28, 11.30], respectively. It is noted that the rise rate (d<i>B</i>/d<i>t</i>) of PMFs plays a major role in inhibiting cancer cell proliferation. Furthermore, when the difference of d<i>B</i>/d<i>t</i> is small, the intensity becomes the main factor affecting cancer cell viability. Overall, this study establishes theoretical and experimental foundations for the study of electromagnetic biological effects and their clinical applications.

The Aqueous Extract of Armadillidium vulgare Latreille Alleviates Neuropathic Pain via Inhibiting Neuron-Astrocyte Crosstalk Mediated by the IL-12-IFN-γ-IFNGR-CXCL10 Pathway

Ethnopharmacological relevanceArmadillidium vulgare Latreille (AV), the dried body of pillbug, was originally described in Shennong’s Classic of Materia Medica. As a common analgesic in animal-based traditional Chinese medicine, it is mainly used to relieve pain, promoting diuresis, relieving fatigue and so on. Our work demonstrated that AV could alleviate various types of acute and chronic pain including neuropathic pain (NP). And transcriptome sequencing analysis revealed that AV could suppress CXCL10 to alleviate NP, however, the upstream mechanisms governing CXCL10 synthesis remain vague.Aim of the study: The research’s goal was to identify the mechanism via which AV regulates CXCL10 to ameliorate NP. Materials and methodsChronic constriction injury (CCI) to the sciatic nerve was used to induce the NP model 14 days following surgery. To identify cell signaling pathways, various approaches were used, including transcriptome sequencing, western blotting, immunofluorescence, as well as ELISA. The in vitro assay involved the cultivation of neuron PC12 cells and astrocyte C6 cells. ResultsBoth in vivo and in vitro results demonstrated that IL-12/IL-18 enhanced IFN-γ production in spinal neurons, which acted on IFN-γ receptors on neurons and astrocytes to upregulate CXCL10 expression in these cells, illustrating the pivotal role of IL-12 in the crosstalk between neurons and astrocytes. The role of IL-12 in pain regulation was elucidated for the first time within the nervous system. Additionally, its synergistic interaction with IL-18 on the downstream IFN-γ-CXCL10 pathway dramatically altered the activation of neurons and astrocytes. And AV could suppress CXCL10 to alleviate NP by mediating the IL-12-IFN-γ-IFNGR signaling pathway. ConclusionsWe explored a new target for NP by regulating neuron-astrocyte crosstalk and provided a theoretical basis for AV in clinical use.

Novel Tricyclo[4.2.1]Nonane and Bicyclo[2.2.1]Heptane Derivatives: Synthesis, in Vitro Biological Activities and in Silico Studies.

The target benzothiazole derivatives (8a-g) were synthesized starting from norbornene. The addition of dichloroketene to norbornene followed by the reduction of chlorine atoms were synthesized tricyclo[4.2.1.02,5]non-7-en-3-one (4). The condensation of benzaldehyde derivatives with compound 4 were obtained chalcone analogs (6a-g). Finally, benzothiazole derivatives (8a-g) were obtained by the reaction of the chalcone analogs with 2-aminobenzothiol in an acidic medium. The antiproliferative activities of compounds 6a-g and 8a-g were determined against C6 (rat brain tumor) and HeLa (human cervical carcinoma) cell lines using a BrdU cell proliferation ELISA assay with 5-fluorouracil (5-FU) as a standard. In both series, when compared with 5-FU (IC50=3.8 μM for C6 and 16.33 μM for HeLa), the most active compounds against C6 cells were 6a and 8g with IC50 values of 14.13 μM and 29.99 μM, respectively. With this, 6a, 6e, 6f, and 8b were the most active compounds against HeLa cells with IC50 values of 0.8, 1.21, 19.33 and 18.13 μM, respectively. Additionally, the SwissADME online web tool was used to predict the physicochemical and ADME properties of the tested compounds. The results showed that all compounds possess promising predicted physiochemical and pharmacokinetic properties and comply with Lipinski's rule of 5, indicating that they are predicted to be orally bioavailable that they possess a predicted bioavailability score of 0.55. Furthermore, in the SwissADME Boiled-Egg chart, all compounds showed high predicted GIT absorption, while compounds 6a-g showed blood-brain barrier (BBB) permeation, and compounds 8a-g did not. Moreover, none of the compounds was (P-gp) substrates. This study investigated the potential interactions between the antiapoptotic proteins Bcl-2, Bcl-xl, Bcl-w, Brag-1, Bfl-1, and Mcl-1 and compounds 6a, 8b, and 8g through molecular docking studies. The findings suggest that these compounds may effectively inhibit antiapoptotic proteins, as evidenced by significant hydrogen bonds and hydrophobic interactions, particularly with Bcl-xl.

Nuciferine inhibits osteoclast formation through suppressing glycolysis metabolic programming and ROS production.

Nuciferine (NCF) is a bioactive compound from lotus leaves and has been proven to prevent osteoclastogenesis and ovariectomy-induced osteoporosis by our previous research. However, the underlying mechanism is still unclear. In this research, Raw264.7 cells were induced into osteoclast with or without NCF. CCK-8 and Edu assays were performed to detect the effects of 30 μM NCF on cell viability and proliferation. TRAP staining and bone resorption assays were performed to observe the role of NCF in osteoclastogenesis and bone resorption. RT-PCR and Western blot were performed to detect the effects of NCF on osteoclast-related genes, glycolysis-related genes, and reactive oxygen species (ROS)-related genes. Seahorse assays, lactate concentration and glucose consumption were performed to observe cell metabolism change. DCFH-DA fluorescent probe was used to detect ROS level. In this work, 30 μM NCF could not influence cell viability and cell proliferation. Osteoclast differentiation could be inhibited by 30 μM NCF. Bone resorption assay could also observe that bone resorption ability was successfully inhibited by 30 μM NCF. In seahorse assay, we discovered that NCF could decrease extracellular acid rate and increase oxygen consumption. RT-PCR and Western blot results showed that NCF could decrease the expression of hexokinase2, pyruvate kinase muscle 2, and lactate dehydrogenase A and that NCF could also weaken the concentration of lactate. However, pyruvate kinase muscle 2 activator (GC69716) and lactate addition could promote osteoclastogenesis and bone resorption and promote the expression of c-Fos and nuclear factor of activated T cells c1. Besides, NCF could also inhibit the production of ROS. In conclusion, NCF might inhibit osteoclast formation through inhibiting glycolysis metabolism and ROS production.

IN VIVO INOCULATION OF GBM CELLS IN RATS AND TREATMENT WITH RUXOLITINIB

GlioStat (patent pending) denotes an invention that addresses the current deficiencies of glioblastoma (GBM) chemotherapy by developing a molecularly imprinted drug reservoir that is specifically designed for post-surgical recovery. The goal of our research was to guarantee the long-term release of the antitumor drug ruxolitinib (RUX), which is specifically designed to target residual infiltrative cancer cells, while simultaneously reducing the risk of adverse effects. In order to achieve this goal, we have successfully developed and characterized four distinctive molecularly imprinted polymers (MIPs), with one of them advancing to in vivo experimentation. The selection of one MIP for further in vivo investigations was guided by the Alamar Blue viability assay on C6 GBM cell cultures, which took into account both the efficacy and the potential toxicity of residual monomers. Over the course of 96 hours, MIP 2 demonstrated the most favorable risk-benefit profile, providing superior efficacy against GBM C6 cells. In contrast, its non-imprinted counterpart (NIP 2) exhibited minimal toxicity. The protocol involved anesthetising the male Wistar rats, immobilising them on a corkboard, without the use of a stereotactic headholder. After shaving the head and local disinfection with iodine solution, we made a linear sagittal incision and exposed the parietal bones. A 3x3 mm burr hole was made with a pneumatic drill in the right parietal bone, revealing the dura mater. Subsequently, we injected 20,000 C6 GBM cells suspended in 5 microliters of solution in the cerebral parenchyma at a depth of 3 mm. Clinical and imaging control was performed. For the animals that developed tumors, a second therapeutic intervention was performed. The rats were anesthetised, disinfected, and readied in the same manner as before. The burr hole was exposed, with the tumor being partially resected via a “microscooping” technique. Next, 5-10 microliters of MIP2 solution (4 mg/mL) were injected into the parenchyma respective of the tumor bed. Five microliters of thrombin solution were then added (100 UI/mL) to form the fibrin network. In comparison to the untreated controls and animals treated with free RUX, animals treated with MIP2 exhibited a substantial increase in survival time during the in vivo evaluation, extending from 20 to 50 days. As such, our research had yielded a potentially life-changing drug delivery system in GBM, with the capacity to significantly increase postoperative survival. More in vivo tests should be conducted to validate our findings.

DDDR-14. IMPROVED ANTI-GLIOBLASTOMA EFFICACY BY BRG399, A NOVEL ORAL MICROTUBULE BINDING AGENT

Abstract Glioblastoma (GBM) is a highly malignant form of brain tumor with a poor prognosis despite advances in treatments. Therapeutic resistance/relapse remains a significant challenge necessitating the development of novel approaches. BRG399 is a brain permeant, non P-gp substrate, microtubule-targeting agent that displays anti-cancer activity in vitro and in vivo. BRG399 was well tolerated in rat and dog toxicology studies. Anti-cancer activity (IC50) of BRG399 in in vitro models of GBM was assessed to have potency ranging from 42nm to 89nM in the 3 cell lines tested. Here, in vivo tumor activity of BRG399 was assessed in Sprague Dawley rats implanted with 3x105 C6 rat glioma cells into the right entorhinal cortex/subiculum region. 14 days post successful implantation tumors were assessed by MRI, rats were randomized to receive vehicle (2% Labrasol) or BRG399 (5, 10, 20 mg/kg groups) twice daily by oral gavage for 16 days, and MRIs were performed on survivors on days 31 and 45 post implantation. BRG399 administration resulted in a marked improvement in survival (from 7.7 ± 2.6 days to 25.5 ± 15.6 days, log-rank test, p:0.007) compared to controls. Six animals receiving BRG399 remained alive beyond day 60 of post-treatment initiation. To assess biodistribution of BRG399 in the brain, rats were implanted with C6 cells and tumor establishment assessed 12 days later by MRI. Animals were treated with vehicle or BRG399 (10, 20, 25 mg/kg) and plasma and brains were collected for bioanalytical assessment. Tissue single cell biodistribution was performed using TIMSTOF FLEX spatial OMICS. These results demonstrate a therapeutic effect of BRG399 on intracranial glioma-bearing rats with survival of the BRG399 treatment groups of strong statistical significance over the control group. Analysis of drug levels in plasma and brain will serve as guidance for dose and scheduling decisions for further therapeutic development.

Assessing antioxidant responses in C6 and U-87 MG cell lines exposed to high copper levels

Copper excess has been tested as an anticancer therapy, due to its properties to generate oxidative stress resulting in tumoral cell death. Thus, this study aimed to evaluate the impact of copper excess on oxidative stress and antioxidant responses in glioma cells, establishing the antioxidant system as a target of copper toxicity in tumoral cells. C6 and U-87 MG cells were exposed to CuSO4 (0–600 μM) for 24-48 h. SOD, CAT, GPx, GR, and CK activities, protein and non-protein thiol levels (PSH and NPSH), and O2− production were assessed, alongside SOD1, GPx1, and GR gene expression. Results revealed a decrease in GPx, GR, and CAT activity after CuSO4 exposure in both cell lines over 24-48 h, while SOD activity initially increased, then declined after 48 h. CK activity was also decreased in C6 cells. NPSH and PSH levels dropped after 24 h, and O2− production was observed in all CuSO4 concentrations. GR mRNA was reduced in both cell lines, contrasting with increased GPx1 mRNA in C6. U-87 MG cells exhibited higher levels of SOD1 mRNA, while C6 cells displayed lower expression. Our findings suggest that copper excess limits antioxidant enzyme activity and thiol levels, particularly in the C6 cells, likely attributable to oxidative stress or direct copper-enzyme interactions. Moreover, our results imply differences in copper toxicity regarding the cell lineage used, highlighting the importance of analyzing high copper levels effects in different models. Moreover, it could be proposed that the antioxidant system is a target of copper toxicity, contributing to glioma cell death.

АСТРОЦИТАРНАЯ РЕАКЦИЯ ГОЛОВНОГО МОЗГА КРЫС ПРИ ПРОГРЕССИРОВАНИИ ГЛИАЛЬНЫХ ОПУХОЛЕЙ

Background. The study of the heterogeneity and plasticity of astrocytes in the brain, in particular in the peritumoral zone, at different stages of neoplasm growth will help to understand their importance in the progression of glial tumors. Aim. To perform morphometric assessment of astrocytes in the rodent brain during glial tumor progression. Material and methods. Glial brain tumor was modeled in rodents using implantation of glioma C6 cells followed by immunohistochemical assessment of GFAP+-astrocytes in the peritumoral zone in the right hemisphere and a similar zone of the left hemisphere of the rodent brain at different experimental periods. Results. In the early stages of glial tumor growth, there was a statistically significant predominance of cell density and a difference in the morphometric parameters of astrocyte cells in the peritumoral zone of the right hemisphere of the rat brain compared with a similar zone of the left hemisphere. The progression of the glial tumor was accompanied by a significant decrease in the cell density of astrocytes in the peritumoral zone with an increase in reactive changes of astrocytes in a similar zone of the contralateral hemisphere. Conclusions. The development of tumor processes in the brain of rodents is accompanied by activation of astrocytes with the acquisition of a reactive phenotype by cells in the peritumoral zone. At the same time, further progression of the neoplasm suppresses active proliferation of astrocytes.

Enoxaparin Protects C6 Glioma Cells from Glutamate-Induced Cytotoxicity by Reducing Oxidative Stress and Apoptosis.

Recent studies suggest enoxaparin may protect the central nervous system (CNS) from damage. However, its specific effects on glial cells and the underlying mechanisms involving cell death and oxidative stress require further investigation. Therefore, this research investigated enoxaparin's potential to safeguard C6 glioma cells against glutamate-induced cytotoxicity, specifically focusing on its influence on oxidative stress and apoptotic mechanisms. To investigate the neuroprotective effects of enoxaparin against glutamate-induced cytotoxicity in C6 cells, four groups were established: a control group, a group exposed to 10mM glutamate, a group treated with enoxaparin at concentrations ranging from 25 to 200µM, and a group receiving both 10mM glutamate and enoxaparin at concentrations ranging from 25 to 200µM. Cell viability was measured using an XTT assay. To evaluate the effects of enoxaparin on oxidative stress, superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured using ELISA, along with total antioxidant status (TAS) and total oxidant status (TOS). Apoptosis was evaluated using flow cytometry, and caspase-3 activity, a key marker of apoptosis, was assessed using caspase-3 immunofluorescence staining. Enoxaparin at 50, 100, and 200µM markedly increased cell viability in the enoxaparin + glutamate group. Enoxaparin treatment in the enoxaparin + glutamate group also significantly elevated levels of SOD and TAS, while concurrently decreasing MDA and TOS levels. These changes indicate a reduction in oxidative stress. Enoxaparin treatment further resulted in a significant decline in cleaved caspase-3 levels, a marker of apoptosis. Enoxaparin pre-treatment reduced cell death according to flow cytometry analysis. This study suggests enoxaparin's potential to shield C6 glioma cells from glutamate-induced cell death by mitigating both oxidative stress and apoptotic pathways. More research is needed to confirm this effect.

Impact of Chondrocyte Inflammation on Glial Cell Activation: The Mediating Role of Nitric Oxide.

This study investigates how the inflammatory response of ATDC5 murine chondrogenic cells influences the activity of C6 (rat) and GL261 (mouse) glial cell lines. Prior research suggested nitric oxide (NO) involvement in cartilage-immune crosstalk. The current study explores whether NO, produced by inflamed chondrocytes, mediates signaling between chondrocytes and glial cells. Pre-challenged ATDC5 cells with 250 ng/ml of lipopolysaccharide (LPS) were cocultured with GL261 or C6 glioma cells for 24 h with a transwell culture system. Cell viability was assessed using MTT assay. Gene and protein expression were evaluated by qRT-PCR and WB, respectively. Real-time reverse transcription-polymerase chain reaction (RT-qPCR) indicated statistically significant upregulation of LCN2, IL-6, TNF-α, IL-1β, and GFAP in glial cells following 24-h coculture with challenged ATDC5 cells. Suppression of LPS-induced NO production by aminoguanidine decreased LPS-mediated LCN2 and IL-6 expression in glioma cells. We identified also the involvement of the ERK1/2 and AKT signaling pathways in the glial neuroinflammatory response. This study demonstrates, for the first time, that NO produced by inflamed murine chondrocytes mediated pro-inflammatory responses in glial cells via ERK1/2 and AKT signaling, highlighting a potential mechanism linking cartilage NO to neuroinflammation and chronic pain in osteoarthritis.

IGF1R signaling in perinatal mesenchymal stem cells determines definitive hematopoiesis in bone marrow

During the transition from embryonic to adult life, the sites of hematopoiesis undergo dynamic shifts across various tissues. In adults, while bone marrow becomes the primary site for definitive hematopoiesis, the establishment of the bone marrow niche for accommodating hematopoietic stem cells (HSCs) remains incompletely understood. Here, we reveal that perinatal bone marrow mesenchymal stem cells (BMSCs) exhibit highly activated insulin-like growth factor 1 receptor (IGF1R) signaling compared to adult BMSCs. Deletion of Igf1r in perinatal BMSCs hinders the transition of HSCs from the fetal liver to the bone marrow in perinatal mice and disrupts hematopoiesis in adult individuals. Conversely, the deletion of Igf1r in adult BMSCs, adipocytes, osteoblasts, or endothelial cells does not affect HSCs in the bone marrow. Mechanistically, IGF1R signaling activates the transcription factor nuclear factor of activated T cells c1 (NFATc1) in perinatal BMSCs, which upregulates CXCL12 and other niche factors for HSC retention. Overall, IGF1R signaling in perinatal BMSCs regulates the development of the bone marrow niche for hematopoiesis.

Synthesis, Cytotoxicity, and Mechanistic Evaluation of Tetrahydrocurcumin-Amino Acid Conjugates as LAT1-Targeting Anticancer Agents in C6 Glioma Cells.

Glioblastoma, a fatal brain cancer with limited treatments and poor prognosis, could benefit from targeting the L-type amino acid transporter I (LAT1). LAT1 is essential for cancer cells to acquire necessary amino acids. Tetrahydrocurcumin (THC), a key curcumin derivative, shows potential for glioblastoma treatment. However, its effectiveness is hindered by poor physicochemical and pharmacokinetic properties. Therefore, this study aims to improve the therapeutic efficacy of THC against glioblastoma by chemically modifying it to target LAT1. A novel series of THC-amino acid conjugates were synthesized by conjugating five amino acids: glycine, leucine, isoleucine, and phenylalanine to THC via carbamate bonds. The therapeutic efficacy of THC-amino acid conjugates was further examined in C6 glioma cells, including the role of LAT1 in their therapeutic effects. Among the conjugates tested, THC conjugated with two phenylalanines (THC-di-Phe) showed remarkably higher cytotoxicity against C6 glioma cells (35.8 μM) compared to THC alone (110.7 μM). THC-di-Phe induced cellular death via necrosis and apoptosis, outperforming THC. Additionally, THC-di-Phe inhibited C6 cell proliferation and migration more effectively than THC. Co-incubation of THC-di-Phe with the LAT1 inhibitor 2-Aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) further increased cellular death. THC-di-Phe also significantly inhibited the P70SK/S6 pathway, regulated by LAT1 inhibitors, more effectively than THC and displayed a similar binding mode with both JX-075 and BCH to the active site of LAT1. Findings suggest the potential role of THC-di-Phe as a LAT1 inhibitor and provide novel insight into its use as a potent antitumor agent in glioma with increased therapeutic efficacy.

MELATONIN ENHANCES TEMOZOLOMIDE-INDUCED APOPTOSIS IN GLIOBLASTOMA AND NEUROBLASTOMA CELLS.

The combination of temozolomide (TMZ) and paclitaxel (PTX) is the most commonly used chemotherapy regimen for glioblastoma, but there is no specific treatment for neuroblastoma due to the acquired multidrug resistance. Approximately half of treated glioblastoma patients develop resistance to TMZ and experience serious side effects. Melatonin (MEL), a multifunctional hormone long known for its antitumor effects, has a great advantage in combination cancer therapy thanks to its ability to affect tumors differently than normal cells. This study aims to evaluate the in vitro inhibitory effects of MEL in combination with TMZ on cancer cell viability and to elucidate the underlying mechanisms in the glioblastoma and neuroblastoma cell lines. C6 (Rattus norvegicus) and N1E-115 (Mus musculus) cancer cell lines and C8-D1A (mice) healthy cell lines were used. Cell proliferation was evaluated using the MTT test. IC50 values were determined by probit analysis. Two concentrations of TMZ (IC50 and 1/2 IC50) were used to induce cytotoxicity in the C6 and N1E-115 cell lines, both alone and in combination with PXT and MEL (all at IC50). The viable, dead, and apoptotic cells were determined by image-based cytometry using Annexin V/PI staining. The gene expression related to signaling pathways was assessed by the quantitative reverse transcription polymerase chain reaction (qRT-PCR), and key proteins were identified by the Western blot analysis. MTT assay showed that the combination of TMZ and MEL significantly reduces the viability of both glioblastoma and neuroblastoma cells compared to the vehicle-treated controls. Notably, MEL combined with 1/2 IC50 TMZ showed a significant death rate of cancer cells compared to controls and PTX. According to qRT-PCR data, the TMZ + MEL combination resulted in the upregulation of the genes of antioxidative enzymes (Sod1 and Sod2) and DNA repair genes (Mlh1, Exo1, and Rad18) in both cell lines. Moreover, the levels of Nfkb1 and Pik3cg were significantly reduced following the TMZ + MEL treatment. The combination of MEL with TMZ also enhanced the cell cycle arrest and increased the expression of p53 and pro-apoptotic proteins (Bax and caspase-3), while significantly decreasing the expression of anti-apoptotic protein Bcl-2. Our findings indicate that the combination of MEL with a low dose of TMZ may serve as an upstream inducer of apoptosis. This suggests the potential development of a novel selective therapeutic strategy as an alternative to TMZ for the treatment of both glioblastoma and neuroblastoma.

Machine learning-based diagnostic prediction of minimal change disease: model development study

Minimal change disease (MCD) is a common cause of nephrotic syndrome. Due to its rapid progression, early detection is essential; however, definitive diagnosis requires invasive kidney biopsy. This study aims to develop non-invasive predictive models for diagnosing MCD by machine learning. We retrospectively collected data on demographic characteristics, blood tests, and urine tests from patients with nephrotic syndrome who underwent kidney biopsy. We applied four machine learning algorithms—TabPFN, LightGBM, Random Forest, and Artificial Neural Network—and logistic regression. We compared their performance using stratified 5-repeated 5-fold cross-validation for the area under the receiver operating characteristic curve (AUROC) and the area under the precision-recall curve (AUPRC). Variable importance was evaluated using the SHapley Additive exPlanations (SHAP) method. A total of 248 patients were included, with 82 cases (33%) were diagnosed with MCD. TabPFN demonstrated the best performance with an AUROC of 0.915 (95% CI 0.896–0.932) and an AUPRC of 0.840 (95% CI 0.807–0.872). The SHAP methods identified C3, total cholesterol, and urine red blood cells as key predictors for TabPFN, consistent with previous reports. Machine learning models could be valuable non-invasive diagnostic tools for MCD.

The Different Responsiveness of C3- and C5-deficient Murine BM Cells to Oxidative Stress Explains Why C3 Deficiency, in Contrast to C5 Deficiency, Correlates with Better Pharmacological Mobilization and Engraftment of Hematopoietic Cells.

The liver-derived circulating in peripheral blood and intrinsic cell-expressed complement known as complosome orchestrate the trafficking of hematopoietic stem/progenitor cells (HSPCs) both during pharmacological mobilization and homing/engraftment after transplantation. Our previous research demonstrated that C3 deficient mice are easy mobilizers, and their HSPCs engraft properly in normal mice. In contrast, C5 deficiency correlates with poor mobilization and defects in HSPCs' homing and engraftment. The trafficking of HSPCs during mobilization and homing/engraftment follows the sterile inflammation cues in the BM microenvironment caused by stress induced by pro-mobilizing drugs or myeloablative conditioning for transplantation. Therefore, to explain deficiencies in HSPC trafficking between C3-KO and C5-KO mice, we evaluated the responsiveness of C3 and C5 deficient cells to low oxidative stress. As reported, oxidative stress in BM is mediated by the activation of purinergic signaling, which is triggered by the elevated level of extracellular adenosine triphosphate (eATP) and by the activation of the complement cascade (ComC). In the current work, we noticed that BM lineage negative cells (lin-) isolated from C3-KO mice display several mitochondrial defects reflected by an impaired ability to adapt to oxidative stress. In contrast, C5-KO-derived BM cells show a high level of adaptation to this challenge. To support this data, C3-KO BM lin- cells were highly responsive to eATP stimulation, which correlates with enhanced levels of reactive oxygen species (ROS) generation and more efficient activation of intracellular Nlrp3 inflammasome. We conclude that the enhanced sensitivity of C3-KO mice cells to oxidative stress and better activation of the Nox2-ROS-Nlrp3 inflammasome signaling axis explains the molecular level differences in trafficking between C3- and C5-deficient HSPCs.

Therapeutic Effect of Boron Neutron Capture Therapy on Boronophenylalanine Administration via Cerebrospinal Fluid Circulation in Glioma Rat Models.

In recent years, various drug delivery systems circumventing the blood-brain barrier have emerged for treating brain tumors. This study aimed to improve the efficacy of brain tumor treatment in boron neutron capture therapy (BNCT) using cerebrospinal fluid (CSF) circulation to deliver boronophenylalanine (BPA) to targeted tumors. Previous experiments have demonstrated that boron accumulation in the brain cells of normal rats remains comparable to that after intravenous (IV) administration, despite BPA being administered via CSF at significantly lower doses (approximately 1/90 of IV doses). Based on these findings, BNCT was conducted on glioma model rats at the Kyoto University Research Reactor Institute (KUR), with BPA administered via CSF. This method involved implanting C6 cells into the brains of 8-week-old Wistar rats, followed by administering BPA and neutron irradiation after a 10-day period. In this study, the rats were divided into four groups: one receiving CSF administration, another receiving IV administration, and two control groups without BPA administration, with one subjected to neutron irradiation and the other not. In the CSF administration group, BPA was infused from the cisterna magna at 8 mg/kg/h for 2 h, while in the IV administration group, BPA was intravenously administered at 350 mg/kg via the tail vein over 1.5 h. Thermal neutron irradiation (5 MW) for 20 min, with an average fluence of 3.8 × 1012/cm2, was conducted at KUR's heavy water neutron irradiation facility. Subsequently, all of the rats were monitored under identical conditions for 7 days, with pre- and post-irradiation tumor size assessed through MRI and pathological examination. The results indicate a remarkable therapeutic efficacy in both BPA-administered groups (CSF and IV). Notably, the rats treated with CSF administration exhibited diminished BPA accumulation in normal tissue compared to those treated with IV administration, alongside maintaining excellent overall health. Thus, CSF-based BPA administration holds promise as a novel drug delivery mechanism in BNCT.

Local anesthetic tetracaine hydrochloride induces pyroptosis via caspase-3/gasdermin E in uveal melanoma

BackgroundEvasion of pyroptosis is an effective survival strategy employed by cancer cells to evade immune cell attacks and drug-induced cytotoxicity. Exploring potent molecules capable of inducing pyroptosis in cancer cells has significant clinical implications for the control of cancer progression. Unexpectedly, we found that the local anesthetic tetracaine hydrochloride (TTC) induced pyroptosis, specifically in uveal melanoma but not in acral or cutaneous melanoma. MethodsWe investigated the effects of TTC on various melanoma cell lines and performed transcriptome sequencing of TTC-treated uveal melanoma cells. The role of gasdermin E (GSDME), an executive protein responsible for pyroptosis, was explored using CRISPR-Cas13d knockdown, caspase-3 inhibitor treatment, and western blot analysis. Differential gene expression and pathway enrichment analyses were performed. Furthermore, we used tissue microarrays to assess GSDME expression levels in melanoma tissues from different anatomical sites. ResultsTTC significantly induced pyroptosis specifically in uveal melanoma cells with high GSDME expression levels. TTC treatment could lead to GSDME cleavage by the caspase-3 in uveal melanoma C918 cells. GSDME knockdown or caspase-3 inhibition suppressed TTC-induced pyroptosis. Transcriptome analysis revealed differentially expressed genes enriched in signaling pathways related to pyroptosis, immunity, and cytokines. ConclusionsThis study showed that the local anesthetic TTC effectively induces pyroptosis in uveal melanoma through the caspase-3/GSDME pathway, highlighting its potential application in immunotherapy. Notably, the use of TTC has potential as an agent for inducing pyroptosis and as an adjuvant anticancer therapy in uveal melanoma.