scholarly journals Gene of the month: IDH1

2020 ◽  
Vol 73 (10) ◽  
pp. 611-615
Author(s):  
Cassandra Bruce-Brand ◽  
Dhirendra Govender

Isocitrate dehydrogenase 1 (IDH1) encodes a protein which catalyses the oxidative decarboxylation of isocitrate to α-ketoglutarate. Mutant IDH1 favours the production of 2-hydroxyglutarate, an oncometabolite with multiple downstream effects which promote tumourigenesis. IDH1 mutations have been described in a number of neoplasms most notably low-grade diffuse gliomas, conventional central and periosteal cartilaginous tumours and cytogenetically normal acute myeloid leukaemia. Post zygotic somatic mutations of IDH1 characterise the majority of cases of Ollier disease and Maffucci syndrome. IDH1 mutations are uncommon in epithelial neoplasia but have been described in cholangiocarcinoma.

2013 ◽  
Vol 34 (2) ◽  
pp. E2 ◽  
Author(s):  
Gavin P. Dunn ◽  
Ovidiu C. Andronesi ◽  
Daniel P. Cahill

The characterization of the genomic alterations across all human cancers is changing the way that malignant disease is defined and treated. This paradigm is extending to glioma, where the discovery of recurrent mutations in the isocitrate dehydrogenase 1 (IDH1) gene has shed new light on the molecular landscape in glioma and other IDH-mutant cancers. The IDH1 mutations are present in the vast majority of low-grade gliomas and secondary glioblastomas. Rapidly emerging work on the consequences of mutant IDH1 protein expression suggests that its neomorphic enzymatic activity catalyzing the production of the oncometabolite 2-hydroxyglutarate influences a range of cellular programs that affect the epigenome, transcriptional programs, hypoxia-inducible factor biology, and development. In the brief time since its discovery, knowledge of the IDH mutation status has had significant translational implications, and diagnostic tools are being used to monitor its expression and function. The concept of IDH1-mutant versus IDH1-wild type will become a critical early distinction in diagnostic and treatment algorithms.


2018 ◽  
Vol 475 (20) ◽  
pp. 3221-3238 ◽  
Author(s):  
Diego Avellaneda Matteo ◽  
Grace A. Wells ◽  
Lucas A. Luna ◽  
Adam J. Grunseth ◽  
Olga Zagnitko ◽  
...  

Mutations in isocitrate dehydrogenase 1 (IDH1) drive most low-grade gliomas and secondary glioblastomas and many chondrosarcomas and acute myeloid leukemia cases. Most tumor-relevant IDH1 mutations are deficient in the normal oxidization of isocitrate to α-ketoglutarate (αKG), but gain the neomorphic activity of reducing αKG to D-2-hydroxyglutarate (D2HG), which drives tumorigenesis. We found previously that IDH1 mutants exhibit one of two reactivities: deficient αKG and moderate D2HG production (including commonly observed R132H and R132C) or moderate αKG and high D2HG production (R132Q). Here, we identify a third type of reactivity, deficient αKG and high D2HG production (R132L). We show that R132Q IDH1 has unique structural features and distinct reactivities towards mutant IDH1 inhibitors. Biochemical and cell-based assays demonstrate that while most tumor-relevant mutations were effectively inhibited by mutant IDH1 inhibitors, R132Q IDH1 had up to a 16 300-fold increase in IC50 versus R132H IDH1. Only compounds that inhibited wild-type (WT) IDH1 were effective against R132Q. This suggests that patients with a R132Q mutation may have a poor response to mutant IDH1 therapies. Molecular dynamics simulations revealed that near the NADP+/NADPH-binding site in R132Q IDH1, a pair of α-helices switches between conformations that are more wild-type-like or more mutant-like, highlighting mechanisms for preserved WT activity. Dihedral angle changes in the dimer interface and buried surface area charges highlight possible mechanisms for loss of inhibitor affinity against R132Q. This work provides a platform for predicting a patient's therapeutic response and identifies a potential resistance mutation that may arise upon treatment with mutant IDH inhibitors.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi173-vi173
Author(s):  
Donghyun Hong ◽  
Noriaki Minami ◽  
Céline Taglang ◽  
Georgios Batsios ◽  
Anne Marie Gillespie ◽  
...  

Abstract Gliomas are the most prevalent type of brain tumor in the central nervous system. Mutations in the cytosolic enzyme isocitrate dehydrogenase 1 (IDH1) are a common feature of primary low-grade gliomas, catalyzing the conversion of α-ketoglutarate (αKG) to the oncometabolite 2-hydroxyglutarate (2HG), and mutant IDH1 is a therapeutic target for these tumors. Several mutant IDH inhibitors are currently in clinical trials, nonetheless, complementary non-invasive early biomarkers to assess drug delivery and potential therapeutic response are still needed. The goal of this study was therefore to determine the potential of 1H and hyperpolarized 13C magnetic resonance spectroscopy (MRS)-based biomarkers as indicators of mutant IDH1 low-grade glioma response to treatment with the clinically-relevant IDH1 inhibitor BAY-1436032 in cells and animal models. Immortalized human astrocytes engineered to express mutant IDH1 were treated with 500nM (IC50 value) of BAY-1436032 and BT257 tumors implanted in rats were treated with 150mg/kg of BAY-1436032. To assess steady-state metabolite levels, 1H MRS spectra were acquired on a 500 MHz MRS cancer for cells and a 3 T scanner for animal studies. To assess metabolic fluxes, we used hyperpolarized 13C MRS and probed the fate of hyperpolarized [1-13C]αKG. 1H MRS showed a significant decrease in 2HG as well as a significant increase in glutamate (Glu) and phosphocholine (PCh) following BAY-1436032 treatment in both cell and animal models compared to controls. Furthermore, hyperpolarized 13C MRS showed that hyperpolarized 2HG production from hyperpolarized [1-13C]αKG was decreased and hyperpolarized glutamate production from hyperpolarized [1-13C]αKG was increased in the BAY-1436032 treated groups compared to controls. These findings are consistent with our previous study, which investigated the MRS-detectable consequences of two other mutant IDH inhibitors: AG120 and AG881. Collectively, our work identifies translatable MRS-based metabolic biomarkers of mutant IDH1 inhibition.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi208-vi208
Author(s):  
Amrita Sule ◽  
Ranjit Bindra

Abstract Mutations in the Isocitrate Dehydrogenase-1 and -2 (IDH1/2) genes occur in the vast majority of low-grade and secondary high-grade gliomas. These neomorphic mutations occur early on in gliomagenesis leading to the production of 2-Hydroxyglutarate (2HG). 2HG has been implicated in tumorigenesis via inhibiting α-ketoglutarate (αKG)-dependent dioxygenases. Our group recently demonstrated that the production of 2HG suppresses the high-fidelity homologous recombination (HR) DNA repair pathway, resulting in a state of “BRCAness”. We initially found that mutant IDH1/2-induced BRCAness confers exquisite sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors, a finding which now has been replicated by multiple independent laboratories. Although IDH1/2 mutations were first identified in gliomas and acute myeloid leukemia (AML) cells, multiple other tumor types have subsequently been shown to harbor these mutations. Current clinical trials are testing the efficacy of PARP inhibitors as a monotherapy, as well as in combination with other DNA repair inhibitors. Here, we demonstrate that novel combinations of DNA repair inhibitors can be utilized to synergistically target IDH1/2-mutant glioma cells. In particular, we demonstrate potent synergy with ATRi and PARPis, a finding which was validated in multiple structurally unique drugs within these classes. As this combination is active in BRCA1/2-mutant cancers, in particular after the emergence of PARPi resistance, these data suggest are consistent with an underlying HR defect in IDH1/2-mutant gliomas. These preclinical investigations will provide a blueprint for future clinical trials combining PARP and ATR inhibitors in the treatment of glioblastoma.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 2504-2504 ◽  
Author(s):  
Ingo K. Mellinghoff ◽  
Katherine B. Peters ◽  
Timothy Francis Cloughesy ◽  
Howard A. Burris III ◽  
Elizabeth Anne Maher ◽  
...  

2504 Background: Isocitrate dehydrogenase 1 and 2 mutations (m IDH1/2) occur in approximately 70% and 4% of low-grade gliomas (LGGs), respectively, promoting oncogenesis via increased production of D-2-hydroxyglutarate. In this ongoing phase 1 trial, VOR, a potent, oral, reversible, brain-penetrant, first-in-class dual inhibitor of mIDH1/2, is being evaluated in advanced m IDH1/2 solid tumors, including gliomas. Safety and preliminary results were presented previously (Mellinghoff et al., J Clin Oncol 2018). Here, we report updated data for the non-enhancing glioma pt population. Methods: Pts with recurrent/progressive m IDH1/2 glioma received VOR daily (continuous 28-day cycles). Key eligibility criteria included: ≥18 years; histologically or cytologically confirmed glioma with documented m IDH1/2; ECOG 0-2; and evaluable disease by RANO-LGG criteria. Dose escalation cohorts enrolled using a Bayesian logistic regression model (BLRM) escalation guided by the overdose control (EWOC). Tumor response was evaluated by MRI every 8 weeks using RANO-LGG criteria by local assessment. Results: As of 28 Nov 2019, 22 pts with non-enhancing glioma had received VOR and 8 (36%) remain on treatment. M/F, 8/14; grade 2/3, 17/5; median age, 47 years; m IDH1/2, 20/1; 1p19q intact, 9/22; median (range) number of prior systemic therapies, 2 (1–4). Common (≥5 pts) treatment-emergent adverse events (AEs) of any grade and regardless of causality included increased ALT/AST (63.6%/59.1%), headache (45.5%), nausea (40.9%), neutropenia (31.8%), fatigue and hyperglycemia (27.3% each), and seizures and decreased white blood cell count (22.7% each). Transaminase elevations were grade 1 in severity at dose levels < 100mg and were less frequent (5 [38.5%] of 13 pts). Three subjects had related grade ≥3 AEs; 2 discontinued due to AEs. Objective response rate was 13.6% (1 partial response, 2 minor responses), and 17 (77.3%) pts achieved stable disease. 60.5% of pts were progression free and alive at 24 months. Conclusions: In this previously treated population with non-enhancing glioma, VOR was associated with a favorable safety profile. The study results also show encouraging preliminary activity within that population, with PFS duration extending to 24 months or longer in 60% of participants. A global randomized phase 3 study of VOR in grade 2 non-enhancing glioma pts who have had surgery only is currently enrolling (NCT04164901). Clinical trial information: NCT02481154 .


2021 ◽  
Vol 70 (1) ◽  
pp. 83-97
Author(s):  
Remco J. Molenaar ◽  
Johanna W. Wilmink

Isocitrate dehydrogenase 1 and 2 (IDH1/2) are enzymes recurrently mutated in various types of cancer, including glioma, cholangiocarcinoma, chondrosarcoma, and acute myeloid leukemia. Mutant IDH1/2 induce a block in differentiation and thereby contribute to the stemness and oncogenesis of their cells of origin. Recently, small-molecule inhibitors of mutant IDH1/2 have been Food and Drug Administration–approved for the treatment of IDH1/2-mutated acute myeloid leukemia. These inhibitors decrease the stemness of the targeted IDH1/2-mutated cancer cells and induce their differentiation to more mature cells. In this review, we elucidate the mechanisms by which mutant IDH1/2 induce a block in differentiation and the biological and clinical effects of the release into differentiation by mutant-IDH1/2 inhibitors. (J Histochem Cytochem 70:83–97, 2022)


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Anja Karlstaedt ◽  
Xiaotian Zhang ◽  
Hernan Vasquez ◽  
Margaret A Goodell ◽  
Heinrich Taegtmeyer

Mutations in isocitrate dehydrogenase 1 and 2 (IDH1, IDH2) have been described in low-grade glioma and in acute myeloid leukemia. Accumulation of the oncometabolite D-2-hydroxyglutaric acid (2HG) and its release into the blood is associated with dilated cardiomyopathy. The mechanisms leading to changes in cardiac metabolism and contractile function are unknown. We studied in the isolated working rat heart preparation metabolic consequences of increased 2HG supply and its impact on cardiac energy provision. In combination with physiological levels of glucose (5mM) and lactate (0.5mM), hearts were perfused at different concentrations with 2HG (0.5mM, 1.0mM). We confirmed the uptake and enrichment of 2HG in the tissue through liquid chromatography followed by mass spectrometry (LC/MS). 2HG markedly decreased cardiac power and cardiac efficiency in a concentration dependent manner. At the same time glucose oxidation increased significantly (1.4±0.1 μmol/min/g dry wt, p<0.05) at higher workloads. The alpha-Ketoglutarate Dehydrogenase activity was reduced by two-fold (2.84±0.56 μmol/min/g dry wt, p<0.01) and production of reactive oxygen species (e.g. H2O2) increased by three-fold (1.06±0.07 μmol/min/g dry wt, p<0.01) in presence of 2HG. Consistent with this reduction in oxidative decarboxylation, the cytosolic NAD+/NADH redox state increased (3.1±0.1, p<0.001), while the cellular energy charge declined (AMP:ATP ratio, 0.15±0.1, p<0.001). Together, our results demonstrate a direct impairment of cardiac energy substrate metabolism with a resulting decline in contractile function. The data suggests that 2HG directly suppresses cardiac function by specific metabolic alterations in a range of pathologies.


Author(s):  
Navya Kalidindi ◽  
Rosemarylin Or ◽  
Sam Babak ◽  
Warren Mason

ABSTRACT:Technological advances in the field of molecular genetics have improved the ability to classify brain tumors into subgroups with distinct clinical features and important therapeutic implications. The World Health Organization’s newest update on classification of gliomas (2016) incorporated isocitrate dehydrogenase 1 and 2 mutations, ATRX loss, 1p/19q codeletion status, and TP53 mutations to allow for improved classification of glioblastomas, low-grade and anaplastic gliomas. This paper reviews current advances in the understanding of diffuse glioma classification and the impact of molecular markers and DNA methylation studies on survival of patients with these tumors. We also discuss whether the classification and grading of diffuse gliomas should be based on histological findings, molecular markers, or DNA methylation subgroups in future iterations of the classification system.


2019 ◽  
Vol 131 (6) ◽  
pp. 1829-1834 ◽  
Author(s):  
Takahide Nejo ◽  
Shota Tanaka ◽  
Masako Ikemura ◽  
Masashi Nomura ◽  
Shunsaku Takayanagi ◽  
...  

Maffucci syndrome (MS) and Ollier disease (OD) are nonhereditary congenital diseases characterized by multiple enchondromas and/or chondrosarcomas. Recent studies have implicated somatic mosaic mutations of isocitrate dehydrogenase 1 or 2 (IDH1/2) as contributing to the pathogenesis of MS and OD. Occasionally, patients with these disorders may also present with central nervous system (CNS) tumors; however, detailed genetic analyses are limited. In this article, the authors report on a male patient with MS, harboring three CNS tumors that share a common genetic alteration. Over a 9-year period, three separate tumor resections were conducted for sellar, intraparenchymal brainstem, and osseous clival tumors. The histopathological diagnoses were pituitary adenoma, diffuse astrocytoma, and chondrosarcoma, respectively. Sanger sequencing revealed a common IDH1 R132C mutation among all three CNS tumors but not in blood DNA. Administering chemotherapy (nimustine) and subsequent radiation therapy to the brainstem glioma and the residual lesion in the clivus have kept the patient progression free for 18 months. This is the first report demonstrating an IDH1 mutation shared among three different CNS tumors in a single patient with MS. The findings support the hypothesis that in MS and OD, a single common IDH1 mutation triggers tumorigenesis in cells of different origins and locations in a somatic mosaic fashion.


2011 ◽  
Vol 64 (10) ◽  
pp. 850-852 ◽  
Author(s):  
Young-Ho Kim ◽  
Daniela Pierscianek ◽  
Michel Mittelbronn ◽  
Anne Vital ◽  
Luigi Mariani ◽  
...  

BackgroundMiscoding mutations of the TET2 gene, which encodes the α-ketoglutarate-dependent enzyme that catalyses the conversion of 5-methylcytosine to 5-hydroxymethylcytosine, thus producing DNA demethylation, have been detected in 10–25% of acute myeloid leukaemias lacking IDH1/2 mutations. Most low-grade diffuse gliomas carry IDH1/2 mutations (>85%), but molecular mechanisms of pathogenesis in those lacking IDH1/2 mutations remain to be elucidated.MethodsMiscoding mutations and promoter methylation of the TET2 gene were screened for in 29 low-grade diffuse gliomas lacking IDH1/2 mutations.ResultsSingle-strand conformational polymorphism followed by direct sequencing showed the absence of miscoding mutations in TET2. Methylation-specific PCR revealed methylation of the TET2 promoter in 5 of 35 cases (14%). In contrast, none of 38 low-grade diffuse gliomas with IDH1/2 mutations had TET2 promoter methylation (p=0.0216).ConclusionResults suggest that TET2 promoter methylation, but not TET2 mutation, may be an alternative mechanism of pathogenesis in a small fraction of low-grade diffuse gliomas lacking IDH1/2 mutations.


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