Clinical relevance of mutations and gene-expression changes in adult acute myeloid leukemia with normal cytogenetics: are we ready for a prognostically prioritized molecular classification?

Differentiation of normal and leukemic cells by 2D light scattering label-free static cytometry

Two-dimensional (2D) light scattering patterns of single microspheres, normal granulocytes and leukemic cells are obtained by label-free static cytometry. Statistical results of experimental 2D light scattering patterns obtained from standard microspheres with a mean diameter of 4.19 μm agree well with theoretical simulations. High accuracy rates (greater than 92%) for label-free differentiation of normal granulocytes and leukemic cells, both the acute and chronic leukemic cells, are achieved by analyzing the 2D light scattering patterns. Our label-free static cytometry is promising for leukemia screening in clinics.

Targeted Cancer Therapy: Vital Oncogenes and a New Molecular Genetic Paradigm for Cancer Initiation Progression and Treatment

It has been declared repeatedly that cancer is a result of molecular genetic abnormalities. However, there has been no working model describing the specific functional consequences of the deranged genomic processes that result in the initiation and propagation of the cancer process during carcinogenesis. We no longer need to question whether or not cancer arises as a result of a molecular genetic defect within the cancer cell. The legitimate questions are: how and why? This article reviews the preeminent data on cancer molecular genetics and subsequently proposes that the sentinel event in cancer initiation is the aberrant production of fused transcription activators with new molecular properties within normal tissue stem cells. This results in the production of vital oncogenes with dysfunctional gene activation transcription properties, which leads to dysfunctional gene regulation, the aberrant activation of transduction pathways, chromosomal breakage, activation of driver oncogenes, reactivation of stem cell transduction pathways and the activation of genes that result in the hallmarks of cancer. Furthermore, a novel holistic molecular genetic model of cancer initiation and progression is presented along with a new paradigm for the approach to personalized targeted cancer therapy, clinical monitoring and cancer diagnosis.

Novel Prognostic and Therapeutic Mutations in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a biologically complex and molecularly and clinically heterogeneous disease, and its incidence increases with age. Cytogenetics and mutation testing remain important prognostic tools for treatment after induction therapy. The post-induction treatment is dependent on risk stratification. Despite rapid advances in determination of gene mutations involved in the pathophysiology and biology of AML, and the rapid development of new drugs, treatment improvements changed slowly over the past 30 years, with the majority of patients eventually experiencing relapse and dying of their disease. Allogenic hematopoietic stem cell transplantation remains the best chance of cure for patients with intermediate- or high-risk disease. This review gives an overview about advances in prognostic markers and novel treatment options for AML, focusing on new prognostic and probably therapeutic mutations, and novel drug therapies such as tyrosine kinase inhibitors.

Mitogen-activated protein kinase binding protein 1 (MAPKBP1) is an unfavorable prognostic biomarker in cytogenetically normal acute myeloid leukemia

Mitogen-activated protein kinase binding protein 1 (MAPKBP1) is a key transcription factor in the NF-κB signalling pathway. In this study, associations between MAPKBP1 expression and molecular and clinical characteristics were evaluated by several microarray datasets. We found that MAPKBP1 was over-expressed in cytogenetically normal AML (CN-AML) patients compared to normal bone marrow. High MAPKBP1 expression (MAPKBP1^high) was associated with significantly shorter event-free survival (EFS; P = 0.0004) and overall survival (OS; P = 0.0006) than low MAPKBP1 expression (MAPKBP1^low) in a cohort of 157 CN-AML patients. In multivariable analyses, MAPKBP1^high remained associated with shorter EFS (P = 0.003) and OS (P = 0.01). Validation in an independent cohort of 162 CN-AML patients further confirmed the prognostic value of MAPKBP1 (OS, P = 0.00172). Gene-expression profiling revealed that some important oncogenes, including MYCN, MYB, CDK6 and CCND2, etc, were up-regulated, while cell signalling pathways leading to apoptosis, antigen processing, and natural killer cell-mediated cytotoxicity were down-regulated in MAPKBP1^high patients with CN-AML. MicroRNA expression profiling revealed thatsome oncogenic microRNAsincluding miR-155 and miR-126 were up-regulated, whilst anti-oncogenic microRNAsincluding miR-148a and miR-193a were down-regulated in MAPKBP1^high patients with CN-AML, which may underlie the pathological processes in this malignancy. Taken together, these findings suggest MAPKBP1^highis a novel, unfavourably prognostic biomarker for CN-AML risk-stratification.

Acute myeloid leukemia in the era of precision medicine: recent advances in diagnostic classification and risk stratification

Acute myeloid leukemia (AML) is a genetically heterogeneous myeloid malignancy that occurs more commonly in adults, and has an increasing incidence, most likely due to increasing age. Precise diagnostic classification of AML requires clinical and pathologic information, the latter including morphologic, immunophenotypic, cytogenetic and molecular genetic analysis. Risk stratification in AML requires cytogenetics evaluation as the most important predictor, with genetic mutations providing additional necessary information. AML with normal cytogenetics comprises about 40%-50% of all AML, and has been intensively investigated. The currently used 2008 World Health Organization classification of hematopoietic neoplasms has been proposed to be updated in 2016, also to include an update on the classification of AML, due to the continuously increasing application of genomic techniques that have led to major advances in our knowledge of the pathogenesis of AML. The purpose of this review is to describe some of these recent major advances in the diagnostic classification and risk stratification of AML.

DNMT3A R882 Mutations Predict a Poor Prognosis in AML: A Meta-Analysis From 4474 Patients

DNA (cytosine-5)-methyltransferase 3 alpha (DNMT3A) mutations were widely believed to be independently associated with inferior prognosis in acute myeloid leukemia (AML) patients. As dominant missense alterations in DNMT3A mutations, R882 mutations cause the focal hypomethylation phenotype. However, there remains debate on the influence of R882 mutations on AML prognosis. Thus, this meta-analysis aimed at further illustrating the prognostic power of DNMT3A R882 mutations in AML patients.Eligible studies were identified from 5 databases containing PubMed, Embase, Web of Science, Clinical Trials, and the Cochrane Library (up to October 25, 2015). Effects (hazard ratios [HRs] with 95% confidence interval [CI]) of relapse-free survival (RFS) and overall survival (OS) were pooled to estimate the prognostic power of mutant DNMT3A R882 in overall patients and subgroups of AML patients.Eight competent studies with 4474 AML patients including 694 with DNMT3A R882 mutations were included. AML patients with DNMT3A R882 mutations showed significant shorter RFS (HR = 1.40, 95% CI = 1.24-1.59, P < 0.001) and OS (HR = 1.47, 95% CI = 1.17-1.86, P = 0.001) in the overall population. DNMT3A R882 mutations predicted worse RFS and OS among the subgroups of patients under age 60 (RFS: HR = 1.44, 95% CI = 1.25-1.66, P < 0.001; OS: HR = 1.48, 95% CI = 1.15-1.90, P = 0.002), over age 60 (RFS: HR = 2.03, 95% CI = 1.40-2.93, P < 0.001; OS: HR = 1.85, 95% CI = 1.36-2.53, P < 0.001), cytogenetically normal (CN)-AML (RFS: HR = 1.52, 95% CI = 1.26-1.83, P < 0.001; OS: HR = 1.67, 95% CI = 1.16-2.41, P = 0.006), and non-CN-AML (RFS: HR = 1.96, 95% CI = 1.20-3.21, P = 0.006; OS: HR = 2.51, 95% CI = 1.52-4.15, P = 0.0038).DNMT3A R882 mutations possessed significant unfavorable prognostic influence on RFS and OS in AML patients.

Economic impact of genomic diagnostics for intermediate-risk acute myeloid leukaemia

Acute Myeloid Leukaemia (AML) is a rare but serious group of diseases that require critical decision-making for curative treatment. Over the past decade, scientific discovery has revealed dozens of prognostic gene mutations for AML while sequencing costs have plummeted. In this study, we compared the cost-effectiveness of multigene integrative analysis (genomic analysis) with the standard molecular testing currently used for diagnosis of intermediate-risk AML. We used a decision analytic model with data for costs and outcomes from British Columbia, Canada, to assess the long-term (10-year) economic impacts. Our results suggest that genomic analysis would result in a 26% increase in the use of first-remission allogeneic stem cell transplantation. The resulting treatment decisions and downstream effects would come at an additional cost of $12 556 [2013 Canadian dollars (CAD)] per person and the incremental cost-effectiveness ratio would be $49 493 per quality-adjusted life-year gained. Cost-effectiveness was dependent on quality of life during the long-term (5-10) years of survival, relapse rates following first-remission chemotherapy and the upfront cost of transplantation. Non-relapse mortality rates, short-term quality of life and the cost of genomic sequencing had only minor impacts. Further research on post-remission outcomes can lead to improvements in the cost-effectiveness of curative treatments for AML.

Acute Myeloid Leukemia: A Concise Review

Acute myeloid leukemia (AML) is a heterogeneous clonal disorder characterized by immature myeloid cell proliferation and bone marrow failure. Cytogenetics and mutation testing remain a critical prognostic tool for post induction treatment. Despite rapid advances in the field including new drug targets and increased understanding of the biology, AML treatment remains unchanged for the past three decades with the majority of patients eventually relapsing and dying of the disease. Allogenic transplant remains the best chance for cure for patients with intermediate or high risk disease. In this review, we discuss the landmark genetic studies that have improved outcome prediction and novel therapies.

Identifying high-risk adult AML patients: epigenetic and genetic risk factors and their implications for therapy

Acute myeloid leukemia (AML) is a heterogeneous disease at molecular level, in response to therapy and prognosis. The molecular landscape of AML is evolving with new technologies revealing complex panorama of genetic abnormalities where genomic instability and aberrations of epigenetic regulators play a key role in pathogenesis. The characterization of AML diversity has led to development of new personalized therapeutic strategies to improve outcome of the patients.

Examination of the FLT3 and NPM1 mutational status in patients with acute myeloid leukemia from southeastern Poland

INTRODUCTION

Acute myeloid leukemia (AML) is a genetically heterogeneous disease at both the cytogenetic and molecular levels. In AML cells many chromosomal aberrations are observed, some of them being characteristic of a particular subtype of patients, and others being less significant. Besides chromosomal abnormalities, the leukemic cells can have a variety of mutations involving individual genes. The aim of this work was to investigate the frequencies of molecular alterations with the focus on FLT3-ITD and NPM1 mutations in AML patients of different age groups living in a southeastern region of Poland.

MATERIAL AND METHODS

The study group comprised 50 consecutive AML patients. We analyzed bone marrow samples by conventional cytogenetics. Cytogenetic evaluation in selected cases was complemented by the FISH technique. The internal tandem mutation in the FLT3 gene was identified using polymerase chain reaction (PCR), and the NPM1 mutation was assessed by direct nucleotide sequencing.

RESULTS

The studies using classical cytogenetics showed chromosomal aberrations in 32 (64%) patients. In 18 cases no changes in the karyotype were found by conventional karyotyping. FLT3-ITD mutation was detected in 4 (8%) patients and mutation of NPM1 in 3 patients with AML (6%).

CONCLUSIONS

The incidence of both mutations in our study group was lower than described elsewhere. We have confirmed that FLT3-ITD occurred more commonly in older patients and it was associated with shorter overall survival. By contrast, mutation of exon 12 of the NPM1 gene seems to be a good prognostic factor in AML patients with normal karyotype.

Molecular and cytogenetic abnormalities in acute myeloid leukemia: review and case studies

OBJECTIVE

To study the frequency of mutations that may lead to a good or bad prognosis, as well as their relation with the karyotype and immunophenotype in patients with acute myeloid leukemia.

METHODS

Thirty samples of patients with acute myeloid leukemia were studied, in which FLT3-ITD, FLT3-TKD and NPM1 mutations were investigated. All samples were submitted to immunophenotyping and 25 to karyotyping.

RESULTS

An occurrence of 33.3% NPM1 mutation and an equal number of FLT3-ITD mutation were observed. When only the cases with normal karyotype were studied, this figures increased to 50 and 40%, respectively. Eight percent of cases with normal karyotype and genotype NPM1+/FLT3- were included in the group of acute myeloid leukemia with good prognosis. The typical phenotype of acute myeloid leukemia with normal karyotype and mutated NPM1 (HLA-DR and CD34 negative) was not observed in this small series.

CONCLUSION

Good prognosis cases were identified in this series, emphasizing the need to include new genetic markers in the diagnostic routine for the correct classification of acute myeloid leukemia, to more properly estimate prognosis and determine treatment.

Molecular cytogenetic analysis of dicentric chromosomes in acute myeloid leukemia

Dicentric chromosomes (DCs) have been described in many hematological diseases, including acute myeloid leukemia (AML). They are markers of cancer and induce chromosomal instability, leading to the formation of other chromosomal aberrations and the clonal evolution of pathological cells. Our knowledge of the roles and behavior of human DCs is often derived from studies of induced DCs and cell lines. It is difficult to identify all the DCs in the karyotypes of patients because of the limitations of metaphase cytogenetic methods. The aim of this study was to revise the karyotypes of 20 AML patients in whom DCs were found with conventional G-banding or multicolor fluorescence in situ hybridization (mFISH) with (multi)centromeric probes and to characterize the DCs at the molecular cytogenetic level. FISH analyses confirmed 23 of the 29 expected DCs in 18 of 20 patients and identified 13 others that had not been detected cytogenetically. Fourteen DCs were altered by other chromosomal changes. In conclusion, karyotypes with DCs are usually very complex, and we have shown that they often contain more than one DC, which can be missed with conventional or mFISH methods. Our study indicates an association between number of DCs in karyotype and very short survival of patients.

Molecular landscape of acute myeloid leukemia in younger adults and its clinical relevance

Recent major advances in understanding the molecular basis of acute myeloid leukemia (AML) provide a double-edged sword. Although defining the topology and key features of the molecular landscape are fundamental to development of novel treatment approaches and provide opportunities for greater individualization of therapy, confirmation of the genetic complexity presents a huge challenge to successful translation into routine clinical practice. It is now clear that many genes are recurrently mutated in AML; moreover, individual leukemias harbor multiple mutations and are potentially composed of subclones with differing mutational composition, rendering each patient's AML genetically unique. In order to make sense of the overwhelming mutational data and capitalize on this clinically, it is important to identify (1) critical AML-defining molecular abnormalities that distinguish biological disease entities; (2) mutations, typically arising in subclones, that may influence prognosis but are unlikely to be ideal therapeutic targets; (3) mutations associated with preleukemic clones; and (4) mutations that have been robustly shown to confer independent prognostic information or are therapeutically relevant. The reward of identifying AML-defining molecular lesions present in all leukemic populations (including subclones) has been exemplified by acute promyelocytic leukemia, where successful targeting of the underlying PML-RARα oncoprotein has eliminated the need for chemotherapy for disease cure. Despite the molecular heterogeneity and recognizing that treatment options for other forms of AML are limited, this review will consider the scope for using novel molecular information to improve diagnosis, identify subsets of patients eligible for targeted therapies, refine outcome prediction, and track treatment response.

Concurrent detection of targeted copy number variants and mutations using a myeloid malignancy next generation sequencing panel allows comprehensive genetic analysis using a single testing strategy

Currently, comprehensive genetic testing of myeloid malignancies requires multiple testing strategies with high costs. Somatic mutations can be detected by next generation sequencing (NGS) but copy number variants (CNVs) require cytogenetic methods including karyotyping, fluorescence in situ hybidization and microarray. Here, we evaluated a new method for CNV detection using read depth data derived from a targeted NGS mutation panel. In a cohort of 270 samples, we detected pathogenic mutations in 208 samples and targeted CNVs in 68 cases. The most frequent CNVs were 7q deletion including LUC7L2 and EZH2, TP53 deletion, ETV6 deletion, gain of RAD21 on 8q, and 5q deletion, including NSD1 and NPM1. We were also able to detect exon-level duplications, including so-called KMT2A (MLL) partial tandem duplication, in 9 cases. In the 63 cases that were negative for mutations, targeted CNVs were observed in 4 cases. Targeted CNV detection by NGS had very high concordance with single nucleotide polymorphism microarray, the current gold standard. We found that ETV6 deletion was strongly associated with TP53 alterations and 7q deletion was associated with mutations in TP53, KRAS and IDH1. This proof-of-concept study demonstrates the feasibility of using the same NGS data to simultaneously detect both somatic mutations and targeted CNVs.

Evolving Therapies in Acute Myeloid Leukemia: Progress at Last?

Acute myeloid leukemia (AML) is an acquired disease characterized by chromosomal translocations and somatic mutations that lead to leukemogenesis. Systemic combination chemotherapy with an anthracycline and cytarabine remains the standard induction regimen for "fit" adults. Patients who achieve complete remission generally receive postinduction therapy with cytarabine-based chemotherapy or an allogeneic bone marrow transplant. Those unfit for induction chemotherapy are treated with hypomethylating agents (HMAs), low-dose cytarabine, or they are offered supportive care alone with transfusions and prophylactic antimicrobials. The revolution in understanding the genetics of AML, facilitated by next-generation sequencing, has led to many new drugs against driver mutations. Better methods of identification of leukemic blasts have provided us with better means to detect the disease left behind after cytotoxic chemotherapy regimens. This measurable residual disease has been correlated with poorer relapse-free survival, demonstrating the need for novel strategies to eradicate it to improve the outcome of patients with acute leukemias. In this article, we discuss adapting and improving AML therapy by age and comorbidities, emerging targeted therapies in AML, and minimal residual disease (MRD) assessment in AML.

BP1 overexpression is associated with adverse prognosis in de novo acute myeloid leukemia

To investigate DLX4 isoforms expression and their clinical significance in acute myeloid leukemia (AML). DLX4 transcript variant 1 (BP1) expression was significantly up-regulated in AML patients compared with normal controls. However, DLX4 transcript variant 2 (DLX7) was significantly down-regulated in AML patients. Both in the overall AML and the non-M3 AML cohorts, those patients with high BP1 expression (BP1(high)) showed significantly lower rates of complete remission than those with low BP1 expression (BP1(low)). BP1(high) cases had significantly shorter overall survival than BP1(low) cases in the overall AML cohort, non-M3 AML, and cytogenetically normal AML (CN-AML). Multivariate analysis confirmed the independent prognostic value of BP1 expression among both the overall AML cohort and non-M3 AML as well as CN-AML patients. However, we did not observe the impact of DLX7 expression on prognosis in AML patients. Our study reveals that BP1 overexpression serves as an independent risk factor in de novo AML patients.

Relation of BAALC and ERG Gene Expression with Overall Survival in Acute Myeloid Leukemia Cases

BACKGROUND

The objectives of this study were to evaluate the expression of brain and acute leukemia, cytoplasmic (BAALC) gene and erythroblast transformation-specific related gene (ERG) in de novo cases of acute myeloid leukemia (AML) and identify roles in disease progression and outcome.

MATERIALS AND METHODS

This study included 50 newly diagnosed AML patients, along with 10 apparently healthy normal controls. BAALC and ERG expression was detected in the bone marrow of both patients and controls using real-time RT-PCR.

RESULTS

BAALC and ERG expression was detected in 52% of cases but not in any controls. There was a statistically significant correlation between BAALC and ERG gene expression and age (p- value=0.004 and 0.019, respectively). No statistical significance was noted for sex, lymphadenopathy, hepatomegaly, splenomegaly, other hematological findings, immunophenotyping and FAB sub-classification except for ERG gene and FAB (p-value=0.058). A statistical significant correlation was found between response to treatment with ERG expression (p-value=0.028) and age (p-value=0.014). A statistically significant variation in overall survival was evident with patient age, BM blast cells, FAB subgroups, BAALC and ERG expression (p-value= <0.001, 0.045, 0.041, <0.008 and 0.025 respectively).

CONCLUSIONS

Our results suggest that BAALC and ERG genes are specific significant molecular markers in AML disease progression, response to treatment and survival.

Systematic analysis of hematopoietic gene expression profiles for prognostic prediction in acute myeloid leukemia

Acute myeloid leukemia (AML) is a hematopoietic disorder initiated by the leukemogenic transformation of myeloid cells into leukemia stem cells (LSCs). Preexisting gene expression programs in LSCs can be used to assess their transcriptional similarity to hematopoietic cell types. While this relationship has previously been examined on a small scale, an analysis that systematically investigates this relationship throughout the hematopoietic hierarchy has yet to be implemented. We developed an integrative approach to assess the similarity between AML patient tumor profiles and a collection of 232 murine hematopoietic gene expression profiles compiled by the Immunological Genome Project. The resulting lineage similarity scores (LSS) were correlated with patient survival to assess the relationship between hematopoietic similarity and patient prognosis. This analysis demonstrated that patient tumor similarity to immature hematopoietic cell types correlated with poor survival. As a proof of concept, we highlighted one cell type identified by our analysis, the short-term reconstituting stem cell, whose LSSs were significantly correlated with patient prognosis across multiple datasets, and showed distinct patterns in patients stratified by traditional clinical variables. Finally, we validated our use of murine profiles by demonstrating similar results when applying our method to human profiles.

Prevalence and Prognostic Impact of Wilms' Tumor 1 (WT1) Gene, Including SNP rs16754 in Cytogenetically Normal Acute Myeloblastic Leukemia (CN-AML): An Iranian Experience

BACKGROUND

The aim of this study was to evaluate the effect of Wilms' tumor 1 (WT1) gene mutations in adult cytogenetically normal acute myeloblastic leukemia (CN-AML) patients on survival and clinical outcome.

PATIENTS AND METHODS

A total of 88 untreated Iranian adult patients with CN-AML were selected as a study group. Exons 7 (including the SNP rs16754), 8, and 9 as a WT1 gene hotspot region were evaluated by polymerase chain reaction and direct sequencing for detection of mutations. Response to treatment and clinical outcome including overall survival (OS) and disease-free survival (DFS) were evaluated according to WT1 gene mutational status.

RESULTS

WT1 gene mutations were found in 12.5% of patients, most of which were found in exon 7. Complete remission was lower and relapse was higher in patients with WT1 gene mutation compared with WT1 gene wild type patients. OS and DFS was significantly lower in patients with WT1 gene mutation compared with patients with WT1 gene wild type (P < .001). Also, we did not find any significant effects of SNP rs16754 in exon 7 on clinical outcome and survival in patients with CN-AML.

CONCLUSION

WT1 gene mutations are a predictor indicator of a poor prognosis factor in CN-AML patients. It is recommended that WT1 gene mutations be included in the molecular testing panel in order to better diagnose and confirm their prognostic significance for better management and treatment strategy.

Outcome of patients with distinct molecular genotypes and cytogenetically normal AML after allogeneic transplantation

In AML with normal cytogenetics, age, response to induction, and FLT3-ITD allow for an estimate of outcome after allogeneic HSCT in CR1. Neither variation of classical transplant techniques nor development of chronic GVHD outweighs the negative impact of FLT3-ITD.

hnRNP K Is a Haploinsufficient Tumor Suppressor that Regulates Proliferation and Differentiation Programs in Hematologic Malignancies

hnRNP K regulates cellular programs, and changes in its expression and mutational status have been implicated in neoplastic malignancies. To directly examine its role in tumorigenesis, we generated a mouse model harboring an Hnrnpk knockout allele (Hnrnpk(+/-)). Hnrnpk haploinsufficiency resulted in reduced survival, increased tumor formation, genomic instability, and the development of transplantable hematopoietic neoplasms with myeloproliferation. Reduced hnRNP K expression attenuated p21 activation, downregulated C/EBP levels, and activated STAT3 signaling. Additionally, analysis of samples from primary acute myeloid leukemia patients harboring a partial deletion of chromosome 9 revealed a significant decrease in HNRNPK expression. Together, these data implicate hnRNP K in the development of hematological disorders and suggest hnRNP K acts as a tumor suppressor.

Oral Maintenance Chemotherapy with 6-Mercaptopurine and Methotrexate in Patients with Acute Myeloid Leukemia Ineligible for Transplantation

For decades, maintenance chemotherapy has failed to improve the cure rate or prolong the survival of patients with acute myeloid leukemia (AML), other than those with acute promyelocytic leukemia. Immediately after the first complete remission following consolidation therapy was obtained, oral maintenance chemotherapy (daily 6-mercaptopurine and weekly methotrexate) was given and continued for two years in transplant-ineligible AML patients. Leukemia-free survival (LFS) and overall survival (OS) were studied and compared between these patients and the historical control group who did not receive maintenance therapy. Consecutive 52 transplant-ineligible AML patients were analyzed. Among these patients, 27 received oral maintenance chemotherapy. No significant difference was found in the patients' characteristics between the maintenance and the control groups. The median OS was 43 (95% CI, 19-67) and 19 (95% CI, 8-30) months in the maintenance and the control groups, respectively (P = 0.202). In the multivariate analysis, the presence of maintenance therapy was an independent prognostic factor for better OS (P = 0.021) and LFS (P = 0.024). Clinical benefit from maintenance chemotherapy was remarkable in older patients (≥ 60 yr) (P = 0.035), those with intermediate or unfavorable cytogenetics (P = 0.006), those with initial low blast count in peripheral blood (P = 0.044), and those receiving less than two cycles of consolidation therapy (P = 0.017). Maintenance oral chemotherapy as a post-remission therapy can prolong the survival of patients with AML who are not eligible for transplantation, particularly older patients, those with intermediate or unfavorable cytogenetics, those with initial low blast count, and those receiving less than two cycles of consolidation therapy.

Pathology Consultation on Gene Mutations in Acute Myeloid Leukemia

OBJECTIVES

Acute myeloid leukemia (AML) is a rapidly fatal disease without the use of aggressive chemotherapy regimens. Cytogenetic and molecular studies are commonly used to classify types of AML based on prognosis, as well as to determine therapeutic regimens.

METHODS

Although there are several AML classifications determined by particular translocations, cytogenetically normal AML represents a molecularly, as well as clinically, heterogeneous group of diseases. Laboratory evaluation of AML will become increasingly important as new mutations with both prognostic and therapeutic implications are being recognized. Moreover, because many patients with AML are being treated more effectively, these mutations may become increasingly useful as markers of minimal residual disease, which can be interpreted in an individualized approach.

RESULTS

Current laboratory studies of gene mutations in AML include analysis of NPM1, FLT3, CEBPA, and KIT. In addition to these genes, many other genes are emerging as potentially useful in determining patients' prognosis, therapy, and disease course.

CONCLUSIONS

This article briefly reviews the current most clinically relevant gene mutations and their clinical and immunophenotypic features, prognostic information, and methods used for detection.

Prognostic Relevance of Cytokine Receptor Expression in Acute Myeloid Leukemia: Interleukin-2 Receptor α-Chain (CD25) Expression Predicts a Poor Prognosis

A variety of cytokine/cytokine receptor systems affect the biological behavior of acute leukemia cells. However, little is known about the clinical relevance of cytokine receptor expression in acute myeloid leukemia (AML). We quantitatively examined the expression of interleukin-2 receptor α-chain (IL-2Rα, also known as CD25), IL-2Rβ, IL-3Rα, IL-4Rα, IL-5Rα, IL-6Rα, IL-7Rα, the common β-chain (βc), γc, granulocyte-macrophage colony-stimulating factor (GM-CSF)Rα, G-CSFR, c-fms, c-mpl, c-kit, FLT3, and GP130 in leukemia cells from 767 adult patients with AML by flow cytometry and determined their prevalence and clinical significance. All cytokine receptors examined were expressed at varying levels, whereas the levels of IL-3Rα, GM-CSFRα, IL-2Rα, γc, c-kit, and G-CSFR exhibited a wide spectrum of ≥10,000 sites/cell. In terms of their French-American-British classification types, GM-CSFRα and c-fms were preferentially expressed in M4/M5 patients, G-CSF in M3 patients, and IL-2Rα in non-M3 patients. Elevated levels of IL-3Rα, GM-CSFRα, and IL-2Rα correlated with leukocytosis. In patients ≤60 years old, higher levels of these 3 receptors correlated with poor responses to conventional chemotherapy, but only IL-2Rα was associated with a shorter overall survival. By incorporating IL-2Rα status into cytogenetic risk stratification, we could sort out a significantly adverse-risk cohort from the cytogenetically intermediate-risk group. Analyses with various phenotypical risk markers revealed the expression of IL-2Rα as an independent prognostic indicator in patients with intermediate-risk cytogenetics. These findings were not observed in patients >60 years old. Our results indicate that several cytokine receptors were associated with certain cellular and clinical features, but IL-2Rα alone had prognostic value that provides an additional marker to improve current risk evaluation in AML patients ≤60 years old.

High serum concentration of L-kynurenine predicts unfavorable outcomes in patients with acute myeloid leukemia

The immunomodulatory effects of indoleamine 2,3-dioxygenase (IDO) are ascribed to its ability to catalyze the breakdown of the L-tryptophan along the L-kynurenine pathway. Because blasts from patients with acute myeloid leukemia (AML) express IDO, the goal of this study was to investigate the role of L-kynurenine as a prognostic marker for AML. We enrolled 48 AML patients. L-kynurenine concentrations were measured by high-performance liquid chromatography. The median serum L-kynurenine level was 1.67 μM. There was no significant difference in the complete remission rate between patients with L-kynurenine < 2.4 (77%) and ≥ 2.4 μM (75%). However, 3-year overall survival (OS) rates were significantly better in patients with low L-kynurenine levels (76%) than in those with high L-kynurenine levels (11%) (p < 0.0001). Furthermore, in intermediate-risk cytogenetics patients, only L-kynurenine was significantly associated with OS (p < 0.005). Multivariate analyses revealed that L-kynurenine and high leukocyte count were independent prognostic factors.

Prognostic significance of the BAALC gene expression in adult patients with acute myeloid leukemia: A meta-analysis

Numerous studies have investigated the prognostic role of brain and acute leukemia, cytoplasmic (BAALC) gene expression in adult patients with acute myeloid leukemia (AML); however, the results are inconclusive. A meta-analysis was conducted to provide a comprehensive evaluation of the prognostic role of BAALC gene expression in AML. Eligible studies were searched through PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure and the China Biology Medicine Disc. Correlations between the BAALC gene expression and clinicopathological features and prognosis were analyzed. A total of 15 studies were examined. The pooled results suggest that high BAALC expression had an unfavorable outcome in AML. The combined hazard ratio (HR) for overall survival (OS) was 1.53 and the summary HR for the disease-free survival rate was 1.64. In addition, subgroup analyses considering cytogenetic and survival analysis were also conducted. High BAALC gene expression appeared to be an adverse prognostic indicator in patients with cytogenetically normal AML (HR for OS, 1.43) and in subgroups of survival analysis with multivariate analysis (HR for OS, 2.35). These results indicate that high BAALC gene expression served as an independent poor prognostic indicator in adult patients with AML.

Identification of prognostic subgroups among acute myeloid leukemia patients with intermediate risk cytogenetics using a flow-cytometry-based assessment of ABC-transporter function

BACKGROUND

A median fluorescence intensity ratio (MFIR) which measures the efflux of mitoxantrone (an ATP Binding Cassette (ABC) transporter substrate) with and without ABC transporter inhibition correlates with expression of MDR1 and BCRP in acute myeloid leukemia (AML) blasts.

METHODS

This study evaluates the impacts of the MFIR on AML outcomes and its interaction with detection of the FLT3 ITD.

RESULTS

Among 200 newly diagnosed AML patients, an MFIR of ≥ 1.9 (MFIR+) was detected in 60 (30%) leukemic blast samples. In multivariate analysis, MFIR was an independent prognostic factor for response to induction chemotherapy (OR=7.2, P<0.00001), DFS (HR=2.3, P=0.004) and OS (HR=2.2, P=0.0005) with the main effect being in the 141 patients with intermediate risk cytogenetics. Among intermediate risk cytogenetics patients: MFIR+ outcomes were similar to unfavorable cytogenetic risk (CR, 53% vs. 52%, P=1.0; OS, 11 vs. 9 months, P=0.79). MFIR status can further stratify the prognostic risk for patients with or without FLT3 ITD mutation.

CONCLUSIONS

MFIR has value in predicting outcomes including DFS and OS as well as induction failure. This is particularly true for patients with intermediate risk cytogenetics and when combined with assessment for the FLT3-ITD mutation.

Prognostic value of brain and acute leukemia cytoplasmic gene expression in egyptian children with acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) accounts for 25%-35% of acute leukemia in children. BAALC gene (Brain and Acute Leukemia Cytoplasmic gene) is a recently identified gene on chromosome 8q22.3 that has prognostic significance in AML. The aim of this work was to study the impact of BAALC gene expression on prognosis of AML in Egyptian children.

PATIENTS AND METHODS

This study was conducted on 40 Egyptian children with newly diagnosed AML who were subjected to full history taking, clinical examination and laboratory investigations including: complete blood count, LDH, bone marrow aspiration, cytochemistry, immunophenotyping and assessment of BAALC Gene by real time PCR in bone marrow aspirate mononuclear cells before the start of chemotherapy.

RESULTS

Positive BAALC gene expression was found in 24 cases (60%) and negative expression in 16 cases (40%). Positive BAALC gene expression group includes 14 males and 10 females with mean age at presentation of 8.35±2.63 while negative BAALC gene expression includes 10 males and 6 females with mean age at presentation of 7.74±3.23 with no statistically significant differences between patients with positive and negative BAALC gene expression regarding age, sex and clinical presentations at time of diagnosis including pallor, purpura, splenomegaly, hepatomegaly and lymphadenopathy and laboratory investigations including WBCs and platelets counts, hemoglobin and LDH levels, and peripheral blood and bone marrow blast cell counts. There was significant association between positive BAALC gene expression and M1 and M2 compared with negative BAALC gene expression which is significantly associated with M4. There were statistically significant differences in disease outcome between positive and negative BAALC gene expression groups with higher rate of relapse and death and lower rate of complete remission and disease free survival in positive BAALC gene expression group compared with negative BAALC gene expression group. (p = 0.017).

CONCLUSION AND RECOMMENDATION

BAALC expression is an important bad prognostic factor in AML patients with normal karyotype and therefore we recommend its incorporation into novel risk-adapted therapeutic strategies to improve the currently disappointing cure rate of patients with AML.

Wilms Tumor 1 rs16754 predicts favorable clinical outcomes for acute myeloid leukemia patients in South Chinese population

The single nucleotide polymorphism (SNP) rs16754 in WT1 shows a clinical implication in Caucasus population. However, the results were not reproducible in different population cohorts. We evaluated the clinical significance of rs16754 for 205 de novo acute myeloid leukemia (AML) patients in South Chinese population, 188 healthy volunteers were recruited as healthy controls. WT1 mRNA expression was investigated in 81 pretreatment bone marrow specimens. WT1(GA/AA) patients showed better overall survival (OS, P=0.006) and relapse-free survival (RFS, P=0.025) as compared with WT1(GG) patients, and the favorable clinical outcomes were most prominent in older patients with superior OS (P=0.001) and RFS (P=0.003). In multivariable analysis, rs16754 was still associated with favorable OS (HR=1.533, P=0.042). The WT1(GG) patients showed significantly higher WT1 mRNA expression than the WT1(GA/AA) patients (P=0.01). In summary, WT1 rs16754 may serve as an independent biomarker in AML patients from South Chinese.

Mitigating Fear and Loathing in Managing Acute Myeloid Leukemia

The contemporary care of patients with acute myeloid leukemia (AML) is made complex by potentially toxic treatments, continuously advancing science, aging patients, and individual treatment goals. By taking a survey of present-day approaches, we aim to dispel some of the trepidation surrounding that care of patients with AML. At the beginning is the initial presentation, and we will discuss whether or not AML should be considered a medical emergency. We will explore the complex realm of patient decision-making about initial therapy, including the intricate straits of patient-doctor communication, and available options for initial treatment. We will then address post-remission approaches and the controversies that lie therein, and survivorship issues. Finally, we will investigate the current role molecular assessments are playing in therapy recommendations.

Down-regulation of GPX3 is associated with favorable/intermediate karyotypes in de novo acute myeloid leukemia

Decreased glutathione peroxidase 3 (GPX3) expression has been identified in numerous solid tumors. However, GPX3 expression pattern in acute myeloid leukemia (AML) remains poorly known. Our study was intended to explore GPX3 expression status and further analyze the clinical relevance of GPX3 expression in AML. GPX3 mRNA level was detected by real-time quantitative PCR in 122 de novo AML patients and 44 normal controls. GPX3 transcript level was significantly decreased compared with normal controls (P<0.001). The patients with low GPX3 expression had significantly higher hemoglobin and platelets than those with high GPX3 expression (P=0.049 and 0.020). The frequency of low GPX3 expression in favorable karyotype (66%, 23/35) and intermediate karyotype (65%, 45/69) was higher than in poor karyotype (29%, 4/14) (P=0.017). No significant differences were observed in both complete remission and overall survival between the GPX3 low-expressed and high-expressed patients (P>0.05). Reduced GPX3 expression is associated with favorable/intermediate karyotypes but not with survival in de novo AML patients.

Prognostic and biologic significance of DNMT3B expression in older patients with cytogenetically normal primary acute myeloid leukemia

DNMT3B encodes a DNA methyltransferase implicated in aberrant epigenetic changes contributing to leukemogenesis. We tested whether DNMT3B expression, measured by NanoString nCounter assay, associates with outcome, gene and microRNA expression and DNA methylation profiles in 210 older (⩾60 years) adults with primary, cytogenetically normal acute myeloid leukemia (CN-AML). Patients were dichotomized into high versus low expressers using median cut. Outcomes were assessed in the context of known CN-AML prognosticators. Gene and microRNA expression, and DNA methylation profiles were analyzed using microarrays and MethylCap-sequencing, respectively. High DNMT3B expressers had fewer complete remissions (CR; P=0.002) and shorter disease-free (DFS; P=0.02) and overall (OS; P<0.001) survival. In multivariable analyses, high DNMT3B expression remained an independent predictor of lower CR rates (P=0.04) and shorter DFS (P=0.04) and OS (P=0.001). High DNMT3B expression associated with a gene expression profile comprising 363 genes involved in differentiation, proliferation and survival pathways, but with only four differentially expressed microRNAs (miR-133b, miR-148a, miR-122, miR-409-3p) and no differential DNA methylation regions. We conclude that high DNMT3B expression independently associates with adverse outcome in older CN-AML patients. Gene expression analyses suggest that DNMT3B is involved in the modulation of several genes, although the regulatory mechanisms remain to be investigated to devise therapeutic approaches specific for these patients.

Identification of let-7a-2-3p or/and miR-188-5p as prognostic biomarkers in cytogenetically normal acute myeloid leukemia

Cytogenetically normal acute myeloid leukemia (CN-AML) is the largest and most heterogeneous AML subgroup. It lacks sensitive and specific biomarkers. Emerging evidences have suggested that microRNAs are involved in the pathogenesis of various leukemias. This paper evaluated the association between microRNA expression and prognostic outcome for CN-AML, based on the RNA/microRNA sequencing data of CN-AML patients. High let-7a-2-3p expression and low miR-188-5p expression were identified to be significantly associated with longer overall survival (OS) and event free survival (EFS) for CN-AML, independently or in a combined way. Their prognostic values were further confirmed in European Leukemia Net (ELN) genetic categories. Also, in multivariable analysis with other known risk factors, high let-7a-2-3p and low miR-188-5p expression remained to be associated with longer OS and EFS. In addition, the prognostic value of these two microRNAs was confirmed in patients who received hematopoietic stem cell transplantation (HSCT). To gain more biological insights of the underlying mechanisms, we derived the genome-wide differential gene/microRNA signatures associated with the expression of let-7a-2-3p and miR-188-5p. Several common microRNA signatures indicating favorable outcome in previous studies were up-regulated in both high let-7a-2-3p expressers and low miR-188-5p expressers, including miR-135a, miR-335 and miR-125b and all members of miR-181 family. Additionally, common up-regulated genes included FOSB, IGJ, SNORD50A and ZNF502, and FOSB was a known favorable signature in AML. These common signatures further confirmed the underlying common mechanisms for these two microRNAs value as favorable prognostic biomarkers. We concluded that high let-7a-2-3p and low miR-188-5p expression could be potentially used as favorably prognostic biomarkers independently or in a combined way in CN-AML patients, whether they received HSCT or not.

Prognostic involvement of nucleophosmin mutations in acute myeloid leaukemia

Nucleophosmin (NPM1) is a protein of highly conserved nature which works as a molecular chaperone and is mostly found in nucleoli. NPM also involved in the maturation of preribosomes and duplication of centrosomes. Furthermore, it is also active in control and regulation of the ARF-p53 tumor suppressor pathway. A high rate of incidence and prognostic involvement is reported by various authors in AML patients. In AML it behaves as a favorable prognostic marker. NPM mutations are more frequently associated with normal-karyotype AML and are usually absent in patients having abnormal or poor cytogenetic. NPM mutations are not frequent in other hematopoietic tumors .Two main types of mutations have been described to date. Both of these cause abnormal cytoplasmic localization of NPM1. Their high incidence rate in normal karyoptype and their favorable nature make those mutations hot spot or front face mutations which should be checked before treatment starts.

Association of ABCB1 polymorphisms with prognostic outcomes of anthracycline and cytarabine in Chinese patients with acute myeloid leukemia

PURPOSE

To investigate the influence of ABCB1 polymorphisms on prognostic outcomes in Chinese patients with de novo intermediate-risk acute myeloid leukemia (AML) and to examine the gene expression level in relation to the genetic variation.

METHODS

In total, 263 Chinese intermediate-risk AML patients treated with anthracycline and cytarabine were enrolled. G2677T, C1236T, and C3435T of the ABCB1 gene were analyzed by the allele-specific matrix-assisted laser desorption. Expression of ABCB1 messenger RNA (mRNA) was tested in 101 patients of known genotype and haplotype for ABCB1 polymorphisms. Basic clinical characteristics of these patients were collected from medical records.

RESULTS

Survival analysis showed that patients with AML (TTT haplotype) had a longer overall survival (OS) (p < 0.001, 29.2 months, 95 % confidence interval [CI], 26.9-31.5 months) and relapse-free survival (RFS) (p = 0.005, 21.8 months, 95 % CI, 19.5-24.0 months) compared with those without TTT haplotype (21.9 months, 95 % CI, 19.6-24.2 months; 16.5 months, 95 % CI, 14.6-18.5 months). After adjusting for age; gender; leukocyte count; hemoglobin level; platelet levels; French, American, and British classification; lactate dehydrogenase levels; Eastern Cooperative Oncology Group performance status; nucleophosmin gene; and fms-related tyrosine kinase 3 gene, the multivariate survival analysis showed that the TTT haplotype appeared to be a predicting factor for OS (p = 0.001, hazard ratio = 1.854, 95 % CI, 1.301-2.641) and RFS (p = 0.009, hazard ratio = 1.755, 95 % CI, 1.153-2.671). Moreover, a significant association between the TTT haplotype and relapse in AML patients was observed in this study (p = 0.002, odds ratio = 0.410, 95 % CI, 0.235-0.715). Gene expression level was significantly lower in patients with the TTT haplotype than in the patients with the other haplotypes (p = 0.004).

CONCLUSIONS

The findings suggested the TTT haplotype was possibly related to the OS, RFS, and relapse in Chinese patients with AML.

The pathological role and prognostic impact of miR-181 in acute myeloid leukemia

In addition to genetic abnormalities, such as chromosomal translocations and somatic mutations that have been widely acknowledged in the leukemogenesis of acute myeloid leukemia (AML), epigenetic modifications also play a vital role in this process. MicroRNA (miRNA) regulation is emerging as a new layer of epigenetic regulation besides DNA methylation and histone modifications. Among the miRNAs first identified to be specifically expressed in hematopoietic cells, the miR-181 family has been implicated in regulating the differentiation of B cells, T cells, and natural killer cells during normal hematopoiesis, and has been linked tightly to the pathogenesis and prognosis of AML. Accumulating evidence indicates that miR-181 acts as a tumor suppressor in the pathogenesis of AML and exhibits a significant impact on the survival of patients with AML. Herein, we review the role of miR-181 as a diagnostic marker and prognostic predictor in AML, and discuss the potential use of miR-181 as a therapeutic target for AML.

Expression and prognostic impact of lncRNAs in acute myeloid leukemia

Long noncoding RNAs (lncRNAs) are transcripts longer than 200 nucleotides, located within the intergenic stretches or overlapping antisense transcripts of protein coding genes. LncRNAs are involved in numerous biological roles including imprinting, epigenetic regulation, apoptosis, and cell cycle. To determine whether lncRNAs are associated with clinical features and recurrent mutations in older patients (aged ≥60 y) with cytogenetically normal (CN) acute myeloid leukemia (AML), we evaluated lncRNA expression in 148 untreated older CN-AML cases using a custom microarray platform. An independent set of 71 untreated older patients with CN-AML was used to validate the outcome scores using RNA sequencing. Distinctive lncRNA profiles were found associated with selected mutations, such as internal tandem duplications in the FLT3 gene (FLT3-ITD) and mutations in the NPM1, CEBPA, IDH2, ASXL1, and RUNX1 genes. Using the lncRNAs most associated with event-free survival in a training cohort of 148 older patients with CN-AML, we derived a lncRNA score composed of 48 lncRNAs. Patients with an unfavorable compared with favorable lncRNA score had a lower complete response (CR) rate [P < 0.001, odds ratio = 0.14, 54% vs. 89%], shorter disease-free survival (DFS) [P < 0.001, hazard ratio (HR) = 2.88] and overall survival (OS) (P < 0.001, HR = 2.95). The validation set analyses confirmed these results (CR, P = 0.03; DFS, P = 0.009; OS, P = 0.009). Multivariable analyses for CR, DFS, and OS identified the lncRNA score as an independent marker for outcome. In conclusion, lncRNA expression in AML is closely associated with recurrent mutations. A small subset of lncRNAs is correlated strongly with treatment response and survival.

Prognostic relevance of Wilms tumor 1 (WT1) gene Exon 7 mutations in-patient with cytogenetically normal acute myeloid leukemia

This study aimed to assess the prognostic influences of Wilms tumor 1 (WT1) gene mutations in cytogenetically normal acute myeloid leukemia (CN-AML) among Egyptian patients. Exon 7 of WT1 was screened for mutations in samples from 82 CN-AML patients out of 203 newly diagnosed AML patients, using a high-resolution capillary electrophoresis. Seven out of 82 AML patients (8.3 %) harbored WT1 mutations. There was no significant difference between the mutant WT1 and wild type AML patients as regard age, sex, French-American-British subtypes and the prevalence of success of induction remission therapy (P < 0.5). AML patients with mutant WT1 had shorter overall survival as compared to those patients with wild WT1 (HR = 1.38; 95 % CI 4.79-6.86; P = 0.004). In conclusion, CN-AML patients with WT1 gene mutation have poor clinical outcome. We recommend testing the WT1 mutations as part of molecularly based risk assessment and risk-adapted treatment stratification of patients with CN-AML.

The effect of calcium channel blockers on the outcome of acute myeloid leukemia

The effect of calcium channel blockers (CCBs), beta blockers and angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) on the prognosis of patients with acute myeloid leukemia (AML) is largely unknown. We collected data on the use of these medications in 1043 patients with AML, excluding promyelocytic leukemia, diagnosed and treated at M. D. Anderson Cancer Center between 2000 and 2012. Treatment with either amlodipine or diltiazem predicted a worse overall survival (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.22-2.06, p < 0.0001). There was no difference in survival depending on whether patients were taking beta blockers, ACE inhibitors or ARBs. The effect of CCBs on survival was independent from the National Comprehensive Cancer Network risk classification, age, performance status, response to treatment, year of diagnosis and CD34 levels, assessed by flow cytometry (HR 1.39, 95% CI 1.05-1.80, p = 0.02). Treatment with either amlodipine or diltiazem predicts worse survival in patients with AML independent of known prognostic factors.

Overexpression of BAALC: clinical significance in Chinese de novo acute myeloid leukemia

To investigate the expression of brain and acute leukemia, cytoplasmic (BAALC) and analyze its clinical significance in Chinese de novo acute myeloid leukemia (AML). Real-time quantitative PCR (RQ-PCR) was carried out to detect BAALC transcript level in 121 de novo AML patients and 41 normal controls. BAALC transcript level in AML patients was significantly up-regulated compared with normal controls (P < 0.001). Patients with high BAALC expression had significantly older age than those with low BAALC expression (P = 0.021). The percentage of blasts in bone marrow of the BAALC high-expressed patients was significantly higher than that in the low-expressed patients (P < 0.001). The incidence of BAALC overexpression was significantly higher in M0/M1 (8/9, 89 %) and M2 subtypes (33/48, 68 %) than in M3 subtype (6/27, 22 %) (P < 0.001). The frequency of IDH1/2 wild type in CN-AML patients with high BAALC expression was significantly higher than those with low BAALC expression (P = 0.031). BAALC high-expressed patients had a significantly lower complete remission than low-expressed patients in both entire AML cohort and CN-AML (P = 0.013 and 0.029, respectively). Furthermore, both whole AML cohort and CN-AML patients with high BAALC expression showed a shorter overall survival than those with low BAALC expression (P = 0.002 and 0.008, respectively). Multivariate analysis confirmed high BAALC expression as an independent adverse prognostic factor in both AML and CN-AML patients. Our study indicates that overexpression of BAALC serves as an independent prognostic biomarker in both whole AML cohort and CN-AML patients.

STAT3 as a possible therapeutic target in human malignancies: lessons from acute myeloid leukemia

STAT3 is important for transcriptional regulation in human acute myeloid leukemia (AML). STAT3 has thousands of potential DNA binding sites but usually shows cell type specific binding preferences to a limited number of these. Furthermore, AML is a very heterogeneous disease, and studies of the prognostic impact of STAT3 in human AML have also given conflicting results. A more detailed characterization of STAT3 functions and the expression of various isoforms in human AML will therefore be required before it is possible to design clinical studies of STAT3 inhibitors in this disease, and it will be especially important to investigate whether the functions of STAT3 differ between patients. Several other malignancies also show extensive biological heterogeneity, and the present discussion and the suggested scientific approaches may thus be relevant for other cancer patients.

Selective inhibitors of nuclear export (SINE)--a novel class of anti-cancer agents

Dysregulation of the nucleo-cytoplasmic transport of proteins plays an important role in carcinogenesis. The nuclear export of proteins depends on the activity of transport proteins, exportins. Exportins belong to the karyopherin β superfamily. Exportin-1 (XPO1), also known as chromosomal region maintenance 1 (CRM1), mediates transport of around 220 proteins. In this review, we summarized the development of a new class of antitumor drugs, collectively known as selective inhibitors of nuclear export (SINE). KPT-330 (selinexor) as an oral agent is showing activities in early clinical trials in both solid tumors and hematological malignancies.

[Current indications of allogeneic stem cell transplant in adults with acute myeloid leukemia]

Allogeneic stem cell transplantation (SCT) is an increasingly important therapeutic option for the treatment of adult patients with acute myeloid leukemia. Here we review the current indications of SCT in this disease. While patients with favorable cytogenetics should receive consolidation chemotherapy, patients with unfavorable karyotype are prime candidates for SCT or new approaches to SCT (which should be done in first complete remission). Patients with intermediate prognoses should also receive SCT in first complete remission. In the absence of a suitable matched related donor, most patients will be able to find an alternative donor to proceed to a potentially curative allogeneic transplantation. The use of reduced-intensity conditioning regimens before SCT has allowed patients in the sixth or seventh decades of life to be routinely transplanted. Despite major differences among transplant centers in the intensity and composition of the conditioning regimen and immunosuppression, choice of graft source, postgraft immune-modulation, and supportive care, there has been a dramatic improvement in terms of tolerance. Although it is presumed to be a curative strategy, major complications of SCT remain graft-versus-host disease, delayed immune recovery, multiple comorbidities, and relapse after transplant.

Mutations in the isocitrate dehydrogenase 2 gene and IDH1 SNP 105C > T have a prognostic value in acute myeloid leukemia

Background

The isocitrate dehydrogenase (IDH1/IDH2) genes are metabolic enzymes, which are frequently mutated in acute myeloid leukemia (AML). The enzymes acquire neomorphic enzymatic activity when they mutated.

Methods

We have investigated the frequency and outcome of the acquired IDH1/IDH2 mutations and the IDH1 SNP 105C > T (rs11554137) in 189 unselected de novo AML patients by polymerase chain reaction amplification followed by direct sequencing. The survival are presented in Kaplan Meier curves with log rank test. Multivariable survival analysis was conducted using Cox regression method, taking age, risk group, treatment, IDH1/2 mutations and IDH1 SNP105 genotype into account.

Results

Overall, IDH1/2 mutations were found in 41/187 (21.7%) of the AML patients. IDH1 codon 132 mutations were present in 7.9%, whereas IDH2 mutations were more frequent and mutations were identified in codon 140 and 172 in a frequency of 11.1% and 2.6%, respectively. The SNP 105C > T was present in 10.5% of the patients, similar to the normal population. A significantly reduced overall survival (OS) for patients carrying IDH2 codon 140 mutation compared with patients carrying wild-type IDH2 gene (p < 0.001) was observed in the intermediate risk patient group. Neither in the entire patient group nor subdivided in different risk groups, IDH1 mutations had any significance on OS compared to the wild-type IDH1 patients. A significant difference in OS between the heterozygous SNP variant and the homozygous wild-type was observed in the intermediate risk FLT3 negative AML patients (p = 0.004).

Conclusions

Our results indicate that AML-patients with IDH2 mutations or the IDH1 SNP 105C > T variant can represent a new subgroup for risk stratification and may indicate new treatment options.