m6A-dependent upregulation of DDX21 by super-enhancer-driven IGF2BP2 and IGF2BP3 facilitates progression of acute myeloid leukaemia.

BACKGROUND: Acute myeloid leukaemia (AML) is a haematological malignancy with unfavourable prognosis. Despite the effectiveness of chemotherapy and targeted therapy, relapse or drug resistance remains a major threat to AML patients. N6-methyladenosine (m6A) RNA methylation and super-enhancers (SEs) are extensively involved in the leukaemogenesis of AML. However, the potential relationship between m6A and SEs in AML has not been elaborated. METHODS: Chromatin immunoprecipitation (ChIP) sequencing data from Gene Expression Omnibus (GEO) cohort were analysed to search SE-related genes. The mechanisms of m6 A-binding proteins IGF2BP2 and IGF2BP3 on DDX21 were explored via methylated RNA immunoprecipitation (MeRIP) assays, RNA immunoprecipitation (RIP) assays and luciferase reporter assays. Then we elucidated the roles of DDX21 in AML through functional assays in vitro and in vivo. Finally, co-immunoprecipitation (Co-IP) assays, RNA sequencing and ChIP assays were performed to investigate the downstream mechanisms of DDX21. RESULTS: We identified two SE-associated transcripts IGF2BP2 and IGF2BP3 in AML. High enrichment of H3K27ac, H3K4me1 and BRD4 was observed in IGF2BP2 and IGF2BP3, whose expression were driven by SE machinery. Then IGF2BP2 and IGF2BP3 enhanced the stability of DDX21 mRNA in an m6A-dependent manner. DDX21 was highly expressed in AML patients, which indicated a poor survival. Functionally, knockdown of DDX21 inhibited cell proliferation, promoted cell apoptosis and led to cell cycle arrest. Mechanistically, DDX21 recruited transcription factor YBX1 to cooperatively trigger ULK1 expression. Moreover, silencing of ULK1 could reverse the promoting effects of DDX21 overexpression in AML cells. CONCLUSIONS: Dysregulation of SE-IGF2BP2/IGF2BP3-DDX21 axis facilitated the progression of AML. Our findings provide new insights into the link between SEs and m6A modification, elucidate the regulatory mechanisms of IGF2BP2 and IGF2BP3 on DDX21, and reveal the underlying roles of DDX21 in AML.

CFL1 is Implicated in Chronic Myeloid Leukemia Response during Imatinib Therapy.

Cofilin (CFL1) is one critical member of the actin deploy family (ADF). Overexpression of CFL1 is associated with aggressive features and poor prognosis in malignancies. We evaluated the expression of CFL1 in patients with chronic myeloid leukemia in the chronic phase (CML-CP), acute myelocytic leukemia (AML) and healthy controls. The role of CFL1 in imatinib therapy was also investigated using cell line. We found that the expression of CFL1 was lower in CML patients than that in healthy controls, and was significantly upregulated after imatinib therapy (p<0.05). CML patients with lower CFL1 achieved higher Major molecular response (MMR) rate after 6 months of imatinib therapy (p<0.05). Cofilin, P-cofilin and F-actin, especially branched F-actin were all upregulated after imatinib therapy. The lower CFL1 expression before treatment may predicts a better response to imatinib. Imatinib affects F-actin remodeling in CML patients by regulating CFL1 expression and activity.

Aging and comprehensive molecular profiling in acute myeloid leukemia.

Acute myeloid leukemia (AML) is an aging-related and heterogeneous hematopoietic malignancy. In this study, a total of 1,474 newly diagnosed AML patients with RNA sequencing data were enrolled, and targeted or whole exome sequencing data were obtained in 94% cases. The correlation of aging-related factors including age and clonal hematopoiesis (CH), gender, and genomic/transcriptomic profiles (gene fusions, genetic mutations, and gene expression networks or pathways) was systematically analyzed. Overall, AML patients aged 60 y and older showed an apparently dismal prognosis. Alongside age, the frequency of gene fusions defined in the World Health Organization classification decreased, while the positive rate of gene mutations, especially CH-related ones, increased. Additionally, the number of genetic mutations was higher in gene fusion-negative (GF-) patients than those with GF. Based on the status of CH- and myelodysplastic syndromes (MDS)-related mutations, three mutant subgroups were identified among the GF- AML cohort, namely, CH-AML, CH-MDS-AML, and other GF- AML. Notably, CH-MDS-AML demonstrated a predominance of elderly and male cases, cytopenia, and significantly adverse clinical outcomes. Besides, gene expression networks including HOXA/B, platelet factors, and inflammatory responses were most striking features associated with aging and poor prognosis in AML. Our work has thus unraveled the intricate regulatory circuitry of interactions among different age, gender, and molecular groups of AML.

Global, regional, and national burden and quality of care of multiple myeloma, 1990-2019.

Background: Multiple myeloma (MM) is the second most common haematologic malignancy, presenting a great disease burden on the general population; however, the quality of care of MM is overlooked. We therefore assessed gains and disparity in quality of care worldwide from 1990 to 2019 based on a novel summary indicator - the quality of care index (QCI) - and examined its potential for improvement. Methods: Using the Global Burden of Disease 2019 data set, we calculated the QCI of MM for 195 countries and territories. We used the principal component analysis to extract the first principal component of ratios with the combinations of mortality to incidence, prevalence to incidence, disability-adjusted life years to prevalence, and years of life lost to years lived with disability as QCI. We also conducted a series of descriptive and comparative analyses of QCI disparities with age, gender, period, geographies, and sociodemographic development, and compared the QCI among countries with similar socio-demographic index (SDI) through frontier analysis. Results: The age-standardised rates of MM were 1.92 (95% uncertainty interval (UI) = 1.68, 2.12) in incidence and 1.42 (95% UI = 1.24, 1.52) in deaths per 100 000 population in 2019, and were predicted to increase in the future. The global age-standardised QCI increased from 51.31 in 1990 to 64.28 in 2019. In 2019, New Zealand had the highest QCI at 99.29 and the Central African Republic had the lowest QCI at 10.74. The gender disparity of QCI was reduced over the years, with the largest being observed in the sub-Saharan region. Regarding age, QCI maintained a decreasing trend in patients aged >60 in SDI quintiles. Generally, QCI improved with the SDI increase. Results of frontier analysis suggested that there is a potential to improve the quality of care across all levels of development spectrum. Conclusions: Quality of care of MM improved during the past three decades, yet disparities in MM care remain across different countries, age groups, and genders. It is crucial to establish local objectives aimed at enhancing MM care and closing the gap in health care inequality.

The ferroptosis landscape in acute myeloid leukemia.

Ferroptosis induction through the suppression of glutathione peroxidase 4 (GPX4) and apoptosis-inducing factor mitochondria-associated 2 (AIFM2) has proven to be an effective approach in eliminating chemotherapy-resistant cells of various types. However, a comprehensive understanding of the roles of GPX4 and AIFM2 in acute myeloid leukemia (AML) has not yet been achieved. Using cBioPortal, DepMap, GEPIA, Metascape, and ONCOMINE, we compared the transcriptional expression, survival data, gene mutation, methylation, and network analyses of GPX4- and AIFM2-associated signaling pathways in AML. The results revealed that high expression levels of GPX4 and AIFM2 are associated with an adverse prognosis for AML patients. Overexpression of AIFM2 correlated with elevated mutation frequencies in NPM1 and DNMT3A. GPX4 upregulation modulated the following pathways: GO:0045333, cellular respiration; R-HSA-5389840, mitochondrial translation elongation; GO:0009060, aerobic respiration; R-HSA-9609507, protein localization; and R-HSA-8953854, metabolism of RNA. On the other hand, the overexpression of AIFM2 influenced the following processes: GO:0048704, embryonic skeletal system morphogenesis; GO:0021546, rhombomere development; GO:0009954, proximal/distal pattern formation; and GO:0048732, gland development. This study identifies the high expression of GPX4 and AIFM2 as novel biomarkers predicting a poor prognosis for AML patients. Furthermore, ferroptosis induction may improve the stratified treatment of AML.

Identification of a novel NPM1 mutation in acute myeloid leukemia.

Nucleophosmin (NPM1) is a widely expressed nucleocytoplasmic shuttling protein with prominent nucleolar localization. It is estimated that 25-35% of adult patients with acute myeloid leukemia (AML) carry NPM1 mutations. The classic NPM1 type A mutation occurs in exon 12, which accounts for 75-80% of adult patients with NPM1-mutated AML. It produces an additional leucine and valine-rich nuclear export signal (NES) at the C-terminus, and causes aberrant cytoplasmic dislocation of NPM1 protein. Notably, emerging evidence indicates that besides the classic type A mutation, rare mutants occurring in other exons may also lead to the imbalance of the nucleocytoplasmic shuttle of NPM1. Identification of novel non-type A mutants is crucial for the diagnosis, prognosis, risk stratification and disease monitoring of potential target populations. Here we reported a novel NPM1 mutation in exon 5 identified from a de novo AML patient. Similar to the classic type A mutation, the exon 5 mutation had the NPM1 mutant bound to exportin-1 and directed the mutant into the cytoplasm by generating an additional NES sequence, resulting in aberrant cytoplasmic dislocation of NPM1 protein, which could be reversed by exportin-1 inhibitor leptomycin B. Our findings strongly support that besides the exon 12 mutation, the exon 5 mutant is another NPM1 "born to be exported" mutant critical for leukemogenesis. Therefore, similar to the classic type A mutation, the identification of our novel NPM1 mutation is beneficial for clinical laboratory diagnosis, genetic risk assessment and MRD monitoring.

circSLC25A13 acts as a ceRNA to regulate AML progression via miR-616-3p/ADCY2 axis.

Circular RNAs (circRNAs), a type of endogenous noncoding RNA (ncRNA), exert vital roles in leukemia progression and are promising prognostic factors. Here, we report a novel circRNA, circSLC25A13 (hsa_circ_0081188), which was increased in acute myeloid leukemia (AML) patients with poor overall survival (OS) comparing to patients with good prognosis. Knockdown of circSLC25A13 in AML cells inhibited proliferation and increased cell apoptosis in vitro and in vivo. Enhanced circSLC25A13 expression promoted the survival of AML cells. Mechanistically, circSLC25A13 played as a microRNA sponge of miR-616-3p, which inhibited the expression of adenylate cyclase 2 (ADCY2). Downregulation of miR-616-3p and overexpression of ADCY2 partially rescued circSLC25A13 deficient induced cell growth arrest. In summary, through competitive absorption of miR-616-3p and thereby upregulating ADCY2 expression, circSLC25A13 promoted AML progression. Moreover, circSLC25A13 may represent a potential novel biomarker for the prognosis of AML and offer a potential therapeutic target for AML treatment.

Activation of Piezo1 promotes osteogenic differentiation of aortic valve interstitial cell through YAP-dependent glutaminolysis.

Hemodynamic overload and dysregulation of cellular metabolism are involved in development of calcific aortic valve disease (CAVD). However, how mechanical stress relates to metabolic changes in CAVD remains unclear. Here, we show that Piezo1, a mechanosensitive ion channel, regulated glutaminase 1 (GLS1)-mediated glutaminolysis to promote osteogenic differentiation of valve interstitial cells (VICs). In vivo, two models of aortic valve stenosis were constructed by ascending aortic constriction (AAC) and direct wire injury (DWI). Inhibition of Piezo1 and GLS1 in these models respectively mitigated aortic valve lesion. In vitro, Piezo1 activation induced by Yoda1 and oscillatory stress triggered osteogenic responses in VICs, which were prevented by Piezo1 inhibition or knockdown. Mechanistically, Piezo1 activation promoted calcium-dependent Yes-associated protein (YAP) activation. YAP modulated GLS1-mediated glutaminolysis, which enhanced osteogenic differentiation through histone acetylation of runt-related transcription factor 2 (RUNX2) promoters. Together, our work provided a cross-talk between mechanotransduction and metabolism in the context of CAVD.

Glutamate dehydrogenase 1: A novel metabolic target in inhibiting acute myeloid leukaemia progression.

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.

CPT1B, a metabolic molecule, is also an independent risk factor in CN-AML.

BACKGROUND: Fatty acid oxidation has been considered as an important energy source for tumorigenesis and development. Several studies have investigated the role of CPT1A, a kind of fatty acid oxidation rate-limiting enzyme, in AML. However, prognostic value and regulatory network of another subtype, CPT1B in AML remains elusive. This study aims to clarify the independent prognostic role of CPT1B in CN-AML based on clinical data and molecular level data (mRNA, miRNA and lncRNA). OBJECTIVE: The aim of this study is to investigate the prognostic value of CPT1B in AML patients. METHODS: First, we analyzed the CPT1B expression in AML cohort via the online database "GEPIA". Subsequently, miRNA-mRNA and ceRNA networks were constructed to help predict the role of CPT1B in AML. Several molecules which showed the prognostic value and metabolic function of CPT1B were identified. Finally, the expression of CPT1B in our own cohort of 324 CN-AML patients was analyzed to clarify the results. RESULTS: It was found that CPT1B was markedly higher in AML patients compared to normal people and this upregulation was associated with the poor clinical outcome. Several molecules revealed the possible regulatory mechanism of CPT1B in AML. CONCLUSION: CPT1B is a potential prognostic factor and a therapeutic target for AML treatment.

Spermatogenesis associated serine rich 2 like plays a prognostic factor and therapeutic target in acute myeloid leukemia by regulating the JAK2/STAT3/STAT5 axis.

BACKGROUND: Spermatogenesis associated serine rich 2 like (SPATS2L) was highly expressed in homoharringtonine (HHT) resistant acute myeloid leukemia (AML) cell lines. However, its role is little known in AML. The present study aimed to investigate the function of SPATS2L in AML pathogenesis and elucidate the underlying molecular mechanisms. METHODS: Overall survival (OS), event-free survival (EFS), relapse-free survival (RFS) were used to evaluate the prognostic impact of SPATS2L for AML from TCGA database and ourcohort. ShRNA was used to knockdown the expression of SPATS2L. Apoptosis was assessed by flow cytometry. The changes of proteins were assessed by Western blot(WB). A xenotransplantation mice model was used to evaluate in vivo growth and survival. RNA sequencing was performed to elucidate the molecular mechanisms underlying the role of SPATS2L in AML. RESULTS: SPATS2L expression increased with increasing resistance indexes(RI) in HHT-resistant cell lines we had constructed. Higher SPATS2L expression was observed in intermediate/high-risk patients than in favorable patients. Meanwhile, decreased SPATS2L expression was observed in AML patients achieving complete remission (CR). Multivariate analysis showed high SPATS2L expression was an independent poor predictor of OS, EFS, RFS in AML. SPATS2L knock down (KD) suppressed cell growth, induced apoptosis, and suppressed key proteins of JAK/STAT pathway, such as JAK2, STAT3, STAT5 in AML cells. Inhibiting SPATS2L expression markedly enhanced the pro-apoptotic effects of traditional chemotherapeutics (Ara-c, IDA, and HHT). CONCLUSIONS: High expression of SPATS2L is a poor prognostic factor in AML, and targeting SPATS2L may be a promising therapeutic strategy for AML patients.

FLOT1 knockdown inhibits growth of AML cells through triggering apoptosis and pyroptosis.

Acute myeloid leukemia (AML) is a group of hematological malignancies characterized by clonal proliferation of immature myeloid cells. Lipid rafts are highly organized membrane subdomains enriched in cholesterol, sphingolipids, and gangliosides and play roles in regulating apoptosis through subcellular redistribution. Flotillin1 (FLOT1) is a component and also a marker of lipid rafts and had been reported to be involved in the progression of cancers and played important roles in cell death. However, the role of FLOT1 in AML remains to be explored. In this study, we found that increased expression of FLOT1 was correlated with poor clinical outcome in AML patients. Knockdown of FLOT1 in AML cells not only promoted cell death in vitro but also inhibited malignant cells engraftment in vivo. Mechanically, FLOT1 knockdown triggered apoptosis and pyroptosis. FLOT1 overexpression promoted AML cell growth and apoptosis resistance. Our findings indicate that FLOT1 is a prognostic factor of AML and may be a potential target for AML treatment.

Dihydropyrimidinase-like 2 can serve as a novel therapeutic target and prognostic biomarker in acute myeloid leukemia.

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.

ACC010, a novel BRD4 inhibitor, synergized with homoharringtonine in acute myeloid leukemia with FLT3-ITD.

Bromodomain-containing protein 4 (BRD4) inhibitors have been clinically developed to treat acute myeloid leukemia (AML), but their application is limited by the possibility of drug resistance, which is reportedly associated with the activation of the WNT/ß-catenin pathway. Meanwhile, homoharringtonine (HHT), a classic antileukemia drug, possibly inhibits the WNT/ß-catenin pathway. In this study, we attempted to combine a novel BRD4 inhibitor (ACC010) and HHT to explore their synergistic lethal effects in treating AML. Here, we found that co-treatment with ACC010 and HHT synergistically inhibited cell proliferation, induced apoptosis, and arrested the cell cycle in FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD)-positive AML cells in vitro, and significantly inhibiting AML progression in vivo. Mechanistically, ACC010 and HHT cooperatively downregulated MYC and inhibited FLT3 activation. Further, when HHT was added, ACC010-resistant cells demonstrated a good synergy. We also extended our study to the mouse BaF3 cell line with FLT3-inhibitor-resistant FLT3-ITD/tyrosine kinase domain mutations and AML cells without FLT3-ITD. Collectively, our results suggested that the combination treatment of ACC010 and HHT might be a promising strategy for AML patients, especially those carrying FLT3-ITD.

Transcriptome-based molecular subtypes and differentiation hierarchies improve the classification framework of acute myeloid leukemia.

The current classification of acute myeloid leukemia (AML) relies largely on genomic alterations. Robust identification of clinically and biologically relevant molecular subtypes from nongenomic high-throughput sequencing data remains challenging. We established the largest multicenter AML cohort (n = 655) in China, with all patients subjected to RNA sequencing (RNA-Seq) and 619 (94.5%) to targeted or whole-exome sequencing (TES/WES). Based on an enhanced consensus clustering, eight stable gene expression subgroups (G1-G8) with unique clinical and biological significance were identified, including two unreported (G5 and G8) and three redefined ones (G4, G6, and G7). Apart from four well-known low-risk subgroups including PML::RARA (G1), CBFB::MYH11 (G2), RUNX1::RUNX1T1 (G3), biallelic CEBPA mutations or -like (G4), four meta-subgroups with poor outcomes were recognized. The G5 (myelodysplasia-related/-like) subgroup enriched clinical, cytogenetic and genetic features mimicking secondary AML, and hotspot mutations of IKZF1 (p.N159S) (n = 7). In contrast, most NPM1 mutations and KMT2A and NUP98 fusions clustered into G6-G8, showing high expression of HOXA/B genes and diverse differentiation stages, from hematopoietic stem/progenitor cell down to monocyte, namely HOX-primitive (G7), HOX-mixed (G8), and HOX-committed (G6). Through constructing prediction models, the eight gene expression subgroups could be reproduced in the Cancer Genome Atlas (TCGA) and Beat AML cohorts. Each subgroup was associated with distinct prognosis and drug sensitivities, supporting the clinical applicability of this transcriptome-based classification of AML. These molecular subgroups illuminate the complex molecular network of AML, which may promote systematic studies of disease pathogenesis and foster the screening of targeted agents based on omics.

Characterization of the Newly Established Homoharringtonine- (HHT-) Resistant Cell Lines and Mechanisms of Resistance.

Homoharringtonine- (HHT-) based HHT, aclarubicin, and cytarabine (HAA) induction regimen is the first-line therapy for nonelder acute myeloid leukemia (AML) patients in China. However, drug resistance is a new challenge, and little attention has been devoted to excavating resistant mechanisms. This study used the classic method to construct six HHT-resistant cell lines with a gradually increasing resistance index (RI) to discover HHT drug resistance mechanisms dynamically. After HHT resistance, the cell growth rate decreased, cell cycle delayed, and P-glycoprotein (p-gp, CD243) expression levels increased. Furthermore, we explored the changes in transcriptomics between HHT-sensitive and HHT-resistant cells using RNA-sequence. Through Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and hub gene analyses, we found that immune activity, especially G-protein coupled receptor (GPR) and related molecules, may mediate HHT resistance. Moreover, Calcitonin Receptor-Like (CALCRL) and G Protein Subunit Alpha I1 (GNAI1), which belong to GPRs, were stimulated in HHT-resistant cell strains in vitro and vivo, indicating that they may play a critical role in HHT resistance. In addition, these two genes have prognostic significance for AML patients. Taken together, we successfully constructed HHT-resistant cell lines with dynamic RIs and explored the resistance mechanisms, which will help identify new drugs for HHT-resistant AML patients.

Homoharringtonine is synergistically lethal with BCL-2 inhibitor APG-2575 in acute myeloid leukemia.

BACKGROUND: Despite advances in targeted agent development, effective treatment of acute myeloid leukemia (AML) remains a major clinical challenge. The B-cell lymphoma-2 (BCL-2) inhibitor exhibited promising clinical activity in AML, acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL) treatment. APG-2575 is a novel BCL-2 selective inhibitor, which has demonstrated anti-tumor activity in hematologic malignancies. Homoharringtonine (HHT), an alkaloid, exhibited anti-AML activity. METHODS: The synergistic effects of APG-2575 and HHT were studied in AML cell lines and primary samples. MTS was used to measure the cell viability. Annexin V/propidium iodide staining was used to measure the apoptosis rate by flow cytometry. AML cell xenografted mouse models were established to evaluate the anti-leukemic effect of BCL-2 inhibitor, HHT and their combination in vivo. Western blot was used to determine the expression of related proteins. RESULTS: APG-2575 showed comparable anti-leukemic effect to the FDA-approved BCL-2 inhibitor ABT-199 in vitro and in vivo. Combined treatment of HHT with APG-2575 synergistically inhibited AML cell growth and engraftment. Mechanistically, HHT promoted degradation of myeloid cell leukemia-1 (MCL-1), which was reported to induce BCL-2 inhibitor resistant, through the PI3K/AKT/GSK3ß signaling pathway. CONCLUSION: Our results provide an effective AML treatment strategy through combination of APG-2575 and HHT, which is worthy of further clinical research.

The global burden and attributable risk factors of chronic lymphocytic leukemia in 204 countries and territories from 1990 to 2019: analysis based on the global burden of disease study 2019.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is the most prevalent subtype of leukemia in Western countries, causing a substantial health burden on patients and society. Comprehensive evaluation of the epidemiological characteristics of CLL is warranted, especially in the current context of global population aging. The main objective of this study is evaluating the disease burden of CLL at global, regional, and national levels from 1990 to 2019. As secondary objectives, we studied the influence of demographic factors and performed risk factor analysis. We hope this study could provide evidence for the evaluation of the effectiveness of previous prevention strategies and the formulation of future global health policies. RESULTS: Based on data of CLL between 1990 to 2019 from the Global Burden of Disease (GBD) study 2019, we depicted the age, gender, and regional structure of the CLL burden population and described the impact of social development on the disease burden of CLL. The distribution and changing trends of attributable risk factors were also investigated. The global burden of CLL has increased dramatically. A high incidence has been achieved in males and elder people. Countries and territories with high social-demographic index (SDI) tended to have higher global burden than low-SDI region. Of risk factors, high body mass index and smoking were the major contributors for CLL-related mortality and disability adjusted life-years (DALYs). CONCLUSION: In summary, the global CLL burden continues to rise over the past 30 years. The relocation of medical resource should be considered on a global scale.

Abivertinib inhibits megakaryocyte differentiation and platelet biogenesis.

Abivertinib, a third-generation tyrosine kinase inhibitor, is originally designed to target epidermal growth factor receptor (EGFR)-activating mutations. Previous studies have shown that abivertinib has promising antitumor activity and a well-tolerated safety profile in patients with non-small-cell lung cancer. However, abivertinib also exhibited high inhibitory activity against Bruton's tyrosine kinase and Janus kinase 3. Given that these kinases play some roles in the progression of megakaryopoiesis, we speculate that abivertinib can affect megakaryocyte (MK) differentiation and platelet biogenesis. We treated cord blood CD34+ hematopoietic stem cells, Meg-01 cells, and C57BL/6 mice with abivertinib and observed megakaryopoiesis to determine the biological effect of abivertinib on MK differentiation and platelet biogenesis. Our in vitro results showed that abivertinib impaired the CFU-MK formation, proliferation of CD34+ HSC-derived MK progenitor cells, and differentiation and functions of MKs and inhibited Meg-01-derived MK differentiation. These results suggested that megakaryopoiesis was inhibited by abivertinib. We also demonstrated in vivo that abivertinib decreased the number of MKs in bone marrow and platelet counts in mice, which suggested that thrombopoiesis was also inhibited. Thus, these preclinical data collectively suggested that abivertinib could inhibit MK differentiation and platelet biogenesis and might be an agent for thrombocythemia.

MAP4K1 functions as a tumor promotor and drug mediator for AML via modulation of DNA damage/repair system and MAPK pathway.

BACKGROUND: Acute myeloid leukemia (AML) is a group of heterogeneous hematologic malignancies correlates with poor prognosis. It is important to identify biomarkers for effective treatment of AML. Kinases participate in many regulatory pathways and biological activities in AML. Previous studies demonstrated that MAP4K1, a serine/threonine kinase, was associated with immune regulation and cancer progression. However, its role and mechanism in acute myeloid leukemia (AML) have not been explored. METHODS: RNA-seq profiling was performed for Homoharringtonine (HHT)-resistant and Homoharringtonine (HHT)-sensitive cell lines. Bioinformatic tools were used for differential analysis. Cell culture and transfection, Cell proliferation, apoptosis and Cell cycle assay, Quantitative RT-PCR, and Western blotting analysis were used to explore biological phenotypes in vitro. FINDINGS: We found that MAP4K1 was highly expressed in HHT-induced resistant AML cell lines. In addition, overexpression of MAP4K1 in AML cells induced resistance of AML cells against HHT. Not only that, the findings of this study showed that overexpression of MAP4K1 was an independent risk factor that predicts poor prognosis of AML. Further, In vitro studies showed that MAP4K1 modulated cell cycle through MAPK and DNA damage/repair pathways. Therefore, MAP4K1 is a potential target for developing therapies for AML. INTERPRETATION: This study demonstrates that MAP4K1 not only regulates HHT resistance but also independently predicts AML prognosis. In addition, understanding the regulatory mechanism of MAP4K1 reveals novel treatment strategies for resistant and refractory AML. Fundings: This work was supported by the National Natural Science Foundation of China (NSFC) (Grant No.81800199, 81670124, 82070118) and the Natural Science Foundation of Zhejiang Province (LY20H080008).