Search Results (53)

The poor clinical outcomes of pediatric high-grade glioma (pHGG) highlight the urgent need for new therapies. Oligodendrocyte lineage transcription factor 2 (OLIG2) is a pro-mitotic transcription factor highly expressed in glioma stem cells and may represent a novel therapeutic target. To evaluate the therapeutic efficacy of an OLIG2 inhibitor CT-179 in pHGG, we determined the OLIG2 mRNA expression in 10 patient-derived orthotopic xenograft (PDOX) models. In vitro activities of CT-179 were analyzed in monolayer and neurosphere cells (0–10 µM) with and without radiation (XRT) (0–8 Gy), brain penetration was evaluated in tumor-bearing PDOX mice, and in vivo efficacy was determined at 15–240 mg/kg (oral) alone or combined with XRT (2 Gy/day × 5 days). Changes in animal survival times were analyzed using the Kaplan–Meier method, followed by pair-wise comparisons. Increased OLIG2 mRNA expression was detected in seven out of ten PDOX models. CT-179 inhibited cell viability in a time- and dose-dependent manner in all eight pGBM xenograft tumors (IC₅₀ 0.03–10 µM) and was potentiated by XRT (0.03–1 µM). Oral gavage (24 mg/kg) of CT-179 for 5 days led to effective penetration in mouse cerebrum (3232.7 ± 569.2 ng/g), cerebellum (1563.3 ± 269.6 ng/g), brain stem (1685.3 ± 309 ng/g), and PDOX tumors (1814 ± 110.3 ng/g) vs. 361.3 ± 1.5 ng/mL in serum. CT-179 alone was not active at 200 mg/kg in four models, although it was moderately effective at 240 mg/kg in one model. When combined with XRT, a significant extension of animal survival times was observed in two out of four models. Doses needed to eliminate OLIG2 expression in vitro varied from 0.3 to >1 µM in pGBM cells. In summary, our data showed that orally administered CT-179 penetrated the blood–brain barrier (BBB) and exhibited potential for inhibiting pGBM growth when combined with XRT. Full article

Background: Low-fat diet (LFD) is widely applied in type 2 diabetes mellitus (T2DM), but the limited efficacy and difficulty in maintaining it hinder its wider promotion. Partially hydrolyzed guar gum (PHGG) is well-known as a probiotic in modulating gut microbiota, which is crucial in T2DM. However, the combined effects of LFD and PHGG remain unknown. Methods: Mice with T2DM were divided into 4 groups: T2DM control (DM-high-fat diet), LFD alone (DM-LFD), or LFD combined with low or high doses of PHGG (PHGG-L/H, 2.5% and 7.5% (w/w)) for 12 weeks. Serum lipid profiles, fasting blood glucose (FBG), HOMA-IR, and intraperitoneal glucose tolerance test (IPGTT) were assessed. Furthermore, microbiota composition, fecal metabolites, and fecal short-chain fatty acids (SCFAs) were determined by 16S rRNA gene sequencing, untargeted metabolomics, and gas chromatography-mass spectrometry, respectively. Results: LFD improved dyslipidemia but not glucose metabolism disorders. However, PHGG remarkably decreased FBG and HOMA-IR, and increased glucose tolerance. PHGG upregulated the abundance of SCFA-producing bacteria, including the genera Dubosiella, Bifidobacterium, and Ruminococcus, which were negatively correlated with FBG, HOMA-IR, and AUC (IPGTT). Moreover, the metabolic pathways altered by PHGG were enriched in tryptophan, tyrosine, and galactose metabolism. Fecal propionic acid and butyric acid, positively correlated with the abundance of genera Dubosiella and Ruminococcus, were markedly decreased by 50% and 44% in the DM-LFD group, but increased 2-fold after PHGG supplementation. Conclusions: PHGG combined with LFD might be a potential strategy to ameliorate glucose metabolic disorders, likely through modulating gut microbiota and the production of propionic acid and butyric acid. Full article

Pediatric-type diffuse high-grade gliomas (pHGGs) tend to have a dismal prognosis. Some of these gliomas feature alterations in genes such as ROS1, ALK, MET, and NTRK1–3. Despite development of targeted agents, the therapeutic application of these agents in pHGGs is still unclear. The aim of this retrospective case series is to report the outcome of two patients with pHGGs who were treated at Arkansas Children’s Hospital with targeted agents (Cabozantinib for a MET fusion in patient 1 and Lorlatinib for an ALK fusion in patient 2) with an initial, objective response followed by treatment resistance. Each diagnosis was determined based on histology, targeted tumor sequencing, and methylation profiling. In both cases, relapse occurred while on targeted inhibition. Recurrent tumor sequencing for patient 2 revealed a MET copy gain suggesting a mechanism of resistance in this patient. Pediatric high-grade gliomas with targetable alterations can show objective responses to pathway inhibition. Relapse after initial response may warrant additional surgical samples to identify new alterations which can lead to changes in therapy. Larger prospective cohorts are needed to study targeted agents in this population, and earlier integration of these agents may be beneficial. Full article

Pediatric high-grade glioma (pHGG) is a devastating group of childhood cancers associated with poor outcomes. Traditionally, diagnosis was based on histologic and immunohistochemical characteristics, including high mitotic activity, presence of necrosis, and presence of glial cell markers (e.g., GFAP). With advances in molecular tumor profiling, these tumors have been recategorized based on specific molecular findings that better lend themselves to prediction of treatment response and prognosis. pHGG is now categorized into four subtypes: H3K27-altered, H3G34-mutant, H3/IDH-WT, and infant-type high-grade glioma (iHGG). Molecular profiling has not only increased the specificity of diagnosis but also improved prognostication. Additionally, these molecular findings provide novel targets for individual tumor-directed therapy. While these therapies are largely still under investigation, continued investigation of distinct molecular markers in these tumors is imperative to extending event-free survival (EFS) and overall survival (OS) for patients with pHGG. Full article

Our previous study reported that male university rugby players tended to have a gut with a dysbiotic environment, characterized by abundant pathobiont bacteria and an accumulation of succinate, when compared with age-matched, non-rugby playing healthy males. In the present study, we conducted a randomized, double-blinded, placebo-controlled experiment to evaluate the potential of blackcurrant extract and/or partially hydrolyzed guar gum (PHGG) to improve the gut environment of university rugby players. Participants were supplemented with blackcurrant extract and/or PHGG or a placebo for 4 weeks. Beneficial gut bacteria such as Megasphaera spp. tended to increase (p < 0.10) and Bifidobacterium spp. increased (p < 0.05) with the intake of blackcurrant extract and/or PHGG. A subgroup analysis further indicated that, unlike in those with a eubiotic gut environment, the dietary supplements also increased the number of beneficial gut bacteria such as Phascolarctobacterium spp. (p < 0.10) and Faecalibacterium spp. (p < 0.10) and fecal SCFA concentrations (p < 0.05) in participants with a possible dysbiotic gut environment. However, a synergistic effect between blackcurrant extract and PHGG was not clearly observed. Although further investigation is recommended, it was concluded that blackcurrant extract and PHGG can at least be used as functional materials to improve gut dysbiosis in university rugby players. Full article

Pediatric high-grade gliomas (pHGGs), particularly diffuse midline gliomas (DMGs), are among the most lethal brain tumors due to poor survival and resistance to therapies. DMGs possess a distinct genetic profile, primarily driven by hallmark mutations such as H3K27M, ACVR1, and PDGFRA mutations/amplifications and TP53 inactivation, all of which contribute to tumor biology and therapeutic resistance. Developing physiologically relevant preclinical models that replicate both tumor biology and the tumor microenvironment (TME) is critical for advancing effective treatments. This review highlights recent progress in in vitro, ex vivo, and in vivo models, including patient-derived brain organoids, genetically engineered mouse models (GEMMs), and region-specific midline organoids incorporating SHH, BMP, and FGF2/8/19 signaling to model pontine gliomas. Key genetic alterations can now be introduced using lipofectamine-mediated transfection, PiggyBac plasmid systems, and CRISPR-Cas9, allowing the precise study of tumor initiation, progression, and therapy resistance. These models enable the investigation of TME interactions, including immune responses, neuronal infiltration, and therapeutic vulnerabilities. Future advancements involve developing immune-competent organoids, integrating vascularized networks, and applying multi-omics platforms like single-cell RNA sequencing and spatial transcriptomics to dissect tumor heterogeneity and lineage-specific vulnerabilities. These innovative approaches aim to enhance drug screening, identify new therapeutic targets, and accelerate personalized treatments for pediatric gliomas. Full article

Background: Pediatric high-grade glioma (pHGG) is a highly aggressive cancer with unique biology distinct from adult high-grade glioma, limiting the effectiveness of standard treatment protocols derived from adult research. Objective: The purpose of this report is to present preliminary results from an ongoing pilot study integrating spectroscopic magnetic resonance imaging (sMRI) to guide proton beam therapy and longitudinal imaging analysis in pediatric patients with high-grade glioma (pHGG). Methods: Thirteen pediatric patients under 21 years old with supratentorial WHO grade III-IV glioma underwent baseline and serial whole-brain spectroscopic MRI alongside standard structural MRIs. Radiation targets were defined using T1-weighted contrast enhanced, T2-FLAIR, and Cho/NAA ≥ 2X maps. Longitudinal analyses included voxel-level metabolic change maps and spatial overlap metrics comparing pre-proton therapy and post-. Results: Six patients had sufficient longitudinal data; five received sMRI-guided PBT. Significant positive correlation (R² = 0.89, p < 0.0001) was observed between T2-FLAIR and Cho/NAA ≥ 2X volumes. Voxel-level difference maps of Cho/NAA and Choline revealed dynamic metabolic changes across follow-up scans. Analyzing Cho/NAA and Cho changes over time allowed differentiation between true progression and pseudoprogression, which conventional MRI alone struggles to achieve. Conclusions: Longitudinal sMRI enhanced metabolic tracking in pHGG, detects early tumor changes, and refines RT targeting beyond structural imaging. This first in-kind study highlights the potential of sMRI biomarkers in tracking treatment effects and emphasizes the complementary roles of metabolic and radiographic metrics in evaluating therapy response in pHGG. Full article

Pediatric gliomas encompass the most common brain tumor in children and are subdivided into pediatric low-grade gliomas (pLGGs) and pediatric high-grade gliomas (pHGGs). The era of molecular diagnosis has shifted the treatment paradigms and management of these patients. RAS/MAPK pathway alterations serve as the driver in the majority of pLGGs, a subset of pHGG and NF1-related plexiform neurofibromas (PNs). The role of small molecule inhibitors in the treatment of these tumors has evolved in the past decade, facilitated through multiple clinical trials and moving into earlier stages of treatment. Although these developments hold promise, questions remain regarding targeted therapy, the long-term toxicities, the duration of treatment and the potential effects on the natural history of the tumor behavior. Full article

Primary central nervous system tumors are the most frequent solid tumors in children, accounting for over 40% of all childhood brain tumor deaths, specifically high-grade gliomas. Compared with pediatric low-grade gliomas (pLGGs), pediatric high-grade gliomas (pHGGs) have an abysmal survival rate. The WHO CNS classification identifies four subtypes of pHGGs, including Grade 4 Diffuse midline glioma H3K27-altered, Grade 4 Diffuse hemispheric gliomas H3-G34-mutant, Grade 4 pediatric-type high-grade glioma H3-wildtype and IDH-wildtype, and infant-type hemispheric gliomas. In recent years, we have seen promising advancements in treatment strategies for pediatric high-grade gliomas, including immunotherapy, CAR-T cell therapy, and vaccine approaches, which are currently undergoing clinical trials. These therapies are underscored by the integration of molecular features that further stratify HGG subtypes. Herein, we will discuss the molecular features of pediatric high-grade gliomas and the evolving landscape for treating these challenging tumors. Full article

Pediatric high-grade glioma (pHGG) encompasses a wide range of gliomas with different genomic, epigenomic, and transcriptomic features. Almost 50% of pHGGs present a mutation in genes coding for histone 3, including the subtype harboring the H3.3-G34 mutation. In this context, histone mutations are frequently associated with mutations in TP53 and ATRX, along with PDGFRA and NOTCH2NL amplifications. Moreover, the H3.3-G34 histone mutation induces epigenetic changes in immune-related genes and exerts modulatory functions on the microenvironment. Also, the functionality of the blood–brain barrier (BBB) has an impact on treatment response. The prognosis remains poor with conventional treatments, thus eliciting the investigation of additional and alternative therapies. Promising molecular targets include PDGFRA amplification, BRAF mutation, EGFR amplification, NF1 loss, and IDH mutation. Considering that pHGGs harboring the H3.3-G34R mutation appear to be more susceptible to immunotherapies (ITs), different options have been recently explored, including immune checkpoint inhibitors, antibody mediated IT, and Car-T cells. This review aims to summarize the knowledge concerning cancer biology and cancer-immune cell interaction in this set of pediatric gliomas, with a focus on possible therapeutic options. Full article

Pediatric high-grade gliomas (pHGG) are malignant and usually fatal central nervous system (CNS) WHO Grade 4 tumors. The majority of pHGG consist of diffuse midline gliomas (DMG), H3.3 or H3.1 K27 altered, or diffuse hemispheric gliomas (DHG) (H3.3 G34-mutant). Due to diffuse tumor infiltration of eloquent brain areas, especially for DMG, surgery has often been limited and chemotherapy has not been effective, leaving fractionated radiation to the involved field as the current standard of care. pHGG has only been classified as molecularly distinct from adult HGG since 2012 through Next-Generation sequencing approaches, which have shown pHGG to be epigenetically regulated and specific tumor sub-types to be representative of dysregulated differentiating cells. To translate discovery research into novel therapies, improved pre-clinical models that more adequately represent the tumor biology of pHGG are required. This review will summarize the molecular characteristics of different pHGG sub-types, with a specific focus on histone K27M mutations and the dysregulated gene expression profiles arising from these mutations. Current and emerging pre-clinical models for pHGG will be discussed, including commonly used patient-derived cell lines and in vivo modeling techniques, encompassing patient-derived xenograft murine models and genetically engineered mouse models (GEMMs). Lastly, emerging techniques to model CNS tumors within a human brain environment using brain organoids through co-culture will be explored. As models that more reliably represent pHGG continue to be developed, targetable biological and genetic vulnerabilities in the disease will be more rapidly identified, leading to better treatments and improved clinical outcomes. Full article

Partially hydrolyzed guar gum (PHGG) is a water-soluble, prebiotic fiber that is used in foods and supplements. The effects of PHGG and its role in gut health are still being studied. The purpose of this study was to evaluate changes in the gut microbiome composition of healthy individuals in response to low-dose PHGG supplementation compared with a low fiber diet. A randomized, double-blind, placebo-controlled crossover study was performed on 33 healthy subjects (17 males, 16 females). Each subject completed three 14-day treatment periods with a 2-week washout between each period. Treatments included supplementation with 3 g PHGG, 6 g PHGG, or a placebo. During all periods, the participants followed a low fiber diet (≤14 g/day). Stools were collected on days 0 and 14 of each period. Gut microbiome profiling was performed using 16S rRNA sequencing. Stools were assessed by investigators with the Bristol Stool Form Scale as a secondary outcome. Saliva cortisol was also measured as a secondary outcome. Supplementation of 3 g and 6 g PHGG significantly increased Verrucomicrobia on day 14 when compared to the placebo (p = 0.0066 and p = 0.0068, respectively). On the genus level, Akkermansia was significantly increased on day 14 with both the 3 g and 6 g PHGG doses (p = 0.0081 and p = 0.0083). Faecalibacterium was significantly decreased on day 14 with 3 g PHGG (p = 0.0054). Supplementing with low doses of PHGG has the potential to cause shifts in the gut microbiome composition. By increasing beneficial microbes, PHGG can improve the microbiome composition of healthy individuals and may play a role in the treatment of inflammatory gastrointestinal diseases. Full article

The consumption of functional foods in a daily diet is a promising approach for the maintenance of cognitive health. The present study examines the effects of water-soluble prebiotic dietary-fiber, partially hydrolyzed guar gum (PHGG), on cognitive function and mental health in healthy elderly individuals. Participants consumed either 5 g/day of PHGG or a placebo daily for 12 weeks in this randomized, double-blind, placebo-controlled, and parallel-group study. An assessment of cognitive functions, sleep quality, and subjective mood evaluations was performed at baseline and after 8 and 12 weeks of either PHGG or placebo intake. The visual memory scores in cognitive function tests and sleepiness on rising scores related to sleep quality were significantly improved in the PHGG group compared to the placebo group. No significant differences were observed in mood parameters between the groups. Vigor–activity scores were significantly improved, while the scores for Confusion–Bewilderment decreased significantly in the PHGG group when compared to the baseline. In summary, supplementation with PHGG was effective in improving cognitive functions, particularly visual memory, as well as enhancing sleep quality and vitality in healthy elderly individuals (UMIN000049070). Full article

Partially hydrolyzed guar gum (PHGG) is a soluble dietary fiber that is effective for defecation control. It influences the gut microbiota, by which it is metabolized to yield short-chain fatty acids (SCFAs), and it was also recently shown to protect against influenza infection in humans. We here investigated the effects of PHGG in a mouse model of influenza H1N1 virus infection. Eight-week-old C57BL/6 mice were fed normal chow with or without PHGG (500 mg/kg per day) for 4 weeks, infected with H1N1 at 10 weeks of age, and analyzed at 12 weeks of age. Administration of PHGG attenuated the decline in body weight induced by H1N1 infection without affecting food intake. It also ameliorated intestinal atrophy and increased the production of SCFAs including acetic acid, propionic acid, and butyric acid in the cecum, thereby preventing the inhibitory effect of H1N1 infection on SCFA production. The H1N1-induced increases in the serum concentrations of inflammatory cytokines including interferon-γ and interleukin-6 and anti-inflammatory cytokine such as interleukin-10 were all inhibited by PHGG intake. In addition, PHGG administration attenuated inflammatory gene expression in the lung and promoted both natural killer cell activity and regulatory T-cell differentiation in the spleen. Our findings suggest that the consumption of PHGG may improve the gut environment and thereby limit the inflammatory response to H1N1 infection. They may thus provide the basis for novel dietary intervention strategies to suppress the excessive inflammation associated with virus infection. Full article

Pediatric high-grade gliomas (pHGGs) are common malignant brain tumors without effective treatment and poor patient survival. Abnormal posttranslational modification at the histone H3 tail plays critical roles in tumor cell malignancy. We have previously shown that the trimethylation of lysine 4 at histone H3 (H3K4me3) plays a significant role in pediatric ependymoma malignancy and is associated with tumor therapeutic sensitivity. Here, we show that H3K4me3 and its methyltransferase WDR82 are elevated in pHGGs. A reduction in H3K4me3 by downregulating WDR82 decreases H3K4me3 promoter occupancy and the expression of genes associated with stem cell features, cell proliferation, the cell cycle, and DNA damage repair. A reduction in WDR82-mediated H3K4me3 increases the response of pediatric glioma cells to chemotherapy. These findings suggest that WDR82-mediated H3K4me3 is an important determinant of pediatric glioma malignancy and therapeutic response. This highlights the need for a more thorough understanding of the potential of WDR82 as an epigenetic target to increase therapeutic efficacy and improve the prognosis for children with malignant gliomas. Full article