Ferritin-mediated mitochondrial iron homeostasis is essential for the survival of hematopoietic stem cells and leukemic stem cells.

Iron metabolism plays a crucial role in cell viability, but its relationship with adult stem cells and cancer stem cells is not fully understood. The ferritin complex, responsible for intracellular iron storage, is important in this process. We report that conditional deletion of ferritin heavy chain 1 (Fth1) in the hematopoietic system reduced the number and repopulation capacity of hematopoietic stem cells (HSCs). These effects were associated with a decrease in cellular iron level, leading to impaired mitochondrial function and the initiation of apoptosis. Iron supplementation, antioxidant, and apoptosis inhibitors reversed the reduced cell viability of Fth1-deleted hematopoietic stem and progenitor cells (HSPCs). Importantly, leukemic stem cells (LSCs) derived from MLL-AF9-induced acute myeloid leukemia (AML) mice exhibited reduced Fth1 expression, rendering them more susceptible to apoptosis induced by the iron chelation compared to normal HSPCs. Modulating FTH1 expression using mono-methyl fumarate increased LSCs resistance to iron chelator-induced apoptosis. Additionally, iron supplementation, antioxidant, and apoptosis inhibitors protected LSCs from iron chelator-induced cell death. Fth1 deletion also extended the survival of AML mice. These findings unveil a novel mechanism by which ferritin-mediated iron homeostasis regulates the survival of both HSCs and LSCs, suggesting potential therapeutic strategies for blood cancer with iron dysregulation.

Iron overload promotes the progression of MLL-AF9 induced acute myeloid leukemia by upregulation of FOS.

Systemic iron overload is a common clinical challenge leading to significantly serious complications in patients with acute myeloid leukemia (AML), which affects both the quality of life and the overall survival of patients. Symptoms can be relieved after iron chelation therapy in clinical practice. However, the roles and mechanisms of iron overload on the initiation and progression of leukemia remain elusive. Here we studied the correlation between iron overload and AML clinical outcome, and further explored the role and pathophysiologic mechanism of iron overload in AML by using two mouse models: an iron overload MLL-AF9-induced AML mouse model and a nude xenograft mouse model. Patients with AML had an increased ferritin level, particularly in the myelomonocytic (M4) or monocytic (M5) subtypes. High level of iron expression correlated with a worsened prognosis in AML patients and a shortened survival time in AML mice. Furthermore, iron overload increased the tumor load in the bone marrow (BM) and extramedullary tissues by promoting the proliferation of leukemia cells through the upregulation of FOS. Collectively, our findings provide new insights into the roles of iron overload in AML. Additionally, this study may provide a potential therapeutic target to improve the outcome of AML patients and a rationale for the prospective evaluation of iron chelation therapy in AML.

Novel Approaches to Treatment of Acute Myeloid Leukemia Relapse Post Allogeneic Stem Cell Transplantation.

The management of patients with acute myeloid leukemia (AML) relapsed post allogeneic hematopoietic stem cell transplantation (HSCT) remains a clinical challenge. Intensive treatment approaches are limited by severe toxicities in the early post-transplantation period. Therefore, hypomethylating agents (HMAs) have become the standard therapeutic approach due to favorable tolerability. Moreover, HMAs serve as a backbone for additional anti-leukemic agents. Despite discordant results, the addition of donor lymphocytes infusions (DLI) generally granted improved outcomes with manageable GvHD incidence. The recent introduction of novel targeted drugs in AML gives the opportunity to add a third element to salvage regimens. Those patients harboring targetable mutations might benefit from IDH1/2 inhibitors Ivosidenib and Enasidenib as well as FLT3 inhibitors Sorafenib and Gilteritinib in combination with HMA and DLI. Conversely, patients lacking targetable mutations actually benefit from the addition of Venetoclax. A second HSCT remains a valid option, especially for fit patients and for those who achieve a complete disease response with salvage regimens. Overall, across studies, higher response rates and longer survival were observed in cases of pre-emptive intervention for molecular relapse. Future perspectives currently rely on the development of adoptive immunotherapeutic strategies mainly represented by CAR-T cells.

Protein-Nanocaged Selenium Induces t(8;21) Leukemia Cell Differentiation via Epigenetic Regulation.

The success of arsenic in degrading PML-RARα oncoprotein illustrates the great anti-leukemia value of inorganics. Inspired by this, the therapeutic effect of inorganic selenium on t(8; 21) leukemia is studied, which has shown promising anti-cancer effects on solid tumors. A leukemia-targeting selenium nanomedicine is rationally built with bioengineered protein nanocage and is demonstrated to be an effective epigenetic drug for inducing the differentiation of t(8;21) leukemia. The selenium drug significantly induces the differentiation of t(8;21) leukemia cells into more mature myeloid cells. Mechanistic analysis shows that the selenium is metabolized into bioactive forms in cells, which drives the degradation of the AML1-ETO oncoprotein by inhibiting histone deacetylases activity, resulting in the regulation of AML1-ETO target genes. The regulation results in a significant increase in the expression levels of myeloid differentiation transcription factors PU.1 and C/EBPα, and a significant decrease in the expression level of C-KIT protein, a member of the type III receptor tyrosine kinase family. This study demonstrates that this protein-nanocaged selenium is a potential therapeutic drug against t(8;21) leukemia through epigenetic regulation.

Potent Personalized Venetoclax Partners for Acute Myeloid Leukemia Identified by Ex Vivo Drug Screening.

SUMMARY: High-throughput screens (HTS) have been utilized to assess the efficacy of single drugs against patient tumor samples with the purpose of optimizing precision therapy, but testing the synergy of drug combinations can identify the ideal second drug to add. With novel sophisticated HTS, effective venetoclax combinations can be revealed that provide the cell state, phenotype, and molecular features of the susceptible and resistant cell populations. See related article by Eide, Kurtz et al., p. 452 (14) .

Clinical status of induction therapy incorporating a hypomethylating agent for newly diagnosed adult acute myeloid leukemia compared to the standard 7+3 regimen.

INTRODUCTION: Cytarabine and anthracycline combination therapy (7 + 3 regimen) is the standard care for induction chemotherapy in adult patients with acute myeloid leukemia (AML). Although this intensive regimen achieves a high response rate, it is highly toxic, especially in elderly or frail patients. Hypomethylating agents approved initially for high-risk myelodysplastic syndrome had longer survival times than conventional care in elderly patients with newly diagnosed AML. AREAS COVERED: We summarize the latest information regarding induction therapy using hypomethylating agents (azacitidine and decitabine) for newly diagnosed AML. EXPERT OPINION: For untreated patients ineligible for an intensive regimen, a phase III trial exhibited the survival benefit of adding the highly selective BCL2 inhibitor venetoclax to azacitidine. The National Comprehensive Cancer Network guidelines recommend azacitidine or decitabine plus venetoclax as an option for patients with poor-risk AML, including those with TP53 mutations and AML with the cytogenetic features of myelodysplastic syndrome. Future studies should evaluate positioning this combination as an induction therapy for younger patients eligible for hematopoietic stem cell transplantation. Without randomized trials, propensity score matching analysis suggested a comparable prognosis between azacitidine combination and intensive chemotherapy. Considering the feasibility of a doublet regimen incorporating azacitidine, a triplet regimen should be examined.

Vitamin C and D supplementation in acute myeloid leukemia.

Recent studies have highlighted the role of vitamin C and D in acute myeloid leukemia (AML). In 2018, we changed our practices to add both vitamins to the supportive care for all consecutive patients with AML undergoing intensive chemotherapy. In this study, we compared the outcomes of patients treated before and after this change in practice. From 2015 to 2020, 431 patients were included, 262 of whom received no supplementation and 169 of whom received vitamin supplementation. Vitamin C and vitamin D was administered from day 10 of chemotherapy until hematologic recovery from induction and consolidation. Most patients presented at diagnosis with low levels of vitamin C and D. Upon recovery from induction, vitamin D levels among the vitamin C/D group significantly increased compared with those at diagnosis, and pretransplant levels were significantly higher in the vitamin C/D group compared with the control group (median of 33 vs 19 ng/mL; P < .0001). During induction, the rates of bacterial or fungal infection, hemorrhage, or macrophage activation syndrome were lower in the vitamin C/D group, whereas there was no difference in response rate, relapse incidence, and overall survival (OS). However, the multivariate analysis for OS showed a significant interaction between vitamin C/D and NPM1 mutation, meaning that vitamin C/D supplementation was significantly and independently associated with better OS in patients with NPM1 mutations (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.30-0.90; P = .019) compared with patients with wild-type NPM1 (HR, 1.01; 95% CI, 0.68-1.51; P = .95). In conclusion, vitamin C/D supplementation is safe and could influence the outcomes of patients with AML undergoing intensive chemotherapy.

The Therapeutic Potential of a Strategy to Prevent Acute Myeloid Leukemia Stem Cell Reprogramming in Older Patients.

Acute myeloid leukemia (AML) is the most common and incurable leukemia subtype. Despite extensive research into the disease's intricate molecular mechanisms, effective treatments or expanded diagnostic or prognostic markers for AML have not yet been identified. The morphological, immunophenotypic, cytogenetic, biomolecular, and clinical characteristics of AML patients are extensive and complex. Leukemia stem cells (LSCs) consist of hematopoietic stem cells (HSCs) and cancer cells transformed by a complex, finely-tuned interaction that causes the complexity of AML. Microenvironmental regulation of LSCs dormancy and the diagnostic and therapeutic implications for identifying and targeting LSCs due to their significance in the pathogenesis of AML are discussed in this review. It is essential to perceive the relationship between the niche for LSCs and HSCs, which together cause the progression of AML. Notably, methylation is a well-known epigenetic change that is significant in AML, and our data also reveal that microRNAs are a unique factor for LSCs. Multiple-targeted approaches to reduce the risk of epigenetic factors, such as the administration of natural compounds for the elimination of local LSCs, may prevent potentially fatal relapses. Furthermore, the survival analysis of overlapping genes revealed that specific targets had significant effects on the survival and prognosis of patients. We predict that the multiple-targeted effects of herbal products on epigenetic modification are governed by different mechanisms in AML and could prevent potentially fatal relapses. Thus, these strategies can facilitate the incorporation of herbal medicine and natural compounds into the advanced drug discovery and development processes achievable with Network Pharmacology research.

Phase II study of cladribine, idarubicin, and ara-C (CLIA) with or without sorafenib as initial therapy for patients with acute myeloid leukemia.

The addition of cladribine, or sorafenib to standard chemotherapy have each demonstrated improved survival in patients with newly-diagnosed acute myeloid leukemia (AML). We studied the combination of cladribine, idarubicin, and intermediate-dose cytarabine (CLIA) in patients ≤65 years of age with newly diagnosed AML, fit to receive intensive therapy. Cladribine (5 mg/m2) IV was administered on days (D)1-5, cytarabine (1 g/m2) on D1-5, and idarubicin (10 mg/m2) on D1-3. Sorafenib was added to the CLIA backbone for patients with FLT3-ITD mutated AML. 80 patients were enrolled: 65 with newly diagnosed AML and 15 with AML arising from previously treated MDS (ts-AML). The median age was 55 years (range, 21-65). CR + CRi was 83% (54/65) and 27% in the untreated and ts-AML cohorts, respectively; 74% and 75% of responding patients, respectively, had undetectable measurable residual disease (MRD). Among patients with FLT3-ITD mutated AML receiving CLIA+sorafenib, the CR + CRi rate was 95%, with 81% negative for MRD. With a median follow-up of 76 months, the 2- and 4-year OS of 57% and 50% compared to 20%, and 13% for ts-AML, respectively. Patients treated with CLIA+sorafenib had 2- and 5-year OS rates of 63% and 59%, respectively. The most common Grade ≥3 adverse events were infection/fever, elevated bilirubin, rash, and nausea. CLIA was safe and effective in young, fit patients with newly diagnosed AML with inferior outcomes among patients with ts-AML. The addition of sorafenib to CLIA in FLT3-ITD mutated AML resulted in high rates of durable remission and excellent long-term survival.

Cryptic KMT2A/MLLT10 fusion detected by next-generation sequencing in a case of pediatric acute megakaryoblastic leukemia.

KMT2A (11q23.3) gene rearrangements are found in acute leukemia and are associated with a poor or intermediate prognosis. MLLT10 is the fourth most common gene fusion partner for KMT2A. A reciprocal translocation t(10;11) is insufficient to produce an in-frame KMT2A/MLLT10 fusion, because the genes involved in the rearrangement have opposite transcriptional orientations. In order to bring KMT2A and MLLT10 into juxtaposition, complex rearrangements are required. Until now, conventional chromosome, fluorescence in situ hybridization (FISH), and reverse transcriptase-polymerase chain reaction (RT-PCR) studies have been used to detect KMT2A/MLLT10 fusions. However, conventional studies have limitations, such as poor and inconsistent resolution, when compared to next-generation sequencing (NGS). In this study, we report a pediatric patient with acute megakaryoblastic leukemia, in whom the cryptic KMT2A/MLLT10 fusion was not detected by KMT2A break-apart probe FISH and chromosome analysis, but detected by NGS. In this patient, NGS showed cryptic insertion of MLLT10 exons 9-24 into intron 9 of KMT2A, resulting in a KMT2A/MLLT10 fusion. Therefore, NGS is a valuable complementary option for the evaluation of structural aberrations, especially those with a cryptic size.

Intensive chemotherapy with or without gemtuzumab ozogamicin in patients with NPM1-mutated acute myeloid leukaemia (AMLSG 09-09): a randomised, open-label, multicentre, phase 3 trial.

BACKGROUND: Acute myeloid leukaemia with mutated NPM1 is associated with high CD33 expression and intermediate-risk cytogenetics. The aim of this study was to evaluate intensive chemotherapy with or without the anti-CD33 antibody-drug conjugate gemtuzumab ozogamicin in participants with newly diagnosed, NPM1-mutated acute myeloid leukaemia. METHODS: This open-label, phase 3 trial was conducted at 56 hospitals in Germany and Austria. Eligible participants were 18 years or older and had newly diagnosed NPM1-mutated acute myeloid leukaemia and an Eastern Cooperative Oncology Group performance status of 0-2. Participants were randomly assigned, using age as a stratification factor (18-60 years vs >60 years), 1:1 to the two treatment groups using allocation concealment; there was no masking of participants and investigators to treatment groups. Participants received two cycles of induction therapy (idarubicin, cytarabine, and etoposide) plus all-trans retinoic acid (ATRA) followed by three consolidation cycles of high-dose cytarabine (or an intermediate dose for those older than 60 years) and ATRA, without or with gemtuzumab ozogamicin (3 mg/m2 administered intravenously on day 1 of induction cycles 1 and 2, and consolidation cycle 1). The primary endpoints were short-term event-free survival and overall survival in the intention-to-treat population (overall survival was added as a co-primary endpoint after amendment four of the protocol on Oct 13, 2013). The secondary endpoints were event-free survival with long-term follow-up, rates of complete remission, complete remission with partial haematological recovery (CRh), and complete remission with incomplete haematological recovery (CRi), cumulative incidences of relapse and death, and number of days in hospital. This trial is registered with ClinicalTrials.gov (NCT00893399) and has been completed. FINDINGS: Between May 12, 2010, and Sept 1, 2017, 600 participants were enrolled, of which 588 (315 women and 273 men) were randomly assigned (296 to the standard group and 292 to the gemtuzumab ozogamicin group). No difference was found in short-term event-free survival (short-term event-free survival at 6-month follow-up, 53% [95% CI 47-59] in the standard group and 58% [53-64] in the gemtuzumab ozogamicin group; hazard ratio [HR] 0·83; 95% CI 0·65-1·04; p=0·10) and overall survival between treatment groups (2-year overall survival, 69% [63-74] in the standard group and 73% [68-78] in the gemtuzumab ozogamicin group; 0·90; 0·70-1·16; p=0·43). There was no difference in complete remission or CRi rates (n=267 [90%] in the standard group vs n=251 [86%] in the gemtuzumab ozogamicin group; odds ratio [OR] 0·67; 95% CI 0·40-1·11; p=0·15) and complete remission or CRh rates (n=214 [72%] vs n=195 [67%]; OR 0·77; 0·54-1·10; p=0·18), whereas the complete remission rate was lower with gemtuzumab ozogamicin (n=172 [58%] vs n=136 [47%]; OR 0·63; 0·45-0·80; p=0·0068). Cumulative incidence of relapse was significantly reduced by gemtuzumab ozogamicin (2-year cumulative incidence of relapse, 37% [95% CI 31-43] in the standard group and 25% [20-30] in the gemtuzumab ozogamicin group; cause-specific HR 0·65; 0·49-0·86; p=0·0028), and there was no difference in the cumulative incidence of death (2-year cumulative incidence of death 6% [4-10] in the standard group and 7% [5-11] in the gemtuzumab ozogamicin group; HR 1·03; 0·59-1·81; p=0·91). There were no differences in the number of days in hospital across all cycles between treatment groups. The most common treatment-related grade 3-4 adverse events were febrile neutropenia (n=135 [47%] in the gemtuzumab ozogamicin group vs n=122 [41%] in the standard group), thrombocytopenia (n=261 [90%] vs n=265 [90%]), pneumonia (n=71 [25%] vs n=64 [22%]), sepsis (n=85 [29%] vs n=73 [25%]). Treatment-related deaths were documented in 25 participants (4%; n=8 [3%] in the standard group and n=17 [6%] in the gemtuzumab ozogamicin group), mostly due to sepsis and infections. INTERPRETATION: The primary endpoints of the trial of event-free survival and overall survival were not met. However, an anti-leukaemic efficacy of gemtuzumab ozogamicin in participants with NPM1-mutated acute myeloid leukaemia is shown by a significantly lower cumulative incidence of relapse rate, suggesting that the addition of gemtuzumab ozogamicin might reduce the need for salvage therapy in these participants. The results from this study provide further evidence that gemtuzumab ozogamicin should be added in the standard of care treatment in adults with NPM1-mutated acute myeloid leukaemia. FUNDING: Pfizer and Amgen.

Improved efficacy of quizartinib in combination therapy with PI3K inhibition in primary FLT3-ITD AML cells.

Acute myeloid leukemia is a heterogeneous hematopoietic malignancy, characterized by uncontrolled clonal proliferation of abnormal myeloid progenitor cells, with poor outcomes. The internal tandem duplication (ITD) mutation of the Fms-like receptor tyrosine kinase 3 (FLT3) (FLT3-ITD) represents the most common genetic alteration in AML, detected in approximately 30% of AML patients, and is associated with high leukemic burden and poor prognosis. Therefore, this kinase has been regarded as an attractive druggable target for the treatment of FLT3-ITD AML, and selective small molecule inhibitors, such as quizartinib, have been identified and trialled. However, clinical outcomes have been disappointing so far due to poor remission rates, also because of acquired resistance. A strategy to overcome resistance is to combine FLT3 inhibitors with other targeted therapies. In this study, we investigated the preclinical efficacy of the combination of quizartinib with the pan PI3K inhibitor BAY-806946 in FLT3-ITD cell lines and primary cells from AML patients. We show here that BAY-806946 enhanced quizartinib cytotoxicity and, most importantly, that this combination increases the ability of quizartinib to kill CD34+ CD38-leukemia stem cells, whilst sparing normal hematopoietic stem cells. Because constitutively active FLT3 receptor tyrosine kinase is known to boost aberrant PI3K signaling, the increased sensitivity of primary cells to the above combination can be the mechanistic results of the disruption of signaling by vertical inhibition.

High-throughput approaches to uncover synergistic drug combinations in leukemia.

We report a comprehensive drug synergy study in acute myeloid leukemia (AML). In this work, we investigate a panel of cell lines spanning both MLL-rearranged and non-rearranged subtypes. The work comprises a resource for the community, with many synergistic drug combinations that could not have been predicted a priori, and open source code for automation and analyses. We base our definitions of drug synergy on the Chou-Talalay method, which is useful for visualizations of synergy experiments in isobolograms, and median-effects plots, among other representations. Our key findings include drug synergies affecting the chromatin state, specifically in the context of regulation of the modification state of histone H3 lysine-27. We report open source high throughput methodology such that multidimensional drug screening can be accomplished with equipment that is accessible to most laboratories. This study will enable preclinical investigation of new drug combinations in a lethal blood cancer, with data analysis and automation workflows freely available to the community.

Exploring underlying mechanism of artesunate in treatment of acute myeloid leukemia using network pharmacology and molecular docking.

BACKGROUND: Acute myeloid leukemia (AML) is a highly heterogeneous hematological cancer. The current diagnosis and therapy model of AML has gradually shifted to personalization and accuracy. Artesunate, a member of the artemisinin family, has anti-tumor impacts on AML. This research uses network pharmacology and molecular docking to anticipate artesunate potential mechanisms of action in the therapy of AML. METHODS: Screening the action targets of artesunate through Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), PubChem, and Swiss Target Prediction databases; The databases of Online Mendelian Inheritance in Man (OMIM), Disgenet, GeneCards, and Drugbank were utilized to identify target genes of AML, and an effective target of artesunate for AML treatment was obtained through cross-analysis. Protein-protein interaction (PPI) networks are built on the Cytoscape platform. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted on the relevant targets using R software. Finally, using molecular docking technology and Pymol, we performed verification of the effects of active components and essential targets. RESULTS: Artesunate 30 effective targets for treating AML include CASP3, EGFR, MAPK1, and STAT3, four targeted genes that may have a crucial function in disease management. The virus infection-related pathway (HeptatisB (HBV), Human papillomavirus (HPV), Epstein-Barr virus (EBV) infection and etc.), FoxO, viral carcinogenesis, and proteoglycans in cancer signaling pathways have all been hypothesized to be involved in the action mechanism of GO, which is enriched in 2044 biological processes, 125 molecular functions, 209 cellular components, and 106 KEGG pathways. Molecular docking findings revealed that artesunate was critically important in the therapy of AML due to its high affinity for the four primary disease targets. Molecular docking with a low binding energy yields helpful information for developing medicines against AML. CONCLUSIONS: Consequently, artesunate may play a role in multi-targeted, multi-signaling pathways in treating AML, suggesting that artesunate may have therapeutic potential for AML.

Clinical and molecular characteristics associated with Vitamin C deficiency in myeloid malignancies; real world data from a prospective cohort.

Vitamin C is an essential vitamin that acts as a co-factor for many enzymes involved in epigenetic regulation in humans. Low vitamin C levels in hematopoietic stem cells (HSC) promote self-renewal and vitamin C supplementation retards leukaemogenesis in vitamin C-deficient mouse models. Studies on vitamin C levels in patients with myeloid malignancies are limited. We thus conducted a retrospective analysis on a prospective cohort of patients with myeloid malignancies on whom plasma vitamin C levels were measured serially at diagnosis and during treatment. Baseline characteristics including hematological indices, cytogenetics, and molecular mutations are described in this cohort. Among 64 patients included in our study, 11 patients (17%) had low vitamin C levels. We noted a younger age at diagnosis for patients with myeloid malignancies who had low plasma vitamin C levels. Patients with low plasma vitamin C levels were more likely to have acute myeloid leukemia compared to other myeloid malignancies. Low vitamin C levels were associated with ASXL1 mutations. Our study calls for further multi-institutional studies to understand the relevance of low plasma vitamin C level in myeloid neoplasms, the role of vitamin C deficiency in leukemogenesis, and the potential benefit of vitamin C supplementation.

Curcumin combined with arsenic trioxide in the treatment of acute myeloid leukemia: network pharmacology analysis and experimental validation.

PURPOSE: This study aimed to evaluate the effects of curcumin by co-administration of arsenic trioxide (As2O3) in acute myeloid leukemia (AML) treatment, using network pharmacology and experimental validation. METHODS: Using Pubchem database, Traditional Chinese Medicine Information Database (TCMID) database, and Swiss target prediction database to predict compound-related targets, AML-associated targets were determined using GeneCards and Online Mendelian Inheritance in Man (OMIM) databases. We identify overlapping common targets by comparing Compounds-related and AML-associated targets and using these targets to perform GO and KEGG functional enrichment analyses. Subsequently, these targets were input into the STRING database, and we used Cytoscape to construct protein-protein interaction (PPI) network. Finally, we used KG1-a cells and the AML mouse model to measure the anti-leukemia effects of curcumin and As2O3 and their combination. RESULTS: Compounds and targets screening hinted that 85 intersection targets were predicted in the curcumin treatment of AML, 75 targets in the As2O3 treatment of AML, and 48 targets in the curcumin combined with the As2O3 treatment of AML. GO and KEGG analyses indicated that the top 10 enriched biological processes and top 20 pathways implicated in the therapeutic effects of curcumin and As2O3 on AML, respectively. In addition, network pharmacology screening revealed STAT3, TP53, EP300, MAPK1, and PIK3CA as the top five genes in PPI network of curcumin treatment of AML and TP53, MAPK3, MAPK1, STAT3, and SRC as the top five genes in PPI network of As2O3 treatment of AML. Moreover, the in vitro experiment demonstrated that curcumin combined with As2O3 inhibited proliferation and induced apoptosis in KG1-a cells, and this effect is more substantial than curcumin or As2O3 alone. Mechanistically, the curcumin combined with As2O3 significantly down-regulated the protein expression of JAK2, STAT3, and Bcl-2, and up-regulated the levels of P53, P27, and Bax. In the mouse model, the survival time of mice in each administration group was drawn out to varying degrees, with the most significant prolongation in the curcumin combined with the As2O3 group. CONCLUSION: Our results suggested that curcumin and As2O3 combination therapy exerts more significant anti-leukemia effects in the treatment of AML than curcumin or As2O3 monotherapy by up-regulating p53 pathway and down-regulating the JAK2/STAT3 pathway.

17ß-neriifolin from unripe fruits of Cerbera manghas suppressed cell proliferation via the inhibition of HOXA9-dependent transcription and the induction of apoptosis in the human AML cell line THP-1.

Homeobox A9 (HOXA9) is a transcription factor that is overexpressed in acute myeloid leukemia (AML). It is associated with the pathogenesis and progression of AML, and is a factor responsible for a poor prognosis. Therefore, the development of HOXA9-targeting molecules may contribute to not only better understanding of the mechanism of HOXA9 regulation, but also the development of therapeutic applications. We constructed a reporter assay system using the promoter region of the KBTBD10 gene, to which HOXA9 directly binds and regulates transcription, in the human acute monocytic leukemia cell line THP-1. Using this luciferase gene assay, we screened 1120 plant extracts and a methanol extract of the unripe fruits of Cerbera manghas was found to suppress the reporter gene expression mediated by the KBTBD10 promoter. From the extract, five steroid-type compounds were identified as the active constituents: 7α-neriifolin (1), 17ß-neriifolin (2), 17α-digitoxigenin ß-D-glucosyl-(1 → 4)-α-L-thevetoside (3), 17ß-digitoxigenin ß-D-glucosyl-(1 → 4)-α-L-thevetoside (4), and acetylthevetin B (5). Among the five compounds, 17ß-neriifolin most potently inhibited HOXA9-dependent gene expression without affecting the HOXA9 mRNA levels, and suppressed cell proliferation by inducing apoptosis. The findings on the structure-activity relationships of the compounds from C. manghas may contribute to the development of small molecule inhibitors of HOXA9.

Cryptanshinone extract of Salvia miltiorrhiza stimulates pediatric acute myeloid leukemia stem cell apoptosis and the anti-inflammatory mechanism via accelerating microRNA-211-5p to supress Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway activation.

This study was designed to explore cryptanshinone (CPT) extract of Salvia miltiorrhiza stimulating pediatric acute myeloid leukemia (AML) stem cell (LSC) apoptosis and anti-inflammatory mechanism via accelerating microRNA (miR)-211-5p to restrain Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway activation. Obtaining blood samples from pediatric acute myeloid leukemia patients and healthy volunteers and detecting miR-211-5p and JAK2 were performed. Purchase of the human AML cell line KG1a was conducted, and sorting of KG1a cells was to gain LSC. Test of miR-211-5p and JAK2, the phosphorylation of JAK2/STAT3 was implemented. Pretreatment of LSCs was with CPT. Variation of miR-211-5p and JAK2 in LSCs was via plasmid transfection to explore their actions in cell advancement with apoptosis and inflammation. Identification of the targeting of miR-211-5p with JAK2 was implemented. In results: MiR-211-5p was declined in endometrial cancer, while JAK2 was elevated; CPT was available to boost LSC apoptosis and restrain the inflammation; elevated miR-211-5p or repressive JAK2 was available to strengthen the acceleration of CPT on LSCs apoptosis and the repression of inflammation; MiR-211-5p targeted JAK2; augmented JAK2 was available to turn around the action of elevated miR-211-5p. We conclude that CPT extract of Salvia miltiorrhiza stimulated pediatric LSC apoptosis and restrained the inflammation via accelerating microRNA (miR)-211-5p to suppress JAK2/STAT3 pathway activation.

HDAC1/3-dependent moderate liquid-liquid phase separation of YY1 promotes METTL3 expression and AML cell proliferation.

Methyltransferase-like protein 3 (METTL3) plays critical roles in acute myeloid leukemia (AML) progression, however, the mechanism of abnormal overexpression of METTL3 in AML remain elusive. In the current study, we uncovered that Yin Yang 1 (YY1) binds to the promoter region of METTL3 as a transcription factor and promotes its expression, which in turn enhances the proliferation of AML cells. Mechanistically, YY1 binds to HDAC1/3 and regulates METTL3 expression in a moderate liquid-liquid phase separation (LLPS) manner. After mutation of the HDAC-binding site of YY1 or HDAC inhibitor (HDACi) treatment, YY1 was separated from HDAC1/3, which resulted in an excessive LLPS state, thereby inhibiting the expression of METTL3 and the proliferation of AML cells. In conclusion, our study clarified the regulatory mechanism of the abnormal expression of METTL3 in AML, revealed the precise "Yin-Yang" regulatory mechanism of YY1 from the perspective of LLPS degree, and provided new ideas for the precise diagnosis and treatment of AML.