Acute myeloid leukemia: 2016 Update on risk-stratification and management

Tripartite prehabilitation of patients with acute myeloid leukaemia and high-risk myelodysplastic syndromes during intensive chemotherapy before allogeneic haematopoietic stem cell transplantation (COHABILIT): protocol for an innovating prospective multicentre study

OBJECTIVES

Acute myeloid leukaemia (AML) and high-risk myelodysplastic syndromes (MDS) are often treated with intensive chemotherapy followed by allogeneic haematopoietic stem cell transplantation (allo-HSCT). The pretransplant treatment results in a general deterioration of the patient's health and quality of life. Furthermore, allo-HSCT can be responsible for significant toxicity with risks of graft-versus-host disease (GvHD). Developing strategies to prevent physical deconditioning, undernutrition and psychological distress could help maintain a satisfactory general state of health before transplantation and thus limit these deleterious effects. This protocol evaluates the feasibility and adherence to a personalised prehabilitation programme, which can be modulated and assisted by connected objects, provided from the diagnosis to the allo-HSCT.

METHODS AND ANALYSIS

This multicentre interventional study will include 50 patients treated for AML or high-risk MDS with intensive chemotherapy and eligible for allo-HSCT. The intervention consists of a coached, supervised or self-directed physical activity programme, organised during the hospitalisation phases and periods at home. At the same time, patients will receive a weekly dietary follow-up. The whole intervention is controlled and modulated through the use of a dedicated application and connected objects allowing adaptation and individualisation. The rate of participation in the prescribed physical activity sessions will assess the feasibility of this study. In addition, the evolution of physical capacities (Short Physical Performance Battery, grip and quadriceps strengths), psychosocial parameters (Functional Assessment of Cancer Therapy - Leukaemia, Functional Assessment of Cancer Therapy - Fatigue, subjective well-being, Hospital Anxiety and Depression Scale, self-efficacy, Coach-Athlete Relationship Questionnaire, interviews) and clinical status (weight, lean body mass, survival rate, number of infections, days of hospitalisation, GvHD) will be evaluated.

ETHICS AND DISSEMINATION

The study procedures have been approved by the National Ethics Committee (21.00223.000003). Consent is given in person by each participant. The information collected on the participants contains only a non-identifiable study identifier. The results of this protocol will be published in a scientific paper and communicated to the medical staff of the medical centre.

TRIAL REGISTRATION NUMBER

NCT03595787.

Prognostic value of NOX2 as a potential biomarker for lung adenocarcinoma using TCGA and clinical validation

Lung adenocarcinoma (LUAD) is associated with high morbidity and mortality; therefore, effective biomarkers are essential. In recent years, a rapid increase in the efficiency of high‑throughput sequencing technologies and the continuous improvement of comprehensive online databases have facilitated the study of the genomic changes that affect tumor progression, including the identification of tumor biomarkers. Therefore, the identification of genes that may affect the progression and prognosis of LUAD is necessary. In the present study, the CIBERSORT and ESTIMATE bioinformatics packages were used to evaluate data from The Cancer Genome Atlas, including assessment of the proportion of tumor‑infiltrating immune cells in the tumor microenvironment, Cox regression analysis of differentially expressed genes and cross analysis of protein‑protein interaction networks. Myeloid cell NADPH oxidase isoform 2 (NOX2), an indispensable gene in the immune system, was demonstrated to serve a vital role in LUAD pathogenesis. Western blotting and immunohistochemistry confirmed that, at the protein level, NOX2 expression was increased in normal cells compared with cancer cells. Furthermore, reverse transcription‑quantitative PCR results at the mRNA level were consistent with these results, which confirmed that the abundance of NOX2 was significantly reduced in LUAD patients. NOX2 may be used as a novel marker and an independent prognostic indicator of LUAD. Its potential function was enriched in tumor immune and metabolic signaling pathways, which could provide clues for the study of the signaling pathways and molecular networks related to the disease progression of LUAD, which would be helpful for the assessment of prognosis in the clinical setting.

Evaluating immune response and metabolic related biomarkers pre-allogenic hematopoietic stem cell transplant in acute myeloid leukemia

Although hematopoietic stem cell transplantation (HCT) is the only curative treatment for acute myeloid leukemia (AML), it is associated with significant treatment related morbidity and mortality. There is great need for predictive biomarkers associated with overall survival (OS) and clinical outcomes. We hypothesized that circulating metabolic, inflammatory, and immune molecules have potential as predictive biomarkers for AML patients who receive HCT treatment. This retrospective study was designed with an exploratory approach to comprehensively characterize immune, inflammatory, and metabolomic biomarkers. We identified patients with AML who underwent HCT and had existing baseline plasma samples. Using those samples (n = 34), we studied 65 blood based metabolomic and 61 immune/inflammatory related biomarkers, comparing patients with either long-term OS (≥ 3 years) or short-term OS (OS ≤ 1 years). We also compared the immune/inflammatory response and metabolomic biomarkers in younger vs. older AML patients (≤30 years vs. ≥ 55 years old). In addition, the biomarker profiles were analyzed for their association with clinical outcomes, namely OS, chronic graft versus host disease (cGVHD), acute graft versus host disease (aGVHD), infection and relapse. Several baseline biomarkers were elevated in older versus younger patients, and baseline levels were lower for three markers (IL13, SAA, CRP) in patients with OS ≥ 3 years. We also identified immune/inflammatory response markers associated with aGVHD (IL-9, Eotaxin-3), cGVHD (Flt-1), infection (D-dimer), or relapse (IL-17D, bFGF, Eotaxin-3). Evaluation of metabolic markers demonstrated higher baseline levels of medium- and long-chain acylcarnitines (AC) in older patients, association with aGVHD (lactate, long-chain AC), and cGVHD (medium-chain AC). These differentially expressed profiles merit further evaluation as predictive biomarkers.

MiR-140 targets lncRNA FAM230B to suppress cell proliferation in acute myeloid leukemia running title: MiR-140 targets FAM230B in AML

BACKGROUND

FAM230B serves as an oncogenic lncRNA in both gastric cancer and papillary thyroid cancer, while its role in acute myeloid leukemia (AML) is unclear. We predicted that FAM230B could be a target of miR-140, a well-characterized tumor suppressor, and analyzed their interaction in AML.

METHODS

Differential expressions of FAM230B and miR-140 in bone marrow mononuclear cells (BMMNCs) were determined by RT-qPCR. Correlations were analyzed by Pearson's correlation coefficient. Subcellular FAM230B location was determined using cellular fractionation assay. The direct interaction between FAM230B and miR-140 was confirmed by RNA pull-down assay. The roles of FAM230B and miR-140 in cell proliferation were explored using BrdU assay.

RESULTS

High FAM230B expression level and low miR-140 expression level were observed in AML. FAM230B and miR-140 were inversely correlated and directly interacted with each other. FAM230B could be detected in both cytoplasm and nuclear samples. MiR-140 overexpression downregulated FAM230B expression and suppressed the enhancing effects of FAM230B overexpression on cell proliferation.

CONCLUSION

MiR-140 may target FAM230B to suppress cell proliferation in AML.

HIVEP3 cooperates with ferroptosis gene signatures to confer adverse prognosis in acute myeloid leukemia

BACKGROUND

The human immunodeficiency virus type I enhancer binding protein (HIVEP) family, which contains zinc finger and acid-rich (ZAS) domains, has been demonstrated to be implicated in vital biological processes, such as cell survival, tumor necrosis factor (TNF) signaling, and tumor formation. However, its expression patterns, prognostic relevance, and functional implications in acute myeloid leukemia (AML) remain elusive.

METHODS

We inspected HIVEP mRNA expression levels in datasets from The Cancer Genome Atlas (TCGA) and GSE24006. Survival analyses were orchestrated using the web-based bioinformatics platforms and R studio in two AML cohorts. Prognostic value and capacity were assessed by Cox regression analyses. Association of HIVEP3 expression levels with clinical characteristics were analyzed with R and UALCAN. Subsequentially, functional enrichment analyses were operated to interpret HIVEP3 co-expressed gene clusters. A prognostic gene signature was created by the least absolute shrinkage and selection operator (LASSO) regression algorithm. Moreover, bone marrow aspirate smears of AML patients were stained for HIVEP3 by immunohistochemistry (IHC). HIVEP3 expression was examined by qRT-PCR in leukemia cell lines treated with ferroptosis compounds in vitro.

RESULTS

Augmented transcriptional levels of HIVEP2 and 3 were noted in AML patients (p<0.001). HIVEP3 not only could confer adverse prognosis independently in AML patients, but also was associated with AML subtypes, age, cytogenetic risk, and disease-related molecules. Co-expressed gene clusters of HIVEP3 were enriched in functional pathways related to AML leukemogenesis, such as ribosome, metabolism, and calcium signaling. Combined with multiple tumorigenesis signaling pathways, we proposed an integrated LASSO model with HIVEP3 and ferroptosis regulators AIFM2 and LPCAT3, to predict the outcome for AML patients. Furthernore, altered HIVEP3 expression at the mRNA or protein level was confirmed in sorted leukemia cells and blast cells in bone marrow tissues. In vitro experiments authenticated the involvement of HIVEP3 in ferroptosis signaling pathways.

CONCLUSIONS

Our findings suggest that HIVEP3 is a de novo independent prognostic indicator, and the crosstalk between HIVEP3 and ferroptosis signaling pathways may inspire a specific perspective on the oncological network of AML.

[Prognostic implications and functional enrichment analysis of LTB4R in patients with acute myeloid leukemia]

OBJECTIVE

To explore the expression patterns, prognostic implications, and biological role of leukotriene B4 receptor (LTB4R) in patients with acute myeloid leukemia (AML).

METHODS

We collected the data of mRNA expression levels and clinical information of patients with AML from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database for mRNA expression analyses, survival analyses, Cox regression analyses and correlation analyses using R studio to assess the expression patterns and prognostic value of LTB4R. The correlation of LTB4R expression levels with clinical characteristics of the patients were analyzed using UALCAN. The co-expressed genes LTB4R were screened from Linkedomics and subjected to functional enrichment analysis. A protein-protein interaction network was constructed using STRING. GSEA analyses of the differentially expressed genes (DEGs) were performed based on datasets from TCGA-LAML stratified by LTB4R expression level. We also collected peripheral blood mononuclear cells (PBMCs) from AML patients and healthy donors for examination of the mRNA expression levels of LTB4R and immune checkpoint genes using qRT-PCR. We also examined serum LTB4R protein levels in the patients using ELISA.

RESULTS

The mRNA expression level of LTB4R was significantly increased in AML patients (4.898±1.220 vs 2.252±0.215, P < 0.001), and an elevated LTB4R expression level was correlated with a poor overall survival (OS) of the patients (P=0.004, HR=1.74). LTB4R was identified as an independent prognostic factor for OS (P=0.019, HR=1.66) and was associated with FAB subtypes, cytogenetic risk, karyotype abnormalities and NPM1 mutations. The co- expressed genes of LTB4R were enriched in the functional pathways closely associated with AML leukemogenesis, including neutrophil inflammation, lymphocyte activation, signal transduction, and metabolism. The DEGs were enriched in differentiation, activation of immune cells, and cytokine signaling. Examination of the clinical serum samples also demonstrated significantly increased expressions of LTB4R mRNA (P=0.044) and protein (P=0.008) in AML patients, and LTB4R mRNA expression was positively correlated with the expression of the immune checkpoint HAVCR2 (r= 0.466, P=0.040).

CONCLUSION

LTB4R can serve as a novel biomarker and independent prognostic indicator of AML and its expression patterns provide insights into the crosstalk of leukemogenesis signaling pathways involving tumor immunity and metabolism.

HCK is a Potential Prognostic Biomarker that Correlates with Immune Cell Infiltration in Acute Myeloid Leukemia

Background. The tumor microenvironment (TME) plays a significant role in the progression and prognosis of acute myeloid leukemia (AML). This study is aimed at exploring TME-associated biomarkers and identify their potential mechanism in the microenvironment of AML. Method. In this study, the stromal, immune, and ESTIMATE scores of AML patients were evaluated with the ESTIMATE and CIBERSORT algorithms; then, the AML samples were divided into high- and low-score groups. We evaluated the association between clinicopathological characteristics, survival rate, and the stromal/immune/ESTIMATE scores. Furthermore, we identified TME-associated differentially expressed genes (DEGs) then carried out pathway enrichment analysis, protein-protein interaction (PPI) network, Cox regression analysis, and Kaplan-Meier survival analysis to select the most crucial genes. In addition, we further explored the potential mechanism of HCK in the AML microenvironment. Results. We identified 624 TME-associated DEGs and found that HCK was the most promising biomarker associated with AML. The results of the gene set enrichment analysis (GSEA) indicated that HCK was mainly involved in immune and inflammation-related signaling pathways. In addition, CIBERSORT analysis showed that HCK was closely related to tumor immune infiltration, with HCK expression associated with various infiltrating immune cells, including B cells, T cells, tumor-associated macrophages (TAM), NK cells, plasma cells, eosinophils, and neutrophils. Furthermore, HCK expression was closely related with ELN risk stratification in patients with AML. Conclusion. HCK could regulate immune cell infiltration in the microenvironment of AML and may act as a potential biomarker for the treatment and prognosis of AML patients.

Palliative cytoreduction with low dose intravenous melphalan in patients with acute myeloid leukemia refractory to prior treatment

BACKGROUND

Hyperproliferative crises with hyperleukocytosis occur frequently in the disease course of refractory or relapsed acute myeloid leukemia (AML). Palliative cytoreduction aims to control blast count in order to avoid life-threatening complications and preserve quality of life in patients unfit for intensive treatment. In our center, low-dose intravenous melphalan is sometimes used with this intent.

METHODS

We performed a retrospective analysis of patients with AML who were treated with low-dose intravenous melphalan (15-30 mg/m²) in a palliative setting.

RESULTS

Thirty patients with AML who received low-dose melphalan (15-25 mg/m²) were identified. In total, 63 administrations of low-dose melphalan were counted. A clear cytoreductive effect (>50%) was seen within a few days in 78% of melphalan administrations. The median duration of response after an individual dose was 17 days (interquartile range [IQR] 10-26). The median overall survival was 29 days (IQR 16-73). Most common side effects were worsening pancytopenia with neutropenic fever and an increase in transfusion dependency and tumor lysis syndrome.

CONCLUSION

Intravenous low-dose melphalan is effective, quick and safe as palliative cytoreductive therapy in patients with hyperproliferative AML. It can be considered in palliative care of patients refractory to prior treatment with preserving acceptable quality of life. Our small retrospective cohort is the first to report the use of low-dose intravenous melphalan as palliative cytoreductive treatment in this population.

Implementing a Functional Precision Medicine Tumor Board for Acute Myeloid Leukemia

We generated ex vivo drug-response and multiomics profiling data for a prospective series of 252 samples from 186 patients with acute myeloid leukemia (AML). A functional precision medicine tumor board (FPMTB) integrated clinical, molecular, and functional data for application in clinical treatment decisions. Actionable drugs were found for 97% of patients with AML, and the recommendations were clinically implemented in 37 relapsed or refractory patients. We report a 59% objective response rate for the individually tailored therapies, including 13 complete responses, as well as bridging five patients with AML to allogeneic hematopoietic stem cell transplantation. Data integration across all cases enabled the identification of drug response biomarkers, such as the association of IL15 overexpression with resistance to FLT3 inhibitors. Integration of molecular profiling and large-scale drug response data across many patients will enable continuous improvement of the FPMTB recommendations, providing a paradigm for individualized implementation of functional precision cancer medicine. SIGNIFICANCE: Oncogenomics data can guide clinical treatment decisions, but often such data are neither actionable nor predictive. Functional ex vivo drug testing contributes significant additional, clinically actionable therapeutic insights for individual patients with AML. Such data can be generated in four days, enabling rapid translation through FPMTB.See related commentary by Letai, p. 290.This article is highlighted in the In This Issue feature, p. 275.

Distinct clinico-biological features in AML patients with low allelic ratio FLT3-ITD: role of allogeneic stem cell transplantation in first remission

The mutant burden of FLT3-ITD modulates its prognostic impact on patients with acute myeloid leukemia (AML). However, for patients with low allelic ratio (AR) FLT3-ITD (FLT3-ITD^low, AR < 0.5), clinical features, as well as genomic and transcriptomic profiles remain unclear, and evidence supporting allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first complete remission (CR1) remains controversial. This study aimed to elucidate the genomic features, prognosis, and transplantation outcome of FLT3-ITD^Iow in AML patients with intermediate-risk cytogenetics. FLT3-ITD^low was associated with a negative enrichment of the leukemic stem cell signature, a marked enrichment of the RAS pathway, and with higher frequencies of RAS pathway mutations, different from those with FLT3-ITD^high. Concurrent CEBPA double mutations were favorable prognostic factors, whereas MLL-PTD, and mutations in splicing factors were unfavorable prognostic factors in FLT3-ITD^low patients. Patients with FLT3-ITD^low had a shorter overall survival (OS) and event-free survival (EFS) than those with FLT3^wt. Allo-HSCT in CR1 was associated with a significantly longer OS and EFS compared with postremission chemotherapy in patients with FLT3-ITD^low. In conclusion, FLT3-ITD^low is associated with different mutational and transcriptomic profiles compared with FLT3-ITD^high. The presence of concomitant poor-risk mutations exert negative prognostic impacts in patients with FLT3-ITD^low, who markedly benefit from allo-HSCT in CR1.

Pre-transplant minimal residual disease assessment and transplant-related factors predict the outcome of acute myeloid leukemia patients undergoing allogeneic stem cell transplantation

We studied pretransplant minimal residual disease (MRD) in 224 patients (median age 44 years; range 17-65) with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplant (HSCT) in complete remission. MRD was evaluated on marrow samples using multicolor flow cytometry and assessment of WT1 gene expression. Both methods showed a strong prognostic value and their combination allowed the identification of three groups of patients with different risk of relapse. In multivariate analysis, combined MRD was the only predictor of cumulative incidence of relapse, regardless of donor type, conditioning regimen, first or second CR at HSCT, HSCT year, and ELN risk group. Multivariate regression model showed that only negative combined MRD status (P < .001) and myeloablative conditioning (P = .004) were independently associated with better OS. Among MRD-positive patients, a reduced incidence of relapse was observed in patients receiving haplo transplant (P < .05) and in patients who showed grade II-IV aGVHD (P < .03). In patients with negative combined MRD, the intensity of conditioning regimen did not affect the overall favorable outcome. We suggest that pretransplant MRD evaluation combined with transplant-related factors can identify AML patients at higher risk for relapse and might help in defining the overall transplant strategy.

Intra-heterogeneity in transcription and chemoresistant property of leukemia-initiating cells in murine Setd2-/- acute myeloid leukemia

BACKGROUND

Heterogeneity of leukemia-initiating cells (LICs) is a major obstacle in acute myeloid leukemia (AML) therapy. Accumulated evidence indicates that the coexistence of multiple types of LICs with different pathogenicity in the same individual is a common feature in AML. However, the functional heterogeneity including the drug response of coexistent LICs remains unclear. Therefore, this study aimed to clarify the intra-heterogeneity in LICs that can help predict leukemia behavior and develop more effective treatments.

METHODS

Spleen cells from the primary Setd2^-/- -AML mouse were transplanted into C57BL/6 recipient mice to generate a transplantable model. Flow cytometry was used to analyze the immunophenotype of the leukemic mice. Whole-genome sequencing was conducted to detect secondary hits responsible for leukemia transformation. A serial transplantation assay was used to determine the self-renewal potential of Setd2^-/- -AML cells. A limiting-dilution assay was performed to identify the LIC frequency in different subsets of leukemia cells. Bulk and single-cell RNA sequencing were performed to analyze the transcriptional heterogeneity of LICs. Small molecular inhibitor screening and in vivo drug treatment were employed to clarify the difference in drug response between the different subsets of LICs.

RESULTS

In this study, we observed an aged Setd2^-/- mouse developing AML with co-mutation of Nras^G12S and Braf^K520E . Further investigation identified two types of LICs residing in the c-Kit⁺ B220⁺ Mac-1^- and c-Kit⁺ B220⁺ Mac-1⁺ subsets, respectively. In vivo transplantation assay disclosed the heterogeneity in differentiation between the coexistent LICs. Besides, an intrinsic doxorubicin-resistant transcriptional signature was uncovered in c-Kit⁺ B220⁺ Mac-1⁺ cells. Indeed, doxorubicin plus cytarabine (DA), the standard chemotherapeutic regimen used in AML treatment, could specifically kill c-Kit⁺ B220⁺ Mac-1^- cells, but it hardly affected c-Kit⁺ B220⁺ Mac-1⁺ cells. Transcriptome analysis unveiled a higher activation of RAS downstream signaling pathways in c-Kit⁺ B220⁺ Mac-1⁺ cells than in c-Kit⁺ B220⁺ Mac-1^- cells. Combined treatment with DA and RAS pathway inhibitors killed both c-Kit⁺ B220⁺ Mac-1^- and c-Kit⁺ B220⁺ Mac-1⁺ cells and attenuated disease progression.

CONCLUSIONS

This study identified two cell subsets enriched for LICs in murine Setd2^-/- -AML and disclosed the transcriptional and functional heterogeneity of LICs, revealing that the coexistence of different types of LICs in this model brings about diverse drug response.

Identification of RHOBTB2 aberration as an independent prognostic indicator in acute myeloid leukemia

Rho-related BTB domain (RhoBTB) proteins belong to Rho guanosine triphosphatases (GTPases). Their putative role implicated in carcinogenesis has been supported by accumulating evidence. However, their expression pattern and potential role in acute myeloid leukemia (AML) remain unclear. We profiled RHOBTB mRNA expression via the Gene Expression Profiling Interactive Analysis 2 (GEPIA2) database. Survival analysis was conducted with GEPIA2 and UALCAN. Univariate and multivariate Cox regression analyses were performed to validate RHOBTB genes as independent prognostic indicators in the LAML cohort from The Cancer Genome Atlas (TCGA). Data regarding expression in different subtypes and relationships with common disease-related genes were retrieved from UALCAN. Co-expressed genes were screened out and subsequently subjected to functional enrichment analysis. We observed aberrant transcription levels of RHOBTB genes in AML patients. RHOBTB2 was identified as a prognostic candidate for overall survival (OS), independent of prognosis-related clinical factors and genetic abnormalities. Moreover, RHOBTB2 expression was increased in non-acute promyelocytic leukemia (APL) subtypes, patients without FLT3 mutation and PML/RAR fusion, and imparted a positive correlation with the expression of FLT3, FHL1, and RUNXs. Co-expressed genes of RHOBTB2 were enriched in functional pathways in AML. Our findings suggest that RHOBTB2 might be a novel biomarker and independent prognostic indicator in AML and provide insights into the leukemogenesis and molecular network of AML.

State-of-Art of Cellular Therapy for Acute Leukemia

With recent clinical breakthroughs, immunotherapy has become the fourth pillar of cancer treatment. Particularly, immune cell-based therapies have been envisioned as a promising treatment option with curative potential for leukemia patients. Hence, an increasing number of preclinical and clinical studies focus on various approaches of immune cell-based therapy for treatment of acute leukemia (AL). However, the use of different immune cell lineages and subsets against different types of leukemia and patient disease statuses challenge the interpretation of the clinical applicability and outcome of immune cell-based therapies. This review aims to provide an overview on recent approaches using various immune cell-based therapies against acute B-, T-, and myeloid leukemias. Further, the apparent limitations observed and potential approaches to overcome these limitations are discussed.

Heat shock factor 1 (HSF1-pSer326) predicts response to bortezomib-containing chemotherapy in pediatric AML: a COG report

Bortezomib (BTZ) was recently evaluated in a randomized phase 3 clinical trial by the Children's Oncology Group (COG) that compared standard chemotherapy (cytarabine, daunorubicin, and etoposide [ADE]) vs standard therapy with BTZ (ADEB) for de novo pediatric acute myeloid leukemia (AML). Although the study concluded that BTZ did not improve outcome overall, we examined patient subgroups benefiting from BTZ-containing chemotherapy using proteomic analyses. The proteasome inhibitor BTZ disrupts protein homeostasis and activates cytoprotective heat shock responses. Total heat shock factor 1 (HSF1) and phosphorylated HSF1 (HSF1-pSer326) were measured in leukemic cells from 483 pediatric patients using reverse phase protein arrays. HSF1-pSer326 phosphorylation was significantly lower in pediatric AML compared with CD34+ nonmalignant cells. We identified a strong correlation between HSF1-pSer326 expression and BTZ sensitivity. BTZ significantly improved outcome of patients with low-HSF1-pSer326 with a 5-year event-free survival of 44% (ADE) vs 67% for low-HSF1-pSer326 treated with ADEB (P = .019). To determine the effect of HSF1 expression on BTZ potency in vitro, cell viability with HSF1 gene variants that mimicked phosphorylated (S326A) and nonphosphorylated (S326E) HSF1-pSer326 were examined. Those with increased HSF1 phosphorylation showed clear resistance to BTZ vs those with wild-type or reduced HSF1-phosphorylation. We hypothesize that HSF1-pSer326 expression could identify patients who benefit from BTZ-containing chemotherapy.

LINC01255 combined with BMI1 to regulate human mesenchymal stromal senescence and acute myeloid leukemia cell proliferation through repressing transcription of MCP-1

BACKGROUND

Long non-coding RNAs (lncRNAs) govern fundamental biochemical and cellular biology processes, for example, participate in chromatin remodeling, imprinting, splicing, transcriptional regulation and translation. Dysregulation of lncRNA expression is act as a feature of various diseases and cancers, including hematopoietic malignancies. However, the clinical relevance of myelodysplastic syndrome (MDS) and acute myeloid leukemia preceded by MDS (MDS-AML) requires further research. Recently, lncRNAs have been demonstrated, which play an important role in hematopoiesis, thus, to further finding more functional lncRNA seemed particularly important.

METHODS

Western blotting, real-time PCR, RNA-pulldown, RIP (RNA immunoprecipitation), Chromatin immunoprecipitation (ChIP), cellular compartments extraction assays, SA-β-gal staining, lentivirus transfection, cell viability assay and cell proliferation assays were used to examine the relationship between lncRNA LINC01255 and its regulation of p53-p21 pathway in human mesenchymal stromal and acute myeloid leukemia cells.

RESULTS

LncRNA LINC01255 is highly expressed in bone marrow cells of AML patients, CD34+ cells of MDS-AML patients and AML cell lines and the higher expression of LINC01255 is associated with poor survival rate of AML patients. LINC01255 can interact with BMI1 and repress the transcription of MCP-1 to active p53-p21 pathway, thus inhibiting the senescence of human mesenchymal stromal and proliferation of acute myeloid leukemia cell.

CONCLUSIONS

We discovered a novel functional lncRNA LINC01255, which can regulate the senescence of human mesenchymal stromal and the proliferation of acute myeloid leukemia cell through inhibiting the transcription of MCP-1.

Genetic biomarkers identify a subgroup of high-risk patients within low-risk NPM1-mutated acute myeloid leukemia

Although acute myeloid leukemia (AML) with NPM1^mut/FLT3-ITD^neg is a low-risk entity, its relapse rate remains high. Out of 333 AML patients, 27 were NPM1^mut, and were analyzed in greater detail in order to find associations between clinical and molecular features and cumulative incidence of relapse. Next-generation sequencing (NGS) was performed on diagnosis and remission samples using two capture-based panels. The presence of the FLT3^D835 variant at diagnosis and a qPCR value of NPM1^mut ≥0.1% after induction chemotherapy were associated with an increased probability of relapse, especially if both conditions are present together. By contrast, patients in which the main clone found at diagnosis harbored NPM1 variant had a lower risk of relapse. Nineteen of the 85 variants found at diagnosis were detected by NGS in remission. AML Subgroup with NPM1^mut/FLT3-ITD^neg is a heterogeneous entity, which can be further risk-stratified based on molecular biomarkers.

Allogeneic Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia of the Elderly: Review of Literature and New Perspectives

Acute myeloid leukemia (AML) in patients over the age of 60 carries a poor prognosis, mainly due to unsatisfactory control of leukemia with chemotherapy alone. Allogeneic hemopoietic stem cell transplantation (HSCT) would provide significant anti-leukemic effect but is associated with morbidity and mortality, especially in older patients with comorbidities. Reduced-intensity conditioning (RIC) and non-myeloablative (NMA) conditioning regimens have been designed and have led to improved outcomes in this older patient population. New targeted agents, such as Flt3 inhibitors, are currently being used to improve the control of AML further and may be incorporated in a transplant approach. The increasing knowledge of AML in the elderly is currently being associated with a multidimensional approach to identify eligibility and design tailored transplant platforms.

A Screening of Antineoplastic Drugs for Acute Myeloid Leukemia Reveals Contrasting Immunogenic Effects of Etoposide and Fludarabine

BACKGROUND

Recent evidence demonstrated that the treatment of acute myeloid leukemia (AML) cells with daunorubicin (DNR) but not cytarabine (Ara-C) results in immunogenic cell death (ICD). In the clinical setting, chemotherapy including anthracyclines and Ara-C remains a gold standard for AML treatment. In the last decade, etoposide (Eto) and fludarabine (Flu) have been added to the standard treatment for AML to potentiate its therapeutic effect and have been tested in many trials. Very little data are available about the ability of these drugs to induce ICD.

METHODS

AML cells were treated with all four drugs. Calreticulin and heat shock protein 70/90 translocation, non-histone chromatin-binding protein high mobility group box 1 and adenosine triphosphate release were evaluated. The treated cells were pulsed into dendritic cells (DCs) and used for in vitro immunological tests.

RESULTS

Flu and Ara-C had no capacity to induce ICD-related events. Interestingly, Eto was comparable to DNR in inducing all ICD events, resulting in DC maturation. Moreover, Flu was significantly more potent in inducing suppressive T regulatory cells compared to other drugs.

CONCLUSIONS

Our results indicate a novel and until now poorly investigated feature of antineoplastic drugs commonly used for AML treatment, based on their different immunogenic potential.

Flow cytometry in detection of Nucleophosmin 1 mutation in acute myeloid leukemia patients: A reproducible tertiary hospital experience

INTRODUCTION

Nucleophosmin 1 (NPM1) mutation is one of the most frequent gene mutations in adult acute myeloid leukemia (AML), being detected in 35% of all cases and in up to 60% of patients with normal karyotype AML. AML with mutated NPM1 has distinct pathology, immunophenotyping, and confirmed favorable prognostic significance. Hence, AML with mutated NPM1 is a separate entity in the revised 2016 World Health Organization classification. This study aimed to evaluate the use of a reproducible flow cytometry approach in the assay of mutant NPM1 protein in AML patients and to correlate flow cytometric results with the NPM1 gene mutation.

METHODS

Eighty-nine newly diagnosed AML patients were evaluated for the expression of mutant NPM1 using flow cytometry and for the presence of NPM1 exon 12 mutations using high-resolution melting polymerase chain reaction (HRM PCR).

RESULTS

The NPM1 mutation was found in 35 (39.3%) patients by HRM PCR. These patients showed a significantly higher level of percentage of positive-stained cells (% positive cells) and normalized median fluorescence intensity (MFI) for mutant NPM1 by flow cytometry than the negative mutation group.

CONCLUSION

Flow cytometric detection of mutant NPM1 offers a possible tool to indicate NPM1 mutational status.

Randomized trial comparing standard vs sequential high-dose chemotherapy for inducing early CR in adult AML

Here we evaluated whether sequential high-dose chemotherapy (sHD) increased the early complete remission (CR) rate in acute myelogenous leukemia (AML) compared with standard-intensity idarubicin-cytarabine-etoposide (ICE) chemotherapy. This study enrolled 574 patients (age, 16-73 years; median, 52 years) who were randomly assigned to ICE (n = 286 evaluable) or sHD (2 weekly 3-day blocks with cytarabine 2 g/m² twice a day for 2 days plus idarubicin; n = 286 evaluable). Responsive patients were risk-stratified for a second randomization. Standard-risk patients received autograft or repetitive blood stem cell-supported high-dose courses. High-risk patients (and standard-risk patients not mobilizing stem cells) underwent allotransplantation. CR rates after 2 induction courses were comparable between ICE (80.8%) and sHD (83.6%; P = .38). sHD yielded a higher single-induction CR rate (69.2% vs 81.5%; P = .0007) with lower resistance risk (P < .0001), comparable mortality (P = .39), and improved 5-year overall survival (39% vs 49%; P = .045) and relapse-free survival (36% vs 48%; P = .028), despite greater hematotoxicity delaying or reducing consolidation blocks. sHD improved the early CR rate in high-risk AML (odds ratio, 0.48; 95% confidence interval [CI], 0.31-0.74; P = .0008) and in patients aged 60 years and less with de novo AML (odds ratio, 0.46; 95% CI, 0.27-0.78; P = .003), and also improved overall/relapse-free survival in the latter group (hazard ratio, 0.70; 95% CI, 0.52-0.94; P = .01), in standard-risk AML, and postallograft (hazard ratio, 0.61; 95% CI, 0.39-0.96; P = .03). sHD was feasible, effectively achieved rapid CR, and improved outcomes in AML subsets. This study is registered at www.clinicaltrials.gov as #NCT00495287.

Comparison of Myeloablative (CyTBI, BuCy) versus Reduced-Intensity (FluBu2TBI400) Peripheral Blood Stem Cell Transplantation in Acute Myeloid Leukemia Patients with Pretransplant Low WT1 Expression

Relapse is a major concern with reduced-intensity conditioning. We analyzed 257 patients with acute myeloid leukemia (AML) who received allogeneic stem cell transplantation (SCT) and fulfilled the following criteria: intermediate- or poor-risk disease by National Comprehensive Cancer Network guidelines (2017, version 3), in first complete remission (CR1) at SCT, received either myeloablative conditioning (MAC; busulfan plus cyclophosphamide or cyclophosphamide plus total body irradiation) or reduced-intensity conditioning (RIC; FluBu2TBI400) peripheral blood SCT from 8/8 matched sibling or unrelated donor, and having bone marrow Wilms tumor gene 1 (WT1) expression results before transplant. We and other groups serially published a predictive value for pretransplant WT1 expression in patients with AML to identify patients at higher risk of relapse. Among the total 257 patients, 191 (74.3%) and 66 (25.7%) patients received MAC and RIC transplants, respectively. WT1 ≥250 copies/10⁴ABL was defined as WT1^high. WT1^high before SCT was found to be an independent prognostic factor for inferior overall survival (OS), disease-free survival (DFS), and higher cumulative incidence of relapse (CIR). There were 201 patients with WT1 low expression based upon pretransplant analysis. There was no significant difference in OS, DFS, CIR, and nonrelapse mortality between MAC and RIC patients. To conclude, post-transplant survival or relapse was not different by conditioning intensity in AML CR1 patients whose WT1 level was below 250 copies per 10⁴ABL at transplantation.

Acute Leukemia: Diagnosis and Treatment

OBJECTIVE

To provide an overview of acute leukemia, comparing incidence, presenting symptoms, diagnosis, prognosis, and treatment of the major subtypes.

DATA SOURCES

Review of articles dated 2010 to present in PubMed and CINAHL, and National Comprehensive Cancer Network Guidelines.

CONCLUSION

The diagnosis of acute leukemia is comprised of a variety of hematopoietic neoplasms that are both complex and unique. Each subtype of acute leukemia has defining characteristics that affect prognosis and treatment.

IMPLICATIONS FOR NURSING PRACTICE

Nurses play an integral role in the care of the patient with acute leukemia during and beyond hospitalization. Therefore, baseline knowledge of these diseases is essential. Early symptom recognition is central in the management of oncologic emergencies.

Fenretinide-induced Apoptosis of Acute Myeloid Leukemia Cells via NR4A1 Translocation into Mitochondria and Bcl-2 Transformation

OBJECTIVE: Fenretinide is reported to induce NR4A1-associated apoptosis in several types of cancer cells. However, it remains unclear about its specific role and the underlying mechanism in acute myeloid leukemia (AML). Therefore, this study aimed to explore the role and mechanism of fenretinide-induced apoptosis in AML.

METHOD: Firstly, the NR4A1 mRNA level in the newly diagnosed AML patients was measured, then AML cells were treated with fenretinide at various time points and doses, and cell viability was investigated by using the cell-counting kit-8 (CCK-8) assay. Additionally, apoptosis and cell cycles were analyzed by using flow cytometry. Moreover, siNR4A1 was utilized to knockdown NR4A1 expression, and leptomycin B (LMB) was adopted to inhibit the nuclear export; afterwards, the apoptosis rate and expression of apoptotic proteins in AML cells were detected. In addition, the expression levels of NR4A1 in the nuclei and mitochondria of fenretinide-treated AML cells were also measured. Meanwhile, the interaction between NR4A1 and Bcl-2, as well as the Bcl-2 transformation, was also examined. The anti-leukemic effect of fenretinide on NOD/SCID mice was also determined through subcutaneous injection of HL-60 cells.

RESULTS: NR4A1 expression in AML patients was markedly down-regulated compared with that in normal donors. Fenretinide induced the expression of NR4A1 and mitochondria-mediated apoptotic pathway-associated proteins in a time- and concentration-dependent manner. Importantly, both siNR4A1 alone or the combination of fenretinide with LMB could attenuate the fenretinide-induced apoptosis and expression of apoptotic proteins. Under the action of fenretinide, the NR4A1 protein expression was down-regulated in nuclear extracts whereas up-regulated in mitochondrial extracts. At the same time, fenretinide promoted NR4A1 translocation from nuclei into mitochondria, and enhanced the interaction between NR4A1 and Bcl-2, thereby exposing the BH3 domain of Bcl-2 to exert the anti-apoptotic effect. Moreover, fenretinide also exhibited an anti-leukemic effect and induced NR4A1 expression in the AML mouse model.

CONCLUSIONS: Fenretinide exerts an obvious effect on AML cells both in vitro and in vivo. Besides, the NR4A1-mediated signaling pathway is highly involved in the fenretinide-induced apoptosis of AML cells.

Chemotherapy-Induced Tumor Cell Death at the Crossroads Between Immunogenicity and Immunotolerance: Focus on Acute Myeloid Leukemia

In solid tumors and hematological malignancies, including acute myeloid leukemia, some chemotherapeutic agents, such as anthracyclines, have proven to activate an immune response via dendritic cell-based cross-priming of anti-tumor T lymphocytes. This process, known as immunogenic cell death, is characterized by a variety of tumor cell modifications, i.e., cell surface translocation of calreticulin, extracellular release of adenosine triphosphate and pro-inflammatory factors, such as high mobility group box 1 proteins. However, in addition to with immunogenic cell death, chemotherapy is known to induce inflammatory modifications within the tumor microenvironment, which may also elicit immunosuppressive pathways. In particular, DCs may be driven to acquire tolerogenic features, such as the overexpression of indoleamine 2,3-dioxygensase 1, which may ultimately hamper anti-tumor T-cells via the induction of T regulatory cells. The aim of this review is to summarize the current knowledge about the mechanisms and effects by which chemotherapy results in both activation and suppression of anti-tumor immune response. Indeed, a better understanding of the whole process underlying chemotherapy-induced alterations of the immunological tumor microenvironment has important clinical implications to fully exploit the immunogenic potential of anti-leukemia agents and tune their application.

GIMEMA AML1310 trial of risk-adapted, MRD-directed therapy for young adults with newly diagnosed acute myeloid leukemia

A risk-adapted, MRD-driven transplant strategy is a feasible approach for the treatment of younger adults with AML. Pretransplant MRD positivity should not contraindicate delivery of an allogeneic stem cell transplant.

Long non-coding RNA HOXB-AS3 promotes myeloid cell proliferation and its higher expression is an adverse prognostic marker in patients with acute myeloid leukemia and myelodysplastic syndrome

Background

Long non-coding RNAs (lncRNAs) represent the majority of cellular transcripts and play pivotal roles in hematopoiesis. However, their clinical relevance in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) remains largely unknown. Here, we investigated the functions of HOXB-AS3, a lncRNA located at human HOXB cluster, in the myeloid cells, and analyzed the prognostic significances in patients with AML and MDS.

Methods

shRNAs were used to downregulate HOXB-AS3 in the cell lines and the effect was evaluated by quantitative polymerase chain reaction. The proliferation of the cell lines was illustrated by proliferation and BrdU flow assays. Further, we retrospectively analyzed the HOXB-AS3 expression in 193 patients with AML and 157 with MDS by microarray analysis, and evaluated its clinical importance.

Results

Downregulation of HOXB-AS3 suppressed cell proliferation. Mechanistically, HOXB-AS3 potentiated the expressions of several key factors in cell cycle progression and DNA replication without affecting the expressions of HOX genes. In AML, patients with higher HOXB-AS3 expression had shorter survival than those with lower HOXB-AS3 expression (median overall survival (OS), 17.7 months versus not reached, P <  0.0001; median relapse-free survival, 12.9 months versus not reached, P = 0.0070). In MDS, patients with higher HOXB-AS3 expression also had adverse prognosis compared with those with lower HOXB-AS3 expression (median OS, 14.6 months versus 42.4 months, P = 0.0018). The prognostic significance of HOXB-AS3 expression was validated in the TCGA AML cohort and another MDS cohort from our institute. The subgroup analyses in MDS patients showed that higher HOXB-AS3 expressions could predict poor prognosis only in lower-risk (median OS, 29.2 months versus 77.3 months, P = 0.0194), but not higher-risk group.

Conclusions

This study uncovers a promoting role of HOXB-AS3 in myeloid malignancies and identifies the prognostic value of HOXB-AS3 expression in AML and MDS patients, particularly in the lower-risk group.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5822-y) contains supplementary material, which is available to authorized users.

Evolutionary trajectory of leukemic clones and its clinical implications

The ontogeny of acute myeloid leukemia is a multistep process. It is driven both by features of the malignant clone itself as well as by environmental pressures, making it a unique process in each individual. The technological advancements of recent years has increased our understanding about the different steps that take place at the genomic level. It is now clear that malignant clones evolve, expand and change even during what seem to be clinically healthy or “cured” periods. This opens a wide window for new therapeutic and monitoring opportunities. Moreover, prediction and even early prevention have become possible goals to be pursued. The aim of this review is to shed light upon recent observations in leukemia evolution and their clinical implications. We present a critical view of these concepts in order to assist clinicians when interpreting results of the ever growing myriad of genomic diagnostic tests. We wish to help clinicians incorporate genetic tests into their clinical assessment and enable them to provide genetic counseling to their patients.

Ten-year outcome of patients with acute myeloid leukemia not treated with allogeneic transplantation in first complete remission

The probability that adult patients with de novo acute myeloid leukemia (AML) receiving intensive chemotherapy in the absence of allogeneic hematopoietic stem cell transplantation (Allo-HCT) in first complete remission (CR1) will be disease-free at 10 years after diagnosis, a long-term surrogate of cure, is unknown. To address this question, we examined 2551 AML patients (1607 aged <60 years, and 944 aged ≥60 years) enrolled in Cancer and Leukemia Group B treatment protocols and the cytogenetics companion protocol 8461 between 1983 and 2004. At 10 years, 267 (16.6%) of patients aged <60 years and 23 (2.4%) of those aged ≥60 years were alive and disease-free. This disease-free AML group consisted predominantly of patients with core-binding factor AML with t(8;21)(q22;q22) or inv(16)(p13q22)/t(16;16)(p13;q22) and those with a normal karyotype. Occurrences of AML beyond 10 years were infrequent and associated with cytogenetic findings different from those at diagnosis. These data provide evidence that the frequency of long-term cure of AML is low among younger and especially older patients in the absence of Allo-HCT in CR1. In older patients not appropriate for Allo-HCT, these data provide further justification for early use of alternative treatments outside of intensive chemotherapy.

In-silico comparison of two induction regimens (7 + 3 vs 7 + 3 plus additional bone marrow evaluation) in acute myeloid leukemia treatment

BACKGROUND

Clinical integration of systems biology approaches is gaining in importance in the course of digital revolution in modern medicine. We present our results of the analysis of an extended mathematical model describing abnormal human hematopoiesis. The model is able to describe the course of an acute myeloid leukemia including its treatment. In first-line treatment of acute myeloid leukemia, the induction chemotherapy aims for a rapid leukemic cell reduction. We consider combinations of cytarabine and anthracycline-like chemotherapy. Both substances are widely used as standard treatment to achieve first remission. In particular, we compare two scenarios: a single-induction course with 7 days cytarabine and 3 day of anthracycline-like treatment (7 + 3) with a 7 + 3 course and a bone marrow evaluation that leads, in case of insufficient leukemic cell reduction, to the provision of a second chemotherapy course. Three scenarios, based on the leukemias growth kinetics (slow, intermediate, fast), were analyzed. We simulated different intensity combinations for both therapy schemata (7 + 3 and 7 + 3 + evaluation).

RESULTS

Our model shows that within the 7 + 3 regimen a wider range of intensity combinations result in a complete remission (CR), compared to 7 + 3 + evaluation (fast: 64.3% vs 46.4%; intermediate: 63.7% vs 46.7%; slow: 0% vs 0%). Additionally, the number of simulations resulting in a prolonged CR was higher within the standard regimen (fast: 59.8% vs 40.1%; intermediate: 48.6% vs 31.0%; slow: 0% vs 0%). On the contrary, the 7 + 3 + evaluation regimen allows CR and prolonged CR by lower chemotherapy intensities compared to 7 + 3. Leukemic pace has a strong impact on treatment response and especially on specific effective doses. As a result, faster leukemias are characterized by superior treatment outcomes and can be treated effectively with lower treatment intensities.

CONCLUSIONS

We could show that 7 + 3 treatment has considerable more chemotherapy combinations leading to a first CR. However, the 7 + 3 + evaluation regimen leads to CR for lower therapy intensity and presumably less side effects. An additional evaluation can be considered beneficial to control therapy success, especially in low dose settings. The treatment success is dependent on leukemia growth dynamics. The determination of leukemic pace should be a relevant part of a personalized medicine.

Impact of elevated anti-apoptotic MCL-1 and BCL-2 on the development and treatment of MLL-AF9 AML in mice

Many acute myeloid leukaemias (AMLs) express high levels of BCL-2 and MCL-1, especially after therapy. To test the impact of these anti-apoptotic proteins on AML development and treatment, we used haemopoietic reconstitution to generate MLL-AF9 AMLs expressing BCL-2 or Mcl-1 transgenes. AMLs with elevated BCL-2 or MCL-1 had a higher proportion of mature myeloid cells but, like conventional MLL-AF9 AMLs, were readily transplantable. Short-term cell lines established from multiple primary AMLs of each genotype were tested in vitro for susceptibility to chemotherapeutics currently used for treating AML (daunorubicin, etoposide, cytarabine); the proteasome inhibitor bortezomib; CDK7/9 inhibitors; and BH3 mimetics, which bind and inhibit pro-survival proteins. The BH3 mimetics tested, alone and in combination with the other drugs, were: ABT-737 which, like its clinical counterpart navitoclax, targets BCL-2, BCL-X_L and BCL-W; BCL-2-specific ABT-199 (venetoclax); BCL-X_L-specific A-1331852; and S63845, a new MCL-1-specific BH3 mimetic. As single agents, daunorubicin and bortezomib had the greatest efficacy. Elevated MCL-1 or BCL-2 reduced sensitivity to daunorubicin but, surprisingly, not to bortezomib. MCL-1 markedly enhanced resistance to ABT-737 and ABT-199 but not S63845, and BCL-2 increased resistance to S63845 but not to ABT-737 or ABT-199. Notable synergies were achieved by combining BH3 mimetics with daunorubicin: S63845 increased the sensitivity of both MCL-1 and BCL-2 overexpressing MLL-AF9 AMLs, and ABT-737 aided in killing those overexpressing BCL-2. Synergy between daunorubicin and ABT-199 was also apparent in vivo, although not curative. Impressive synergistic responses were achieved for human MLL-fusion AML cell lines treated with daunorubicin plus either ABT-737, ABT-199 or S63845, and with ABT-199 plus S63845, with or without daunorubicin. Our data suggest that AML patients may benefit from combining conventional cytotoxic drugs with BH3 mimetics targeting BCL-2 or MCL-1 or, if tolerated, both these agents.

Signatures of CD8+ T cell dysfunction in AML patients and their reversibility with response to chemotherapy

BACKGROUND

Our understanding of phenotypic and functional signatures of CD8+ T cell dysfunction in acute myeloid leukemia (AML) is limited. Deciphering these deranged T cell functional states and how they are impacted by induction chemotherapy is essential for incorporation of novel immune-based strategies to restore and maintain antileukemia immunity.

METHODS

We utilized high-dimensional immunophenotyping, gene expression, and functional studies to characterize peripheral blood and bone marrow CD8+ T cells in 72 AML patients at diagnosis and after induction chemotherapy.

RESULTS

Our data suggest that multiple aspects of deranged T cell function are operative in AML at diagnosis, with exhaustion and senescence being the dominant processes. Following treatment, the phenotypic and transcriptional profile of CD8+ T cells diverged between responders and nonresponders. Response to therapy correlated with upregulation of costimulatory, and downregulation of apoptotic and inhibitory, T cell signaling pathways, indicative of restoration of T cell function. In functional studies, AML blasts directly altered CD8+ T cell viability, expansion, co-signaling and senescence marker expression. This CD8+ T cell dysfunction was in part reversible upon PD-1 blockade or OX40 costimulation in vitro.

CONCLUSION

Our findings highlight the uniqueness of AML in sculpting CD8+ T cell responses and the plasticity of their signatures upon chemotherapy response, providing a compelling rationale for integration of novel immunotherapies to augment antileukemia immunity.

FUNDING

This work was supported by the Leukemia & Lymphoma Society grant no. 6449-13; NIH grants UM1-CA186691 and R01-HL110907-01; the American Society for Blood and Marrow Transplantation New Investigator Award/Gabrielle's Angel Foundation; the Vienna Fund for Innovative Cancer Research; and by fellowships from the Wenner-Gren Foundation and the Swedish Society for Medical Research.

Signatures of CD8+ T cell dysfunction in AML patients and their reversibility with response to chemotherapy

BACKGROUND

Our understanding of phenotypic and functional signatures of CD8+ T cell dysfunction in acute myeloid leukemia (AML) is limited. Deciphering these deranged T cell functional states and how they are impacted by induction chemotherapy is essential for incorporation of novel immune-based strategies to restore and maintain antileukemia immunity.

METHODS

We utilized high-dimensional immunophenotyping, gene expression, and functional studies to characterize peripheral blood and bone marrow CD8+ T cells in 72 AML patients at diagnosis and after induction chemotherapy.

RESULTS

Our data suggest that multiple aspects of deranged T cell function are operative in AML at diagnosis, with exhaustion and senescence being the dominant processes. Following treatment, the phenotypic and transcriptional profile of CD8+ T cells diverged between responders and nonresponders. Response to therapy correlated with upregulation of costimulatory, and downregulation of apoptotic and inhibitory, T cell signaling pathways, indicative of restoration of T cell function. In functional studies, AML blasts directly altered CD8+ T cell viability, expansion, co-signaling and senescence marker expression. This CD8+ T cell dysfunction was in part reversible upon PD-1 blockade or OX40 costimulation in vitro.

CONCLUSION

Our findings highlight the uniqueness of AML in sculpting CD8+ T cell responses and the plasticity of their signatures upon chemotherapy response, providing a compelling rationale for integration of novel immunotherapies to augment antileukemia immunity.

FUNDING

This work was supported by the Leukemia & Lymphoma Society grant no. 6449-13; NIH grants UM1-CA186691 and R01-HL110907-01; the American Society for Blood and Marrow Transplantation New Investigator Award/Gabrielle's Angel Foundation; the Vienna Fund for Innovative Cancer Research; and by fellowships from the Wenner-Gren Foundation and the Swedish Society for Medical Research.

A comparison of patients with acute myeloid leukemia and high-risk myelodysplastic syndrome treated on versus off study

Patients with newly diagnosed (ND) and relapsed/refractory (RR) acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS, ≥10% blasts) often receive intensive chemotherapy at diagnosis and relapse. We retrospectively identified 365 patients and categorized the reasons for receiving treatment off study (medical, logistical, or unclear). The pretreatment characteristics of the on and off study groups were similar. Rates of the complete remission (CR) without measurable residual disease were significantly higher for ND patients treated on versus off study (61% versus 35%), but CR rates and survival were low for all RR patients regardless of study assignment. The subset of ND patients treated off study for medical reasons had significantly decreased overall survival and relapse-free survival. Standard, stringent study eligibility criteria may delineate a population of ND, but not RR, patients with improved outcomes with intensive induction chemotherapy.

Bridging Strategies to Allogeneic Transplant for Older AML Patients

Treatment options for older patients with intermediate or high-risk acute myeloid leukemia (AML) remain unsatisfactory. Allogeneic stem cell transplantation, the treatment of choice for the majority of younger AML patients, has been hampered in elderly patients by higher treatment related mortality, comorbidities and lack of a suitable donor. With the higher availability of suitable donors as well as of reduced intensity conditioning regimens, novel low intensity treatments prior to transplantation and optimized supportive care, the number of older AML patients being successfully transplanted is steadily increasing. Against this background, we review current treatment strategies for older AML patients planned for allogeneic stem cell transplantation based on clinical trial data, discussing differences between approaches with advantages and pitfalls of each. We summarize pre-treatment considerations that need to be taken into account in this highly heterogeneous older population. Finally, we offer an outlook on areas of ongoing clinical research, including novel immunotherapeutic approaches that may improve access to curative therapies for a larger number of older AML patients.

Early changes in rpS6 phosphorylation and BH3 profiling predict response to chemotherapy in AML cells

Blasts from different patients with acute myeloid leukemia (AML) vary in the agent(s) to which they are most responsive. With a myriad of novel agents to evaluate, there is a lack of predictive biomarkers to precisely assign targeted therapies to individual patients. Primary AML cells often survive poorly in vitro, thus confounding conventional cytotoxicity assays. The purpose of this work was to assess the potential of two same-day functional predictive assays in AML cell lines to predict long-term response to chemotherapy. (i) Ribosomal protein S6 (rpS6) is a downstream substrate of PI3K/akt/mTOR/ kinase and MAPK kinase pathways and its dephosphorylation is also triggered by DNA double strand breaks. Phospho-rpS6 is reliably measurable by flow cytometry and thus has the potential to function as a biomarker of responsiveness to several therapeutic agents. (ii) A cell's propensity for apoptosis can be interrogated via a functional assay termed "Dynamic BH3 Profiling" in which mitochondrial outer membrane permeabilization in drug-treated cells can be driven by pro-apoptotic BH3 domain peptides such as PUMA-BH3. The extent to which a particular cell is primed for apoptosis by the drug can be determined by measuring the amount of cytochrome C released on addition of BH3 peptide. We demonstrate that phospho-rpS6 expression and PUMA-BH3 peptide-induced cytochrome C release after 4 hours both predict long term chemoresponsiveness to tyrosine kinase inhibitors and DNA double strand break inducers in AML cell lines. We also describe changes in expression levels of the prosurvival BCL-2 family member Mcl-1 and the pro-apoptotic protein BIM after short term drug culture.

Expression of multiple leukemic stem cell markers is associated with poor prognosis in de novo acute myeloid leukemia

Leukemic stem cells (LSCs) play a crucial role in chemotherapy resistance in acute myeloid leukemia (AML). Although the association between the expression of individual LSC markers and poor prognosis has been reported, few studies have evaluated the prognostic effect of multiple LSC markers in patients with AML. Herein, we examined three LSC markers (CD25, CD96, and CD123) and the combined effect of their expression on clinical outcome. We retrospectively analyzed 80 adult patients with de novo AML who received intensive chemotherapy. Multiple LSC marker expression was significantly associated with shorter three-year overall survival (OS), compared with single or no LSC marker expression (18.2 vs. 65.0%, p < .001). Multivariate analysis showed that the expression of multiple LSC markers remained significant in terms of three-year OS (hazard ratio: 3.80, p = .001). Therefore, the combined evaluation of several LSC markers can predict the clinical outcome in patients with AML.

Midostaurin: A New Oral Agent Targeting FMS-Like Tyrosine Kinase 3-Mutant Acute Myeloid Leukemia

Acute myeloid leukemia (AML), a clonal hematologic malignancy that results in bone marrow failure, is the most common acute leukemia in adults (median age of diagnosis 67 yrs), and treatment options, especially in the elderly population, are limited. Induction chemotherapy with 7 + 3, the combination of continuous-infusion cytarabine and intermittent dosing of an anthracycline administered over 7 and 3 days, respectively, has remained the standard of care since its introduction in 1973 in the United States. Midostaurin is a first-generation FMS-like tyrosine kinase 3 (FLT3) inhibitor (TKI) that was approved by the U.S. Food and Drug Administration in April 2017 for the treatment of FLT3-mutant AML. We performed a search of the PubMed database (January 1990-January 2017) to review pertinent clinical trials of midostaurin. Phase I, II, and III trials reported in English evaluating the safety and efficacy of midostaurin in patients with AML or myelodysplastic syndrome were included. The ClinicalTrials.gov database was also searched for ongoing trials. In the only phase III trial that has been conducted to date, midostaurin demonstrated significant improvement compared with placebo in overall and event-free survival in patients aged 18-59 years with newly diagnosed FLT3-mutant AML treated with standard induction chemotherapy. The median overall survival for patients randomized to the midostaurin group was 74.7 months versus 25.6 months in the placebo group (hazard ratio [HR] 0.78, 95% confidence interval [CI] 0.63-0.96, p=0.009). Median event-free survival was 8.2 months with midostaurin compared with 3.0 months with placebo (HR 0.78, 95% CI 0.66-0.93, p=0.002). In addition to being evaluated in combination with conventional chemotherapy, midostaurin has been studied as monotherapy, in combination with the hypomethylating agents azacitidine and decitabine, and as single-agent maintenance. Studies evaluating midostaurin in the maintenance setting after allogeneic stem cell transplantation are underway. Midostaurin is the first oral multitargeted TKI to improve overall survival in patients with FLT3-mutant AML and represents an important addition to the limited armamentarium against AML.

High prognostic value of pre-allogeneic stem cell transplantation minimal residual disease detection by WT1 gene expression in AML transplanted in cytologic complete remission

We analyzed the outcome of allogeneic stem cell transplantation (allo-SCT) in acute myeloid leukemia (AML) patients according to molecular Minimal Residual Disease (MRD) status prior to allo-SCT. MRD was assessed by the quantitative expression of the pan-leukemic marker Wilms' tumor (WT1) gene, according to the validated LeukemiaNet method. Between 2005 and 2016, 122 consecutive AML patients, WT1 positive at diagnosis, received allo-SCT in cytologic complete remission (cCR). The median age at SCT was 53 years (range 18-70). Quantitative analysis of WT1 gene expression (bone marrow samples) was available in all cases both at diagnosis (100% of samples overexpressed WT1 with a mean of 8607±8187 copies/10⁴ Abelson) and immediately before allo-SCT. Eighty one cases (66%) were MRD-WT1 negative (WT1 <250 copies) and 41/122 (44%) cases were MRD-WT1 positive (WT1 >250 copies) prior to allo-SCT. We evaluated post-SCT overall survival (OS), disease free survival (DFS) and relapse rate (RR), according to MRD-WT1 status pre-SCT. Both post-allo-SCT OS and DFS were significantly improved in patients who were MRD-WT1 negative at the time of SCT compared with those who were MRD-WT1 positive, with a median OS and DFS not reached in the MRD-WT1 negative group and 9 and 8 months, respectively, in the WT1 positive group (OS log-rank p<0.0001; hazard ratio [HR] 3.9, 95% confidence interval [95% CI] 2.0-7.38; DFS log-rank p<0.0001; HR 3.73, 95% CI 2.0-6.72). The RR after SCT was 15% (12/81) in pre-SCT MRD-WT1 negative cases and 44% (18/41) in MRD-WT1 positive cases (p=0.00073). Univariate analysis showed that MRD-WT1 negativity pre-SCT and grade <2 acute GVHD were significant prognostic factors for improved OS and DFS. However multivariate analysis showed MRD-WT1 negativity pre-SCT was the only independent prognostic factor for improved OS and DFS. These data show that pre allo-SCT molecular MRD evaluation using WT1 expression is a powerful predictor of post allo-SCT outcomes in AML undergoing SCT in cCR. Patients with both cCR and MRD-WT1 negativity before SCT have a very good outcome with lower RR and improved OS. The pre allo-SCT MRD-WT1 stratification in AML is a valuable tool to identify patients at high risk of post-SCT relapse, and can influence conditioning regimen intensification and/or post-SCT preemptive strategies.

Induction treatment of acute myeloid leukemia in an elderly patient with intramarrow injection/administration of cytarabine. Second case report

We show for the second time that intramarrow injection/administration of chemotherapeutic agents such as cytarabine (Ara-C) can be used safely and effectively and is associated with no toxicity, promising antileukemic activity and possible improved survival.

Dexrazoxane for cardioprotection in older adults with acute myeloid leukemia

Anthracyclines constitute the backbone of intensive adult acute myeloid leukemia (AML) therapy. Cardiotoxicity is one of its most serious adverse effects, and its incidence increases with cumulative dose. Dexrazoxane is a cardioprotective agent used in conjunction with anthracycline therapy. There is limited data of its usage in adult AML patients. We report the outcomes of six older adults at high risk of anthracycline-induced cardiotoxicity who received dexrazoxane during induction/re-induction therapy. Five had preserved left-ventricular function while two proceeded onto stem-cell transplantation. Additional investigation of dexrazoxane in adult leukemia therapy is warranted, particularly in older patients at highest risk for cardiovascular mortality.

Bone marrow evaluation for diagnosis and monitoring of acute myeloid leukemia

The diagnosis of acute myeloid leukemia (AML) can be made based on peripheral blood or bone marrow blasts. In this review, we will discuss the role of bone marrow evaluation and peripheral blood monitoring in the diagnosis, management, and follow up of AML patients. For patients with circulating blasts, it is reasonable to perform the necessary studies needed for diagnosis and risk stratification, including multiparametric flow cytometry, cytogenetics, and molecular analysis, on a peripheral blood specimen. The day 14 marrow is used to document hypocellularity in response to induction chemotherapy, but it is unclear if that assessment is necessary as it often does not affect immediate management. Currently, response assessments performed at count recovery for evaluation of remission and measurable residual disease rely on bone marrow sampling. For monitoring of relapse, peripheral blood evaluation may be adequate, but the sensitivity of bone marrow testing is in some cases superior. While bone marrow evaluation can certainly be avoided in particular situations, this cumbersome and uncomfortable procedure currently remains the de facto standard for response assessment.

Targeting acute myeloid leukemia with TP53-independent vosaroxin

Vosaroxin is a quinolone compound that intercalates DNA and induces TP53-independent apoptosis, demonstrating activity against acute myeloid leukemia (AML) in Phase I-III trials. Here, we examine vosaroxin's mechanism of action and pharmacology, and we review its use in AML to date, focusing on details of individual clinical trials. Most recently, when combined with cytarabine in a randomized Phase III trial (VALOR), vosaroxin improved outcomes versus cytarabine alone for relapsed/refractory AML in patients older than 60 years and for patients in early relapse. We consider its continued role in the context of a multifaceted strategy against AML, including its current use in clinical trials. Prospective use will define its role in the evolving landscape of AML therapy.