Recurring mutations found by sequencing an acute myeloid leukemia genome

Epigenetic regulation of ferroptosis in gastrointestinal cancers (Review)

Ferroptosis is a type of iron‑dependent cell death characterized by excessive lipid peroxidation and may serve as a potential therapeutic target in cancer treatment. While the mechanisms governing ferroptosis continue to be explored and elucidated, an increasing body of research highlights the significant impact of epigenetic modifications on the sensitivity of cancer cells to ferroptosis. Epigenetic processes, such as DNA methylation, histone modifications and non‑coding RNAs, have been identified as key regulators that modulate the expression of ferroptosis‑related genes. These alterations can either enhance or inhibit the sensitivity of gastrointestinal cancer (GIC) cells to ferroptosis, thereby affecting the fate of GICs. Drugs that target epigenetic markers for advanced‑stage cancer have shown promising results in enhancing ferroptosis and inhibiting tumor growth. This review explores the intricate relationship between epigenetic regulation and ferroptosis in GICs. Additionally, the potential of leveraging epigenetic modifications to trigger ferroptosis in GICs is investigated. This review highlights the importance of further research to elucidate the specific mechanisms underlying epigenetic control of ferroptosis and to advance the development of novel therapeutic approaches.

Advances in IDH-mutant glioma management: IDH inhibitors, clinical implications of INDIGO trial, and future perspectives

The discovery of isocitrate dehydrogenase (IDH) mutation in gliomas marked the new era of molecular classification of CNS tumors. Understanding the complex role of IDH mutation in oncogenesis led to the evaluation of novel small molecules targeting this enzyme as a potential therapeutic intervention. Vorasidenib, a brain-penetrant inhibitor of both IDH1 and IDH2-mutant enzymes, was one such agent. The phase 3 INDIGO trial evaluated vorasidenib and demonstrated its efficacy in IDH-mutant low-grade gliomas (LGG). This study established vorasidenib as an effective inhibitor of both IDH1 and IDH2-mutant enzymes, highlighting its great potential in advancing the therapeutic armamentarium for patients with LGG. While vorasidenib has been recently included in several treatment guidelines for CNS tumors, further research on the use of this novel agent, as monotherapy or in combination with other drugs, becomes imperative to exploit fully its potential in the management of IDH-mutant gliomas.

Deconvoluting clonal and cellular architecture in IDH-mutant acute myeloid leukemia

Isocitrate dehydrogenase 1/2 (IDH) mutations are early initiating events in acute myeloid leukemia (AML). The complex clonal architecture and cellular heterogeneity in IDH-mutant AML underlies the heterogeneous clinical presentation and outcomes. Integrating single-cell genotyping and transcriptomics, we demonstrate a stem-like and inflammatory phenotype of IDH-mutant AML and identify clone-specific programs associated with NPM1, NRAS, and SRSF2 co-mutations. Furthermore, these clones had distinct responses to treatment with combination IDH inhibitors and chemotherapy, including elimination, reconstitution of myeloid differentiation, or retention within progenitor populations. At relapse after IDH inhibitor monotherapy, we identify upregulated stemness, inflammation, mitochondrial metabolism, and anti-apoptotic factors, as well as downregulated major histocompatibility complex (MHC) class II antigen presentation. At the pre-leukemic stage, we observe upregulation of IDH2-associated pathways, including inflammation. We deliver a detailed phenotyping of IDH-mutant AML and a framework for dissecting contributions of recurrently mutated genes in AML at diagnosis and following therapy, with implications for precision medicine.

Metabolism in hematology: Technological advances open new perspectives on disease biology and treatment

The term metabolism refers to the multi-faceted biochemical reactions within a cell or an organism that occur to maintain energy homeostasis, cell growth, and oxidative balance. Cells possess a high metabolic plasticity, allowing them to adapt to the dynamic requirements of their functional state and environment. Deregulated cellular metabolism is a hallmark of many diseases, including benign and malignant hematological conditions. In the last decade, multiple technological innovations in the metabolism field have made in-depth metabolic analysis broadly applicable. Such studies are shedding new light on normal and malignant hematopoiesis and open avenues to a better understanding of the biology of hematological diseases. In this review, we will first give a brief overview of central metabolic processes. Furthermore, we discuss the most commonly used methods to study metabolism. We begin by elaborating on the use of next-generation sequencing to detect metabolism-related genomic mutations and study transcriptional signatures. Furthermore, we discuss methods for measuring protein expression, such as mass spectrometry (MS), flow cytometry, and cytometry time-of-flight. Next, we describe the use of nuclear magnetic resonance spectroscopy, MS, and flow cytometry for metabolite quantification. Finally, we highlight functional assays to probe metabolic pathways in real-time. We illustrate how these technologies and their combination have advanced our understanding of the role of metabolism. Our goal is to provide hematologists with a comprehensive guide to modern techniques in metabolism research, their benefits and disadvantages, and how they guide our understanding of disease and potentially future personalized therapy decisions.

Acute Myeloid Leukemia: 2025 Update on Diagnosis, Risk-Stratification, and Management

DISEASE OVERVIEW

Acute myeloid leukemia (AML) is a bone marrow stem cell cancer that is often fatal despite available treatments. Diagnosis, risk assessment, monitoring, and therapeutic management of AML have changed dramatically in the last decade due to increased pathophysiologic understanding, improved assessment technology, and the addition of at least 12 approved therapies.

DIAGNOSIS

The diagnosis is based on the presence of immature leukemia cells in the blood, and/or bone marrow or less often in extra-medullary tissues. New biological insights have been integrated into recent classification systems.

RISK ASSESSMENT

The European Leukemia Network has published risk classification algorithms for both intensively and non-intensively treated patients based on cytogenetic and on molecular findings. Prognostic factors may differ based on the therapeutic approach.

MONITORING

Our increasing ability to quantify lower levels of measurable residual disease (MRD) potentially allows better response assessment, as well as dynamic monitoring of disease status. The incorporation of MRD findings into therapeutic decision-making is rapidly evolving.

RISK ADAPTED THERAPY

The availability of 12 newly approved agents has been welcomed; however, optimal strategies incorporating newer agents into therapeutic algorithms are debated. The overarching approach integrates patient and caregiver goals of care, comorbidities, and disease characteristics.

Understanding and Targeting Metabolic Vulnerabilities in Acute Myeloid Leukemia: An Updated Comprehensive Review

Acute Myeloid Leukemia (AML) is characterized by aggressive proliferation and metabolic reprogramming that support its survival and resistance to therapy. This review explores the metabolic distinctions between AML cells and normal hematopoietic stem cells (HSCs), emphasizing the role of altered mitochondrial function, oxidative phosphorylation (OXPHOS), and biosynthetic pathways in leukemic progression. AML cells exhibit distinct metabolic vulnerabilities, including increased mitochondrial biogenesis, reliance on glycolysis and amino acid metabolism, and unique signaling interactions that sustain leukemic stem cells (LSCs). These dependencies provide potential therapeutic targets, as metabolic inhibitors have demonstrated efficacy in disrupting AML cell survival while sparing normal hematopoietic cells. We examine current and emerging metabolic therapies, such as inhibitors targeting glycolysis, amino acid metabolism, and lipid biosynthesis, highlighting their potential in overcoming drug resistance. However, challenges remain in translating these strategies into clinical practice due to AML's heterogeneity and adaptability. Further research into AML's metabolic plasticity and precision medicine approaches is crucial for improving treatment outcomes. Understanding and exploiting AML's metabolic vulnerabilities could pave the way for novel, more effective therapeutic strategies.

CD44-mediated metabolic rewiring is a targetable dependency of IDH-mutant leukemia

ABSTRACT

Recurrent isocitrate dehydrogenase (IDH) mutations catalyze nicotinamide adenine dinucleotide phosphate (NADPH)-dependent production of oncometabolite (R)-2-hydroxyglutarate (R-2HG) for tumorigenesis. IDH inhibition provides clinical response in a subset of acute myeloid leukemia (AML) cases; however, most patients develop resistance, highlighting the need for more effective IDH-targeting therapies. By comparing transcriptomic alterations in isogenic leukemia cells harboring CRISPR base-edited IDH mutations, we identify the activation of adhesion molecules including CD44, a transmembrane glycoprotein, as a shared feature of IDH-mutant leukemia, consistent with elevated CD44 expression in IDH-mutant AML patients. CD44 is indispensable for IDH-mutant leukemia cells through activating pentose phosphate pathway and inhibiting glycolysis by phosphorylating glucose-6-phosphate dehydrogenase and pyruvate kinase muscle isozyme M2, respectively. This metabolic rewiring ensures efficient NADPH generation for mutant IDH-catalyzed R-2HG production. Combining IDH inhibition with CD44 blockade enhances the elimination of IDH-mutant leukemia cells. Hence, we describe an oncogenic feedforward pathway involving CD44-mediated metabolic rewiring for oncometabolite production, representing a potentially targetable dependency of IDH-mutant malignancies.

Safety profile of isocitrate dehydrogenase inhibitors in cancer therapy: a pharmacovigilance study of the FDA Adverse Event Reporting System

BACKGROUND

Isocitrate dehydrogenase (IDH) inhibitors hold promise for IDH-mutated cancer patients and demonstrated favorable clinical efficacy. Nonetheless, a comprehensive understanding of the associated toxicities of IDH inhibitors remains notably lacking.

RESEARCH DESIGN AND METHODS

This pharmacovigilance analysis utilized the FDA Adverse Event Reporting System (FAERS) database to assess notable adverse events (AEs) attributed to IDH inhibitors (enasidenib and ivosidenib) from January 2018 to December 2023.

RESULTS

In the FAERS database, 2,905 enasidenib-associated and 1,289 ivosidenib-related AEs records were identified, respectively. The toxicity profiles of IDH1 and IDH2 inhibitors exhibited notable similarities. The most commonly significant system-organ classes induced by IDH inhibitors encompassed general disorders and administration site conditions, investigations, gastrointestinal disorders, and infections and infestations. The most common AEs included nausea, fatigue, diarrhea, decreased appetite, decreased platelet count, fever, pneumonia, weakness, sepsis, constipation, vomiting, rash, and reduced hemoglobin levels. Notably, temporal analysis of AEs shows enasidenib and ivosidenib have median onset times of 137 and 75 days, with distinct initial peak frequencies.

CONCLUSION

The reversible nature of the toxicities associated with IDH inhibitors underscores their promise as a therapeutic agent with a favorable safety profile.

Advancing Systemic Therapy in Chondrosarcoma: New Horizons

The systemic treatment landscape for advanced and metastatic chondrosarcoma, a malignancy with limited responsiveness to conventional therapies, has always been notoriously challenging. While standard chemotherapy offers minimal benefits, certain subtypes, such as mesenchymal and dedifferentiated chondrosarcomas, have shown some response to systemic therapies initially developed for other sarcomas. Investigational strategies are focusing on molecular targets, including mutations in the isocitrate dehydrogenase gene (IDH), signaling pathways, such as hedgehog and death receptor 5 (DR5) and immune modulation. IDH mutations, notably found in conventional and dedifferentiated chondrosarcomas, have prompted the evaluation of IDH inhibitors, which have demonstrated promising efficacy in preclinical and early clinical trials, despite limited data in chondrosarcoma. Additionally, the hedgehog pathway, implicated in chondrosarcoma progression, has been targeted with inhibitors, although clinical translation has shown mixed results. Immunotherapy, including programmed cell death 1 (PD-1) checkpoint inhibitors and chimeric antigen receptor-T (CAR-T) cells, is also being investigated but faces challenges due to the immunosuppressive tumour microenvironment. Among new approaches, DR5 agonists such as INBRX-109 have shown single-agent efficacy, with minimal toxicity, opening possibilities for use in combination therapies to improve outcomes. Given the heterogenous and treatment-resistant nature of chondrosarcoma, we highlight the need for multi-omics and genetic profiling to guide personalized, combination therapies that target multiple carcinogenic pathways. The integration of multi-targeted approaches could enhance efficacy, address tumour heterogeneity, and overcome resistance, presenting a hopeful direction for systemic therapy in this challenging cancer. The investigation of combination regimens with IDH inhibitors, immunotherapy and DR5 agonists hold promise for transforming the management of advanced chondrosarcoma.

Frontline Therapy of AML in the Fit and Younger Population-Incorporating Molecularly Targeted Agents

Backbone therapy for acute myeloid leukemia for younger adults has for 50 years been based on a combination of cytarabine and anthracycline. Over the past 10 years the addition of several targeted agents has been found to improve the outcomes of subsets of AML with particular molecular changes. In this review we will examine the data generated to date on the addition of agents targeting CD33, FLT3, IDH, and BCL2 to standard high intensity therapies. We will also review the potential for future studies evaluating the application of highly active lower intensity therapies developed in older adults to patients considered "fit for high intensity induction." Lastly, we review the data around the role of stem cell transplant in the modern targeted era.

Molecular Analysis of Genes CEBPA, NPM1, IDH1, and RUNX1 Polymorphisms as Biomarker Potential in Leukemia Patients

Leukemia is found in approximately 2.3 million people worldwide and causes many deaths all over the world. This research study was conducted to figure out the link of single nucleotide polymorphisms of genes CEBPA (rs34529039), NPM1 (rs753788683), IDH1 (of rs11554137) and RUNX1 (rs13051066) polymorphisms as biomarker potential in leukemia patients. A total of 600 subjects were included in the study which included 300 patients and 300 healthy controls with age and gender matched. After DNA extraction, PCR was carried out to analyze polymorphisms of selected genes. A significant association with increased risk of leukemia by almost twofolds is observed in homozygous mutant (AA) of rs34529039 SNP of gene CEBPA (odds ratio [OR] = 1.71; 95% confidence interval [CI] = 1.04-2.82; p = 0.03) while highly significant association but with decrease risk of leukemia is observed in heterozygote genotype (CA) of same SNP (OR = 0.36; 95% CI = 0.22-0.59; p = 0.0001). A highly significant association with increased risk of leukemia up to twofolds is observed in heterozygote genotype (AG) of rs753788683 of gene NPM1 (OR 2.10: 95% CI 1.32-3.36 p = 0.0017) while increasing risk by two-fold and show significant association in homozygous mutant (AA) (OR = 1.75; 95% Cl = 1.09-2.79; p = 0.01). Leukemia risk increases by twofold and shows significant association in the homozygous mutant (AA) of rs11554137 (OR = 1.75; 95%Cl = 1.09-2.79; p = 0.01). Leukemia risk increases by twofold and shows significant association in the homozygous mutant (AA) of rs13051066 of gene RUNX1 (OR = 0.63; 95%Cl = 0.39-1.63; p = 0.06).

Allogeneic hematopoietic stem cell transplantation could overcome the poor prognosis of DNMT3AmutNPM1mutFLT3-ITDmut in acute myeloid leukemia: real-world multicenter analysis in China

The cooccurrence of NPM1, FLT3-ITD, and DNMT3A mutations (i.e., triple mutation) is related to dismal prognosis in patients with acute myeloid leukemia (AML) receiving chemotherapy alone. In this multicenter retrospective cohort study, we aimed to identify whether allogeneic hematopoietic stem cell transplantation (allo-HSCT) could overcome the poor prognosis of DNMT3AmutNPM1mutFLT3-ITDmut AML across four transplant centers in China. Fifty-three patients with triple-mutated AML receiving allo-HSCT in complete remission were enrolled. The 1.5-year probabilities of relapse, leukemia-free survival, and overall survival after allo-HSCT were 11.9%, 80.3%, and 81.8%, respectively. Multivariate analysis revealed that more than one course of induction chemotherapy and allo-HSCT beyond CR1 were associated with poor survival. To our knowledge, this work is the largest study to explore the up-to-date undefined role of allo-HSCT in patients with triple-mutated AML. Our real-world data suggest that allo-HSCT could overcome the poor prognosis of DNMT3AmutNPM1mutFLT3-ITDmut in AML.

Uridine Metabolism as a Targetable Metabolic Achilles' Heel for chemo-resistant B-ALL

Relapse continues to limit survival for patients with B-cell acute lymphoblastic leukemia (B-ALL). Previous studies have independently implicated activation of B-cell developmental signaling pathways and increased glucose consumption with chemo-resistance and relapse risk. Here, we connect these observations, demonstrating that B-ALL cells with active signaling, defined by high expression of phosphorylated ribosomal protein S6 ("pS6+ cells"), are metabolically unique and glucose dependent. Isotope tracing and metabolic flux analysis confirm that pS6+ cells are highly glycolytic and notably sensitive to glucose deprivation, relying on glucose for de novo nucleotide synthesis. Uridine, but not purine or pyrimidine, rescues pS6+ cells from glucose deprivation, highlighting uridine is essential for their survival. Active signaling in pS6+ cells drives uridine production through activating phosphorylation of carbamoyl phosphate synthetase (CAD), the enzyme catalyzing the initial steps of uridine synthesis. Inhibition of signaling abolishes glucose dependency and CAD phosphorylation in pS6+ cells. Primary pS6+ cells demonstrate high expression of uridine synthesis proteins, including dihydroorotate dehydrogenase (DHODH), the rate-limiting catalyst of de novo uridine synthesis. Gene expression demonstrates that increased expression of DHODH is associated with relapse and inferior event-free survival after chemotherapy. Further, the majority of B-ALL genomic subtypes demonstrate activity of DHODH. Inhibiting DHODH using BAY2402232 effectively kills pS6+ cells in vitro, with its IC50 correlated with the strength of pS6 signaling across 14 B-ALL cell lines and patient-derived xenografts (PDX). In vivo DHODH inhibition prolongs survival and decreases leukemia burden in pS6+ B-ALL cell line and PDX models. These findings link active signaling to uridine dependency in B-ALL cells and an associated risk of relapse. Targeting uridine synthesis through DHODH inhibition offers a promising therapeutic strategy for chemo-resistant B-ALL as a novel therapeutic approach for resistant disease.

IDH-mutant gliomas in children and adolescents - from biology to clinical trials

Gliomas account for nearly 30% of all primary central nervous system (CNS) tumors in children and adolescents and young adults (AYA), contributing to significant morbidity and mortality. The updated molecular classification of gliomas defines molecularly diverse subtypes with a spectrum of tumors associated with age-distinct incidence. In adults, gliomas are characterized by the presence or absence of mutations in isocitrate dehydrogenase (IDH), with mutated IDH (mIDH) gliomas providing favorable outcomes and avenues for targeted therapy with the emergence of mIDH inhibitors. Despite their rarity, IDH mutations have been reported in 5-15% of pediatric glioma cases. Those with primary mismatch-repair deficient mIDH astrocytomas (PMMRDIA) have a particularly poor prognosis. Here, we describe the biology of mIDH gliomas and review the literature regarding the emergence of mIDH inhibitors, including clinical trials in adults. Given the paucity of clinical trial data from pediatric patients with mIDH glioma, we propose guidelines for the inclusion of pediatric and AYA patients with gliomas onto prospective trials and expanded access programs as well as the potential of combined mIDH inhibition and immunotherapy in the treatment of patients with PMMRDIA at high risk of progression.

Somatic mtDNA mutation burden shapes metabolic plasticity in leukemogenesis

The role of somatic mitochondrial DNA (mtDNA) mutations in leukemogenesis remains poorly characterized. To determine the impact of somatic mtDNA mutations on this process, we assessed the leukemogenic potential of hematopoietic progenitor cells (HPCs) from mtDNA mutator mice (Polg D257A) with or without NMyc overexpression. We observed a higher incidence of spontaneous leukemogenesis in recipients transplanted with heterozygous Polg HPCs and a lower incidence of NMyc-driven leukemia in those with homozygous Polg HPCs compared to controls. Although mtDNA mutations in heterozygous and homozygous HPCs caused similar baseline impairments in mitochondrial function, only heterozygous HPCs responded to and supported altered metabolic demands associated with NMyc overexpression. Homozygous HPCs showed altered glucose utilization with pyruvate dehydrogenase inhibition due to increased phosphorylation, exacerbated by NMyc overexpression. The impaired growth of NMyc-expressing homozygous HPCs was partially rescued by inhibiting pyruvate dehydrogenase kinase, highlighting a relationship between mtDNA mutation burden and metabolic plasticity in leukemogenesis.

GPR68 supports AML cells through the calcium/calcineurin pro-survival pathway and confers chemoresistance by mediating glucose metabolic symbiosis

Accumulating evidence demonstrates that the "Warburg effect" that glycolysis is enhanced even in the presence of oxygen existed in hematopoietic malignancies, contributing to extracellular acidosis. G-protein coupled receptor 68 (GPR68), as a proton sensing GPCR responding to extracellular acidosis, is expected to play a critical role in hematopoietic malignancies. In the present study, we found that GPR68 was overexpressed in acute myeloid leukemia (AML) cells, and GPR68 deficiency impaired AML cell survival in vitro and cell engraftment in vivo. Mechanistic studies revealed that unlike GPR68 regulates Calpain1 in myelodysplastic syndromes (MDS) cells, GPR68 deficiency reduced cytosolic Ca2+ levels and calcineurin (CaN) activity in AML cells through an NFAT-independent mechanism. Moreover, the decreased Ca2+ levels disturbed cellular respiration (i.e., oxidative phosphorylation, OxPhos) by inhibiting isocitrate dehydrogenase (IDH) activity; this was more pronounced when BCL2 was inhibited simultaneously. Interestingly, GPR68 inhibition also decreased aerobic glycolysis in AML cells in a Ca2+-independent manner, suggesting that GPR68 mediated glucose metabolic symbiosis. As glucose metabolic symbiosis and the heterogeneous dependencies on aerobic glycolysis and cellular respiration tremendously impact chemosensitivity, the inhibition of GPR68 potentiated the tumoricidal effect of first-line chemotherapeutic agents, including BCL-2 inhibitors targeting OxPhos and cytarabine (Ara-C) targeting glycolysis. Consistent with these in vitro observations, higher levels of GPR68 were associated with inferior clinical outcomes in AML patients who received chemotherapies. In short, GPR68 drives the Ca2+/CaN pro-survival pathway and mediates glucose metabolic pathways in AML cells. Targeting GPR68 eradicates AML cells and alleviates chemoresistance, which could be exploited as a therapeutic target.

IDH1/2 Mutations in Cancer: Unifying Insights and Unlocking Therapeutic Potential for Chondrosarcoma

Chondrosarcomas, a rare form of bone sarcomas with multiple subtypes, pose a pressing clinical challenge for patients with advanced or metastatic disease. The lack of US Food and Drug Administration (FDA)-approved medications underscores the urgent need for further research and development in this area. Patients and their families face challenges as there are no systemic therapeutic options available with substantial effectiveness. A significant number (50-80%) of chondrosarcomas have a mutation in the isocitrate dehydrogenase (IDH) genes. This review focuses on IDH-mediated pathogenesis and recent pharmacological advances with novel IDH inhibitors, explores their potential therapeutic value, and proposes potential future avenues for clinical trials combining IDH inhibitors with other systemic agents for chondrosarcomas.

Oncometabolites at the crossroads of genetic, epigenetic and ecological alterations in cancer

By the time a tumor reaches clinical detectability, it contains around 108-109 cells. However, during tumor formation, significant cell loss occurs due to cell death. In some estimates, it could take up to a thousand cell generations, over a ~ 20-year life-span of a tumor, to reach clinical detectability, which would correspond to a "theoretical" generation of ~1030 cells. These rough calculations indicate that cancers are under negative selection. The fact that they thrive implies that they "evolve", and that their evolutionary trajectories are shaped by the pressure of the environment. Evolvability of a cancer is a function of its heterogeneity, which could be at the genetic, epigenetic, and ecological/microenvironmental levels [1]. These principles were summarized in a proposed classification in which Evo (evolutionary) and Eco (ecological) indexes are used to label cancers [1]. The Evo index addresses cancer cell-autonomous heterogeneity (genetic/epigenetic). The Eco index describes the ecological landscape (non-cell-autonomous) in terms of hazards to cancer survival and resources available. The reciprocal influence of Evo and Eco components is critical, as it can trigger self-sustaining loops that shape cancer evolvability [2]. Among the various hallmarks of cancer [3], metabolic alterations appear unique in that they intersect with both Evo and Eco components. This is partly because altered metabolism leads to the accumulation of oncometabolites. These oncometabolites have traditionally been viewed as mediators of non-cell-autonomous alterations in the cancer microenvironment. However, they are now increasingly recognized as inducers of genetic and epigenetic modifications. Thus, oncometabolites are uniquely positioned at the crossroads of genetic, epigenetic and ecological alterations in cancer. In this review, the mechanisms of action of oncometabolites will be summarized, together with their roles in the Evo and Eco phenotypic components of cancer evolvability. An evolutionary perspective of the impact of oncometabolites on the natural history of cancer will be presented.

In vivo models of subclonal oncogenesis and dependency in hematopoietic malignancy

Cancer evolution is a multifaceted process leading to dysregulation of cellular expansion and differentiation through somatic mutations and epigenetic dysfunction. Clonal expansion and evolution is driven by cell-intrinsic and -extrinsic selective pressures, which can be captured with increasing resolution by single-cell and bulk DNA sequencing. Despite the extensive genomic alterations revealed in profiling studies, there remain limited experimental systems to model and perturb evolutionary processes. Here, we integrate multi-recombinase tools for reversible, sequential mutagenesis from premalignancy to leukemia. We demonstrate that inducible Flt3 mutations differentially cooperate with Dnmt3a, Idh2, and Npm1 mutant alleles, and that changing the order of mutations influences cellular and transcriptional landscapes. We next use a generalizable, reversible approach to demonstrate that mutation reversion results in rapid leukemic regression with distinct differentiation patterns depending upon co-occurring mutations. These studies provide a path to experimentally model sequential mutagenesis, investigate mechanisms of transformation and probe oncogenic dependency in disease evolution.

Efficacy and safety of IDH inhibitors in IDH-mutated cancers: a systematic review and meta-analysis of 4 randomized controlled trials

BACKGROUND

Isocitrate dehydrogenase (IDH) inhibitors have shown great promise in the treatment of cancers with IDH mutations. There have been numerous clinical trials conducted on IDH inhibitors, and to evaluate their efficacy and safety, we aim to perform a meta-analysis.

METHODS

To gather data on the efficacy and safety of IDH inhibitors for IDH-mutated cancers, we systematically searched through databases including PubMed, EMBASE, and Cochrane Library. Using RevMan5.4, we performed a meta-analysis and calculated the odds ratio (OR) or weighted mean difference (WMD) with a 95% confidence interval (95%CI). The parameters considered were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), treatment-related adverse events (TRAEs), and TRAEs ≥ 3.

RESULTS

This meta-analysis included four studies, involving a total of 751 patients. According to the analysis, there was no significant difference in overall survival, treatment-related adverse events, and severe treatment-related adverse events between the experimental group (receiving IDH inhibitors) and the control group. However, the progression-free survival, objective response rate, and disease control rate in the experimental group were significantly higher than those in the control group.

CONCLUSION

The overall efficacy of IDH inhibitors in treating cancers with IDH mutations is superior to that of conventional medical therapy, potentially providing more clinical benefits to patients. The incidence of adverse events was not significantly different from conventional medical therapy. Therefore, IDH inhibitors should be considered as the preferred choice for treating cancers with IDH mutations. However, further randomized controlled clinical trials are still required for verification.

Isocitrate dehydrogenase (IDH) 1 and 2 mutations predict better outcome in patients with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplantation: a study of the ALWP of the EBMT

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) mutations have uncertain prognostic implications in AML. We investigate the impact IDH1 and IDH2 mutations in AML patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) in first complete remission (CR1). In total, 1515 adult patients were included, 15.91% (n = 241) carried IDH1 mutation (mIDH1), and 26.27% (n = 398) IDH2 mutation (mIDH2) and 57.82% (n = 876) had no-IDH mutation. NPM1 was frequently encountered with IDH1 mutation (no-IDH group, n = 217, 24.8%, mIDH1, n = 103, 42.7%, mIDH2, n = 111, 27.9%, p < 0.0001). At day 180, the cumulative incidence (CI) of grade II-IV acute graft-versus-host disease (GVHD) was significantly lower in mIDH1 and mIDH2 compared to no-IDH groups (Hazard ratio [HR] = 0.66 (95% CI 0.47-0.91), p = 0.011; HR = 0.73 (95% CI 0.56-0.96), p = 0.025, respectively). In the mIDH1 group, overall survival (OS) was improved compared to no-IDH (HR = 0.68 (95% CI 0.48-0.94), p = 0.021), whereas mIDH2 was associated with lower incidence of relapse (HR = 0.49 (95% CI 0.34-0.7), p < 0.001), improved leukemia free survival (LFS) (HR = 0.7 (95% CI 0.55-0.9), p = 0.004) and OS (HR = 0.74 (95% CI 0.56-0.97), p = 0.027). In the subgroup of NPM1 wild type, only IDH2 was associated with improved outcomes. In conclusion, our data suggest that IDH1 and IDH2 mutations are associated with improved outcomes in patients with AML undergoing allo-HCT in CR1.

Multiomic profiling identifies predictors of survival in African American patients with acute myeloid leukemia

Genomic profiles and prognostic biomarkers in patients with acute myeloid leukemia (AML) from ancestry-diverse populations are underexplored. We analyzed the exomes and transcriptomes of 100 patients with AML with genomically confirmed African ancestry (Black; Alliance) and compared their somatic mutation frequencies with those of 323 self-reported white patients with AML, 55% of whom had genomically confirmed European ancestry (white; BeatAML). Here we find that 73% of 162 gene mutations recurrent in Black patients, including a hitherto unreported PHIP alteration detected in 7% of patients, were found in one white patient or not detected. Black patients with myelodysplasia-related AML were younger than white patients suggesting intrinsic and/or extrinsic dysplasia-causing stressors. On multivariable analyses of Black patients, NPM1 and NRAS mutations were associated with inferior disease-free and IDH1 and IDH2 mutations with reduced overall survival. Inflammatory profiles, cell type distributions and transcriptional profiles differed between Black and white patients with NPM1 mutations. Incorporation of ancestry-specific risk markers into the 2022 European LeukemiaNet genetic risk stratification changed risk group assignment for one-third of Black patients and improved their outcome prediction.

The Key Enzymes of Carbon Metabolism and the Glutathione Antioxidant System Protect Yarrowia lipolytica Yeast Against pH-Induced Stress

In this study, we first thoroughly assayed the response of the key enzymes of energy metabolism and the antioxidant system in Yarrowia lipolytica yeast at extreme pH. The activity of the tricarboxylic acid cycle enzymes, namely NAD-dependent isocitrate dehydrogenase, aconitate hydratase, NAD-dependent malate dehydrogenase, and fumarate hydratase, NADPH-producing enzymes of glucose-6-P dehydrogenase and NADP-dependent isocitrate dehydrogenase, and the enzymes of the glutathione system was assessed. All the enzymes that were tested showed a significant induction contrary to some decrease in the aconitate hydratase activity with acidic and alkaline stress. It is probable that a change in the enzyme activity in the mitochondria matrix is involved in the regulation of the cellular metabolism of Y. lipolytica, which allows the species to prosper at an extreme ambient pH. It distinguishes it from any other type of ascomycete. A close relationship between the induction of the Krebs cycle enzymes and the key enzymes of the glutathione system accompanied by an increased level of reduced glutathione was shown. The assumption that the increased activity of the Krebs cycle dehydrogenases and promotion of the pentose phosphate pathway at pH stress launches a set of events determining the adaptive response of Y. lipolytica yeast.

ROCK2 increases drug resistance in acute myeloid leukemia via metabolic reprogramming and MAPK/PI3K/AKT signaling

Rho-associated coiled-coil kinase 2 (ROCK2) is classified as a member of the serine/threonine protein kinase family and has been identified as a key driver of the development of various forms of cancer. The cause of ROCK2's impact on acute myeloid leukemia (AML) is still unknown. We found that ROCK2 expression was higher in AML patients, leading to lower complete response rates and worse overall survival. Additionally, ROCK2 expression was elevated in the doxorubicin-resistant leukemia cell line HL-60/ADM when compared to their individual parent cells. Moreover, the suppression or inhibition of ROCK2 leads to enhanced drug sensitivity in both AML cell lines and primary AML specimens, along with a notable decrease in downstream signaling pathways. Furthermore, the suppression of ROCK2 caused disruption of cellular energy production pathways by directly affecting the functionality of proteins within the mitochondrial electron transport chain. Finally, we discovered that TRIM26, a specific E3 ligase, is capable of ubiquitylating ROCK2, and the upregulation of TRIM26 within HL-60/ADM cells resulted in heightened sensitivity to the drug and reduced resistance. Thus, our study presents a new strategy for overcoming drug resistance in AML through targeting ROCK2/AKT/MAPK signaling pathway.

Met-Flow analyses of the metabolic heterogeneity associated with different stages of cord blood-derived hematopoietic cell differentiation

Background

The differentiation of hematopoietic cells is significantly affected by cell metabolic activity. However, despite increasing interest in this field, there has been no comprehensive investigation of the metabolic functions of human hematopoietic cells during specific phases of differentiation. Thus, this study was conducted to develop a method for comparing hematopoietic cell lineage differentiation based on the metabolic functions of the cell. The metabolic activity of human umbilical cord-derived hematopoietic cells was examined during various phases of differentiation, specifically, hematopoietic stem cells (HSCs), hematopoietic progenitor cells, and differentiated blood cells. This approach was used to develop comprehensive metabolic maps corresponding to the different stages.

Results

HSCs were found to have robust fatty acid (FA) synthesis, FA oxidation, pentose phosphate pathway (PPP) activity, and glucose uptake, shown by their significantly higher expression of ACAC, CPT1A, G6PD, and GLUT1 as compared to differentiated pluripotent progenitor cells, common myeloid progenitors, megakaryocyte erythroid progenitors, lympho-myeloid primed progenitors, and granulocyte-macrophage progenitor cell populations. In monocytic differentiation, higher levels of ACAC, ASS1, ATP5A, CPT1A, G6PD, GLUT1, IDH2, PRDX2, and HK1 protein expression were evident in classical and intermediate monocytes relative to non-classical monocytes, consistent with high anabolic and catabolic levels. Compared with myelocytes and mature cells, the meta-myelocyte and pro-myelocyte populations of granulocytes show significantly elevated levels of ACAC, ASS1, ATP5A, CPT1A, G6PD, IDH2, PRDX2, and HK. In contrast to naïve and regulatory B cells, pro-B cells had higher levels of oxidative phosphorylation, while regulatory B cells showed greater PPP activity, glucose uptake, and tricarboxylic acid cycle activity. The analyses of T cells also indicated significantly higher ACAC, ASS1, ATP5A, CPT1A, G6PD, GLUT1, IDH2, PRDX2, and HK1 expression levels in CD4+ populations compared with CD8+ populations.

Conclusions

The results provide comprehensive analytical methods and reference values for future systematic studies into the metabolic functions of various cord blood-derived hematopoietic cell populations in different pathological or physiological conditions. These findings could also contribute to research on the connection between cellular metabolism and cancer or aging.

Gaining Insight into the Catalytic Mechanism of the R132H IDH1 Mutant: A Synergistic DFT Cluster and Experimental Investigation

Human isocitrate dehydrogenase 1 (IDH1) is an enzyme that is found in humans that plays a critical role in aerobic metabolism. As a part of the citric acid cycle, IDH1 becomes responsible for catalyzing the oxidative decarboxylation of isocitrate to form α-ketoglutarate (αKG), with nicotinamide adenine dinucleotide phosphate (NADP+) as a cofactor. Strikingly, mutations of the IDH1 enzyme have been discovered in several cancers including glioblastoma multiforme (GBM), a highly aggressive form of brain cancer. It has been experimentally determined that single-residue IDH1 mutations occur at a very high frequency in GBM. Specifically, the IDH1 R132H mutation is known to produce (D)2-hydroxyglutarate (2HG), a recognized oncometabolite. Using the previously determined catalytic mechanism of IDH1, a DFT QM model was developed to study the mechanistic properties of IDH1 R132H compared to wild type enzyme. Validating these insights, biochemical in vitro assays of metabolites produced by mutant vs wild type enzymes were measured and compared. From the results discussed herein, we discuss the mechanistic impact of mutations in IDH1 on its ability to catalyze the formation of αKG and 2HG.

Advancements in genetic analysis: Insights from a case study and review of next-generation sequencing techniques for veterinary oncology applications

Acute myeloid leukemia (AML) poses significant challenges in veterinary medicine, with limited treatment options and poor survival rates. While substantial progress has been made in characterizing human AML, translating these advancements to veterinary practice has been hindered by limited molecular understanding and diagnostic tools. The case study presented illustrates the application of whole genome sequencing in diagnosing AML in a dog, showcasing its potential in veterinary oncology. Our approach facilitated comprehensive genomic analysis, identifying mutations in genes that may be associated with AML pathogenesis in dogs, such as KRAS, IKZF1, and RUNX1. However, without supportive evidence of its clinical utility (eg, association with response to treatment or prognosis), the information is limited to exploration. This article reviews the comparative features of canine AML with human AML and discusses strategies to shrink the knowledge gap between human and veterinary medicine with cost-effective next-generation sequencing (NGS) techniques. By utilizing these approaches, the unique and shared molecular features with human AML can be identified, aiding in molecular classification and therapeutic development for both species. Despite the promise of NGS, challenges exist in implementing it into routine veterinary diagnostics. Cost considerations, turnaround times, and the need for robust bioinformatics pipelines and quality control measures must be addressed. Most importantly, analytical and clinical validation processes are essential to ensure the reliability and clinical utility of NGS-based assays. Overall, integrating NGS technologies into veterinary oncology holds great potential for advancing our understanding of AML and improving disease stratification, in hopes of improving clinical outcomes.

Benzene exposure and pediatric leukemia: From molecular clues to epidemiological insights

According to the International Agency for Research on Cancer, leukemia ranks 14th in incidence and 11th in mortality and has a 5-year prevalence of approximately 1300,000 cases. Acute lymphoblastic leukemia is the most common hematopoietic syndrome in children during the first 5 years of life and represents approximately 75 % of all neoplasms among the pediatric population. The development of leukemia is strongly governed by DNA alterations that accelerate the growth of bone marrow cells. Currently, the most examined factor in pediatric leukemia is exposure to multiple compounds, such as hydrocarbons. Benzene, an aromatic hydrocarbon, can cause health challenges and is categorized as a carcinogen. Benzene toxicity has been widely associated with occupational exposure. Importantly, studies are underway to generate evidence that can provide clues regarding the risk of environmental benzene exposure and hematological problems in children. In this review, we summarize the existing evidence regarding the effects of benzene on pediatric leukemia, the associations between the effect of benzene on carcinogenesis, and the presence of certain molecular signatures in benzene-associated pediatric leukemia. Although there is sufficient evidence regarding the effects of benzene on carcinogenesis and leukemia, epidemiological research has primarily focused on occupational risk. Moreover, most benzene-induced molecular and cytogenetic alterations have been widely described in adults but not in the pediatric population. Thus, epidemiological efforts are crucial in the pediatric population in terms of epidemiological, clinical, and biomedical research.

Epigenetic modifications in hematopoietic ecosystem: a key tuner from homeostasis to acute myeloid leukemia

Hematopoietic stem cells (HSCs) maintain homeostasis in the hematopoietic ecosystem, which is tightly regulated at multiple layers. Acute myeloid leukemia (AML) is a severe hematologic malignancy driven by genetic and epigenetic changes that lead to the transformation of leukemia stem cells (LSCs). Since somatic mutations in DNA methylation-related genes frequently occur in AML, DNA methylation is widely altered and functions as a starting engine for initiating AML. Additionally, RNA modifications, especially N6-methyladenosine (m6A), also play an important role in the generation and maintenance of the hematopoietic ecosystem, and AML development requires reprogramming of m6A modifications to facilitate cells with hallmarks of cancer. Given the complex pathogenesis and poor prognosis of AML, it is important to fully understand its pathogenesis. Here, we mainly focus on DNA methylation and RNA m6A modification in hematopoiesis and AML and summarize recent advances in this field.

A novel biomarker GATM suppresses proliferation and malignancy of cholangiocarcinoma cells by modulating the JNK/c-Jun signalling pathways

Background

Cholangiocarcinoma (CCA) is the second most common primary malignancy of the liver and is associated with poor prognosis. Despite the emerging role of glycine amidinotransferase (GATM) in cancer development, its function in CCA remains elusive. This study investigated the biological significance and molecular mechanisms of GATM in CCA.

Method

GATM expression was measured using immunohistochemistry and western blotting. Cell proliferation, migration, and invasion were assessed through CCK-8, EdU, clone formation, wound healing, and Transwell assays. Rescue experiments were performed to determine whether the JNK/c-Jun pathway is involved in GATM-mediated CCA development. Immunoprecipitation and mass spectrometry were performed to screen for proteins that interact with GATM. The role of GATM in vivo was investigated according to the xenograft experiment.

Result

GATM expression was downregulated in CCA tissues and cells (p < 0.05) and had a significant suppressive effect on CCA cell proliferation, migration, and invasion in vitro as well as on tumour growth in vivo (p < 0.05); conversely, GATM knockdown promoted these phenotypes (p < 0.05). Notably, GATM inhibited the JNK/c-Jun pathway, and JNK activation abrogated GATM's antitumor effects (p < 0.05). Isocitrate dehydrogenase 1 (IDH1) interacts with GATM, and IDH1 knockdown significantly attenuated GATM protein degradation. Overexpression of IDH1 restored the biological function of CCA by reversing the inhibition of JNK/c-Jun pathway phosphorylation by GATM (p < 0.05).

Conclusion

GATM acts as a tumour suppressor in CCA by regulating the phosphorylation of the JNK/c-Jun pathway. IDH1 interacted with GATM to regulate CCA progression.

Ollier Disease, Acute Myeloid Leukemia, and Brain Glioma: IDH as the Common Denominator

Ollier disease (OD), acute myeloid leukemia (AML), and brain glioma (BG) are three apparently completely different neoplasms in terms of histopathology, clinic, natural history, and management, but they can affect the same patient. This study aimed to identify the common molecular pathways involved in the pathogenesis of all three diseases and discuss their current and potential role as therapeutic targets. A detailed and comprehensive systematic literature review according to PRISMA guidelines on OD patients harboring BG and/or AML was made. In addition, the unique case of a patient affected by all three considered diseases has been added to our case series. Demographic, pathological, treatment, and outcome data were analyzed and discussed, mainly focusing on the molecular findings. Twenty-eight studies reported thirty-three patients affected by OD and BG, and only one study reported one patient with OD and AML, while only our patient harbored all three pathologies. The IDH R132H mutation was the only genetic alteration shared by all three pathologies and was simultaneously detected in enchondromas and brain glioma in 100% (3/3) of OD patients with BG and also in the neoplastic blood cells of the single patient hosting all three diseases. The IDH1-R132H gene mutation is the etiopathogenetic common denominator among three apparently different tumors coexisting in the same patient. The adoption of mutant-specific IDH1 inhibitor molecules could represent a potential panacea for these conditions in the era of targeted therapies. Further studies with larger clinical series are needed to confirm our results and hypothesis.

Frontline therapy of acute myeloid leukemia with lower intensity regimens: Where are we now and where can we go?

The advent of molecularly targeted therapeutics has transformed the management of patients with acute myeloid leukemia (AML). Particularly for individuals unfit for intensive chemotherapy, lower intensity therapies (LIT) incorporating small molecules have significantly improved patient outcomes. With BCL2, IDH1, IDH2, and FLT3 inhibitors widely used for relapsed AML, combination regimens are now utilized in the frontline. Expansion of these targeted LIT combinations, along with development of novel agents including menin inhibitors, exemplifies the promise of precision medicine. Further understanding of molecular drivers of leukemic transformation and mechanisms of relapse will continue to advance frontline treatment options for patients with AML.

Molecular Features and Treatment Paradigms of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a common hematologic malignancy that is considered to be a disease of aging, and traditionally has been treated with induction chemotherapy, followed by consolidation chemotherapy and/or allogenic hematopoietic stem cell transplantation. More recently, with the use of next-generation sequencing and access to molecular information, targeted molecular approaches to the treatment of AML have been adopted. Molecular targeting is gaining prominence, as AML mostly afflicts the elderly population, who often cannot tolerate traditional chemotherapy. Understanding molecular changes at the gene level is also important for accurate disease classification, risk stratification, and prognosis, allowing for more personalized medicine. Some mutations are well studied and have an established gene-specific therapy, including FLT3 and IDH1/2, while others are being investigated in clinical trials. However, data on most known mutations in AML are still minimal and therapeutic studies are in pre-clinical stages, highlighting the importance of further research and elucidation of the pathophysiology involving these genes. In this review, we aim to highlight the key molecular alterations and chromosomal changes that characterize AML, with a focus on pathophysiology, presently available treatment approaches, and future therapeutic options.

Dual-targeted NAMPT inhibitors as a progressive strategy for cancer therapy

In mammals, nicotinamide phosphoribosyltransferase (NAMPT) is a crucial enzyme in the nicotinamide adenine dinucleotide (NAD+) synthesis pathway catalyzing the condensation of nicotinamide (NAM) with 5-phosphoribosyl-1-pyrophosphate (PRPP) to produce nicotinamide mononucleotide (NMN). Given the pivotal role of NAD+ in a range of cellular functions, including DNA synthesis, redox reactions, cytokine generation, metabolism, and aging, NAMPT has become a promising target for many diseases, notably cancer. Therefore, various NAMPT inhibitors have been reported and classified as first and second-generation based on their chemical structures and design strategies, dual-targeted being one. However, most NAMPT inhibitors suffer from several limitations, such as dose-dependent toxicity and poor pharmacokinetic properties. Consequently, there is no clinically approved NAMPT inhibitor. Hence, research on discovering more effective and less toxic dual-targeted NAMPT inhibitors with desirable pharmacokinetic properties has drawn attention recently. This review summarizes the previously reported dual-targeted NAMPT inhibitors, focusing on their design strategies and advantages over the single-targeted therapies.

Olutasidenib in post-venetoclax patients with mutant isocitrate dehydrogenase 1 (mIDH1) acute myeloid leukemia (AML)

Olutasidenib, a potent, selective, oral, mutant isocitrate dehydrogenase 1 (mIDH1) inhibitor, is FDA-approved for relapsed/refractory (R/R) acute myeloid leukemia (AML). Here we report efficacy and safety of olutasidenib in 18 patients with mIDH1 AML who were relapsed (10), refractory (6) or had complete remission with incomplete hematologic recovery (CRi; 2) to a venetoclax combination. Of the 16 patients who were R/R, 4 (25%) achieved complete remission (CR), one (6.3%) achieved CR with partial hematologic recovery (CRh), and 7 (43.8%) achieved a composite complete remission (CRc). Median time to CRc was 1.9 months (range 1-2.8). As of data cutoff (18 June 2021), median duration of CRc was not reached (range, 1.2-NR, ongoing at 30.4+ months). Both patients with CRi at study entry achieved a CR. Safety was consistent with the overall profile of olutasidenib. Olutasidenib offers a valuable treatment option for patients with mIDH1 AML previously treated with venetoclax.

The Leukemic Isocitrate Dehydrogenase (IDH) 1/2 Mutations Impair Myeloid and Erythroid Cell Differentiation of Primary Human Hematopoietic Stem and Progenitor Cells (HSPCs)

How hematopoietic stem and progenitor cell (HSPC) fate decisions are affected by genetic alterations acquired during AML leukemogenesis is poorly understood and mainly explored in animal models. Here, we study isocitrate dehydrogenase (IDH) gene mutations in the human model of HSPC and discuss the available literature on this topic. IDH1/2 mutations occur in ~20% of AML cases, are recognized among the mutations earliest acquired during leukemogenesis, and are targets of specific inhibitors (ivosidenib and enasidenib, respectively). In order to investigate the direct effects of these mutations on HSPCs, we expressed IDH1-R132H or IDH2-R140Q mutants into human CD34+ healthy donor cells via lentiviral transduction and analyzed the colony-forming unit (CFU) ability. CFU ability was dramatically compromised with a complete trilineage block of differentiation. Strikingly, the block was reversed by specific inhibitors, confirming that it was a specific effect induced by the mutants. In line with this observation, the CD34+ leukemic precursors isolated from a patient with IDH2-mutated AML at baseline and during enasidenib treatment showed progressive and marked improvements in their fitness over time, in terms of CFU ability and propensity to differentiate. They attained clonal trilinear reconstitution of hematopoiesis and complete hematological remission.

Mitochondrial bioenergetics as a cell fate rheostat for responsive to Bcl-2 drugs: New cues for cancer chemotherapy

Pro-survival BCL-2 proteins prevent the initiation of intrinsic apoptosis (mitochondria-dependent pathway) by inhibiting the pro-apoptotic proteins BAX and BAK, while BH3-only proteins promote apoptosis by blocking pro-survival BCL-2 proteins. Disruptions in this delicate balance contribute to cancer cell survival and chemoresistance. Recent advances in cancer therapeutics involve a new generation of drugs known as BH3-mimetics, which are small molecules designed to mimic the action of BH3-only proteins. Promising effects have been observed in patients with hematological and solid tumors undergoing treatment with these agents. However, the rapid emergence of mitochondria-dependent resistance to BH3-mimetics has been reported. This resistance involves increased mitochondrial respiration, altered mitophagy, and mitochondria with higher and tighter cristae. Conversely, mutations in isocitrate dehydrogenase 1 and 2, catalyzing R-2-hydroxyglutarate production, promote sensitivity to venetoclax. This evidence underscores the urgency for comprehensive studies on bioenergetics-based adaptive responses in both BH3 mimetics-sensitive and -resistant cancer cells. Ongoing clinical trials are evaluating BH3-mimetics in combination with standard chemotherapeutics. In this article, we discuss the role of mitochondrial bioenergetics in response to BH3-mimetics and explore potential therapeutic opportunities through metabolism-targeting strategies.

The Tricarboxylic Acid Cycle Metabolites for Cancer: Friend or Enemy

The tricarboxylic acid (TCA) cycle is capable of providing sufficient energy for the physiological activities under aerobic conditions. Although tumor metabolic reprogramming places aerobic glycolysis in a dominant position, the TCA cycle remains indispensable for tumor cells as a hub for the metabolic linkage and interconversion of glucose, lipids, and certain amino acids. TCA intermediates such as citrate, α-ketoglutarate, succinate, and fumarate are altered in tumors, and they regulate the tumor metabolism, signal transduction, and immune environment to affect tumorigenesis and tumor progression. This article provides a comprehensive review of the modifications occurring in tumor cells in relation to the intermediates of the TCA cycle, which affects tumor pathogenesis and current therapeutic strategy for therapy through targeting TCA cycle in cancer cells.

Olutasidenib: a novel mutant IDH1 inhibitor for the treatment of relapsed or refractory acute myeloid leukemia

INTRODUCTION

Recurrent mutations in isocitrate dehydrogenase 1 (mIDH1) occur in about 7% to 14% of all cases of acute myeloid leukemia (AML). The discovery of targetable mutations in AML, including IDH mutations, expanded the therapeutic landscape of AML and led to the development of targeted agents. Despite significant advances in current treatment options, remission and overall survival rates remain suboptimal. The IDH1 inhibitor, olutasidenib, demonstrated encouraging safety and clinical benefits as monotherapy in patients with relapsed or refractory (R/R) mIDH1 AML.

AREAS COVERED

This review outlines the olutasidenib drug profile and summarizes key safety and efficacy data, focusing on the 150 mg twice daily dose from the pivotal registrational cohort of the phase 2 trial that formed the basis for the US Food and Drug Administration approval of olutasidenib in patients with R/R AML with a susceptible IDH1 mutation.

EXPERT OPINION

Olutasidenib offers patients with R/R mIDH1 AML a new treatment option, with improved complete remission and a longer duration of response than other targeted mIDH1 treatment options. Olutasidenib provided clinical benefit with a manageable safety profile. Additional analyses to further characterize the safety and efficacy of olutasidenib in frontline and R/R settings as monotherapy and as combination therapy are ongoing.

Phosphorylation of IDH1 Facilitates Progestin Resistance in Endometrial Cancer

The progestin regimen is one of the main therapeutic strategies for women with endometrial cancer who undergo conservative management. Although many patients respond well to initial therapy, progestin-refractory disease inevitably emerges, and the molecular basis underlying progestin resistance has not been comprehensively elucidated. Herein, they demonstrated progestin results in p38-dependent IDH1 Thr 77 phosphorylation (pT77-IDH1). pT77-IDH1 translocates into the nucleus and is recruited to chromatin through its interaction with OCT6. IDH1-produced α-ketoglutarate (αKG) then facilitates the activity of OCT6 to promote focal adhesion related target gene transcription to confer progestin resistance. Pharmacological inhibition of p38 or focal adhesion signaling sensitizes endometrial cancer cells to progestin in vivo. The study reveals p38-dependent pT77-IDH1 as a key mediator of progestin resistance and a promising target for improving the efficacy of progestin therapy.

Mutant IDH inhibitors induce lineage differentiation in IDH-mutant oligodendroglioma

A subset of patients with IDH-mutant glioma respond to inhibitors of mutant IDH (IDHi), yet the molecular underpinnings of such responses are not understood. Here, we profiled by single-cell or single-nucleus RNA-sequencing three IDH-mutant oligodendrogliomas from patients who derived clinical benefit from IDHi. Importantly, the tissues were sampled on-drug, four weeks from treatment initiation. We further integrate our findings with analysis of single-cell and bulk transcriptomes from independent cohorts and experimental models. We find that IDHi treatment induces a robust differentiation toward the astrocytic lineage, accompanied by a depletion of stem-like cells and a reduction of cell proliferation. Furthermore, mutations in NOTCH1 are associated with decreased astrocytic differentiation and may limit the response to IDHi. Our study highlights the differentiating potential of IDHi on the cellular hierarchies that drive oligodendrogliomas and suggests a genetic modifier that may improve patient stratification.

Active site remodeling in tumor-relevant IDH1 mutants drives distinct kinetic features and potential resistance mechanisms

Mutations in human isocitrate dehydrogenase 1 (IDH1) drive tumor formation in a variety of cancers by replacing its conventional activity with a neomorphic activity that generates an oncometabolite. Little is understood of the mechanistic differences among tumor-driving IDH1 mutants. We previously reported that the R132Q mutant unusually preserves conventional activity while catalyzing robust oncometabolite production, allowing an opportunity to compare these reaction mechanisms within a single active site. Here, we employ static and dynamic structural methods and observe that, compared to R132H, the R132Q active site adopts a conformation primed for catalysis with optimized substrate binding and hydride transfer to drive improved conventional and neomorphic activity over R132H. This active site remodeling reveals a possible mechanism of resistance to selective mutant IDH1 therapeutic inhibitors. This work enhances our understanding of fundamental IDH1 mechanisms while pinpointing regions for improving inhibitor selectivity.

Comparison of venetoclax and ivosidenib/enasidenib for unfit newly diagnosed patients with acute myeloid leukemia and IDH1/2 mutation: a network meta-analysis

Because of lacking of head-to-head comparison between venetoclax and IDH1/IDH2 inhibitors (ivosidenib/enasidenib) for newly diagnosed unfit patients with acute myeloid leukemia (AML), the optimal option for these patients still remains undefined. We searched relevant published reports. Three RCTs with 180 IDH1 mutant and 165 IDH2 mutant patients were identified. Indirect comparison of OS using fixed effects network meta-analysis (NMA) models indicated venetoclax plus azacitidine (Ven-Aza) significantly improved survival than enasidenib plus azacitidine (Ena-Aza) (HR:0.30, p = 0.005) for those newly diagnosed patients with AML and IDH2 Mutation. And, for those IDH2 mutation patients, Ven-Aza also had the highest probability of 98.3% (OS analysis) and 84.0% (CR/CRi analysis) to be the best intervention among these first-line treatment regimens (Ven-Aza, Ena-Aza and Aza). And, there was a favorable trend towards Ven-Aza in survival analysis (HR:0.69, p = 0.42), when compared to ivosidenib plus azacitidine (Ivo-Aza) for those newly diagnosed patients with AML and IDH1 Mutation. For those IDH1 Mutation, venetoclax plus azacitidine (Ven-Aza) had the highest probability of 65.8% (OS analysis) and 73.0% (CR/CRi analysis) to be the best intervention among these first-line treatment regimens (Ven-Aza, ivosidenib plus azacitidine (Ivo-Aza) and azacitidine (Aza)). In conclusion, venetoclax plus azacitidine could be a good option for unfit newly diagnosed patients with acute myeloid leukemia and IDH1/2 mutation. Considering our limits (only trial data-based network meta-analysis et al.), future trials directly comparing these regimens are warranted.

Management of isocitrate dehydrogenase 1/2 mutated acute myeloid leukemia

The emergence of next generation sequencing and widespread use of mutational profiling in acute myeloid leukemia (AML) has broadened our understanding of the heterogeneous molecular basis of the disease. Since genetic sequencing has become a standard practice, several driver mutations have been identified. Accordingly, novel targeted therapeutic agents have been developed and are now approved for the treatment of subsets of patients that carry mutations in FLT3, IDH1, and IDH2 [1, 2]. The emergence of these novel agents in AML offers patients a new modality of therapy, and shifts treatment paradigms toward individualized medicine. In this review, we outline the role of IDH mutations in malignant transformation, focus in on a novel group of targeted therapeutic agents directed toward IDH1- and IDH2-mutant AML, and explore their impact on prognosis in patients with AML.

RIPK3 deficiency blocks R-2-hydroxyglutarate-induced necroptosis in IDH-mutated AML cells

Mutant isocitrate dehydrogenases (IDHs) produce R-2-hydroxyglutarate (R-2HG), which inhibits the growth of most acute myeloid leukemia (AML) cells. Here, we showed that necroptosis, a form of programmed cell death, contributed to the antileukemia activity of R-2HG. Mechanistically, R-2HG competitively inhibited the activity of lysine demethylase 2B (KDM2B), an α-ketoglutarate-dependent dioxygenase. KDM2B inhibition increased histone 3 lysine 4 trimethylation levels and promoted the expression of receptor-interacting protein kinase 1 (RIPK1), which consequently caused necroptosis in AML cells. The expression of RIPK3 was silenced because of DNA methylation in IDH-mutant (mIDH) AML cells, resulting in R-2HG resistance. Decitabine up-regulated RIPK3 expression and repaired endogenous R-2HG-induced necroptosis pathway in mIDH AML cells. Together, R-2HG induced RIPK1-dependent necroptosis via KDM2B inhibition in AML cells. The loss of RIPK3 protected mIDH AML cells from necroptosis. Restoring RIPK3 expression to exert R-2HG's intrinsic antileukemia effect will be a potential therapeutic strategy in patients with AML.

Comprehensive Molecular Profiling of NPM1-Mutated Acute Myeloid Leukemia Using RNAseq Approach

Acute myeloid leukemia (AML) is a complex hematologic malignancy with high morbidity and mortality. Nucleophosmin 1 (NPM1) mutations occur in approximately 30% of AML cases, and NPM1-mutated AML is classified as a distinct entity. NPM1-mutated AML patients without additional genetic abnormalities have a favorable prognosis. Despite this, 30-50% of them experience relapse. This study aimed to investigate the potential of total RNAseq in improving the characterization of NPM1-mutated AML patients. We explored genetic variations independently of myeloid stratification, revealing a complex molecular scenario. We showed that total RNAseq enables the uncovering of different genetic alterations and clonal subtypes, allowing for a comprehensive evaluation of the real expression of exome transcripts in leukemic clones and the identification of aberrant fusion transcripts. This characterization may enhance understanding and guide improved treatment strategies for NPM1mut AML patients, contributing to better outcomes. Our findings underscore the complexity of NPM1-mutated AML, supporting the incorporation of advanced technologies for precise risk stratification and personalized therapeutic strategies. The study provides a foundation for future investigations into the clinical implications of identified genetic variations and highlights the importance of evolving diagnostic approaches in leukemia management.

Innovations in conditioning and post-transplant maintenance in AML: genomically informed revelations on the graft-versus-leukemia effect

Acute Myeloid Leukemia (AML) is the prototype of cancer genomics as it was the first published cancer genome. Large-scale next generation/massively parallel sequencing efforts have identified recurrent alterations that inform prognosis and have guided the development of targeted therapies. Despite changes in the frontline and relapsed standard of care stemming from the success of small molecules targeting FLT3, IDH1/2, and apoptotic pathways, allogeneic stem cell transplantation (alloHSCT) and the resulting graft-versus-leukemia (GVL) effect remains the only curative path for most patients. Advances in conditioning regimens, graft-vs-host disease prophylaxis, anti-infective agents, and supportive care have made this modality feasible, reducing transplant related mortality even among patients with advanced age or medical comorbidities. As such, relapse has emerged now as the most common cause of transplant failure. Relapse may occur after alloHSCT because residual disease clones persist after transplant, and develop immune escape from GVL, or such clones may proliferate rapidly early after alloHSCT, and outpace donor immune reconstitution, leading to relapse before any GVL effect could set in. To address this issue, genomically informed therapies are increasingly being incorporated into pre-transplant conditioning, or as post-transplant maintenance or pre-emptive therapy in the setting of mixed/falling donor chimerism or persistent detectable measurable residual disease (MRD). There is an urgent need to better understand how these emerging therapies modulate the two sides of the GVHD vs. GVL coin: 1) how molecularly or immunologically targeted therapies affect engraftment, GVHD potential, and function of the donor graft and 2) how these therapies affect the immunogenicity and sensitivity of leukemic clones to the GVL effect. By maximizing the synergistic action of molecularly targeted agents, immunomodulating agents, conventional chemotherapy, and the GVL effect, there is hope for improving outcomes for patients with this often-devastating disease.