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Summary: Large amounts of azurophilic granules are considered to be a morphological feature of acute promyelocytic leukaemia (APL). However, a small percentage of acute myeloid leukaemia (AML) patients also have a large number of azurophilic granules. A large cohort of 3210 AML patients in our hospital was screened to identify AML patients who had a large number of azurophilic granules. The clinical parameters of these patients were collected and compared with typical AML patients (control Group 1) and APL patients (control Group 2). The incidence of AML with a large number of azurophilic granules was 1.26%. The fibrinogen and D‐dimer levels of patients in the study group were more similar to those of patients in control Group 2, as was the incidence of bleeding events. Additionally, patients in the study group had higher FLT3‐ITD and NPM1 mutation rates than patients in control Group 1. Finally, patients in the study group had a higher 30‐day mortality rate than those in control Group 2 (24.2% vs. 9.09%) and showed a higher 30‐day mortality trend than those in control Group 1. Therefore, we should pay more attention to the prevention of coagulation dysfunction and bleeding events for these patients. [ABSTRACT FROM AUTHOR]

Previous evidence has confirmed that branched-chain aminotransferase-1 (BCAT1), a key enzyme governing branched-chain amino acid (BCAA) metabolism, has a role in cancer aggression partly by restricting αKG levels and inhibiting the activities of the αKG-dependent enzyme family. The oncogenic role of BCAT1, however, was not fully elucidated in acute myeloid leukemia (AML). In this study, we investigated the clinical significance and biological insight of BCAT1 in AML. Using q-PCR, we analyzed BCAT1 mRNAs in bone marrow samples from 332 patients with newly diagnosed AML. High BCAT1 expression independently predicts poor prognosis in patients with AML. We also established BCAT1 knockout (KO)/over-expressing (OE) AML cell lines to explore the underlying mechanisms. We found that BCAT1 affects cell proliferation and modulates cell cycle, cell apoptosis, and DNA damage/repair process. Additionally, we demonstrated that BCAT1 regulates histone methylation by reducing intracellular αKG levels in AML cells. Moreover, high expression of BCAT1 enhances the sensitivity of AML cells to the Poly (ADP-ribose) polymerase (PARP) inhibitor both in vivo and in vitro. Our study has demonstrated that BCAT1 expression can serve as a reliable predictor for AML patients, and PARP inhibitor BMN673 can be used as an effective treatment strategy for patients with high BCAT1 expression. Key messages: High expression of BCAT1 is an independent risk factor for poor prognosis in patients with CN-AML. High BCAT1 expression in AML limits intracellular αKG levels, impairs αKG-dependent histone demethylase activity, and upregulates H3K9me3 levels. H3K9me3 inhibits ATM expression and blocks cellular DNA damage repair process. Increased sensitivity of BCAT1 high expression AML to PARP inhibitors may be used as an effective treatment strategy in AML patients. [ABSTRACT FROM AUTHOR]

Summary: Glutamine metabolic reprogramming in acute myeloid leukaemia (AML) cells contributes to the decreased sensitivity to antileukemic drugs. Leukaemic cells, but not their myeloid counterparts, largely depend on glutamine. Glutamate dehydrogenase 1 (GDH1) is a regulation enzyme in glutaminolysis. However, its role in AML remains unknown. Here, we reported that GDH1 was highly expressed in AML: high GDH1 was one of the independent negative prognostic factors in AML cohort. The dependence of leukaemic cells on GDH1 was proved both in vitro and in vivo. High GDH1 promoted cell proliferation and reduced survival time of leukaemic mice. Targeting GDH1 eliminated the blast cells and delayed AML progression. Mechanistically, GDH1 knockdown inhibited glutamine uptake by downregulating SLC1A5. Moreover, GDH1 invalidation also inhibited SLC3A2 and abrogated the cystine‐glutamate antiporter system Xc−. The reduced cystine and glutamine disrupted the synthesis of glutathione (GSH) and led to the dysfunction of glutathione peroxidase‐4 (GPX4), which maintains the lipid peroxidation homeostasis by using GSH as a co‐factor. Collectively, triggering ferroptosis in AML cells in a GSH depletion manner, GDH1 inhibition was synthetically lethal with the chemotherapy drug cytarabine. Ferroptosis induced by inhibiting GDH1 provides an actionable therapeutic opportunity and a unique target for synthetic lethality to facilitate the elimination of malignant AML cells. [ABSTRACT FROM AUTHOR]

After one course of VAA regimen, 10 patients (83.3%) achieved CR, 1 patient (8.3%) achieved CRi and 1 patient (8.3%) achieved partial remission (PR). The VEN-sensitive AML cells MV4-11 (IC SB 50 sb = 4.506 nM) and VEN-resistant AML cells THP-1 (IC50 = 738.4 nM; Figure S1A) were used to evaluate whether the combination treatment of LDAC plus VA regimen performed robust synergistic killing in AML cells. [Extracted from the article]

Background: Identifying therapeutic targets and prognostic biomarkers significantly contributes to individualized treatment of acute myeloid leukemia (AML). Dihydropyrimidinase‐like 2 (DPYSL2) expression was decreased in homoharringtonine (HHT)‐resistant AML cells, which were established by our group. DPYSL2 plays an important role in axon growth and has oncogene effect in glioblastoma. However, little research has been conducted to investigate the function of DPYSL2 in AML pathogenesis. Methods: Auto‐docking was used to reveal the targeting relationship between HHT and DPYSL2. Overall survival (OS), event‐free survival (EFS), and relapse‐free survival (RFS) were used to evaluate the prognostic impact of DPYSL2 for AML. ShRNA was used to knockdown the expression of SPATS2L. Apoptosis was assessed by flow cytometry. In vivo growth and survival were assessed using a xenotransplantation mice model. RNA sequencing was performed to elucidate the molecular mechanisms underlying the role of SPATS2L in AML and were confirmed by Western blot. Results: We found DPYSL2 was the target of HHT. Next, we found AML cell lines and patients had higher DPYSL2 expression levels than the normal samples. Further multivariate analysis demonstrated that high DPYSL2 expression was an independent poor prognostic factor for OS, EFS, and RFS in AML. Inhibition of DPYSL2 expression suppressed cell growth, induced apoptosis in AML cell lines, and prolonged the survival of AML xenograft NCG mice. Through RNA‐seq analysis from TCGA and our data, the JAK2/STAT3/STAT5‐PI3K P85/AKT/GSK3b axis was thought to be the critical pathway in regulating DPYSL2 in AML development. Conclusions: We first time confirmed that DPYSL2 was a target of HHT and played an oncogene role in AML by regulating JAK/STAT signaling pathway. Therefore, DPYSL2 could serve as a novel prognostic marker and therapeutic target for AML treatment. [ABSTRACT FROM AUTHOR]

Recently, platelet to white blood cell ratio (PWR) was reported as an independent prognostic predictor in acute promyelocytic leukemia. Acute myeloid leukemia (AML) often presents with abnormal platelet counts and white blood cell counts (WBC) at disease diagnosis. However, the clinical impact of PWR on cytogenetically normal AML (CN-AML) is still unclear. Therefore, we evaluate its prognostic impact on CN-AML patients. We recorded the clinical information at the time of disease diagnosis, and calculated the ratio of platelet counts to WBC in 338 patients with CN-AML. To assess the prognostic value of PWR, we divided patients into low, intermediate and high group based on the values of PWR. The independent prognostic value of PWR was investigated in the context of the well-established predictors including white blood cell counts, age, and genes of NPM1, FLT3-ITD, CEBPA, and DNMT3A mutations. Receiver operating characteristic (ROC) curve was used to assess the performance of its prognostic prediction. Higher PWR have the higher levels of platelet counts, but lower levels of white blood cell counts, percentage of bone marrow blasts, FLT3-ITD and NPM1 mutations. The performance of survival prediction was comparable between PWR alone and combined molecular biomarkers. Moreover, PWR had the additional prognostic information to the molecular biomarkers. Finally, PWR was associated with favorable overall survival and event free survival in CN-AML patients independent of genetic subtypes and clinical parameters. We found PWR was an independent prognostic predictor in CN-AML. [ABSTRACT FROM AUTHOR]

Core Binding Factor (CBF)-AML is one of the most common somatic mutations in acute myeloid leukemia (AML). t(8;21)/AML1-ETO-positive acute myeloid leukemia accounts for 5-10% of all AMLs. In this study, we consecutively included 254 AML1-ETO patients diagnosed and treated at our institute from December 2009 to March 2020, and evaluated molecular mutations by 185-gene NGS platform to explore genetic co-occurrences with clinical outcomes. Our results showed that high KIT VAF(≥15%) correlated with shortened overall survival compared to other cases with no KIT mutation (3-year OS rate 26.6% vs 59.0% vs 69.6%, HR 1.50, 95%CI 0.78-2.89, P=0.0005). However, no difference was found in patients' OS whether they have KIT mutation in two or three sites. Additionally, we constructed a risk model by combining clinical and molecular factors; this model was validated in other independent cohorts. In summary, our study showed that c-kit other than any other mutations would influence the OS in AML1-ETO patients. A proposed predictor combining both clinical and genetic factors is applicable to prognostic prediction in AML1-ETO patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: The interest in plasma biomarkers has increased recently. Plasma exosome-derived microRNA-532 is aberrantly expressed in a variety of human cancers and has the prognostic value in many solid tumors. However, the prognostic impact of the expression value on AML remains unclear. OBJECTIVE: The aim of this study is to investigate the prognostic value of exosome-derived microRNA-532 in AML patients. METHODS: We performed the real-time PCR to quantify exosome-derived microRNA-532 in plasma of 198 AML patients. To assess the prognostic value, we performed Cox regression analyses in the context of well-established clinical and molecular markers. Cellular metabolic profile was conducted to help us understand the biological insight of its expression. RESULTS: The expression level was not associated with white blood cell counts, age, FAB subtypes, cytogenetic risk groups and genes of FLT3-ITD, NPM1, CEBPA and DNMT3A mutations. Interestingly, high expressers had a favorable overall survival in the univariate analysis. This prognostic value was testified in the multivariate analysis. Moreover, up-regulation of miR-532 was negatively associated with cellular energy like fructose and glutamine. CONCLUSION: We found plasma exosome-derived microRNA-532 can be used as a novel survival predictor for acute myeloid leukemia. [ABSTRACT FROM AUTHOR]

Approximately 50% of older patients with acute myeloid leukemia (AML) do not obtain chromosomal abnormalities as an effective risk‐stratification, and present cytogenetically normal AML (CN‐AML). To develop a reliable prediction model for stratifying the risk of these elderly patients, we conducted a study with a discovery and validation design. As a result, we found the top 6 mutated genes in the discovery cohort of 26 case by the whole exome sequencing, and verified as recurrent mutations in the large cohort of 329 patients by Sanger sequencing. The top 6 genes were NPM1, FLT3‐ITD, DNMT3A, CEBPA double allele, IDH1 and IDH2 mutations, and the frequency of each gene in the combining cohort was 36.8%, 19.8%, 20.1%, 5.8%, 14.9% and 22.5%, respectively. In addition, clinical variables such as age, white blood cell counts, genes of IDH1 and DNMT3A mutations, European LeukemiaNet genotype (NPM1 mutations and lacking FLT3‐ITD or CEBPA double allele mutations) and treatment protocols were independent factors for predicting the probabilities of overall and event‐free survival. The prediction nomograms based on these significant factors showed accurate discrimination. In conclusion, we developed a reliable prediction model for stratifying the risk of elderly patients with CN‐AML. [ABSTRACT FROM AUTHOR]