DNMT3A and IDH mutations in acute myeloid leukemia and other myeloid malignancies: associations with prognosis and potential treatment strategies

Prognostic impact of co-mutations in adults with IDH1/2-mutated acute myeloid leukemia

Acute myeloid leukemia (AML) is characterized by the accumulation of cytogenetic and molecular abnormalities. Isocitrate dehydrogenase 1 and 2 (IDH1/2) mutations occur in 11% to 20% of adults with AML. The outcome of IDH1/2-mutated AML is heterogeneous and affected by co-mutational patterns. We retrospectively analyzed 118 patients with IDH1/2-mutated AML who were retrieved from 1597 patients newly diagnosed with AML and treated with intensive chemotherapy. Univariate analysis revealed the NPM1 mutation was a favorable factor (p = 0.019) for overall survival (OS), whereas the DNMT3A mutation was consistently associated with a poor outcome (3-year OS, 52.0%; 3-year relapse-free survival [RFS], 44.8%; and 3-year cumulative incidence of relapse [CIR], 42.6%). Interestingly, the DNMT3A mutation still identified patients with a poorer prognosis, even when measurable residual disease (MRD) was negative after 2 courses of chemotherapy. In a multivariate regression model, age, DNMT3A mutation and MRD positivity were retained as independent adverse markers for OS, RFS, and CIR. In the absence of the DNMT3A or FLT3-ITD mutations, the NPM1 mutation identified patients with a very favorable OS (3-year OS, 96.3% and 86.3%, respectively). Finally, hematopoietic stem cell transplantation in first complete remission significantly improved RFS (p = 0.015) and there was a trend toward improvement in OS (p = 0.282) for patients with the DNMT3A mutation but it did not benefit 2 subgroups with the IDH1/2+/NPM1+/DNMT3A- and IDH1/2+/NPM1+/FLT3-ITD- genotypes. In summary, this study provides a reference for risk stratification and treatment implications for patients with IDH1/2-mutated AML as well as for comparison with results of IDH inhibitor- or venetoclax-based combination therapy.

Getting the right combination to break the epigenetic code

Rapid advances in the field of epigenetics have facilitated the development of novel therapeutics targeting epigenetic mechanisms that are hijacked by cancer cells to support tumour growth and progression. Several epigenetic agents have been approved by the FDA for the treatment of cancer; however, the efficacy of these drugs is dependent on the underlying biology and drivers of the disease, with inherent differences between solid tumours and haematological malignancies. The efficacy of epigenetic drugs as single agents remains limited across most cancer types, which has spurred the clinical development of combination therapies, with the hope of attaining synergistic activity and/or overcoming treatment resistance. In this Review we discuss clinical advances that have been achieved with the use of epigenetic agents in combination with chemotherapies, immunotherapies or other targeted agents, including epigenetic-epigenetic combinations, as well as limitations and challenges associated with these combinatorial strategies. So far, the success of combination therapies targeting epigenetic mechanisms has generally been confined to haematological malignancies, with limited efficacy observed in patients with solid tumours. Nevertheless, this Review captures the field of epigenetic combination therapies across the spectra of haematology and oncology, highlighting opportunities for precision therapy to effectively harness the potential of epigenetic agents and produce meaningful improvements in clinical outcomes.

Recent advances in the methods and clinical applications of next-generation sequencing in genomic profiling and precision cancer therapy

Cancer is a major cause of death worldwide. Next-generation sequencing (NGS) has dramatically increased the sequencing data output and transformed biomedical investigations. NGS enables the generations of genetic data specific to patients from tumor tissue samples so that targeted therapies can be used. The obtained data further allows the prioritization of effective therapies based on the tumor-specific genotype. Practitioners in the field of clinical genomics can make the best use of testing facilities while lessening the possible off-targets by choosing a priori gene set. Therefore, targeted sequencing has arisen as a more affordable technique for the genomic profiling of tumors. Drug resistance is commonly observed in cancer because of mutations. Thus, precise genetic and molecular profiling of tumors ought to be routinely done prior to the use of targeted therapy or precision cancer therapy. NGS already has the capacity to ameliorate genetic screening in families with previous histories of the high occurrence of various cancer-associated genes, including TP53, APC, BRCA2, and BRCA1. By using NGS system, researchers detected increased variants in cancer cells with greater specificity and sensitivity than conventional diagnostic approaches, which suggest the potential of NGS in diagnosis. The field of precision cancer therapy is continuously growing and because of their specificity at the molecular level has improved the management and treatment of numerous cancers. These therapies are less toxic and more efficient compared to conventional chemotherapies used in cancer treatment. The field of precision cancer therapy is likely to significantly expand as NGS system advances. This review provides extensive information regarding current advances in the NGS field in terms of methods, clinical applications, genomic profiling, and the role of NGS of precision cancer therapy.

Cancer epigenetic therapy: recent advances, challenges, and emerging opportunities

Epigenetic dysregulation is an important nexus in the development and maintenance of human cancers. This review provides an overview of how understanding epigenetic dysregulation in cancers has led to insights for novel cancer therapy development. Over the past two decades, significant strides have been made in drug discovery efforts targeting cancer epigenetic mechanisms, leading to successes in clinical development and approval of cancer epigenetic therapeutics. This article will discuss the current therapeutic rationale guiding the discovery and development of epigenetic therapeutics, key learnings from clinical experiences and new opportunities on the horizon.

Acute myeloid leukemia treatment outcomes with isocitrate dehydrogenase mutations: A systematic review and meta-analysis

BACKGROUND

Isocitrate dehydrogenase (IDH) gene alterations and acute myeloid leukemia (AML) treatment results remain controversial. This study reviews the literature on IDH mutations in AML to determine the foundation of individualized therapy and improve effectiveness, survival time, and recurrence rate.

METHODS

Seven English and 2 Chinese databases were searched for literature on IDH mutations and AML outcomes. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Twenty studies were included in this analysis. For the prognostic influence of IDH mutation on AML patients, the pooled HRs of overall survival in AML patients were 0.76 (95% CI, 0.63-0.93); the pooled HRs of event-free survival were 1.34 (95% CI, 1.15-1.57; heterogeneity: I2 = 52.2%, P = .027 < 0.05); the pooled HRs of recurrence free survival were 0.79 (95% CI, 0.61-1.02). The pooled HRs of overall survival in AML patients with mutant IDH1 were 1.62 (95% CI, 1.42-1.86) and of mutant IDH2 were 1.07 (95% CI, 0.89-1.29). The pooled HRs for event-free survival in AML patients with mutant IDH1 were 1.71 (95% CI, 1.40-2.08) and of mutant IDH2 were 0.93 (95% CI, 0.65-1.34). No evidence of publication bias was observed.

CONCLUSIONS

Different subtypes of IDH mutations may lead to different AML prognoses, suggesting the feasibility of personalized treatment for AML patients.

Lactate reprograms glioblastoma immunity through CBX3-regulated histone lactylation

Glioblastoma (GBM), an aggressive brain malignancy with a cellular hierarchy dominated by GBM stem cells (GSCs), evades antitumor immunity through mechanisms that remain incompletely understood. Like most cancers, GBMs undergo metabolic reprogramming toward glycolysis to generate lactate. Here, we show that lactate production by patient-derived GSCs and microglia/macrophages induces tumor cell epigenetic reprogramming through histone lactylation, an activating modification that leads to immunosuppressive transcriptional programs and suppression of phagocytosis via transcriptional upregulation of CD47, a "don't eat me" signal, in GBM cells. Leveraging these findings, pharmacologic targeting of lactate production augments efficacy of anti-CD47 therapy. Mechanistically, lactylated histone interacts with the heterochromatin component chromobox protein homolog 3 (CBX3). Although CBX3 does not possess direct lactyltransferase activity, CBX3 binds histone acetyltransferase (HAT) EP300 to induce increased EP300 substrate specificity toward lactyl-CoA and a transcriptional shift toward an immunosuppressive cytokine profile. Targeting CBX3 inhibits tumor growth by both tumor cell-intrinsic mechanisms and increased tumor cell phagocytosis. Collectively, these results suggest that lactate mediates metabolism-induced epigenetic reprogramming in GBM that contributes to CD47-dependent immune evasion, which can be leveraged to augment efficacy of immuno-oncology therapies.

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.

DNA methylation stochasticity is linked to transcriptional variability and identifies convergent epigenetic disruption across genetically-defined subtypes of AML

Disruption of the epigenetic landscape is of particular interest in acute myeloid leukemia (AML) due to its relatively low mutational burden and frequent occurrence of mutations in epigenetic regulators. Here, we applied an information-theoretic analysis of methylation potential energy landscapes, capturing changes in mean methylation level and methylation entropy, to comprehensively analyze DNA methylation stochasticity in subtypes of AML defined by mutually exclusive genetic mutations. We identified AML subtypes with CEBPA double mutation and those with IDH mutations as distinctly high-entropy subtypes, marked by methylation disruption over a convergent set of genes. We found a core program of epigenetic landscape disruption across all AML subtypes, with discordant methylation stochasticity and transcriptional dysregulation converging on functionally important leukemic signatures, suggesting a genotype-independent role of stochastic disruption of the epigenetic landscape in mediating leukemogenesis. We further established a relationship between methylation entropy and gene expression variability, connecting the disruption of the epigenetic landscape to transcription in AML. This approach identified a convergent program of epigenetic dysregulation in leukemia, clarifying the contribution of specific genetic mutations to stochastic disruption of the epigenetic and transcriptional landscapes of AML.

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.

A Simple HPLC-UV Method for Ivosidenib Determination in Human Plasma

Ivosidenib is used for the treatment of acute myeloid leukemia (AML) with isocitrate dehydrogenase 1 (IDH1) mutations. However, increased blood concentrations of ivosidenib are associated with a risk of a prolonged QT interval in patients with AML. Therapeutic drug monitoring in patients with AML with IDH1 mutation offers the potential to improve treatment efficacy while minimizing toxicity. In this study, we developed an efficient high-performance liquid chromatography-ultraviolet (HPLC-UV) method for the quantification of ivosidenib in plasma. Human plasma samples (50 μL) were processed by protein precipitation using acetonitrile, followed by chromatographic separation on a reversed-phase column with an isocratic mobile phase of 0.5% KH₂PO₄ (pH 4.5) and acetonitrile (45:55, v/v) at a flow rate of 1.0 mL/min, with ultraviolet detection at 245 nm. Calibration curves were linear over the range of 0.25-20 μg/mL with a coefficient of determination (r2) of 0.99999. Intra-day and inter-day precision were 1.20-8.04% and 0.69-4.20%, respectively. The assay accuracy was -2.00% to 1.93% and recovery was >91.2%. These findings support the effectiveness of the newly developed HPLC-UV method for the quantification of ivosidenib in human plasma. This simple and cost-effective method is expected to expand ivosidenib monitoring in laboratories lacking LC-MS/MS instruments.

Identifying key genes and functionally enriched pathways in acute myeloid leukemia by weighted gene co-expression network analysis

Acute myeloid leukemia (AML) is characterized by the uncontrolled proliferation of myeloid leukemia cells in the bone marrow and other hematopoietic tissues and is highly heterogeneous. While with the progress of sequencing technology, understanding of the AML-related biomarkers is still incomplete. The purpose of this study is to identify potential biomarkers for prognosis of AML. Based on WGCNA analysis of gene mutation expression, methylation level distribution, mRNA expression, and AML-related genes in public databases were employed for investigating potential biomarkers for the prognosis of AML. This study screened a total of 6153 genes by analyzing various changes in 103 acute myeloid leukemia (AML) samples, including gene mutation expression, methylation level distribution, mRNA expression, and AML-related genes in public databases. Moreover, seven AML-related co-expression modules were mined by WGCNA analysis, and twelve biomarkers associated with the AML prognosis were identified from each top 10 genes of the seven co-expression modules. The AML samples were then classified into two subgroups, the prognosis of which is significantly different, based on the expression of these twelve genes. The differentially expressed 7 genes of two subgroups (HOXB-AS3, HOXB3, SLC9C2, CPNE8, MEG8, S1PR5, MIR196B) are mainly involved in glucose metabolism, glutathione biosynthesis, small G protein-mediated signal transduction, and the Rap1 signaling pathway. With the utilization of WGCNA mining, seven gene co-expression modules were identified from the TCGA database, and there are unreported genes that may be potential driver genes of AML and may be the direction to identify the possible molecular signatures to predict survival of AML patients and help guide experiments for potential clinical drug targets.

Epigenetic alterations in AML: Deregulated functions leading to new therapeutic options

Acute myeloid leukemia (AML) results in disruption of the hematopoietic differentiation process. Crucial progress has been made, and new therapeutic strategies for AML have been developed. Induction chemotherapy, however, remains the main option for the majority of AML patients. Epigenetic dysregulation plays a central role in AML pathogenesis, supporting leukemogenesis and maintenance of leukemic stem cells. Here, we provide an overview of the intricate interplay of altered epigenetic mechanisms, including DNA methylation, histone modifications, and chromatin remodeling, in AML development. We explore the role of epigenetic regulators, such as DNMTs, HMTs, KDMs, and HDACs, in mediating gene expression patterns pushing towards leukemic cell transformation. Additionally, we discuss the impact of cytogenetic lesions on epigenomic remodeling and the potential of targeting epigenetic vulnerabilities as a therapeutic strategy. Understanding the epigenetic landscape of AML offers insights into novel therapeutic avenues, including epigenetic modifiers and particularly their use in combination therapies, to improve treatment outcomes and overcome drug resistance.

Loss of Dnmt3a increases self-renewal and resistance to pegIFN-α in JAK2-V617F-positive myeloproliferative neoplasms

ABSTRACT

Pegylated interferon alfa (pegIFN-α) can induce molecular remissions in patients with JAK2-V617F-positive myeloproliferative neoplasms (MPNs) by targeting long-term hematopoietic stem cells (LT-HSCs). Additional somatic mutations in genes regulating LT-HSC self-renewal, such as DNMT3A, have been reported to have poorer responses to pegIFN-α. We investigated whether DNMT3A loss leads to alterations in JAK2-V617F LT-HSC functions conferring resistance to pegIFN-α treatment in a mouse model of MPN and in hematopoietic progenitors from patients with MPN. Long-term treatment with pegIFN-α normalized blood parameters and reduced splenomegaly and JAK2-V617F chimerism in single-mutant JAK2-V617F (VF) mice. However, pegIFN-α in VF;Dnmt3aΔ/Δ (VF;DmΔ/Δ) mice worsened splenomegaly and failed to reduce JAK2-V617F chimerism. Furthermore, LT-HSCs from VF;DmΔ/Δ mice compared with VF were less prone to accumulate DNA damage and exit dormancy upon pegIFN-α treatment. RNA sequencing showed that IFN-α induced stronger upregulation of inflammatory pathways in LT-HSCs from VF;DmΔ/Δ than from VF mice, indicating that the resistance of VF;DmΔ/Δ LT-HSC was not due to failure in IFN-α signaling. Transplantations of bone marrow from pegIFN-α-treated VF;DmΔ/Δ mice gave rise to more aggressive disease in secondary and tertiary recipients. Liquid cultures of hematopoietic progenitors from patients with MPN with JAK2-V617F and DNMT3A mutation showed increased percentages of JAK2-V617F-positive colonies upon IFN-α exposure, whereas in patients with JAK2-V617F alone, the percentages of JAK2-V617F-positive colonies decreased or remained unchanged. PegIFN-α combined with 5-azacytidine only partially overcame resistance in VF;DmΔ/Δ mice. However, this combination strongly decreased the JAK2-mutant allele burden in mice carrying VF mutation only, showing potential to inflict substantial damage preferentially to the JAK2-mutant clone.

Comprehensive characterization of immunogenic cell death in acute myeloid leukemia revealing the association with prognosis and tumor immune microenvironment

BACKGROUND

This study aimed to explore the clinical significance of immunogenic cell death (ICD) in acute myeloid leukemia (AML) and its relationship with the tumor immune microenvironment characteristics. It also aimed to provide a potential perspective for bridging the pathogenesis of AML and immunological research, and to provide a theoretical basis for precise individualized treatment of AML patients.

METHODS

Firstly, we identified two subtypes associated with ICD by consensus clustering and explored the biological enrichment pathways, somatic mutations, and tumor microenvironment landscape between the ICD subtypes. Additionally, we developed and validated a prognostic model associated with ICD-related genes. Finally, we conducted a preliminary exploration of the construction of disease regulatory networks and prediction of small molecule drugs based on five signature genes.

RESULTS

Differentially expressed ICD-related genes can distinguish AML into subgroups with significant differences in clinical characteristics and survival prognosis. The relationship between the ICD- high subgroup and the immune microenvironment was tight, showing significant enrichment in immune-related pathways such as antibody production in the intestinal immune environment, allograft rejection, and Leishmaniasis infection. Additionally, the ICD- high subtype showed significant upregulation in a variety of immune cells such as B_cells, Macrophages_M2, Monocytes, and T_cells_CD4. We constructed a prognostic risk feature based on five signature genes (TNF, CXCR3, CD4, PIK3CA and CALR), and the time-dependent ROC curve confirmed the high accuracy in predicting the clinical outcomes.

CONCLUSION

There is a strong close relationship between the ICD- high subgroup and the immune microenvironment. Immunogenicity-related genes have the potential to be a prognostic biomarker for AML.

Novel Therapeutic Targets in Acute Myeloid Leukemia (AML)

PURPOSE OF REVIEW

This review seeks to identify and describe novel genetic and protein targets and their associated therapeutics currently being used or studied in the treatment of acute myeloid leukemia (AML).

RECENT FINDINGS

Over the course of the last 5-6 years, several targeted therapies have been approved by the FDA, for the treatment of both newly diagnosed as well as relapsed/refractory AML. These novel therapeutics, as well as several others currently under investigation, have demonstrated activity in AML and have improved outcomes for many patients. Patient outcomes in AML have slowly improved over time, though for many patients, particularly elderly patients or those with relapsed/refractory disease, mortality remains very high. With the identification of several molecular/genetic drivers and protein targets and development of therapeutics which leverage those mechanisms to target leukemic cells, outcomes for patients with AML have improved and continue to improve significantly.

CD7-positive leukemic blasts with DNMT3A mutations predict poor prognosis in patients with acute myeloid leukemia

Background

DNMT3A mutations can be detected in premalignant hematopoietic stem cells and are primarily associated with clonal hematopoiesis of indeterminate potential; however, current evidence does not support assigning them to a distinct European Leukemia Net (ELN) prognostic risk stratification. CD7 is a lymphoid antigen expressed on blasts in approximately 30% of acute myeloid leukemia (AML), and its role in AML remains unclear and depends on subgroup evaluation. This study investigated the prognostic value of DNMT3A mutation combined with CD7 expression in AML.

Methods

We retrospectively analyzed the clinical data of 297 newly diagnosed non-M3 AML patients. According to the DNMT3A mutation and CD7 expression in AML cells, patients were divided into the DNMT3A-mutated/CD7-positive (CD7+), DNMT3A-mutated/CD7-negative (CD7-), DNMT3A-wild-type/CD7+, and DNMT3A-wild-type/CD7- groups.

Results

The DNMT3A-mutated/CD7+ group had lower complete remission rates and higher relapse rates. Importantly, these patients had significantly shorter overall survival (OS) and relapse-free survival (RFS). Furthermore, multivariate analysis showed that CD7+ with DNMT3A mutation was an independent risk factor for OS and RFS.

Conclusion

CD7+ with DNMT3A mutation predicts a poor prognosis in AML patients, and the immunophenotype combined with molecular genetic markers can help to further refine the current risk stratification of AML.

Therapeutic biomarkers in acute myeloid leukemia: functional and genomic approaches

Acute myeloid leukemia (AML) is clinically and genetically a heterogeneous disease characterized by clonal expansion of abnormal hematopoietic progenitors. Genomic approaches to precision medicine have been implemented to direct targeted therapy for subgroups of AML patients, for instance, IDH inhibitors for IDH1/2 mutated patients, and FLT3 inhibitors with FLT3 mutated patients. While next generation sequencing for genetic mutations has improved treatment outcomes, only a fraction of AML patients benefit due to the low prevalence of actionable targets. In recent years, the adoption of newer functional technologies for quantitative phenotypic analysis and patient-derived avatar models has strengthened the potential for generalized functional precision medicine approach. However, functional approach requires robust standardization for multiple variables such as functional parameters, time of drug exposure and drug concentration for making in vitro predictions. In this review, we first summarize genomic and functional therapeutic biomarkers adopted for AML therapy, followed by challenges associated with these approaches, and finally, the future strategies to enhance the implementation of precision medicine.

Aberrant HIF1- α and SIX-1 Expression is Associated with Poor Prognosis in Acute Myeloid Leukemia Patients with Isocitrate Dehydrogenase 1 Mutations

BACKGROUND

IDH1 mutations are common in many cancers, however, their role in promoting the Warburg effect remains elusive. This study elucidates the putative involvement of mutant-IDH1 in regulating hypoxia-inducible factor (HIF1-α) and Sine-Oculis Homeobox-1 (SIX-1) expression.

METHODOLOGY

Genetic screening was performed using the ARMS-PCR in acute myeloid leukemia (AML), brain, and breast cancer (BC) cohorts, while transcript expression was determined using qPCR. Further, a meta-analysis of risk factors associated with the R132 mutation was performed.

RESULTS

Approximately 32% of AML and ∼60% of glioma cases were mutants, while no mutation was found in the BC cohort. 'AA' and TT' were associated with higher disease risk (OR = 12.18 & 4.68) in AML and had significantly upregulated IDH1 expression. Moreover, downregulated HIF1-α and upregulated SIX-1 expression was also observed in these patients, suggesting that mutant-IDH1 may alter glucose metabolism. Perturbed IDH1 and HIF-α levels exhibited poor prognosis in univariate and multivariate analysis, while age and gender were found to be contributory factors as well. Based on the ROC model, these had a good potential to be used as prognostic markers. A significant variation in frequencies of R132 mutations in AML among different populations was observed. Cytogenesis (R2 = 12.2%), NMP1 mutation status (R2 = 18.5%), and ethnic contributions (R2 = 73.21%) were critical moderators underlying these mutations. Women had a higher risk of R132 mutation (HR = 1.3, P < 0.04). The pooled prevalence was calculated to be 0.29 (95% CI 0.26-0.33, P < 0.01), indicating that IDH1 mutations are a significant prognostic factor in AML.

CONCLUSION

IDH1 and HIF1-α profiles are linked to poor survival and prognosis, while high SIX-1 expression in IDH1 mutants suggests a role in leukemic transformation and therapy response in AML.

Impact of Frontline Ivosidenib on Volumetric Growth Patterns in Isocitrate Dehydrogenase-mutant Astrocytic and Oligodendroglial Tumors

PURPOSE

Isocitrate dehydrogenase (IDH)-mutant gliomas are usually treated with radiotherapy and chemotherapy, which increases the risk for neurocognitive sequelae during patients' most productive years. We report our experience using off-label first-in-class mutant IDH1 inhibitor ivosidenib and its impact on tumor volume in IDH-mutant gliomas.

EXPERIMENTAL DESIGN

We retrospectively analyzed patients ages ≥18 years with radiation/chemotherapy-naïve, mutant IDH1, nonenhancing, radiographically active, grade 2/3 gliomas, and ≥2 pretreatment and ≥2 on-treatment ivosidenib MRIs. T2/FLAIR-based tumor volumes, growth rates, and progression-free survival (PFS) were analyzed. log-linear mixed-effect modeling of growth curves adjusted for grade, histology, and age was performed.

RESULTS

We analyzed 116 MRIs of 12 patients [10 males, median age 46 years (range: 26-60)]: 8 astrocytomas (50% grade 3) and 4 grade 2 oligodendrogliomas. Median on-drug follow-up was 13.2 months [interquartile range (IQR): 9.7-22.2]. Tolerability was 100%. A total of 50% of patients experienced ≥20% tumor volume reduction on-treatment and absolute growth rate was lower during treatment (-1.2 ± 10.6 cc/year) than before treatment (8.0 ± 7.7 cc/year; P ≤ 0.05). log-linear models in the Stable group (n = 9) showed significant growth before treatment (53%/year; P = 0.013), and volume reduction (-34%/year; P = 0.037) after 5 months on treatment. After treatment, volume curves were significantly lower than before treatment (after/before treatment ratio 0.5; P < 0.01). Median time-to-best response was 11.2 (IQR: 1.7-33.4) months, and 16.8 (IQR: 2.6-33.5) months in patients on drug for ≥1 year. PFS at 9 months was 75%.

CONCLUSIONS

Ivosidenib was well tolerated and induced a high volumetric response rate. Responders had significant reduction in tumor growth rates and volume reductions observed after a 5-month delay. Thus, ivosidenib appears useful to control tumor growth and delay more toxic therapies in IDH-mutant nonenhancing indolently growing gliomas. See related commentary by Lukas and Horbinski, p. 4709.

Cancer vaccine strategies for the treatment of diffusely infiltrating gliomas

Diffusely infiltrating gliomas - including glioblastoma (GBM), isocitrate dehydrogenase (IDH) mutant gliomas, and histone 3 (H3) altered gliomas - are primary brain tumors with an invariably fatal outcome. Despite advances in the understanding of their biology, standard, targeted and immune checkpoint inhibitor immunotherapies have proven ineffective in arresting their inexorable progression and associated morbidity and mortality. Recognizing the unique aspects of the immunogenicity of cancer cells, the last decade has seen the development and evaluation of vaccine-based therapies for the treatment of solid tumors, including gliomas. Here we review the current vaccine strategies for the treatment of GBM, IDH-mutant gliomas and diffuse midline glioma H3 K27M-altered. We discuss potential benefits and challenges of vaccine therapies in these specific patient populations.

Differentiation Syndrome in Acute Leukemia: APL and Beyond

Differentiation syndrome (DS) is a frequent and potentially life-threatening clinical syndrome first recognized with the advent of targeted therapeutics for acute promyelocytic leukemia (APL). DS was subsequently observed more broadly with targeted therapeutics for acute myeloid leukemia (AML). DS is typically characterized by fever, dyspnea, hypotension, weight gain, pleural or pericardial effusions, and acute renal failure. The incidence in patients with APL ranges from 2 to 37%, with the wide variation likely attributed to different diagnostic criteria, use of prophylactic treatment, and different treatment regimens. Treatment with corticosteroids +/- cytoreductive therapy should commence as soon as DS is suspected to reduce DS-related morbidity and mortality. The targeted anti-leukemic therapy should be discontinued in patients with severe DS. Here, we discuss the pathogenesis of DS, clinical presentations, diagnostic criteria, management strategies, and implementation of prospective tracking on clinical trials.

Structure-Based Drug Design of Novel Triaminotriazine Derivatives as Orally Bioavailable IDH2R140Q Inhibitors with High Selectivity and Reduced hERG Inhibitory Activity for the Treatment of Acute Myeloid Leukemia

Neomorphic IDH2R140Q mutation is commonly found in acute myeloid leukemia (AML), and inhibiting its activity has been validated as an effective treatment for AML. Herein, we report a series of highly potent and selective IDH2R140Q inhibitors. Among them, compound 36 was identified as the most promising inhibitor, with an IC50 value of 29 nM and more than 490-fold selectivity over wild-type IDH2. The compound significantly suppressed D2HG production (IC50 = 10 nM) and induced differentiation in TF-1/IDH2R140Q cells. Furthermore, it showed reasonable pharmacokinetic properties with high bioavailability (F = 90.3%) and an appropriate half-life (T1/2 = 6.4 h). In vivo, oral administration of compound 36 at a dose of 25 mg/kg effectively reduced D2HG levels in the tumor of TF-1/IDH2R140Q xenograft mouse model. Besides, compound 36 displayed little effect on the hERG current. These results suggest that compound 36 has the potential to be an efficacious treatment for AML.

Ivosidenib in acute myeloid leukemia

INTRODUCTION

Traditional treatment strategies for acute myeloid leukemia (AML) have primarily relied on standard chemotherapy regimens for four decades. Indeed, the landscape of AML therapy has evolved substantially in recent years, mainly due to the introduction of hypomethylating agents and small molecules.Bcl2 inhibitor venetoclax, Fms-like tyrosine kinase 3 (FLT3) inhibitors such as midostaurin and gilteritinib, and isocitrate dehydrogenases 1 and 2 (IDH1 and IDH2) inhibitors ivosidenib and enasidenib, as well as hedgehog (HH) pathway inhibitor glasdegib represented a significant step forward in AML therapeutic armamentarium. Smoothened (SMO) inhibitor in combination with low-dose cytarabine marks a recent milestone.

AREAS COVERED

Ivosidenib, the first-in-class, selective, allosteric IDH1R132 inhibitor, showed the capability to induce in vitro differentiation of primary mIDH1 AML blasts. Clinical data highlighted its exceptional safety profile, as a standalone therapy and in combination strategy. Additionally, comprehensive studies consistently demonstrated its effectiveness, both in monotherapy and in association with chemotherapy.

EXPERT OPINION

The identified ivosidenib's strengths, including its remarkable safety record and ability to yield positive therapeutic outcomes, position it as an ideal partner for both classic chemotherapy and biological treatments, i.e. hypometilant agents and/or venetoclax. Further studies are warranted to explore strategies for overcoming the occurrence of ivosidenib resistance.

Clonal haematopoiesis and dysregulation of the immune system

Age-related diseases are frequently linked to pathological immune dysfunction, including excessive inflammation, autoreactivity and immunodeficiency. Recent analyses of human genetic data have revealed that somatic mutations and mosaic chromosomal alterations in blood cells - a condition known as clonal haematopoiesis (CH) - are associated with ageing and pathological immune dysfunction. Indeed, large-scale epidemiological studies and experimental mouse models have demonstrated that CH can promote cardiovascular disease, chronic obstructive pulmonary disease, chronic liver disease, osteoporosis and gout. The genes most frequently mutated in CH, the epigenetic regulators TET2 and DNMT3A, implicate increased chemokine expression and inflammasome hyperactivation in myeloid cells as a possible mechanistic connection between CH and age-related diseases. In addition, TET2 and DNMT3A mutations in lymphoid cells have been shown to drive methylation-dependent alterations in differentiation and function. Here we review the observational and mechanistic studies describing the connection between CH and pathological immune dysfunction, the effects of CH-associated genetic alterations on the function of myeloid and lymphoid cells, and the clinical and therapeutic implications of CH as a target for immunomodulation.

IRX1 is a novel gene, overexpressed in high-grade IDH-mutant astrocytomas

BACKGROUND

IDH-mutant astrocytomas include CNS WHO grade 2 (A2), grade 3 (A3) and grade 4 (A4), of which A3 and A4 are high-grade. A3 has a heterogenous clinical outcome that cannot be explained entirely by the existing molecular biomarkers. We comprehensively studied the transcriptome profile of A3 to determine clinical significance.

METHODS

TCGA mRNA-sequencing data of A3 was analyzed to derive differentially expressed genes (DEG), which were short-listed using various approaches. mRNA expression of the short-listed genes was validated using NanoString platform on a uniformly treated and molecularly characterized A3 cohort. Protein expression of one prognostically significant gene, Iroquois-class homeodomain (IRX1) was assessed by immunohistochemistry and correlated with patient survival and tumor recurrence. IRX1 expression was also studied in different grades of astrocytoma. Since DNA methyltransferase 3 alpha (DNMT3A) influences IRX1 expression, its mutations were evaluated in a subset of tumors.

RESULTS

TCGA analysis identified 96 DEG in A3 tumours. 57 genes were short-listed and finally narrowed down to 14 genes. mRNA values of 12/14 genes validated in our cohort. On multiple-variable analysis, IRX1 was the most prognostically relevant gene, with respect to progression free survival of patients. Further, IRX1 immunoexpression was significantly higher in A3 and A4 when compared to A2 and glioblastoma. Higher IRX1 immunoexpression correlated with poor prognosis in patients with A3 tumours. Also, a higher IRX1 expression was associated with DNMT3A mutation.

CONCLUSION

Our study identifies IRX1 as a novel biomarker overexpressed in high-grade IDH-mutant astrocytomas with prognostic significance in A3. DNMT3A mutation probably modulates IRX1 expression.

SLC25A1-associated prognostic signature predicts poor survival in acute myeloid leukemia patients

Background: Acute myeloid leukemia (AML) is a heterogeneous malignant disease. SLC25A1, the gene encoding mitochondrial carrier subfamily of solute carrier proteins, was reported to be overexpressed in certain solid tumors. However, its expression and value as prognostic marker has not been assessed in AML. Methods: We retrieved RNA profile and corresponding clinical data of AML patients from the Beat AML, TCGA, and TARGET databases (TARGET_AML). Patients in the TCGA cohort were well-grouped into two group based on SLC25A1 and differentially expressed genes were determined between the SLC25A1 high and low group. The expression of SLC25A1 was validated with clinical samples. The survival and apoptosis of two AML cell lines were analyzed with SLC25A1 inhibitor (CTPI-2) treatment. Cox and the least absolute shrinkage and selection operator (LASSO) regression analyses were applied to Beat AML database to identify SLC25A1-associated genes for the construction of a prognostic risk-scoring model. Survival analysis was performed by Kaplan-Meier and receiver operator characteristic curves. Results: Our analysis revealed that high expressed level of SLC25A1 in AML patients correlates with unfavorable prognosis. Moreover, SLC25A1 expression was positively associated with metabolism activity. We further demonstrated that the inhibition of SLC25A1 could inhibit the proliferation and increase the apoptosis of AML cells. In addition, a panel of SLC25A1-associated genes, was identified to construct a prognostic risk-scoring model. This SLC25A1-associated prognostic signature (SPS) is an independent risk factor with high area under curve (AUC) values of receiver operating characteristic (ROC) curves. A high SPS in leukemia patients is associated with poor survival. A Prognostic nomogram including the SPS and other clinical parameters, was constructed and its predictive efficiency was confirmed. Conclusion: We have successfully established a SPS prognostic model that predict outcome and risk stratification in AML. This risk model can be used as an independent biomarker to assess prognosis of AML.

How I treat with maintenance therapy after allogeneic HCT

Disease relapse is the leading cause of failure for patients receiving allogeneic hematopoietic cell transplantation (allo-HCT). Maintenance therapy administered after allo-HCT is a promising strategy to reduce the incidence of relapse and enhance the curative potential of allo-HCT. Research investigations and clinical applications of this approach have greatly increased in recent years, with an expanding number of available therapeutic agents to introduce in the posttransplant setting. However, many questions and challenges remain regarding the feasibility and clinical impact of maintenance. In this article, we present four common case scenarios addressing select available therapeutic agents as a framework to review published data and ongoing studies and describe our current standard practice in the rapidly evolving field of maintenance therapy after allo-HCT.

SFXN3 is Associated with Poor Clinical Outcomes and Sensitivity to the Hypomethylating Therapy in Non-M3 Acute Myeloid Leukemia Patients

BACKGROUND

DNA hypermethylation plays a critical role in the occurrence and progression of acute myeloid leukemia (AML). The mitochondrial serine transporter, SFXN3, is vital for onecarbon metabolism and DNA methylation. However, the impact of SFXN3 on the occurrence and progression of AML has not been reported yet.

OBJECTIVE

In this study, we hypothesized that SFXN3 indicates a poor prognosis and suggested tailored treatment for AML patients.

METHODS

We used GEPIA and TCGA repository data to analyze the expression of SFXN3 and its correlation with survival in AML patients. RT-qPCR was used to detect the SFXN3 level in our enrolled AML patients and volunteers. Additionally, Whole Genome Bisulfite Sequencing (WGBS) was used to detect the genomic methylation level in individuals.

RESULTS

Through the TCGA and GEPIA databases, we found that SFXN3 was enriched in AML patients, predicting shorter survival. Furthermore, we confirmed that SFXN3 was primarily overexpressed in AML patients, especially non-M3 patients, and that high SFXN3 in non-M3 AML patients was found to be associated with poor outcomes and frequent blast cells. Interestingly, non-M3 AML patients with high SFXN3 levels who received hypomethylating therapy showed a higher CR ratio. Finally, we found that SFXN3 could promote DNA methylation at transcription start sites (TSS) in non-M3 AML patients. These sites were found to be clustered in multiple vital cell functions and frequently accompanied by mutations in DNMT3A and NPM1.

CONCLUSION

In conclusion, SXFN3 plays an important role in the progression and hypermethylation in non-M3 AML patients and could be a potential biomarker for indicating a high CR rate for hypomethylating therapy.

Identification of three novel DNMT3A mutations with compromising methylation capacity in human acute myeloid leukaemia

BACKGROUND

Acute myeloid leukaemia (AML) is a complex and heterogeneous hematopoietic stem and progenitor cell malignancy characterised by the accumulation of immature blast cells in the bone marrow, blood, and other organs linked to environmental, genetic, and epigenetic factors. Somatic mutations in the gene DNA (cytosine-5)-methyltransferase 3A (DNMT3A; NM_022552.4) are common in AML patients.

METHODS

In this study, we used Sanger sequencing to detect the mutations in the DNMT3A gene in 61 Iraqi AML patients, Hence, the protein function and stability within alterations were identified and analyzed using a variety of computational tools with the goal of determining how these changes affect total protein stability, and then the capacity of methylation was analyzed by methylation specific PCR MSP status at CpG islands.

RESULTS

Three novel mutations in exon 23 of DNMT3A were identified in 14 patients (22.9%; V877I, N879delA, and L888Q). The V877I and L888Q substitutions are caused by heterozygous C2629G > A and C2663T > A mutations, respectively, while frameshift mutation C2635delA caused protein truncation with stop codon N879T*. Methylation was detected in the DNMT3A promoter region in 9 patients carrying DNMT3A mutations (64.28%) by MSP, and we found significant correlations between DNMT3A mutations and promoter methylation (p = 8.52 × 10⁵). In addition, we found a significant overrepresentation of DNMT3A methylation status in patients ≥ 50 years old (p = 0.025).

CONCLUSION

Our findings highlight the importance of studying the effects of DNMT3A methylation alteration in Iraqi populations beyond R882 substitutions in the leukemogenic pathway so that patient treatment can be tailored to prevent therapeutic resistance and relapse.

Genetics and Epigenetics in Neoplasms with Plasmacytoid Dendritic Cells

Simple Summary

Differential diagnosis between Blastic pDC Neoplasm (BPDCN) and Acute Myeloid Leukemia with pDC expansion (pDC-AML) is particularly challenging, and genomic features can help in diagnosis. This review aims at clarifying recent data on genomics features because the past five years have generated a large amount of original data regarding pDC neoplasms. The genetic landscape of BPDCN is now well-defined, with important updates concerning MYC/MYC rearrangements, but also epigenetic defects and novel concepts in oncogenic and immune pathways. Concerning pDC-AML, they now appear to exhibit an original mutation landscape, especially with RUNX1 mutations, which is of interest for diagnostic criteria and for therapeutic purposes. We highlight here these two different profiles, which contribute to differential diagnosis between BPDCN and pDC-AML. This point is particularly important for the study of different therapeutic strategies between BPDCN and AML.

Abstract

Plasmacytoid Dendritic Cells (pDC) are type I interferon (IFN)-producing cells that play a key role in immune responses. Two major types of neoplastic counterparts for pDC are now discriminated: Blastic pDC Neoplasm (BPDCN) and Mature pDC Proliferation (MPDCP), associated with myeloid neoplasm. Two types of MPDCP are now better described: Chronic MyeloMonocytic Leukemia with pDC expansion (pDC-CMML) and Acute Myeloid Leukemia with pDC expansion (pDC-AML). Differential diagnosis between pDC-AML and BPDCN is particularly challenging, and genomic features can help for diagnosis. Here, we systematically review the cytogenetic, molecular, and transcriptional characteristics of BPDCN and pDC-AML. BPDCN are characterized by frequent complex karyotypes with recurrent MYB/MYC rearrangements as well as recurrent deletions involving ETV6, IKZF1, RB1, and TP53 loci. Epigenetic and splicing pathways are also particularly mutated, while original processes are dysregulated, such as NF-kB, TCF4, BCL2, and IFN pathways; neutrophil-specific receptors; and cholinergic signaling. In contrast, cytogenetic abnormalities are limited in pDC-AML and are quite similar to other AML. Interestingly, RUNX1 is the most frequently mutated gene (70% of cases). These typical genomic features are of potential interest for diagnosis, and also from a prognostic or therapeutic perspective.

Hedgehog/GLI signaling in hematopoietic development and acute myeloid leukemia-From bench to bedside

While the underlying genetic alterations and biology of acute myeloid leukemia (AML), an aggressive hematologic malignancy characterized by clonal expansion of undifferentiated myeloid cells, have been gradually unraveled in the last decades, translation into clinical treatment approaches has only just begun. High relapse rates remain a major challenge in AML therapy and are to a large extent attributed to the persistence of treatment-resistant leukemic stem cells (LSCs). The Hedgehog (HH) signaling pathway is crucial for the development and progression of multiple cancer stem cell driven tumors, including AML, and has therefore gained interest as a therapeutic target. In this review, we give an overview of the major components of the HH signaling pathway, dissect HH functions in normal and malignant hematopoiesis, and specifically elaborate on the role of HH signaling in AML pathogenesis and resistance. Furthermore, we summarize preclinical and clinical HH inhibitor studies, leading to the approval of the HH pathway inhibitor glasdegib, in combination with low-dose cytarabine, for AML treatment.

How Genetics Can Drive Initial Therapy Choices for Older Patients with Acute Myeloid Leukemia

OPINION STATEMENT

Treatment of older adults with acute myeloid leukemia (AML) is challenging. Therapy decisions must be guided by multiple factors including aging-related conditions (e.g., comorbidities, functional impairment), therapy benefits and risks, patient preferences, and disease characteristics. Balancing these factors requires understanding the unique, and frequently higher-risk cytogenetic and molecular characteristics of AML in older adult populations, which should caution providers not to reduce therapy intensity on the basis of age alone. Instead, geriatric assessments should be employed to determine fitness for therapy. Treatment options in AML are increasingly targeted to specific mutations or recognized to have differential benefits on the basis of genomics, and representation of older adults and geriatric outcome reporting in clinical trials is improving. Additionally, newer studies have begun to explore personalized therapy strategies on the basis of initial genetic testing. Review and refinement of practice guidelines for older patients on the basis of these advances is needed and is anticipated to remain an important topic in ongoing hematology/oncology clinical education.

Drug Resistance Mechanisms of Acute Myeloid Leukemia Stem Cells

Acute myeloid leukemia (AML) is a polyclonal and heterogeneous hematological malignancy. Relapse and refractory after induction chemotherapy are still challenges for curing AML. Leukemia stem cells (LSCs), accepted to originate from hematopoietic stem/precursor cells, are the main root of leukemogenesis and drug resistance. LSCs are dynamic derivations and possess various elusive resistance mechanisms. In this review, we summarized different primary resistance and remolding mechanisms of LSCs after chemotherapy, as well as the indispensable role of the bone marrow microenvironment on LSCs resistance. Through a detailed and comprehensive review of the spectacle of LSCs resistance, it can provide better strategies for future researches on eradicating LSCs and clinical treatment of AML.

The Molecular Mechanisms of Resistance to IDH Inhibitors in Acute Myeloid Leukemia

Gain-of-function mutations of isocitrate dehydrogenases 1/2 (IDH1/2) play crucial roles in the development and progression of acute myeloid leukemia (AML), which provide promising therapeutic targets. Two small molecular inhibitors, ivosidenib and enasidenib have been approved for the treatment of IDH1- and IDH2-mutant AML, respectively. Although these inhibitors benefit patients with AML clinically, drug resistance still occurs and have become a major problem for targeted therapies of IDH-mutant AML. A number of up-to-date studies have demonstrated molecular mechanisms of resistance, providing rationales of novel therapeutic strategies targeting mutant IDH1/2. In this review, we discuss mechanisms of resistance to ivosidenib and enasidenib in patients with AML.

Clonal hematopoiesis: Mutation-specific adaptation to environmental change

Clonal hematopoiesis of indeterminate potential (CHIP) describes a widespread expansion of genetically variant hematopoietic cells that increases exponentially with age and is associated with increased risks of cancers, cardiovascular disease, and other maladies. Here, we discuss how environmental contexts associated with CHIP, such as old age, infections, chemotherapy, or cigarette smoking, alter tissue microenvironments to facilitate the selection and expansion of specific CHIP mutant clones. Further, we consider major remaining gaps in knowledge, including intrinsic effects, clone size thresholds, and factors affecting clonal competition, that will determine future application of this field in transplant and preventive medicine.

Molecular genetic and clinical characterization of acute myeloid leukemia with trisomy 8 as the sole chromosome abnormality

INTRODUCTION

The aim of the study was to determine molecular genetic and clinical characterization of acute myeloid leukemia (AML) with trisomy 8 as the sole chromosome abnormality, a recurrent but rare chromosomal abnormality in AML.

METHODS

Interphase fluorescence in situ hybridization, reverse transcriptase-quantitative polymerase chain reaction for gene rearrangement and next-generation sequencing (NGS) were performed on sole trisomy 8 AML patients.

RESULTS

A total of 35 AML patients with trisomy 8 as the sole chromosome abnormality were screened. The most frequently mutated genes were DNMT3A(37.1%), RUNX1(28.6%), FLT3-ITD(28.6%), IDH2(22.9%), NPM1(17.1%), and ASXL1 (14.3%). The sole +8 AML patients exhibited more mutations in RUNX1 (28.6% vs. 4.8%, P = 0.001) and ASXL1 (14.3% vs. 4.8%, P = 0.039) by comparing with normal karyotype AML (NK AML) patients(n = 63). The sole +8 AML patients(n = 35) with RUNX1 or IDH2 mutations showed significantly lower WBC counts, while FLT3-ITD showed higher white blood cell (WBC) counts as compared to the corresponding wild-type groups. Total of 45.7% patients achieved complete remission (CR) after the first induction therapy. The CR rate of patients with FLT3-ITD or IDH1 mutation was significantly lower than that in the corresponding wild-type cases (P = 0.047, 0.005, respectively). The median overall survival (OS) and disease-free survival (PFS) were 18.0 (95% CI: 10.8-25.2) and 10 (95% CI: 6.7-13.3) months, respectively. FLT3-ITD mutations and allogeneic hematopoietic stem cell transplantation (allo-HSCT) were independent prognostic markers for OS in multivariable analysis.

CONCLUSION

The results suggest a possible association between trisomy 8 and additional mutations that may influence clinical feature and prognosis.

Isocitrate dehydrogenase mutations are associated with altered IL-1β responses in acute myeloid leukemia

Mutations in isocitrate dehydrogenase 2 (IDH2) have been noted to impact cellular differentiation in addition to DNA and histone methylation. However, little is known about the impact of IDH2 mutations on intracellular signaling. Using an isogenic cell line model, we investigated both differentiation and signaling responses in IDH2 mutant cells and show augmented responses to inflammatory immune ligands. Using phospho-specific flow and mass cytometry, we demonstrate IDH2 mutant cells were significantly more sensitive to IL-1β at multiple downstream readouts. Further, bulk RNA sequencing confirmed increases in cytokine-related signaling pathways and NF-κB target genes. Single-cell RNA sequencing of unstimulated and stimulated cells confirmed altered IL-1β transcriptional responses in the IDH2 mutant cells. Targeted inhibition of the IKK complex reduced IL-1β responses and induced cell death in primary IDH-mutated leukemia samples. Together, these results confirm altered IL-1β signaling in IDH2 mutant cells and identify this pathway as a potential therapeutic target.

Haematological malignancies implications during the times of the COVID-19 pandemic

The COVID-19 pandemic has complicated current healthcare services for cancer patients. Patients with haematological malignancies specifically seem vulnerable to SARS-CoV-2 infection due to their immunosuppressed status. The COVID-19 pandemic influences every step of the assessment and treatment of a haematological malignancy. Clinicians must adhere to strict policies to not spread the virus to their patients while they must also adjust their workflow for maximum productivity. These difficulties accentuate the ever-present need to improve the healthcare services for cancer patients. This improvement is needed not only to combat the problems that arose from the COVID-19 pandemic but also to establish a framework for the management of patients with haematological malignancies in potential future pandemics.

Differential impact of IDH1/2 mutational subclasses on outcome in adult AML: Results from a large multicenter study

Patients with IDH1-R132C have a lower complete remission rate and a trend toward reduced OS.

Patients with IDH2-R172K in the European LeukemiaNet intermediate/adverse-risk group have significantly better relapse-free survival and OS.

Mutations of the isocitrate dehydrogenase-1 (IDH1) and IDH2 genes are among the most frequent alterations in acute myeloid leukemia (AML) and can be found in ∼20% of patients at diagnosis. Among 4930 patients (median age, 56 years; interquartile range, 45-66) with newly diagnosed, intensively treated AML, we identified IDH1 mutations in 423 (8.6%) and IDH2 mutations in 575 (11.7%). Overall, there were no differences in response rates or survival for patients with mutations in IDH1 or IDH2 compared with patients without mutated IDH1/2. However, distinct clinical and comutational phenotypes of the most common subtypes of IDH1/2 mutations could be associated with differences in outcome. IDH1-R132C was associated with increased age, lower white blood cell (WBC) count, less frequent comutation of NPM1 and FLT3 internal tandem mutation (ITD) as well as with lower rate of complete remission and a trend toward reduced overall survival (OS) compared with other IDH1 mutation variants and wild-type (WT) IDH1/2. In our analysis, IDH2-R172K was associated with significantly lower WBC count, more karyotype abnormalities, and less frequent comutations of NPM1 and/or FLT3-ITD. Among patients within the European LeukemiaNet 2017 intermediate- and adverse-risk groups, relapse-free survival and OS were significantly better for those with IDH2-R172K compared with WT IDH, providing evidence that AML with IDH2-R172K could be a distinct entity with a specific comutation pattern and favorable outcome. In summary, the presented data from a large cohort of patients with IDH1/2 mutated AML indicate novel and clinically relevant findings for the most common IDH mutation subtypes.

Molecular and genomic landscapes in secondary & therapy related acute myeloid leukemia

Acute myeloid leukemia (AML) is a complex, aggressive myeloid neoplasm characterized by frequent somatic mutations that influence different functional categories' genes, resulting in maturational arrest and clonal expansion. AML can arise de novo (dn-AML) or can be secondary AML (s-AML) refers to a leukemic process which may arise from an antecedent hematologic disorder (AHD-AML), mostly from a myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN) or can be the result of an antecedent cytotoxic chemotherapy or radiation therapy (therapy-related AML, t-AML). Clinical and biological features in secondary and therapy-related AML are distinct from de novo AML. Secondary and therapy-related AML occurs mainly in the elderly population and responds worse to therapy with higher relapse rates due to resistance to cytotoxic chemotherapy. Over the last decade, advances in molecular genetics have disclosed the sub-clonal architecture of secondary and therapy-related AML. Recent investigations have revealed that cytogenetic abnormalities and underlying genetic aberrations (mutations) are likely to be significant factors dictating prognosis and critical impacts on treatment outcome. Secondary and therapy-related AML have a poorer outcome with adverse cytogenetic abnormalities and higher recurrences of unfavorable mutations compared to de novo AML. In this review, we present an overview of the clinical features of secondary and therapy-related AML and address the function of genetic mutations implicated in the pathogenesis of secondary leukemia. Detailed knowledge of the pathogenetic mechanisms gives an overview of new prognostic markers, including targetable mutations that will presumably lead to the designing and developing novel molecular targeted therapies for secondary and therapy-related AML. Despite significant advances in knowing the genetic aspect of secondary and therapy-related AML, its influence on the disease's pathophysiology, standard treatment prospects have not significantly evolved during the past three decades. Thus, we conclude this review by summarizing the modern and developing treatment strategies in secondary and therapy-related acute myeloid leukemia.

Germline mutations among Polish patients with acute myeloid leukemia

BACKGROUND

A small but important proportion of patients (4-10 %) with AML have germline mutations. They can cause the development of AML at an earlier age, confer a higher risk of relapse or predispose to secondary leukemias, including therapy-related leukemias. The analysis of germline mutations in a patient and his/her family is also critical for the selection of suitable family donors if the patient is a candidate for hematopoietic stem cell transplantation (HSCT).

METHODS

103 unrelated consecutive patients with de novo AML were enrolled in the study. Control group consisted of 103 persons from the general population. We performed NGS sequencing of bone marrow cells and buccal swabs DNA of six genes: CEBPA, DDX41, ETV6, TERT, GATA2, and IDH2 to detect germline pathogenic mutations.

RESULTS

In the investigated group, 49 variants were detected in six genes. 26 of them were somatic and 23 germline. Germline variants were detected in all six tested genes. Eight pathogenic germline mutations were detected in 7 AML patients, in three genes: CEBPA, ETV6, and IDH2. One patient had two pathogenic germinal mutations, one in ETV6 and one in CEBPA gene. We identified one novel pathogenic germline mutation in CEBPA gene. The difference in frequency of all pathogenic germline mutations between the tested (7.77 %) and control groups (0.97 %) was statistically significant (p = 0.046). In the tested group, the median age at AML diagnosis was 11 years lower in patients with pathogenic germline mutations than in patients without them (p = 0.028).

CONCLUSIONS

We showed higher frequency of CEBPA, ETV6, and IDH2 germline mutations in AML patients than in control group, which confirms the role of these mutations in the development of AML. We also showed that the median age at the onset of AML in patients with pathogenic germline mutations is significantly lower than in patients without them.

Mutation profile of acute myeloid leukaemia in a Chinese cohort by targeted next-generation sequencing

Background

Acute myeloid leukaemia (AML) results from the clonal expansion of blast cells of myeloid origin driven by genomic defects. The advances in next‐generation sequencing (NGS) have allowed the identification of many mutated genes important in the pathogenesis of AML.

Aims

In this study, we aimed to assess the mutation types and frequency in a Chinese cohort presenting with de novo AML cohort using a targeted NGS strategy.

Methods

In total, we studied samples from 87 adult patients with de novo AML who had no prior history of cytotoxic chemotherapy. Samples were evaluated using a 120‐gene targeted NGS panel to assess the mutation profile.

Results

Of the 87 AML patients, there were 60 (69%) with a normal karyotype. 89.7% of patients had variants, with an average of 1.9 mutations per patient (range: 0–5 mutations per patient). DNMT3A variants were the most common, being detected in 33 patients (37.9%). NPM1 (34.5%), IDH1/2 (24.1%) and FLT3‐ITD (20.7%) mutations was the next most common. Of the patients with DNMT3A mutations, 24.2% also had mutations NPM1 and FLT3‐ITD and 6.1% NPM1, FLT3‐ITD and IDH mutations.

Conclusion

Both DNMT3A and NPM1 mutations were more common than in other Chinese and Western AML cohorts that have been studied. DNMT3A mutations tended to co‐occur with NPM1 and FLT3‐ITD mutations and were most commonly seen with a normal karyotype.

Synergistic cytotoxicity of dual PI3K/mTOR and FLT3 inhibition in FLT3-ITD AML cells

Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy, characterized by a heterogeneous genetic landscape and complex clonal evolution, with poor outcomes. Mutation at the internal tandem duplication of FLT3 (FLT3-ITD) is one of the most common somatic alterations in AML, associated with high relapse rates and poor survival due to the constitutive activation of the FLT3 receptor tyrosine kinase and its downstream effectors, such as PI3K signaling. Thus, aberrantly activated FLT3-kinase is regarded as an attractive target for therapy for this AML subtype, and a number of small molecule inhibitors of this kinase have been identified, some of which are approved for clinical practice. Nevertheless, acquired resistance to these molecules is often observed, leading to severe clinical outcomes. Therapeutic strategies to tackle resistance include combining FLT3 inhibitors with other antileukemic agents. Here, we report on the preclinical activity of the combination of the FLT3 inhibitor quizartinib with the dual PI3K/mTOR inhibitor PF-04691502 in FLT3-ITD cells. Briefly, we show that the association of these two molecules displays synergistic cytotoxicity in vitro in FLT3-ITD AML cells, triggering 90% cell death at nanomolar concentrations after 48 h.

SOHO State of the Art Updates and Next Questions: IDH Inhibition

There has been extraordinary progress in the field of targeted therapy for myeloid malignancies in the last few years, especially due to the approval of various agents that can be used as monotherapy or in combination as first-line treatment or when facing a refractory or relapsed disease. Many successful trials have been conducted recently, and a consistent body of work about the efficacy of novel molecules is now available. In this review, we sought to explain how enasidenib and ivosidenib have changed the face of myeloid neoplasm treatment through isocitrate dehydrogenase inhibition and to summarize the trials results that have led to the current commercial indications for the two molecules.

Isocitrate Dehydrogenase 2 Inhibitors for the Treatment of Hematologic Malignancies: Advances and Future Opportunities

Tumor cells frequently reprogram cellular metabolism from oxidative phosphorylation to glycolysis. Isocitrate dehydrogenase 2 (IDH2) has been intensively studied due to its involvement in the metabolic activity of cancer cells. Mutations in IDH2 promote neomorphic activity through the generation of oncometabolite 2-hydroxyglutarate (2-HG). The overproduced 2-HG can competitively inhibit α-KG-dependent dioxygenases to trigger cell differentiation disorders, a major cause of blood tumors. This review outlines recent progress in the identification of IDH2 inhibitors in blood cancer to provide a reference for ongoing and future clinical studies.

Additional mutations in IDH1/2-mutated patients with acute myeloid leukemia

OBJECTIVE

Somatic mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) frequently emerge in acute myeloid leukemia (AML), but the clinical features and molecular characteristics of IDH mutational status and other coexisting mutations have not been investigated in a large extensively characterized AML series. The aim of this study was to gain insight into the mutational profile of IDH-mutated patients, such as the frequency and clinical characteristics of coexisting mutated genes.

MATERIALS AND METHODS

We investigated 485 newly diagnosed AML patients (range 18-81 years). DNA was extracted from bone marrow samples at the time of diagnosis. All samples were investigated with a panel of 49 mutational genes using next-generation sequencing (NGS). FLT3-ITD, NPM1, and CEBPA mutations were detected by Sanger PCR sequencing.

RESULTS

We found 84 patients (17.3%) with IDH1 or IDH2 mutations. There were 40 IDH1^R132 , 15 IDH2^R140Q , 17 IDH2^R172K , and 12 uncommon mutations. No patient was found to have both IDH1 and IDH2 mutations. Patients with IDH2^R140Q mutations were more frequently older and presented with significantly lower average platelet counts, while IDH2^R172K -mutated patients had significantly lower white blood cell (WBC) counts. On the background of IDH mutations, the presence of a normal karyotype showed a balanced distribution. The four most frequently coexisting mutated genes were NPM1, DNMT3A, TET2, and FLT3-ITD. The majority of coexisting mutated genes were involved in regulating transcription and DNA methylation. IDH mutation status had no effect on the CR rate, regardless of other molecular abnormalities.

CONCLUSION

Isocitrate dehydrogenases mutations are associated with a complex coexisting mutation cluster in AML. Future investigation is needed to reveal the association between IDH mutations and other genetic abnormalities, which may have an impact on the progression and prognosis of disease.

IDH1 mutation contributes to myeloid dysplasia in mice by disturbing heme biosynthesis and erythropoiesis

Isocitrate dehydrogenase (IDH) mutations are common genetic alterations in myeloid disorders, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Epigenetic changes, including abnormal histone and DNA methylation, have been implicated in the pathogenic build-up of hematopoietic progenitors, but it is still unclear whether and how IDH mutations themselves affect hematopoiesis. Here, we show that IDH1-mutant mice develop myeloid dysplasia in that these animals exhibit anemia, ineffective erythropoiesis, and increased immature progenitors and erythroblasts. In erythroid cells of these mice, D-2-hydroxyglutarate, an aberrant metabolite produced by the mutant IDH1 enzyme, inhibits oxoglutarate dehydrogenase activity and diminishes succinyl-coenzyme A (CoA) production. This succinyl-CoA deficiency attenuates heme biosynthesis in IDH1-mutant hematopoietic cells, thus blocking erythroid differentiation at the late erythroblast stage and the erythroid commitment of hematopoietic stem cells, while the exogenous succinyl-CoA or 5-ALA rescues erythropoiesis in IDH1-mutant erythroid cells. Heme deficiency also impairs heme oxygenase-1 expression, which reduces levels of important heme catabolites such as biliverdin and bilirubin. These deficits result in accumulation of excessive reactive oxygen species that induce the cell death of IDH1-mutant erythroid cells. Our results clearly show the essential role of IDH1 in normal erythropoiesis and describe how its mutation leads to myeloid disorders. These data thus have important implications for the devising of new treatments for IDH-mutant tumors.