Somatic mutations of isocitrate dehydrogenases 1 and 2 are prognostic and follow-up markers in patients with acute myeloid leukaemia with normal karyotype

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.

Pediatric acute myeloid leukemia: Insight into genetic landscape and novel targeted approaches

Acute myeloid leukemia (AML) is a very heterogeneous hematological malignancy that accounts for approximately 20% of all pediatric leukemia cases. The outcome of pediatric AML has improved over the last decades, with overall survival rates reaching up to 70%. Still, AML is among the leading types of pediatric cancers by its high mortality rate. Modulation of standard therapy, like chemotherapy intensification, hematopoietic stem cell transplantation and optimized supportive care, could only get this far, but for the significant improvement of the outcome in pediatric AML, development of novel targeted therapy approaches is necessary. In recent years the advances in genomic techniques have greatly expanded our knowledge of the AML biology, revealing molecular landscape and complexity of the disease, which in turn have led to the identification of novel therapeutic targets. This review provides a brief overview of the genetic landscape of pediatric AML, and how it's used for precise molecular characterization and risk stratification of the patients, and also for the development of effective targeted therapy. Furthermore, this review presents recent advances in molecular targeted therapy and immunotherapy with an emphasis on the therapeutic approaches with significant clinical benefits for pediatric AML.

Genetic Polymorphism Study of IDH 1/2 and TET2 Genes in Acute Myeloid leukemia Patients

BACKGROUND AND OBJECTIVE

Isocitrate dehydrogenase genes (IDH1 and IDH2) encode important enzymes that play pivotal role in cellular metabolism. Mutations in TET2 have been demonstrated to contribute to DNA hypermethylation, either expression of mutant IDH1/2 or TET2 resulted in poor cell differentiation and epigenetic alterations in hematopoietic cells, suggesting a sharing of the oncogenetic impact. In this study, we investigated the frequency of genetic alterations in IDH1/2 and TET2 genes in Egyptian cohort of adult patients with de novo AML, and the association of IDH1/2 and TET2 genetic Polymorphism with AML prognostic criteria and explore prognostic molecular markers with clinical outcome.

METHODS

The SNP assay for IDH1, IDH2 and TET2 genes polymorphism tested with RT-PCR included three polymorphisms that are rs121913500, rs121913503, and rs2454206 respectively, were tested on 141 adult Egyptian patients fulfilling the AML diagnostic criteria.

RESULT

The incidence of IDH mutations is 11/141 (7.8%); 5/141 (3.5%) IDH1 mutant and 6/141 (4.3%) IDH2 mutant. And the incidence of TET2 mutations is 72/141 (51.1%); 15/141 (10.7%) homozygous mutation and 57/141 (40.4%) heterozygous mutations. IDH1, IDH2 and TET2 genes mutations with DFS and OS in AML patients were not significantly correlated.

CONCLUSIONS

TET2 SNP is common in Egyptian AML patients. Further research on IDH, TET2 and their relationships to other hematological malignancies and leukemogenesis transformation is advised and a study of a larger number of cases is needed for potential statistical significance.

Emerging pharmacotherapies for elderly acute myeloid leukemia patients

INTRODUCTION

Acute myeloid leukemia (AML) is a disease mainly seen in the elderly, for which treatment is undergoing rapid changes. Although recent studies have supported the survival benefit of induction chemotherapy in fit patients and that of hypomethylating agents (HMAs) in non-induction candidates, treatment of this patient age population remains a significant challenge for the treating oncologist.

AREAS COVERED

In this review, we will examine effectiveness and safety outcomes of upcoming novel treatment strategies in elderly (≥60 years old) patients with AML, highlight the current literature and ongoing trials able to maximize therapeutic options in this heterogeneous patient population.

EXPERT OPINION

Current developments including new chemotherapeutic strategies and combinations of HMAs with novel drugs targeting epigenetic or immunomodulatory pathways are underway to improve patient survival and quality of life.

IDH Mutations in AML Patients; A higher Association with Intermediate Risk Cytogenetics

Objective:

IDH mutations diversely affect the prognosis of cyogenetically normal acute myeloid leukemia (CN-AML) adult patients. The aim of this study is to assess the frequency of IDH mutations and to evaluate its role in AML prognosis.

Methods:

We have analyzed IDH1 and 2 mutations using High Resolution Melting curve analysis (HRM) in 70 denovo AML patients.

Results:

The median age of AML patients is 40 years (16-75). Incidence of IDH mutations is 10/70 (14.3%); 2 (2.9%) IDH1 mutant and 8 (11.4%) IDH2 mutant. Median PB blasts of mutant IDH patients was 67.5% (25-96) vs. 44% (0-98) for wild type (p=0.065). Eight/10 (80%) mutant IDH patients had B.M blasts ≥50% vs. 2/10 (20%) <50% (p<0.001) and were classified as intermediate risk cytogenetics (p=0.020) with wild FLT3-ITD (p=0.001). Ten/10 (100%) mutant IDH patients showed wild NPM1 (p=0.049). Median OS of mutant IDH in the intermediate risk cytogenetics was 1.8 years (0.7-3.1) vs. 3.1 years (1.1-5.5) for wild IDH (p=0.05).

Conclusion:

IDH mutation is mainly associated with intermediate risk AML and when integrated in this specific subgroup displays a lower survival and can be considered an additional integrated molecular risk marker for AML prognosis.

Minimal residual disease may be an early prognostic indicator for newly diagnosed acute myeloid leukemia patients induced by decitabine-based chemotherapy

Objectives: To analyze the efficacy and safety of decitabine combined with low/reduced-dose chemotherapy in newly diagnosed acute myeloid leukemia (AML) patients unfit for intensive therapy and to investigate the early prognostic indicators for these patients. Methods: The eligible patients treated with decitabine-based chemotherapy were retrospectively analyzed. Responses and long-term survival were calculated and their correlation with clinical characteristics was analyzed. Minimal residual disease (MRD) detected by flow cytometry (FCM) after the induction therapy was measured, and the association with prognosis was explored. Results: Fifty-five newly diagnosed AML patients were enrolled. The overall response rate (ORR) was 80.0%, with a complete remission (CR) rate of 63.64% and partial remission (PR) rate of 16.36%. Grade 4 hematological toxicity was common, and the incidence of infections was 83.64%, with 18.18% of patients suffered from severe infections. No serious bleeding or non-hematological adverse events occurred. Treatment-related mortality was 3.64%. The median overall survival (OS) and disease-free survival (DFS) were 17.0 (13.7-20.3) months and 17.0 (10.2-23.8) months, respectively. Multivariate analysis showed that an advanced age (≥ 60 years) and higher MRD (≥ 1.34%) after induction therapy were adverse prognostic factors for patients who had achieved CR. Conclusions: Decitabine-based chemotherapy may be a suitable therapeutic alternative for newly diagnosed AML patients who are unfit for intensive chemotherapy. An advanced age (≥ 60 years) and higher MRD (≥ 1.34%) were considered adverse prognostic factors.

Molecular Minimal Residual Disease Testing in Acute Myeloid Leukemia: A Review for the Practicing Clinician

Minimal residual disease (MRD) testing in acute myeloid leukemia is increasingly being used to assess treatment response and stratify the risk of relapse for individual patients. Molecular methods for MRD testing began with PCR-based assays for individual recurrent mutations. To date, there is robust evidence for testing NPM1, CBFB-MYH11, and RUNX1/RUNXT1 mutations using this approach, though the best timing and threshold level for each mutation varies. More recent approaches have been with PCR-based multigene panels, occasionally combined with flow cytometric techniques, and next-generation sequencing techniques. This review outlines the various techniques used in molecular approaches to MRD, the evidence behind individual mutation testing, and the novel approaches for evaluating multigene MRD so that clinicians can understand and incorporate these evaluations into their practice.

The role of IDH mutations in acute myeloid leukemia

Isocitrate dehydrogenases (IDHs) are enzymes involved in multiple metabolic and epigenetic cellular processes. Mutations in IDH1 or IDH2 are detected in approximately 20% of patients with acute myeloid leukemia (AML) and induce amino acid changes in conserved residues resulting in neomorphic enzymatic function and production of an oncometabolite, 2-hydroxyglutarate (R-2-HG). This leads to DNA hypermethylation, aberrant gene expression, cell proliferation and abnormal differentiation. IDH mutations diversely affect prognosis of patients with AML based on the location of the mutation and other co-occurring genomic abnormalities. Recently, novel therapies specifically targeting mutant IDH have opened new avenues of therapy for these patients. In the present review, we will provide an overview of the biological, clinical and therapeutic implications of IDH mutations in AML.

The Synonymous Isocitrate Dehydrogenase 1 315C>T SNP Confers an Adverse Prognosis in Egyptian Adult Patients with NPM1-/CEBPA-Negative Acute Myeloid Leukemia

Although the clinical features of isocitrate dehydrogenase (IDH) genetic aberrations have been well-characterized in acute myeloid leukemia (AML), definitive information on their prognostic significance is lacking. We aimed to explore the prognostic significance of IDH gene alterations in an Egyptian cohort of adult patients with de novo AML. Diagnostic peripheral blood samples from 51 AML patients were analyzed for the presence of mutations/SNPs in exon 4 of IDH1 and IDH2 genes using polymerase chain reaction amplification followed by direct sequencing. IDH mutational status had no impact on event-free survival (EFS) and overall survival (OS), whereas the presence of IDH1 315C>T SNP was significantly associated with inferior EFS (P = 0.037) and OS (P = 0.034) as compared with wild-type IDH1. IDH1 315C>T SNP but not IDH mutations is associated with unfavorable outcomes, suggesting that AML patients with IDH1 315C>T SNP can represent a new subgroup of patients which allows refined risk stratification.

The DNA damage response pathway in normal hematopoiesis and malignancies

In mammalian cells, the DNA damage response (DDR) prevents the replication and propagation of DNA errors to the next generation, thus maintaining genomic stability. At the heart of the DDR are the related signaling kinases ATM, ATR, and DNA-PK, which regulate DNA repair and associated events such as cell cycle checkpoints, chromatin remodeling, transcription, and ultimately apoptosis. Several findings highlight the occurrence of DDR in hemopoietic stem cells (HSCs), and persistence of DNA lesions in these cells promotes their functional decline and accumulation of leukemogenic mutations. Besides favoring tumor formation and progression, molecular defects that directly or indirectly inactivate certain DDR pathways can provide a therapeutic opportunity, since a reduced ability to repair DNA lesions renders hemopoietic malignancies vulnerable to genotoxic drugs acting also through synthetic lethal interactions. Here, we discuss the essential role of DDR in HSC maintenance and protection against leukemogenesis, and how acquired DDR dysfunctions or pharmacological agents that block this pathway can be effectively exploited for the treatment of various hematopoietic malignancies.