Microenvironment matters: In vitro 3D bone marrow niches differentially modulate survival, phenotype and drug responses of acute myeloid leukemia (AML) cells.

Acute myeloid leukemia (AML) is a deadly form of leukemia with ineffective traditional treatment and frequent chemoresistance-associated relapse. Personalized drug screening holds promise in identifying optimal regimen, nevertheless, primary AML cells undergo spontaneous apoptosis during cultures, invalidating the drug screening results. Here, we reconstitute a 3D osteogenic niche (3DON) mimicking that in bone marrow to support primary AML cell survival and phenotype maintenance in cultures. Specifically, 3DON derived from osteogenically differentiated mesenchymal stem cells (MSC) from healthy and AML donors are co-cultured with primary AML cells. The AML cells under the AML_3DON niche showed enhanced viability, reduced apoptosis and maintained CD33+ CD34-phenotype, associating with elevated secretion of anti-apoptotic cytokines in the AML_3DON niche. Moreover, AML cells under the AML_3DON niche exhibited low sensitivity to two FDA-approved chemotherapeutic drugs, further suggesting the physiological resemblance of the AML_3DON niche. Most interestingly, AML cells co-cultured with the healthy_3DON niche are highly sensitive to the same sample drugs. This study demonstrates the differential responses of AML cells towards leukemic and healthy bone marrow niches, suggesting the impact of native cancer cell niche in drug screening, and the potential of re-engineering healthy bone marrow niche in AML patients as chemotherapeutic adjuvants overcoming chemoresistance, respectively.

Flow cytometry in acute myeloid leukemia and detection of minimal residual disease.

Acute myeloid leukemia (AML) is a common type of acute leukemia (AL), belonging to malignant tumors of the hematopoietic system with the characteristics of rapid disease development, control with extreme difficulties, easy recurrence, poor prognosis, and incidence rate increasing with age. The traditionally diagnostic standard of French American British (FAB), being based on the morphological examination with high human subjectivity, can no longer meet the demand of clinical diagnosis and treatment of AML. Requirements of objective accuracy and low-dose sample, have become the indispensable method for AML diagnosis and monitoring prognosis. Flow cytometry is a modern technology that can quickly and accurately detect the series, antigen distribution, differentiation stage of AML cells, minimal residual lesions after AML therapy, so as to provide the great significance in guiding clinical diagnosis, hierarchical treatment, and prognosis judgement. This article will systematically elaborate on the application of flow cytometry in the diagnosis and classification of AML, and the detection of minimal residual lesions, thereby providing reference significance for dynamic monitoring and prognostic observation of AML with different immune subtypes of FAB.

Unlocking reproducible transcriptomic signatures for acute myeloid leukaemia: Integration, classification and drug repurposing.

Acute myeloid leukaemia (AML) is a highly heterogeneous disease, which lead to various findings in transcriptomic research. This study addresses these challenges by integrating 34 datasets, including 26 control groups, 6 prognostic datasets and 2 single-cell RNA sequencing (scRNA-seq) datasets to identify 10,000 AML-related genes (ARGs). We focused on genes with low variability and high consistency and successfully discovered 191 AML signatures (ASs). Leveraging machine learning techniques, specifically the XGBoost model and our custom framework, we classified AML subtypes with both scRNA-seq and bulk RNA-seq data, complementing the ELN2022 classification approach. Our research also identified promising treatments for AML through drug repurposing, with solasonine showing potential efficacy for high-risk AML patients, supported by molecular docking and transcriptomic analyses. To enhance reproducibility and customizability, we developed CSAMLdb, a user-friendly database platform. It facilitates the reuse and personalized analysis of nearly all results obtained in this research, including single-gene prognostics, multi-gene scoring, enrichment analysis, machine learning risk assessment, drug repositioning analysis and literature abstract named entity recognition. CSAMLdb is available at http://www.csamldb.com.

Enhancing Therapeutic Efficacy of FLT3 Inhibitors with Combination Therapy for Treatment of Acute Myeloid Leukemia.

FMS-like tyrosine kinase 3 (FLT3) mutations are genetic changes found in approximately thirty percent of patients with acute myeloid leukemia (AML). FLT3 mutations in AML represent a challenging clinical scenario characterized by a high rate of relapse, even after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The advent of FLT3 tyrosine kinase inhibitors (TKIs), such as midostaurin and gilteritinib, has shown promise in achieving complete remission. However, a substantial proportion of patients still experience relapse following TKI treatment, necessitating innovative therapeutic strategies. This review critically addresses the current landscape of TKI treatments for FLT3+ AML, with a particular focus on gilteritinib. Gilteritinib, a highly selective FLT3 inhibitor, has demonstrated efficacy in targeting the mutant FLT3 receptor, thereby inhibiting aberrant signaling pathways that drive leukemic proliferation. However, monotherapy with TKIs may not be sufficient to eradicate AML blasts. Specifically, we provide evidence for integrating gilteritinib with mammalian targets of rapamycin (mTOR) inhibitors and interleukin-15 (IL-15) complexes. The combination of gilteritinib, mTOR inhibitors, and IL-15 complexes presents a compelling strategy to enhance the eradication of AML blasts and enhance NK cell killing, offering a potential for improved patient outcomes.

Distinct FLT3 Pathways Gene Expression Profiles in Pediatric De Novo Acute Lymphoblastic and Myeloid Leukemia with FLT3 Mutations: Implications for Targeted Therapy.

Activating FLT3 mutations plays a crucial role in leukemogenesis, but identifying the optimal candidates for FLT3 inhibitor therapy remains controversial. This study aims to explore the impacts of FLT3 mutations in pediatric acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) and to compare the mutation profiles between the two types to inspire the targeted application of FLT3 inhibitors. We retrospectively analyzed 243 ALL and 62 AML cases, grouping them into FLT3-mutant and wild-type categories, respectively. We then assessed the associations between FLT3 mutations and the clinical manifestations, genetic characteristics, and prognosis in ALL and AML. Additionally, we compared the distinct features of FLT3 mutations between ALL and AML. In ALL patients, those with FLT3 mutations predominantly exhibited hyperdiploidy (48.6% vs. 14.9%, p < 0.001) and higher FLT3 expression (108.02 [85.11, 142.06] FPKM vs. 23.11 [9.16, 59.14] FPKM, p < 0.001), but lower expression of signaling pathway-related genes such as HRAS, PIK3R3, BAD, MAP2K2, MAPK3, and STAT5A compared to FLT3 wild-type patients. There was no significant difference in prognosis between the two groups. In contrast, AML patients with FLT3 mutations were primarily associated with leucocytosis (82.90 [47.05, 189.76] G/L vs. 20.36 [8.90, 55.39] G/L, p = 0.001), NUP98 rearrangements (30% vs. 4.8%, p = 0.018), elevated FLT3 expression (74.77 [54.31, 109.46] FPKM vs. 34.56 [20.98, 48.28] FPKM, p < 0.001), and upregulated signaling pathway genes including PIK3CB, AKT1, MTOR, BRAF, and MAPK1 relative to FLT3 wild-type, correlating with poor prognosis. Notably, internal tandem duplications were the predominant type of FLT3 mutation in AML (66.7%) with higher inserted base counts, whereas they were almost absent in ALL (6.3%, p < 0.001). In summary, our study demonstrated that the forms and impacts of FLT3 mutations in ALL differed significantly from those in AML. The gene expression profiles of FLT3-related pathways may provide a rationale for using FLT3 inhibitors in AML rather than ALL when FLT3 mutations are present.

Mitochondria and Acute Leukemia: A Clinician's Perspective.

Acute leukemia is a group of aggressive hematological malignancies, with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) being the most common types. The biology of acute leukemia involves complex genetic and epigenetic alterations that lead to uncontrolled cell proliferation and resistance to apoptosis. Mitochondrial dysfunction is a feature of acute leukemia that results in altered energy production, unregulated cell death pathways, and increased cancer cell survival. Apoptosis, particularly via the mitochondrial pathway, is crucial for cellular homeostasis and cancer prevention. In acute leukemia, disruption of apoptosis is pivotal in disease development and progression, with elevated levels of anti-apoptotic proteins conferring a survival advantage to leukemia cells and promoting resistance to conventional therapies. Targeting mitochondrial apoptosis using BH3 mimetics and anti-apoptotic protein inhibitors is a viable therapeutic strategy. Alterations in the mitochondrial membrane potential, metabolism, and dynamics also contribute to the pathogenesis of acute leukemia. Continued research is vital for developing novel therapies and enhancing survival outcomes in patients with acute leukemia while minimizing the long-term adverse effects of treatment. In this narrative review, we provide a birds-eye view of the available scientific literature on the importance of mitochondria in acute leukemia, and discuss the role of BH3 mimetics in targeting the mitochondrial internal apoptotic machinery.

Analysis of action of 1,4-naphthoquinone scaffold-derived compounds against acute myeloid leukemia based on network pharmacology, molecular docking and molecular dynamics simulation.

1,4-Naphthoquinone scaffold-derived compounds has shown considerable pharmacological properties against cancer, including acute myeloid leukemia (AML) However, its impact and mechanisms in AML are uncertain. In this study, the mechanisms of 1,4-naphthoquinone scaffold-derived compounds against AML were investigated via network pharmacology, molecular docking and molecular dynamics simulation. ASINEX database was used to collect the 1,4-naphthoquinone scaffold-derived compounds, and compounds were extracted from the software to evaluate their drug similarity and toxicity. The potential targets of compounds were retrieved from the SwissTargetPrediction Database and the Similarity Ensemble Approach Database, while the potential targets of AML were obtained from the GeneCards databases and Gene Expression Omnibus. The STRING database was used to construct a protein-protein interaction (PPI) network, topologically and Cyto Hubb plugin of Cytoscape screen the central targets. After selecting the potential key targets, the gene ontology (GO) function annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed for the intersection targets, and a network map of "compounds-potential targets-pathway-disease" were constructed. Molecular docking of the compounds with the core target was performed, and core target with the strongest binding force and 1,4-naphthoquinone scaffold-derived compounds was selected for further molecular dynamics simulation and further molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) approach verification. In addition, the Bloodspot database was applied to perform the overall survival of core targets. A total of 19 1,4-naphthoquinone scaffold-derived compounds were chosen out, and then 836 targets of compounds, 96 intersection targets of AML were screened. Core targets include STAT3, TLR4, HSP90AA1, JUN, MMP9, PTPRC, JAK2, PTGS2, KIT and CSF1R. GO functional enrichment analysis revealed that 90 biological processes, 10 cell components and 12 molecular functions were enriched while KEGG pathway enrichment analysis revealed 34 enriched signaling pathways. Analysis of KEGG enrichment hinted that these 10 core genes were located in the pathways in cancer, suggesting that 1,4-naphthoquinone scaffold-derived compounds had potential activity against AML. Molecular docking analysis revealed that the binding energies between 1,4-naphthoquinone scaffold-derived compounds and the core proteins were all higher than - 6 kcal/mol, indicating that the 10 core targets all had strong binding ability with compounds. Moreover, a good binding capacity was inferred from molecular dynamics simulations between compound 7 and MMP9. The total binding free energy calculated using the MM/GBSA approach revealed values of - 6356.865 kcal/mol for the MMP9-7 complex. In addition, Bloodspot database results exhibited that HSP90AA1, MMP9 and PTPRC were associated with overall survival. The findings provide foundations for future studies into the interaction underlying the anti-AML potential of compounds with 1,4-naphthoquinone-based scaffold structures. Compounds with 1,4-naphthoquinone-based scaffold structures exhibits considerable potential in mitigating and treating AML through multiple targets and pathways.

BATF is a major driver of NK cell epigenetic reprogramming and dysfunction in AML.

Myelodysplastic syndrome and acute myeloid leukemia (AML) belong to a continuous disease spectrum of myeloid malignancies with poor prognosis in the relapsed/refractory setting necessitating novel therapies. Natural killer (NK) cells from patients with myeloid malignancies display global dysfunction with impaired killing capacity, altered metabolism, and an exhausted phenotype at the single-cell transcriptomic and proteomic levels. In this study, we identified that this dysfunction was mediated through a cross-talk between NK cells and myeloid blasts necessitating cell-cell contact. NK cell dysfunction could be prevented by targeting the αvß-integrin/TGF-ß/SMAD pathway but, once established, was persistent because of profound epigenetic reprogramming. We identified BATF as a core transcription factor and the main mediator of this NK cell dysfunction in AML. Mechanistically, we found that BATF was directly regulated and induced by SMAD2/3 and, in turn, bound to key genes related to NK cell exhaustion, such as HAVCR2, LAG3, TIGIT, and CTLA4. BATF deletion enhanced NK cell function against AML in vitro and in vivo. Collectively, our findings reveal a previously unidentified mechanism of NK immune evasion in AML manifested by epigenetic rewiring and inactivation of NK cells by myeloid blasts. This work highlights the importance of using healthy allogeneic NK cells as an adoptive cell therapy to treat patients with myeloid malignancies combined with strategies aimed at preventing the dysfunction by targeting the TGF-ß pathway or BATF.

Continued decitabine/all-trans retinoic acid treatment: extended complete remission in an elderly AML patient with multi-hit TP53 lesions and complex-monosomal karyotype.

DNA-hypomethylating agents (HMAs) induce notable remission rates in AML/MDS patients with TP53 mutations; however, secondary resistance often develops rapidly. In the DECIDER trial (NCT00867672), elderly AML patients (also those with adverse genetics) randomized to all-trans retinoic acid (ATRA) added to decitabine (DEC) attained significantly delayed time-to-resistance. An 82-year-old patient with a non-disruptive, in-frame TP53 mutation (p.Cys238_Asn239delinsTyr, VAF 90%) and complex-monosomal karyotype attained a complete hematologic and cytogenetic remission with DEC + ATRA, with 3.7 years survival after 30 treatment cycles that were well-tolerated. Further HMA + ATRA studies appear warranted in AML/MDS patients of different genetic risk groups ineligible for more intensive treatment.Trial registration: This trial was registered at ClinicalTrials.gov identifier: NCT00867672.

Effectiveness of Nutrition Support Team Intervention in Pediatric Patients with Cancer.

Malnutrition in children with cancer is associated with poor prognosis. This study aimed to determine whether nutritional support team (NST) interventions prevent adverse events and improve the nutritional status in pediatric patients admitted for cancer treatment. This was a historical cohort study of pediatric patients with acute lymphocytic leukemia, acute myeloid leukemia, neuroblastoma, or brain tumor who received chemotherapy or underwent hematopoietic stem cell transplantation. Patients admitted between June 2013 and October 2014 were classified into the intervention group. Those admitted between January 2011 and December 2012 were classified into the control group. We created a homogeneous probability model using the inverse probability of treatment weighting method, and compared outcomes. A total of 75 patients were included in the study (38 and 37 in the intervention and control groups, respectively). The intervention group had significantly fewer incidents of nothing by mouth (nil per os [NPO]) (p=0.037) and days of NPO (p=0.046) than the control group. There was no significant difference between the intervention and control groups regarding the change in body mass index z-score between admission and discharge (p=0.376). NST interventions for children with cancer were associated with a reduction in the number of NPO occurrences and NPO days. These findings suggest that NST interventions contribute to continued oral intake.

[Concentration of gilteritinib in the cerebrospinal fluid of a patient with relapsed FLT3-ITD positive acute myeloid leukemia with optic nerve involvement].

A 72-year-old woman with relapsed FLT3-ITD-positive acute myeloid leukemia was treated with gilteritinib and achieved complete remission with incomplete hematological recovery. However, two months later, she developed optic nerve infiltration and lost vision in her right eye while maintaining hematological remission on gilteritinib. Intrathecal injection of cytotoxic drugs reduced the number of blasts in the cerebrospinal fluid (CSF), but her vision did not recover. At the onset of optic nerve infiltration, at a dose of 80 mg/day gilteritinib, the plasma trough and CSF levels of gilteritinib were 151.9 ng/ml and 1.9 ng/ml, respectively, with a central nervous system (CNS) penetration rate of 1.3%. Hematologic progressive disease (PD) was detected after 40 days, and the patient died one month later. Target sequencing at the time of hematologic PD revealed the FLT3 F691L mutation, which is known to confer resistance to gilteritinib. In this patient, pharmacokinetic (low CNS penetration of gilteritinib) and pharmacodynamic (acquisition of a drug resistance mutation) mechanisms were thought to be responsible for the CNS relapse and hematologic PD, respectively. We believe this is a valuable case to report considering the scarcity of data on CNS penetration of FLT3 inhibitors and their effects on CNS disease in the literature.

Investigating the impact of multidisciplinary prehabilitation on deconditioning in patients eligible for haematopoietic allogenic stem cell transplantation: protocol for a feasibility trial.

BACKGROUND: Assessing multidisciplinary prehabilitation strategies becomes crucial to pre-emptively counter the physical, psychological and social negative impacts experienced during an allogenic haematopoietic stem cell transplant (allo-HSCT) among acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) patients. Current evidence is restricted to studies during induction chemotherapy, omitting rehabilitation interventions and predominantly using exercise-only approaches without a multidisciplinary framework. The aim of this study is to investigate the feasibility, safety and preliminary efficacy of multidisciplinary prehabilitation in adults offered allo-HSCT. METHODS AND ANALYSIS: This 8-week single-group pre-post feasibility study aims to pilot a multidisciplinary prehabilitation intervention for participants undergoing allo-HSCT, with a focus on feasibility and safety. Participants, aged 18 or older, diagnosed with AML or MDS, and offered allo-HSCT, will be recruited between June 2023 and July 2024. The multidisciplinary prehabilitation intervention, conducted by the cancer allied health team at the Royal Adelaide Hospital, includes exercise physiology, physiotherapy, dietetics, social work, occupational therapy and psychology interventions. Consistent with a multidisciplinary treatment approach, each component is tailored to address different aspects of patient care, and adherence calculations will assess patient engagement and compliance. In addition, participants will continue to receive usual care from cancer allied health staff. The primary outcome of the study is to assess the feasibility of a multidisciplinary prehabilitation intervention by evaluating intervention uptake, retention, adherence, acceptability and safety. Secondary outcomes are leg strength, upper-body strength, aerobic fitness, falls risk, anthropometry, nutritional status, quality of life, anxiety, depression, self-efficacy for coping with cancer and distress. ETHICS AND DISSEMINATION: Ethics approval for this study has been provided by the Central Adelaide Local Health Network (HREC 2022/HRE00284). Recruitment for the study commenced in June 2023 and will continue until July 2024. The methods have been designed and are reported according to the SPIRIT and CONSORT-pilot study checklist. TRIAL REGISTRATION NUMBER: The Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12623000052639.

Immune isolation-enabled nanoencapsulation of donor T cells: a promising strategy for mitigating GVHD and treating AML in preclinical models.

BACKGROUND: In allogeneic-hematopoietic stem cell transplantation for acute myeloid leukemia (AML), donor T cells combat leukemia through the graft-versus-leukemia (GVL) effect, while they also pose a risk of triggering life-threatening graft-versus-host disease (GVHD) by interacting with recipient cells. The onset of GVHD hinges on the interplay between donor T cells and recipient antigen-presenting cells (APCs), sparking T-cell activation. However, effective methods to balance GVHD and GVL are lacking. METHODS: In our study, we crafted nanocapsules by layering polycationic aminated gelatin and polyanionic alginate onto the surface of T cells, examining potential alterations in their fundamental physiological functions. Subsequently, we established an AML mouse model and treated it with transplantation of bone marrow cells (BMCs) combined with encapsulated T cells to investigate the GVL and anti-GVHD effects of encapsulated T cells. In vitro co-culture was employed to probe the effects of encapsulation on immune synapses, co-stimulatory molecules, and tumor-killing pathways. RESULTS: Transplantation of BMCs combined with donor T cells selectively encapsulated onto AML mice significantly alleviates GVHD symptoms while preserving essential GVL effects. Encapsulated T cells exerted their immunomodulatory effects by impeding the formation of immune synapses with recipient APCs, thereby downregulating co-stimulatory signals such as CD28-CD80, ICOS-ICOSL, and CD40L-CD40. Recipient mice receiving encapsulated T-cell transplantation exhibited a marked increase in donor Ly-5.1-BMC cell numbers, accompanied by unaltered in vivo expression levels of perforin and granzyme B. While transient inhibition of donor T-cell cytotoxicity in the tumor microenvironment was observed in vitro following single-cell nanoencapsulation, subsequent restoration to normal antitumor activity ensued, attributed to selective permeability of encapsulated vesicle shells and material degradation. Moreover, the expression of apoptotic proteins and FAS-FAS ligand pathway at normal levels was still observed in leukemia tumor cells. CONCLUSIONS: Encapsulated donor T cells effectively mitigate GVHD while preserving the GVL effect by minimizing co-stimulatory signaling with APCs through early immune isolation. Subsequent degradation of nanocapsules restores T-cell cytotoxic efficacy against AML cells, mediated by cytotoxic pathways. Using transplant-encapsulated T cells offers a promising strategy to suppress GVHD while preserving the GVL effect.

Research on the mechanism of HOPX-HDAC2 interaction inducing differentiation blockage in acute myeloid leukemia.

Homeodomain-only protein homeobox (HOPX) mainly exerts its transcriptional repression by physically sequestering the serum co-repressor and recruiting histone deacetylase (HDAC), possessing important potential as a prognostic gene in acute myeloid leukemia (AML). HDACs play crucial roles in cell growth, gene regulation, and metabolism, and they are also important factors in promoting AML progression. Therefore, this project attempts to investigate whether HOPX affects AML progression by interacting with HDAC2 protein. Bioinformatics analysis was employed to identify potential prognostic genes in AML. Flow cytometry and MTT assays were performed to analyze the cellular biological functions of the AML prognostic marker HOPX. The interaction network of HOPX was analyzed using the Search Tool for the Retrieval of Interacting Genes database, and the interaction between HOPX and HDAC2 was observed using endogenous and exogenous immunoprecipitation. HOPX is highly expressed in AML cells. Further research uncovered that low expression of HOPX can repress the proliferation activity, anti-apoptotic ability, and differentiation blockage of AML cells. Moreover, mechanistically, HOPX induced AML differentiation blockage and malignant progression through interaction with HDAC. HOPX can serve as a prognostic marker for AML and can interact with HDAC2 to induce AML differentiation blockage and malignant progression.

Routes and molecular mechanisms of central nervous system involvement in acute myeloid leukemia (Review).

Acute myeloid leukemia (AML) is a predominant form of leukemia. Central nervous system (CNS) involvement complicates its diagnosis due to limited diagnostic tools, as well as its treatment due to inadequate therapeutic methodologies and poor prognosis. Furthermore, its incidence rate is unclear. The mechanisms of AML cell mobilization from the bone marrow (BM) to the CNS are not fully elucidated, and the molecular factors contributing to CNS infiltration are insufficiently recognized. The present review aimed to enhance the understanding of CNS involvement of AML and its impact on CNS. The latest research on the pathways and mechanisms facilitating AML cells to escape the BM and infiltrate the CNS was reviewed. Additionally, novel therapeutic strategies targeting specific molecules and genes for treating CNS involvement in AML were examined.