Understanding Of Acute Myeloid Leukemia Research Articles

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.

Biomarkers of Response to Venetoclax Therapy in Acute Myeloid Leukemia.

Recent progress in the use of massive sequencing technologies has greatly enhanced our understanding of acute myeloid leukemia (AML) pathology. This knowledge has in turn driven the development of targeted therapies, such as venetoclax, a BCL-2 inhibitor approved for use in combination with azacitidine, decitabine, or low-dose cytarabine for the treatment of newly diagnosed adult patients with AML who are not eligible for intensive chemotherapy. However, a significant number of AML patients still face the challenge of disease relapse. In this review, we will explore biomarkers that may predict disease progression in patients receiving venetoclax-based therapy, considering both clinical factors and genetic changes. Despite the many advances, we conclude that the identification of molecular profiles for AML patients who will respond optimally to venetoclax therapy remains an unmet clinical need.

A CD8+ T cell related immune score predicts survival and refines the risk assessment in acute myeloid leukemia.

Although advancements in genomic and epigenetic research have deepened our understanding of acute myeloid leukemia (AML), only one-third of patients can achieve durable remission. Growing evidence suggests that the immune microenvironment in bone marrow influences prognosis and survival in AML. There is a specific association between CD8+ T cells and the prognosis of AML patients. To develop a CD8+ T cell-related immune risk score for AML, we first evaluated the accuracy of CIBERSORTx in predicting the abundance of CD8+ T cells in bulk RNA-seq and found it significantly correlated with observed single-cell RNA sequencing data and the proportions of CD8+ T cells derived from flow cytometry. Next, we constructed the CTCG15, a 15-gene prognostic signature, using univariate and LASSO regression on the differentially expressed genes between CD8+ THigh and CD8+ TLow groups. The CTCG15 was further validated across six datasets in different platforms. The CTCG15 has been shown to be independent of established prognostic markers, and can distill transcriptomic consequences of several genetic abnormalities closely related to prognosis in AML patients. Finally, integrating this model into the 2022 European LeukemiaNet contributed to a higher predictive power for prognosis prediction. Collectively, our study demonstrates that CD8+ T cell-related signature could improve the comprehensive risk stratification and prognosis prediction in AML.

Role of Cytogenetics and Fluorescence In Situ Hybridization in the Laboratory Workup of Acute Myeloid Leukemias

AbstractA new understanding of acute myeloid leukemia as a varied group of unique biologic entity has emerged, as a result of the identification of various chromosomal aberrations and their association with clinical prognosis and diagnosis. Following induction treatment, cytogenetic examination can establish the presence of any residual malignant cells, it's recurrence, clonal evolution if any, or the formation of novel abnormalities. The G-banded karyotype has been the gold standard method for detecting all of these aberrations for years. The capacity to examine the entire genome through karyotype analysis quickly enabled the detection of deletions, duplications, and structural rearrangements across every chromosome, and the more frequent ones were associated with particular aberrant clinical symptoms. Fluorescence in situ hybridization (FISH) is a sensitive technology that aids in differential diagnosis or therapeutic planning and provides rapid results. Furthermore, the combination of cytogenetic and molecular profiling enables a more precise evaluation of disease prognosis, diagnosis, classification, risk stratification, and patient treatment. Interphase FISH analysis, in conjunction with G-banded chromosomal analysis, can be used as a major testing tool for the evaluation of hematological neoplasms. For accurate and consistent descriptions of genomic changes identified by karyotyping and FISH, a specified terminology is necessary. The International System for Human Cytogenomic Nomenclature is the main source and provides instructions for documenting cytogenetic and molecular findings in laboratory reports. This review discusses the two methods, karyotyping and FISH, their advantages and limitations, sample requirements, various FISH probes that are used, nomenclature for results reporting, and the necessary quality control measures.

Novel Tools for Diagnosis and Monitoring of AML.

In recent years, major advances in the understanding of acute myeloid leukemia (AML) pathogenesis, together with technological progress, have led us into a new era in the diagnosis and follow-up of patients with AML. A combination of immunophenotyping, cytogenetic and molecular studies are required for AML diagnosis, including the use of next-generation sequencing (NGS) gene panels to screen all genetic alterations with diagnostic, prognostic and/or therapeutic value. Regarding AML monitoring, multiparametric flow cytometry and quantitative PCR/RT-PCR are currently the most implemented methodologies for measurable residual disease (MRD) evaluation. Given the limitations of these techniques, there is an urgent need to incorporate new tools for MRD monitoring, such as NGS and digital PCR. This review aims to provide an overview of the different technologies used for AML diagnosis and MRD monitoring and to highlight the limitations and challenges of current versus emerging tools.

Leukemic stem cells and advances in hematopoietic stem cell transplantation for acute myeloid leukemia: a narrative review of clinical trials.

The purpose of this literature review is to summarize and provide a brief overview of our current understanding of acute myeloid leukemia (AML) and the role of stem cell transplantation (SCT) in its management. AML is a malignant hematological disorder that is characterized by the uncontrolled proliferation of myeloid blood cells. This disease has been associated with various risk factors such as ionizing radiation, cigarette smoke, pesticides/herbicides, and chemotherapy. SCT remains the most beneficial treatment for medically fit AML patients due to superior survival outcomes. A thorough search was conducted on PubMed, Scopus, ClinicalTrials.gov, Embase and Web of Science using related keywords. Current articles on the uses of stem cell therapy in AML patients were selected. Long term exposure to ionizing radiation and other harmful substances such as benzene, cigarette smoke and chemotherapeutic drugs plays an important role in AML carcinogenesis. Mutations in certain genes (e.g., ASXL1, RUNX1, KIT, TP53, BCR-ABL1) seem to accelerate the process as they affect normal cellular proliferation and cell death. These events may give rise to a small subpopulation of leukemic stem cells (LSC) which continuously sustain tumor development and growth. Patients who are deemed to be medically "fit" should receive an allogenic hematopoietic stem cell transplantation (allo-HSCT) due to improved overall survival (OS) (~50%) and decreased relapsed risk (32% vs. 59%). Several studies have revealed that the medically "unfit" may benefit from more conventional agents such as azacytidine, decitabine, venetoclax or sorafenib.

Diagnosis and management of AML in adults: 2022 recommendations from an international expert panel on behalf of the ELN

AbstractThe 2010 and 2017 editions of the European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) in adults are widely recognized among physicians and investigators. There have been major advances in our understanding of AML, including new knowledge about the molecular pathogenesis of AML, leading to an update of the disease classification, technological progress in genomic diagnostics and assessment of measurable residual disease, and the successful development of new therapeutic agents, such as FLT3, IDH1, IDH2, and BCL2 inhibitors. These advances have prompted this update that includes a revised ELN genetic risk classification, revised response criteria, and treatment recommendations.

Genome-Wide Gene Expression Profiling Defines the Mechanism of Anticancer Effect of Colorectal Cancer Cell-Derived Conditioned Medium on Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is the most common type of leukemia in adults, accounting for 30% of all adult leukemia cases. While there have been recent improvements in the prognosis of the disease, the prognosis remains grim, and further understanding of AML and the development of new therapeutic agents is critical. This study aimed to investigate the potential interaction between colorectal cancer (CRC) cells and AML cells. Unexpectedly, we found that CRC cell-derived conditioned medium (CM) showed anticancer activities in AML cells by inducing apoptosis and differentiation. Mechanistic studies suggest that these phenotypes are closely associated with the suppression of PI3K/AKT/mTOR and MAPK survival signaling, the upregulation of myeloid differentiation-promoting transcription factors c/EBPα and PU.1, and the augmentation of executioner caspases-3/7. Importantly, bioinformatic analyses of our gene expression profiling data, including that derived from principal component analysis (PCA), volcano plots, boxplots, heat maps, kyoto encyclopedia of genes and genomes (KEGG) pathways, and receiver operating characteristic (ROC) curves, which evaluate gene expression profiling data, provided deeper insight into the mechanism in which CRC-CM broadly modulates apoptosis-, cell cycle arrest-, and differentiation-related gene expression, such as BMF, PLSCR3, CDKN1C, and ID2, among others, revealing the genes that exert anticancer effects in AML cells at the genomic level. Collectively, our data suggest that it may be worthwhile to isolate and identify the molecules with tumor-suppressive effects in the CM, which may help to improve the prognosis of patients with AML.

Inhibition of TKI-activated MIF/CXCR2 Pathway as a Novel Therapeutic Strategy in Acute Myeloid Leukemia

Abstract Despite significant advancements in our understanding of acute myeloid leukemia (AML), relapsed and refractory disease remains a major cause of treatment failure. Approximately 50% of patients with AML will develop relapsed disease following induction chemotherapy, which results in a dismal 5-year overall survival rate of 29%. The development of FMS-like tyrosine kinase 3 (FLT3) inhibitors have led to improved outcomes among patients with FLT3-mutated AML. However many patients eventually relapse and succumb to chemo-resistant disease, highlighting the need to characterize the molecular pathways which confer early TKI resistance. To explore the possible mechanisms responsible for the survival and proliferation of tyrosine kinase inhibitor (TKI) resistant blasts, we compared in vitro and ex vivo cytokine expression of gilteritinib (GILT)-treated and untreated blasts. Here we report that the pro-inflammatory cytokine macrophage migration inhibitory factor (MIF) is significantly expressed by GILT-treated blasts when compared to untreated controls. We further demonstrate that MIF expression promotes blast proliferation through the upregulation of its receptor CXCR2. Most remarkably we found that combination of CXCR2-inhibitor plus GILT works synergistically to reduce the percentage of viable blasts. Together these findings support that targeting the TKI-activated MIF/CXCR pathway could be a novel therapeutic strategy for both newly diagnosed and relapsed/refractory AML. This study is supported by Loma Linda University GRASP and Loma Linda University Research Innovation Grant

Fructose Metabolism and Acute Myeloid Leukemia

The dietary consumption of fructose has increased in the last five decades, paralleled by an increase in obesity. Excess fructose intake is linked to obesity, metabolic syndrome, non-alcoholic fatty liver disease, diabetes, hypertension, cardiac disease, and several aggressive types of cancer. The incidence of acute myeloid leukemia (AML), a lethal hematologic malignancy, has also increased in parallel. Despite significant advances in our understanding of AML, including molecular genetics and more effective targeted therapies, relapse is frequent and outcomes remain poor. Moreover, except for several known causes for a small proportion of AML cases, virtually nothing is known about the initial causative leukemogenic event. In this study, the author asked and intended to answer the question, “can excess fructose intake lead to the initial cellular event that causes AML?” The author reviewed published literature to answer the above question and, subsequently, to identify novel AML therapies based on fructose metabolism. In this article, fructose metabolism and its relationship with metabolic pathways essential for AML, including regulation by hypoxia inducible factor, are described. Evidence for the potential etiologic role of fructose in AML is summarized for the first time. To conclude, excess fructose can lead to the initial AML-causative cellular event. Based on this study, future studies are warranted to determine if restricting fructose intake can prevent AML. Therapeutically, the development of hypoxia inducible factor and glucose transporter 5 inhibitors should be pursued for the treatment of AML.

Effect of Chidamide, a Novel HDAC Inhibitor, on AML Cell Lines and Patients

Background: Although the understanding of acute myeloid leukemia (AML) and the development of novel drugs are in rapid progress, the current outcome of AML therapy is not satisfactory. Demethylated drug decitabine (DAC) or Cytarabine has great therapeutic effect on myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). However, these two Drugs alone or combination could imporve the response rate in some AML and MDS patients. We aimed to investigate the effects of the combination of DAC and a novel histone deacetylase inhibitor-chidamide in the AML cell lines and some refractory/replaspsed AML patients' primary cell lines, including MV4-11,THP-1,Kasumi-1 and HL60 cell lines and investigage the underlying mechanisms.Methods: Cell viability was estimated by MTT assay. cell cycle were detected by PI staining. Cell apoptosis were detected by flow cytometry analysis and Annexin V /PI staining.To detect the expression of apoptosis-related proteins, including BCL-2,BCL-XL and casepase 8,western blot were performed. The target downstream of molecules were analyzed by RNA seqencing and westrn blot. The effects of the combinations were estimated using compusyn software. Results: Histone deacetylase inhibitor, chidamide is synergistic with DAC or Cytarabine,although the effect of these two combinations on these cells is not exactly the same.Histone deacetylase inhibitors in combination with Demethylated drug or Anti - pyrimidine antimetabolites both affected cell cycle and significantly induced apoptosis in AML cell lines. Conclusion: The combination of DAC or Cytarabine has synergistic effects on cell viability inhibition and enhancement effects on cell apoptosis in MV4-11,THP-1,Kasumi-1 and HL60 cell lines. These data suggest that DAC or Cytarabine used in combination with chidamide has clinical potential in the treatment of AML. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

TET2/IDH1/2/WT1 and NPM1 Mutations Influence the RUNX1 Expression Correlations in Acute Myeloid Leukemia.

Background and objectives: Mutational analysis has led to a better understanding of acute myeloid leukemia (AML) biology and to an improvement in clinical management. Some of the most important mutations that affect AML biology are represented by mutations in genes related to methylation, more specifically: TET2, IDH1, IDH2 and WT1. Because it has been shown in numerous studies that mutations in these genes lead to similar expression profiles and phenotypes in AML, we decided to assess if mutations in any of those genes interact with other genes important for AML. Materials and Methods: We downloaded the clinical data, mutational profile and expression profile from the TCGA LAML dataset via cBioPortal. Data were analyzed using classical statistical methods and functional enrichment analysis software represented by STRING and GOrilla. Results: The first step we took was to assess the 196 AML cases that had a mutational profile available and observe the mutations that overlapped with TET2/IDH1/2/WT1 mutations. We observed that RUNX1 mutations significantly overlap with TET2/IDH1/2/WT1 mutations. Because of this, we decided to further investigate the role of RUNX1 mutations in modulating the level of RUNX1 mRNA and observed that RUNX1 mutant cases presented higher levels of RUNX1 mRNA. Because there were only 16 cases of RUNX1 mutant samples and that mutations in this gene determined a change in mRNA expression, we further observed the correlation between RUNX1 and other mRNAs in subgroups regarding the presence of hypermethylating mutations and NPM1. Here, we observed that both TET2/IDH1/2/WT1 and NPM1 mutations increase the number of genes negatively correlated with RUNX1 and that these genes were significantly linked to myeloid activation. Conclusions: In the current study, we have shown that NPM1 and TET2/IDH1/2/WT1 mutations increase the number of negative correlations of RUNX1 with other transcripts involved in myeloid differentiation.

Longitudinal Tracking of Acute Myeloid Leukemia Stem Cells in Xenografts and Patients By microRNA Reporters and Single Cell RNA Sequencing

Current understanding of acute myeloid leukemia (AML) assumes a developmental hierarchy, in which a minor fraction of primitive and quiescent leukemia stem cells (LSC) sustain clonal propagation of disease. These therapy-resistant LSC may be the basis of relapse, as supported by data correlating the presence of LSC gene expression signatures at diagnosis with poor prognosis (Ng et al, Nature 2016). Novel approaches tracing LSC fates at single cell level before, during and after chemotherapy (CTX) are needed to confirm their biological relevance and derive new, LSC-focused diagnostic and therapeutic strategies. We and others have previously linked key LSC properties, such as quiescence and therapy resistance, to complex transcriptional regulation orchestrated by miR-126 (Lechman et al, Cancer Cell 2016). Furthermore, we provided proof of concept that LSCs could be prospectively isolated as miR-126(high) cells exploiting a lentiviral reporter vector capturing miR-126 bioactivity in live cells with single cell resolution. To extend these studies, we transduced primary blasts from n=3 AML patients (pts) carrying NPM1 and FLT3-ITD mutations with the miR-126 reporter, followed by xenografting (PDX). Blasts showed intra-tumor heterogeneity (ITH) in terms of miR-126 activity, with a minor fraction identified as miR-126(high). Limiting dilution secondary transplantation of FACS sorted miR-126(high) and -(low) blasts proved strong enrichment of repopulating activity within the miR-126(high) compartment in all 3 pts. On the contrary, no LSC enrichment could be verified in the CD34+CD38- fraction in 1 patient, suggesting that high miR-126 activity represents a more robust LSC identifier than commonly used surface markers. Next, we investigated the impact of daunorubicin and cytarabine CTX on miR-126-reporter+ blasts (n=3 AML) in PDX. Surprisingly, overall miR-126 activity diminished in post CTX residual AML compared to controls, compatible with a loss of blast quiescence. CTX accentuated ITH by uncovering a subset of blasts with very high levels of miR-126, distinct from the bulk population, which may correspond to residual quiescent LSC (Fig A). We then performed bulk RNA sequencing on miR-126(high) and miR-126(low) subsets from CTX and control PDX. While miR-126(low) blasts from both groups expressed markers of myeloid differentiation, miR-126(high) blasts were enriched for published hematopoietic stem cell hallmark signatures. Integrating differentially expressed genes between miR-126(high) and-(low) subsets at steady state and post CTX, we extrapolated a novel 8 gene signature associated with miR-126(high) blasts. Of note, patients from the AML TCGA PanCancer Atlas Cohort (n=161) harboring overexpression in one or more of these 8 genes had significantly decreased overall survival (10 vs 19 months, Logrank test p-value = 0.018). To further test whether our 8-gene miR-126(high) signature reveals ITH in patients, we performed single cell RNA sequencing (scRNAseq) of AML patient BM aspirates at diagnosis (n= 6). Blasts were identified based on the detection of mutated NPM1 transcripts in single cells. In 5 out of 7 patients expression of the miR-126 signature mapped to specific clusters of blasts identified by unsupervised shared nearest neighbor algorithm, confirming that it identifies ITH in patient samples. Interestingly, we detected miR-126 signature(high) blasts in pts with poor prognosis (n=4) and not in those with favorable outcome (n=2) (Fig B). To investigate ITH across longitudinal samples, we next performed scRNAseq of residual AML from a representative patient assessed early after CTX. In line with our PDX CTX model displaying increased miR-126 ITH, blasts on day14 of induction CTX segregated into 2 different clusters: cluster 1 containing LSC-like cells with miR-126(high) signature and similar transcriptional profile to the diagnosis counterpart; cluster 2, instead, was composed of actively cycling blasts. Residual blasts at day30, in addition to uniformly expressing the miR-126(high) signature, differed from diagnosis and day14 blasts by displaying cell cycle quiescence and induction of oxidative phosphorylation genes (Fig C). In summary, we have set up and applied PDX LSC modeling to clinically relevant patient samples to address AML intra-tumor heterogeneity and to pinpoint novel relevant transcriptomic features of LSC at diagnosis and after chemotherapy. Figure Disclosures Gentner: Genenta Science: Consultancy, Equity Ownership, Research Funding.

Transcriptome analysis offers a comprehensive illustration of the genetic background of pediatric acute myeloid leukemia

AbstractRecent advances in the genetic understanding of acute myeloid leukemia (AML) have improved clinical outcomes in pediatric patients. However, ∼40% of patients with pediatric AML relapse, resulting in a relatively low overall survival rate of ∼70%. The objective of this study was to reveal the comprehensive genetic background of pediatric AML. We performed transcriptome analysis (RNA sequencing [RNA-seq]) in 139 of the 369 patients with de novo pediatric AML who were enrolled in the Japanese Pediatric Leukemia/Lymphoma Study Group AML-05 trial and investigated correlations between genetic aberrations and clinical information. Using RNA-seq, we identified 54 in-frame gene fusions and 1 RUNX1 out-of-frame fusion in 53 of 139 patients. Moreover, we found at least 258 gene fusions in 369 patients (70%) through reverse transcription polymerase chain reaction and RNA-seq. Five gene rearrangements were newly identified, namely, NPM1-CCDC28A, TRIP12-NPM1, MLLT10-DNAJC1, TBL1XR1-RARB, and RUNX1-FNBP1. In addition, we found rare gene rearrangements, namely, MYB-GATA1, NPM1-MLF1, ETV6-NCOA2, ETV6-MECOM, ETV6-CTNNB1, RUNX1-PRDM16, RUNX1-CBFA2T2, and RUNX1-CBFA2T3. Among the remaining 111 patients, KMT2A-PTD, biallelic CEBPA, and NPM1 gene mutations were found in 11, 23, and 17 patients, respectively. These mutations were completely mutually exclusive with any gene fusions. RNA-seq unmasked the complexity of gene rearrangements and mutations in pediatric AML. We identified potentially disease-causing alterations in nearly all patients with AML, including novel gene fusions. Our results indicated that a subset of patients with pediatric AML represent a distinct entity that may be discriminated from their adult counterparts. Based on these results, risk stratification should be reconsidered.

Epigenetic Therapies for Acute Myeloid Leukemia and Their Immune-Related Effects.

Over the past decades, our molecular understanding of acute myeloid leukemia (AML) pathogenesis dramatically increased, thanks also to the advent of next-generation sequencing (NGS) technologies. Many of these findings, however, have not yet translated into new prognostic markers or rationales for treatments. We now know that AML is a highly heterogeneous disease characterized by a very low mutational burden. Interestingly, the few mutations identified mainly reside in epigenetic regulators, which shape and define leukemic cell identity. In the light of these discoveries and given the increasing number of drugs targeting epigenetic regulators in clinical development and testing, great interest is emerging for the use of small molecules targeting leukemia epigenome. Together with their effects on leukemia cell-intrinsic properties, such as proliferation and survival, epigenetic drugs may affect the way leukemic cells communicate with the surrounding components of the tumor and immune microenvironment. Here, we review current knowledge on alterations in the AML epigenetic landscape and discuss the promises of epigenetic therapies for AML treatment. Finally, we summarize emerging molecular studies elucidating how epigenetic rewiring in cancer cells may as well exert immune-modulatory functions, boost the immune system, and potentially contribute to better patient outcomes.

Defining the in vivo characteristics of acute myeloid leukemia cells behavior by intravital imaging

The majority of acute myeloid leukemia (AML) patients have a poor response to conventional chemotherapy. The survival of chemoresistant cells is thought to depend on leukemia‐bone marrow (BM) microenvironment interactions, which are not well understood. The CXCL12/CXCR4 axis has been proposed to support AML growth but was not studied at the single AML cell level. We recently showed that T‐cell acute lymphoblastic leukemia (T‐ALL) cells are highly motile in the BM; however, the characteristics of AML cell migration within the BM remain undefined. Here, we characterize the in vivo migratory behavior of AML cells and their response to chemotherapy and CXCR4 antagonism, using high‐resolution 2‐photon and confocal intravital microscopy of mouse calvarium BM and the well‐established MLL‐AF9‐driven AML mouse model. We used the Notch1‐driven T‐ALL model as a benchmark comparison and AMD3100 for CXCR4 antagonism experiments. We show that AML cells are migratory, and in contrast with T‐ALL, chemoresistant AML cells become less motile. Moreover, and in contrast with T‐ALL, the in vivo exploratory behavior of expanding and chemoresistant AML cells is unaffected by AMD3100. These results expand our understanding of AML cells‐BM microenvironment interactions, highlighting unique traits of leukemia of different lineages.

Transcriptome Analysis Offers a Comprehensive Illustration of the Genetic Background of Pediatric Acute Myeloid Leukemia: Japan Pediatric Leukemia/Lymphoma Study Group AML-05

Background Recent advances in the genetic understanding of acute myeloid leukemia (AML) have improved clinical outcomes in pediatric patients. However, approximately 40% of patients with pediatric AML relapse, contributing to a relatively low overall survival (OS) rate of approximately 70%. The objective of this study was to reveal the comprehensive genetic background of pediatric AML. Methods We performed transcriptome analysis (RNA-seq) in 139 of the 369 patients with de novo pediatric AML who were enrolled in the Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) AML-05 trial and investigated correlations between genetic aberrations and clinical information. Findings Using RNA-seq, we identified 54 in-frame gene fusions and one RUNX1 out-of-frame fusion in 53 out of 139 patients. Moreover, we found at least 258 gene fusions in 369 patients (70%) through RT-PCR and RNA-seq. Six gene rearrangements were newly identified, namely, NPM1-CCDC28A, TRIP12-NPM1, NPM1-DNAJC1, TBL1XR1-RARB, ETV6-CTNNB1, and RUNX1-FNBP1. In addition, we found rare gene rearrangements, namely, MYB-GATA1, NPM1-MLF1, ETV6-NCOA2, ETV6-MECOM, RUNX1-PRDM16, RUNX1-CBFA2T2, and RUNX1-CBFA2T3. Among the remaining 111 patients, KMT2A-PTD, biallelic CEBPA, and NPM1 gene mutations were found in 11, 23, and 17 patients, respectively. These mutations were completely mutually exclusive with any gene fusions. Interpretation RNA-seq unmasked the complexity of gene rearrangements and mutations in pediatric AML. We identified potentially driver alterations in nearly all patients with AML, including novel gene fusions. Based on the results of the RNA-seq, risk stratification should be reconsidered. Funding Statement: Ministry of Education, Culture, Sports, Science, and Technology of Japan and Japan Agency for Medical Research and Development. Declaration of Interests: I have no financial relationships to disclose. Ethics Approval Statement: The present study was conducted in accordance with the Declaration of Helsinki and approved by the institutional review boards of Gunma Children’s Medical Center and the participating institutes and the ethical review board of the JPLSG AML-05 trial.

How Genomic Data Are Changing the Leukemia Treatment Landscape

How Genomic Data Are Changing the Leukemia Treatment Landscape

Xenograft Models of Primary Acute Myeloid Leukemia for the Development of Imaging Strategies and Evaluation of Novel Targeted Therapies.

Despite the tremendous progress made in the comprehension of acute myeloid leukemia (AML) over the last 30 years most patients die from their disease. Our understanding of AML has relied on an intensive in-vitro research approach, based on AML cell lines as well as primary AML patient cells. However, experimental insight into the early events of AML leukemogenesis before they become clinically observable is not possible in humans. Thus, preclinical animal models have served the purpose to extend our knowledge of the disease as well as to develop innovative therapeutic strategies. Today, xenograft models using patient-derived neoplastic/leukemia cells represent the strategy of choice for preclinical studies of AML. These models exhibit several key advantages over AML cell lines. In fact, patient-derived cells, in contrast to AML cell lines, encompass the entire complexity of AML disease and can therefore provide more trustworthy results on the efficacy outcome of novel therapies. One other important aspect in the development of xenograft models of AML is the possibility to use imaging techniques to monitor in-vivo the progression of the disease. Imaging techniques also authorize the evaluation of the efficacy of an experimental treatment on tumor growth. This review will focus on the description of xenograft models of AML and will provide researchers and clinicians an overview of how these models have been used for the development of new therapeutic options and new imaging approaches to study AML in-vivo.

Next Generation Sequencing of Acute Myeloid Leukemia: Influencing Prognosis

Acute myeloid leukemia (AML) is a clonal disorder of the blood forming cells characterized by accumulation of immature blast cells in the bone marrow and peripheral blood. Being a heterogeneous disease, AML has been the subject of numerous studies that focus on unraveling the clinical, cellular and molecular variations with the aim to better understand and treat the disease. Cytogenetic-risk stratification of AML is well established and commonly used by clinicians in therapeutic management of cases with chromosomal abnormalities. Successive inclusion of novel molecular abnormalities has substantially modified the classification and understanding of AML in the past decade. With the advent of next generation sequencing (NGS) technologies the discovery of novel molecular abnormalities has accelerated. NGS has been successfully used in several studies and has provided an unprecedented overview of molecular aberrations as well as the underlying clonal evolution in AML. The extended spectrum of abnormalities discovered by NGS is currently under extensive validation for their prognostic and therapeutic values. In this review we highlight the recent advances in the understanding of AML in the NGS era.