Isocitrate Dehydrogenase Research Articles

FOXM1 requires IDH1 for late genes expression in mitotic cells.

Isocitrate dehydrogenase 1 (IDH1) is a metabolic enzyme that converts isocitrate to α-ketoglutarate in cells. However, research on IDH1 is more focused on the metabolite D-2-hydroxyglutarate than the cellular roles of the IDH1 protein. Metabolic enzymes can moonlight by participating in diverse cellular processes in cancer cells. This moonlighting function of the metabolic enzymes can contribute to changes in gene expression. It is unknown whether IDH1 associates with any transcription factor. We asked whether IDH1 coordinates with forkhead box protein M1 (FOXM1) in mitotic cells to regulate late genes expression. We found that depletion of IDH1 reduces canonical FOXM1-target expression in mitotic cells. Also, IDH1 binds to FOXM1 and a subset of MuvB proteins, Lin-9 and Lin-54, in mitotic cells. Based on these observations, we suggest that IDH1 coordinates with FOXM1 in mitotic cells to regulate late genes expression.

Symptomatic spinal metastasis of a supratentorial glioblastoma in a pediatric patient: a case report and comprehensive review of the literature

Spinal metastasis of Glioblastoma is a rare occurrence, especially in pediatric patients, and extremely rare to become symptomatic. The pathology is poorly understood and remains with unclear dissemination mechanisms. The treatment approaches are varied and multimodal therapy (surgery, chemotherapy, and radiotherapy) can be employed to manage this type of metastasis. We report a case of a 17-year-old female who underwent a gross-total resection of a right frontal glioblastoma and had adjuvant therapy with chemo- and radiotherapy. In the sixth month of follow-up, the patient presented a paraparesis, and a distant recurrence at T7-T8 was detected. The patient was treated with gross-total resection of the tumor through a laminectomy. The histopathological results were consistent with an isocitrate dehydrogenase (IDH) wildtype GBM metastasis. The patient was treated with multimodal therapy, including surgery, radiotherapy, and chemotherapy. A complementary comprehensive review of current available literature on this topic is also presented.

Histopathological Spectrum of Gliomas and Its Immunohistochemical Correlation in a Tertiary Care Setup.

Introduction Central nervous system (CNS) tumors pose significant diagnostic challenges due to their varied morphological and differentiating characteristics. Modern advancements in immunohistochemistry (IHC) and molecular pathology have greatly enhanced prognostication, screening, and therapeutic management. Gliomas, a type of tumor originating from glial cells in the CNS, can develop from astrocytes, oligodendrocytes, or ependymal cells. According to the 2021 update, the classification of diffuse gliomas is primarily based on the presence or absence of isocitrate dehydrogenase (IDH1/2) mutations. IDH-wildtype gliomas (glioblastomas) have a significantly poorer prognosis compared to IDH-mutant gliomas (astrocytomas and oligodendrogliomas). Gliomas are highly infiltrative and resistant to treatment, making them largely incurable regardless of their grade and prognosis. Objective This study aimed to determine the histopathological diversity of gliomas and its correlation with protein expressions of IDH, ATRX gene (α-thalassemia/mental retardation syndrome X-linked), Ki-67, and p53 mutations (tumor suppressor gene-53), according to the 2021 World Health Organization (WHO) Classification of CNS Tumors, Fifth Edition. Methods This descriptive cross-sectional study was carried out in the Department of Pathology at a tertiary care center, focusing on various types of gliomas received over a two-year period. A total of 54 specimens of gliomas received from the Department of Neurosurgery were subjected to histopathological examination. Sections were stained using hematoxylin and eosin (H&E), and IHC was performed using four markers (IDH, ATRX, p53, Ki-67) in each case. Results were analyzed according to the 2021 WHO Classification of CNS Tumors, Fifth Edition. Results The majority of individuals were between the age group of 40 and 60 years, showing a male predominance (65%). The most common site was the frontal lobe. Glioblastoma constituted the largest proportion (46.2%) of the total cases, followed by astrocytoma (20.3%), oligodendroglioma (18.5%), pilocytic astrocytoma (7.4%), and ependymoma (7.4%). All 11 cases of astrocytoma exhibited IDH mutation and ATRX loss, with p53 positive in the majority of cases. Strong nuclear p53 immunohistochemical positivity in >10% of tumor nuclei correlates with TP53 mutations. Among 25 cases of glioblastoma, IDH was negative, ATRX was retained in all cases, and 11 cases were positive for p53 mutation. For oligodendroglioma, out of 10 cases, IDH mutation was positive, and ATRX was retained in all cases. p53 mutation was not seen in any case. All cases of pilocytic astrocytoma were negative for IDH and p53 mutations, with ATRX retained in all cases. In all cases of ependymoma, IDH and p53 mutations were negative, and ATRX was retained in all cases. Glioblastomas exhibited the highest Ki-67 expression. Conclusion The 2021 WHO Classification of CNS Tumors, Fifth Edition, was updated, building on previously established concepts and continuing to evolve. The final diagnosis of gliomas relies on a comprehensive combination of clinical evaluation, neuroimaging, pathological examination, and molecular analysis. Nonetheless, histopathological examination, along with IHC, remains the cornerstone of diagnosis.

PARP inhibitor therapy in patients with IDH1 mutated cholangiocarcinoma.

Isocitrate dehydrogenase 1 (IDH1) missense mutations occur at a frequency of 10%-15% in intrahepatic cholangiocarcinoma (iCCA). IDH1 mutations result in accumulation of (R)-2-hydroxyglutarate, an oncometabolite that leads to DNA hypermethylation and impairment of homologous recombination (HR). Impairment of HR results in a "BRCAness" phenotype which may confer sensitivity to poly(ADP ribose) polymerase (PARP) inhibition. We conducted a retrospective cohort review to identify patients with advanced, IDH1 mutated iCCA treated with a PARP inhibitor (PARPi) at the University of Michigan between 2018 and 2023. Patients are described with respect to prior lines of therapy, response to platinum-based chemotherapy, and progression-free survival (PFS) and overall survival (OS) from the time of PARPi initiation. Between 2018 and 2023 we identified 40 patients with IDH1 mutated iCCA of which 6 patients were treated with a PARPi as monotherapy or in combination with an ATR inhibitor or anti-PD-1 immune checkpoint inhibitor. Majority of patients (n = 5) carried an IDH1 R132C mutation per tissue-based next generation sequencing. All patients had previously received at least one line of cisplatin-based systemic therapy for advanced disease prior to treatment with PARPi. PFS and OS from time of PARPi initiation ranged from 1.4 to 18.5 months and 2.8 to 42.4 months, respectively. Best response on PARPi therapy included 2 partial responses. This is the first case series to describe PARPi treatment in IDH1 mutated iCCA. Results underscore the limitation of PARPi monotherapy, potentially support combined PARPi therapies, and highlight a need for effective treatment options for patients with IDH1 mutated iCCA.

Direct Itaconate Production from Brown Macroalgae Using Engineered Vibrio sp. dhg.

Itaconate is a promising platform chemical with broad applicability, including the synthesis of poly(methyl methacrylate). Most studies on microbial itaconate production entail the use of crop-based feedstock, which imposes constraints due to its limited supply. Brown macroalgae have recently gained attention as next-generation biomass owing to their high biomass productivity and carbohydrate content and amenability to mass production. Therefore, the use of macroalgae for itaconate production warrants exploration. In this study, the direct production of itaconate from brown macroalgae was demonstrated using engineered Vibrio sp. dhg, which has emerged as an efficient platform host for brown macroalgal biorefineries. Specifically, to enhance production, cis-aconitate decarboxylase (Cad) from Aspergillus terreus was heterologously expressed and isocitrate dehydrogenase (icd) was deleted. Notably, the resulting strain, VIC, achieved itaconate titers of 2.5 and 1.5 g/L from a mixture of alginate and mannitol (10 g/L of each) and 40 g/L of raw Saccharina japonica (S. japonica), respectively. Overall, this study highlights the utility of brown macroalgae as feedstock, as well as that of Vibrio sp. dhg as a platform strain for improving itaconate bioproduction.

Mutations in glioblastoma proteins do not disrupt epitope presentation and recognition, maintaining a specific CD8 T cell immune response potential

Antigen-specific cytotoxic CD8 T cells are extremely effective in controlling tumor growth and have been the focus of immunotherapy approaches. We leverage in silico tools to investigate whether the occurrence of mutations in proteins previously described as immunogenic and highly expressed by glioblastoma multiforme (GBM), such as Epidermal Growth Factor Receptor (EGFR), Isocitrate Dehydrogenase 1 (IDH1), Phosphatase and Tensin homolog (PTEN) and Tumor Protein 53 (TP53), may be contributing to the differential presentation of immunogenic epitopes. We recovered Class I MHC binding information from wild-type and mutated proteins using the Immune Epitope Database (IEDB). After that, we built peptide-MHC (pMHC-I) models in HLA-arena, followed by hierarchical clustering analysis based on electrostatic surface features from each complex. We identified point mutations that are determinants for the presentation of a set of peptides from TP53 protein. We point to structural features in the pMHC-I complexes of wild-type and mutated peptides, which may play a role in the recognition of CD8 T cells. To further explore these features, we performed 100 ns molecular dynamics simulations for the peptide pairs (wt/mut) selected. In pursuit of novel therapeutic targets for GBM treatment, we selected peptides where our predictive results indicated that mutations would not disrupt epitope presentation, thereby maintaining a specific CD8 T cell immune response. These peptides hold potential for future GBM interventions, including peptide-based or mRNA vaccine development applications.

Clinical Implications of Isocitrate Dehydrogenase Mutations and Targeted Treatment of Acute Myeloid Leukemia with Mutant Isocitrate Dehydrogenase Inhibitors-Recent Advances, Challenges and Future Prospects.

Despite the better understanding of the molecular mechanisms contributing to the pathogenesis of acute myeloid leukemia (AML) and improved patient survival in recent years, AML therapy still remains a clinical challenge. For this reason, it is important to search for new therapies that will enable the achievement of remission. Recently, the Food and Drug Administration approved three mutant IDH (mIDH) inhibitors for the treatment of AML. However, the use of mIDH inhibitors in monotherapy usually leads to the development of resistance and the subsequent recurrence of the cancer, despite the initial effectiveness of the therapy. A complete understanding of the mechanisms by which IDH mutations influence the development of leukemia, as well as the processes that enable resistance to mIDH inhibitors, may significantly improve the efficacy of this therapy through the use of an appropriate synergistic approach. The aim of this literature review is to present the role of IDH1/IDH2 mutations in the pathogenesis of AML and the results of clinical trials using mIDH1/IDH2 inhibitors in AML and to discuss the challenges related to the use of mIDH1/IDH2 inhibitors in practice and future prospects related to the potential methods of overcoming resistance to these agents.

Roles of α-1,3-glucosyltransferase in growth and polysaccharides biosynthesis of Ganoderma lucidum

Ganoderma lucidum polysaccharides are valuable natural compounds possessing significant biological activity, with glycosyltransferases playing a crucial role in their biosynthesis. Although the function of β-1,3-glucosyltransferase in polysaccharides production is well understood, the role of α-1,3-glucosyltransferase in edible fungi remains unclear. In this study, over-expression of the α-1,3-glucosyltransferase gene in G. lucidum (glagt) was found to suppress the growth, with the maximum biomass and mycelial growth rate decreasing by 21.78 % and 79.61 %, respectively, a behavior distinct from β-1,3-glucosyltransferase. The fungal pellet diameter decreased by 38 % and the cell-wall thickness by 32.44 %, whereas intracellular and extracellular polysaccharides production increased by 27.58 % and 66.08 %, respectively. In the transcription level, overexpressing the glagt gene i) downregulated the citrate synthase and isocitrate dehydrogenase gene in the TCA cycle, disrupting energy metabolism and fungal growth; ii) upregulated key enzymes involved in UDP-glucose synthesis and glycosyltransferases (gl24465, gl24971, and gl22535); and iii) universally increased the transcriptional level of glucosidases gl21451, gl30087, and gl24581 by 22 %–397 %, contributing to cell-wall thinning to facilitate polysaccharides export. Conversely, the glagt gene downregulation promoted G. lucidum growth and decreased polysaccharides production. The results elucidate the roles of GLAGT and are expected to inspire in-depth exploration of polysaccharides biosynthesis pathways.

Metabolic engineering of Komagataella phaffii for the efficient utilization of methanol

BackgroundKomagataella phaffii, a type of methanotrophic yeast, can use methanol, a favorable non-sugar substrate in eco-friendly bio-manufacturing. The dissimilation pathway in K. phaffii leads to the loss of carbon atoms in the form of CO2. However, the ΔFLD strain, engineered to lack formaldehyde dehydrogenase—an essential enzyme in the dissimilation pathway—displayed growth defects when exposed to a methanol-containing medium.ResultsInhibiting the dissimilation pathway triggers an excessive accumulation of formaldehyde and a decline in the intracellular NAD+/NADH ratio. Here, we designed dual-enzyme complex with the alcohol oxidase1/dihydroxyacetone synthase1 (Aox1/Das1), enhancing the regeneration of the formaldehyde receptor xylulose-5-phosphate (Xu5P). This strategy mitigated the harmful effects of formaldehyde accumulation and associated toxicity to cells. Concurrently, we elevated the NAD+/NADH ratio by overexpressing isocitrate dehydrogenase in the TCA cycle, promoting intracellular redox homeostasis. The OD600 of the optimized combination of the above strategies, strain DF02-1, was 4.28 times higher than that of the control strain DF00 (ΔFLD, HIS4+) under 1% methanol. Subsequently, the heterologous expression of methanol oxidase Mox from Hansenula polymorpha in strain DF02-1 resulted in the recombinant strain DF02-4, which displayed a growth at an OD600 4.08 times higher than that the control strain DF00 in medium containing 3% methanol.ConclusionsThe reduction of formaldehyde accumulation, the increase of NAD+/NADH ratio, and the enhancement of methanol oxidation effectively improved the efficient utilization of a high methanol concentration by strain ΔFLD strain lacking formaldehyde dehydrogenase. The modification strategies implemented in this study collectively serve as a foundational framework for advancing the efficient utilization of methanol in K. phaffii.

Idh-1 neomorphic mutation confers sensitivity to vitamin B12 in Caenorhabditis elegans.

In humans, a neomorphic isocitrate dehydrogenase mutation (idh-1neo) causes increased levels of cellular D-2-hydroxyglutarate (D-2HG), a proposed oncometabolite. However, the physiological effects of increased D-2HG and whether additional metabolic changes occur in the presence of an idh-1neo mutation are not well understood. We created a Caenorhabditis elegans model to study the effects of the idh-1neo mutation in a whole animal. Comparing the phenotypes exhibited by the idh-1neo to ∆dhgd-1 (D-2HG dehydrogenase) mutant animals, which also accumulate D-2HG, we identified a specific vitamin B12 diet-dependent vulnerability in idh-1neo mutant animals that leads to increased embryonic lethality. Through a genetic screen, we found that impairment of the glycine cleavage system, which generates one-carbon donor units, exacerbates this phenotype. In addition, supplementation with alternate sources of one-carbon donors suppresses the lethal phenotype. Our results indicate that the idh-1neo mutation imposes a heightened dependency on the one-carbon pool and provides a further understanding of how this oncogenic mutation rewires cellular metabolism.

Incorporation of Edited MRS into Clinical Practice May Improve Care of Patients with IDH-Mutant Glioma.

Isocitrate dehydrogenase (IDH) mutation and 1p/19q codeletion classify adult-type diffuse gliomas into 3 tumor subtypes with distinct prognoses. We aimed to evaluate the performance of edited MR spectroscopy for glioma subtyping in a clinical setting, via the quantification of D-2-hydroxyglutarate (2HG) and cystathionine. The delay between this noninvasive classification and the integrated histomolecular analysis was also quantified. Subjects with presumed low-grade gliomas eligible for surgery (cohort 1) and subjects with IDH-mutant gliomas previously treated and with progressive disease (cohort 2) were prospectively examined with a single-voxel Mescher-Garwood point-resolved spectroscopy sequence at 3T. Spectra were quantified using LCModel. The Cramér-Rao lower bounds threshold was set to 20%. Integrated histomolecular analysis according to the 2021 WHO classification was considered as ground truth. Thirty-four consecutive subjects were enrolled. Due to poor spectra quality and lack of histologic specimens, data from 26 subjects were analyzed. Twenty-one belonged to cohort 1 (11 women; median age, 42 years); and 5, to cohort 2 (3 women; median age, 48 years). Edited MR spectroscopy showed 100% specificity for detection of IDH-mutation and 91% specificity for the prediction of 1p/19q-codeletion status. Sensitivities for the prediction of IDH and 1p/19q codeletion were 69% and 33%, respectively. The median Cramér-Rao lower bounds values were 16% (13%-28%) for IDH-mutant and 572% (554%-999%) for IDH wild type tumors. The time between MR spectroscopy and surgery was longer for low-grade than for high-grade gliomas (P = .03), yet the time between MR spectroscopy and WHO diagnosis did not differ between grades (P = .07), possibly reflecting molecular analyses-induced delays in high-grade gliomas. Our results, acquired in a clinic setting, confirmed that edited MR spectroscopy is highly specific for both IDH-mutation and 1p/19q-codeletion predictions and can provide a faster prognosis stratification. In the upcoming IDH-inhibitor treatment era, incorporation of edited MR spectroscopy into clinical workflow is desirable.

Mutant IDH1 inhibition induces dsDNA sensing to activate tumor immunity.

Isocitrate dehydrogenase 1 (IDH1) is the most commonly mutated metabolic gene across human cancers. Mutant IDH1 (mIDH1) generates the oncometabolite (R)-2-hydroxyglutarate, disrupting enzymes involved in epigenetics and other processes. A hallmark of IDH1-mutant solid tumors is T cell exclusion, whereas mIDH1 inhibition in preclinical models restores antitumor immunity. Here, we define a cell-autonomous mechanism of mIDH1-driven immune evasion. IDH1-mutant solid tumors show selective hypermethylation and silencing of the cytoplasmic double-stranded DNA (dsDNA) sensor CGAS, compromising innate immune signaling. mIDH1 inhibition restores DNA demethylation, derepressing CGAS and transposable element (TE) subclasses. dsDNA produced by TE-reverse transcriptase (TE-RT) activates cGAS, triggering viral mimicry and stimulating antitumor immunity. In summary, we demonstrate that mIDH1 epigenetically suppresses innate immunity and link endogenous RT activity to the mechanism of action of a US Food and Drug Administration-approved oncology drug.

Stanniocalcin-2 expression in glioblastoma - A novel prognostic biomarker: An observational study.

The objective of this study was to assess the prognostic relevance of Stanniocalcin-2 (STC2) expression, as determined via immunohistochemistry in tumor tissue, in a cohort of 83 patients diagnosed with glioblastoma who underwent maximal safe surgical resection followed by radiotherapy concurrent with adjuvant temozolomide. STC2 expression levels were categorized using a 3-tiered semiquantitative system: negative expression (level 0-), low expression (level 1+), and high expression (levels 2 + and 3+). Patients were categorized into 2 distinct groups according to their STC2 expression levels: negative STC2 (-/+) and positive STC2 (++/+++). The primary outcome measure was the relationship between STC2 expression and progression-free survival (PFS), with overall survival (OS) serving as the secondary endpoint. Kaplan-Meier survival analysis confirmed that patients exhibiting high STC2 expression had significantly shorter OS (8 vs 20 months, P < .001) and PFS (6 vs 18 months, P < .001) than those with low or negative STC2 expression. Multivariate analysis revealed that STC2 expression was an independent prognostic factor for both OS (hazard ratio: 0.4; 95% confidence interval: 0.2-0.8; P < .05) and PFS (hazard ratio: 0.3; 95% confidence interval: 0.2-0.4; P < .05) in patients with glioblastoma. Furthermore, elevated STC2 expression in GBM was correlated with several established aggressive clinicopathological characteristics, including advanced age (≥65 years), low ECOG PS (≥2), and isocitrate dehydrogenase mutation negativity. These findings underscore that heightened STC2 expression within the tumor tissue of GBM patients functions as an adverse prognostic marker, correlating with an elevated risk of progression and reduced OS. Therapeutic interventions targeting the AKT-mTOR, ERK1-2, and mitogen-activated protein kinase pathways as well as immune checkpoint inhibitors and vascular endothelial growth factor blockade, as well as potential forthcoming antibody-drug conjugates targeting the STC2 molecule, have the potential to broaden the scope of combined treatment strategies.

Non-invasive detection of IDH-1 mutation in brain gliomas based on proton MR spectroscopy

Mutations of isocitrate dehydrogenase (IDH) have important prognostic significance for patients with glial brain tumor. The method of proton MR spectroscopy makes it possible to non-invasively determine the metabolic properties of the tumor tissue at the preoperative stage. The aim of this work was to study the possibility of determining the IDH status, by using magnetic resonance spectroscopy (MRS) to detect the 2-hydroxyglutarate (2HG), a metabolic product of the IDH enzyme. We examined 33 patients with glial tumors varying degrees of malignancy (Gr. 2–4), followed by identification of IDH mutations. IDH mutation identified in 20 cases, according to proton magnetic resonance spectroscopy, was confirmed by immunohistochemistry. Peak of 2HG did not detect in 13 cases on the MR spectrum, and the analysis for IDH did not reveal mutations. Using of proton magnetic resonance spectroscopy showed a high sensitivity of this technique in predicting the mutational status of glial brain tumors, which makes this method an important in preoperative diagnostics.

IDH1-mutant metabolite D-2-hydroxyglutarate inhibits proliferation and sensitizes glioma to temozolomide via down-regulating ITGB4/PI3K/AKT

The heterogeneous molecular subtypes of gliomas demonstrate varied responses to chemotherapy and distinct prognostic outcomes. Gliomas with Isocitrate dehydrogenase 1 (IDH1) mutation are associated with better outcomes and are more responsive to temozolomide (TMZ) compared to those without IDH1 mutation. IDH1-mutant gliomas elevate D-2-hydroxyglutarate (D-2HG) levels, with potential dual effects on tumor progression. Limited research has explored the potential anti-glioma effects of D-2HG in combination with TMZ. Clinical data from over 2500 glioma patients in our study confirms that those with IDH1 mutations exhibit enhanced responsiveness to TMZ chemotherapy and a significantly better prognosis compared to IDH1 wild-type patients. In subsequent cellular experiments, we found that the IDH1-mutant metabolite D-2HG suppresses Integrin subunit beta 4 (ITGB4) expression, and down-regulate the phosphorylation levels of PI3K and AKT, ultimately inhibiting cell proliferation while promoting apoptosis, thereby improving glioma prognosis. Additionally, we have demonstrated the synergistic effect of D-2HG and TMZ in anti-glioma therapy involved inhibiting the proliferation of glioma cells and promoting apoptosis. Finally, by integrating data from the CGGA and TCGA databases, it was validated that ITGB4 expression was lower in IDH1-mutant gliomas, and patients with lower ITGB4 expression were associated with better prognosis. These findings indicate that ITGB4 may be a promising therapeutic target for gliomas and D-2HG inhibits proliferation and sensitizes glioma to temozolomide via down-regulating ITGB4/PI3K/AKT. These findings drive theoretical innovation and research progress in glioma therapy.

T2-FLAIR Mismatch Sign Predicts DNA Methylation Subclass and CDKN2A/B Status in IDH-Mutant Astrocytomas.

DNA methylation profiling stratifies isocitrate dehydrogenase (IDH)-mutant astrocytomas into methylation low- and high-grade groups. We investigated the utility of the T2-fluid-attenuated inversion recovery (T2-FLAIR) mismatch sign for predicting DNA methylation grade and cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) homozygous deletion, a molecular biomarker for grade 4 IDH-mutant astrocytomas, according to the 2021 World Health Organization classification. Preoperative MRI scans of IDH-mutant astrocytomas subclassified by DNA methylation profiling (n = 71) were independently evaluated by two radiologists for the T2-FLAIR mismatch sign. The diagnostic utility of T2-FLAIR mismatch in predicting methylation grade, CDKN2A/B status, copy number variation, and survival was analyzed. The T2-FLAIR mismatch sign was present in 21 of 45 (46.7%) methylation low-grade and 1 of 26 (3.9%) methylation high-grade cases (P < 0.001), resulting in 96.2% specificity, 95.5% positive predictive value, and 51.0% negative predictive value for predicting low methylation grade. The T2-FLAIR mismatch sign was also significantly associated with intact CDKN2A/B status (P = 0.028) with 87.5% specificity, 86.4% positive predictive value, and 42.9% negative predictive value. Overall multivariable Cox analysis showed that retained CDKN2A/B status remained significant for progression-free survival (P = 0.01). Multivariable Cox analysis of the histologic grade 3 subset, which was nearly evenly divided by CDKN2A/B status, copy number variation, and methylation grade, showed trends toward significance for DNA methylation grade with overall survival (P = 0.045) and CDKN2A/B status with progression-free survival (P = 0.052). The T2-FLAIR mismatch sign is highly specific for low methylation grade and intact CDKN2A/B in IDH-mutant astrocytomas.

Nano-Se exhibits limited protective effect against heat stress induced poor breast muscle meat quality of broilers compared with other selenium sources

BackgroundAt present, heat stress (HS) has become a key factor that impairs broiler breeding industry, which causes growth restriction and poor meat quality of broilers. Selenium (Se) is an excellent antioxidant and plays a unique role in meat quality improvement. Recent years, nano-selenium (NanoSe) has received tremendous attention in livestock production, due to its characteristic and good antibacterial performance in vitro. Here, we developed the heat stressed-broiler model to investigate the protective effects of NanoSe on growth performance and meat quality of broilers and compare whether there are differences with that of other Se sources (Sodium selenite, SS; Selenoyeast, SeY; Selenomethionine, SeMet).ResultsHS jeopardized the growth performance and caused poor meat quality of breast muscle in broilers, which were accompanied by lowered antioxidant capacity, increased glycolysis, increased anaerobic metabolism of pyruvate, mitochondrial stress and abnormal mitochondrial tricarboxylic acid (TCA) cycle. All Se sources supplementation exhibited protective effects, which increased the Se concentration and promoted the expression of selenoproteins, improved the mitochondrial homeostasis and the antioxidant capacity, and promoted the TCA cycle and the aerobic metabolism of pyruvate, thus improved the breast muscle meat quality of broilers exposed to HS. However, unlike the other three Se sources, the protective effect of NanoSe on meat quality of heat stressed-broilers was not ideal, which exhibited limited impact on the pH value, drip loss and cooking loss of the breast muscle. Compared with the other Se sources, broilers received NanoSe showed the lowest levels of slow MyHC, the highest levels of fast MyHC and glycogen, the highest mRNA levels of glycolysis-related genes (PFKM and PKM), the highest protein expression of HSP60 and CLPP, and the lowest enzyme activities of GSH-Px, citroyl synthetase (CS) and isocitrate dehydrogenase (ICD) in breast muscle. Consistent with the SS, the Se deposition in breast muscle of broilers received NanoSe was lower than that of broilers received SeY or SeMet. Besides, the regulatory efficiency of NanoSe on the expression of key selenoproteins (such as SELENOS) in breast muscle of heat stressed-broilers was also worse than that of other Se sources.ConclusionThrough comparing the meat quality, Se deposition, muscle fiber type conversion, glycolysis, mitochondrial homeostasis, and mitochondrial TCA cycle-related indicators of breast muscle in heat stressed broilers, we found that the protective effects of organic Se (SeY and SeMet) are better than that of inorganic Se (SS) and NanoSe. As a new Se source, though NanoSe showed some protective effect on breast muscle meat quality of heat stressed broilers, the protective effect of NanoSe is not ideal, compared with other Se sources.

Systemic Candida abscess after hypofractionated radiotherapy with temozolomide for glioblastoma in an older patient: illustrative case.

Hypofractionated radiotherapy with temozolomide is recommended for older patients with glioblastoma. Nevertheless, a potential complication of treatment is opportunistic infections with immunosuppression. An 86-year-old man presented with hemiparesis, prompting an investigation that revealed a right frontotemporal glioblastoma, isocitrate dehydrogenase wildtype. After the diagnostic biopsy, hypofractionated radiotherapy with temozolomide was administered. Lymphocytopenia was observed before the start of chemoradiotherapy and gradually worsened until 2 months later, possibly as a side effect of the treatment. One month after the completion of the initial treatment, the patient developed septic shock, leading to death within 2 days. Postmortem examination with autopsy revealed evidence of an invasive Candida infection possibly originating from the urinary catheter. Immunodeficiency, which is a side effect of radiation therapy with temozolomide, can cause rare and potentially fatal invasive Candida infections, especially in older and frail patients with newly diagnosed glioblastoma, even with short-term hypofractionated chemoradiotherapy. https://thejns.org/doi/10.3171/CASE24175.

3D-QSAR, Scaffold Hopping, Virtual Screening, and Molecular Dynamics Simulations of Pyridin-2-one as mIDH1 Inhibitors.

Isocitrate dehydrogenase 1 (IDH1) is a necessary enzyme for cellular respiration in the tricarboxylic acid cycle. Mutant isocitrate dehydrogenase 1 (mIDH1) has been detected overexpressed in a variety of cancers. mIDH1 inhibitor ivosidenib (AG-120) was only approved by the Food and Drug Administration (FDA) for marketing, nevertheless, a range of resistance has been frequently reported. In this study, several mIDH1 inhibitors with the common backbone pyridin-2-one were explored using the three-dimensional structure-activity relationship (3D-QSAR), scaffold hopping, absorption, distribution, metabolism, excretion (ADME) prediction, and molecular dynamics (MD) simulations. Comparative molecular field analysis (CoMFA, R2 = 0.980, Q2 = 0.765) and comparative molecular similarity index analysis (CoMSIA, R2 = 0.997, Q2 = 0.770) were used to build 3D-QSAR models, which yielded notably decent predictive ability. A series of novel structures was designed through scaffold hopping. The predicted pIC50 values of C3, C6, and C9 were higher in the model of 3D-QSAR. Additionally, MD simulations culminated in the identification of potent mIDH1 inhibitors, exhibiting strong binding interactions, while the analyzed parameters were free energy landscape (FEL), radius of gyration (Rg), solvent accessible surface area (SASA), and polar surface area (PSA). Binding free energy demonstrated that C2 exhibited the highest binding free energy with IDH1, which was -93.25 ± 5.20 kcal/mol. This research offers theoretical guidance for the rational design of novel mIDH1 inhibitors.

PET imaging of gliomas: Status quo and quo vadis?

PET imaging, particularly using amino acid tracers, has become a valuable adjunct to anatomical MRI in the clinical management of patients with glioma. Collaborative international efforts have led to the development of clinical and technical guidelines for PET imaging in gliomas. The increasing readiness of statutory health insurance agencies, especially in European countries, to reimburse amino acid PET underscores its growing importance in clinical practice. Integrating artificial intelligence and radiomics in PET imaging of patients with glioma may significantly improve tumor detection, segmentation, and response assessment. Efforts are ongoing to facilitate the clinical translation of these techniques. Considerable progress in computer technology developments (eg quantum computers) may be helpful to accelerate these efforts. Next-generation PET scanners, such as long-axial field-of-view PET/CT scanners, have improved image quality and body coverage and therefore expanded the spectrum of indications for PET imaging in Neuro-Oncology (eg PET imaging of the whole spine). Encouraging results of clinical trials in patients with glioma have prompted the development of PET tracers directing therapeutically relevant targets (eg the mutant isocitrate dehydrogenase) for novel anticancer agents in gliomas to improve response assessment. In addition, the success of theranostics for the treatment of extracranial neoplasms such as neuroendocrine tumors and prostate cancer has currently prompted efforts to translate this approach to patients with glioma. These advancements highlight the evolving role of PET imaging in Neuro-Oncology, offering insights into tumor biology and treatment response, thereby informing personalized patient care. Nevertheless, these innovations warrant further validation in the near future.