scholarly journals Inflammation-driven activation of JAK/STAT signaling reversibly accelerates acute myeloid leukemia in vitro

2020 ◽  
Vol 4 (13) ◽  
pp. 3000-3010 ◽  
Author(s):  
Jan Habbel ◽  
Lucas Arnold ◽  
Yiyang Chen ◽  
Michael Möllmann ◽  
Kirsten Bruderek ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Inflammatory Responses ◽  
Janus Kinase ◽  
Antileukemic Activity ◽  
Hematopoietic Stem ◽  
Stat Signaling ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is characterized by a high relapse rate and dismal long-term overall survival which is related to persistence of leukemia-initiating cells in their niche. Different animal models of myeloid malignancies reveal how neoplastic cells alter the structural and functional characteristics of the hematopoietic stem cell niche to reinforce malignancy. Understanding and disruption of the microenvironmental interactions with AML cells are a vital need. Malignant niches frequently go along with inflammatory responses, but their impact on cancerogenesis often remains unexplored. Here, we uncovered an aberrant production of inflammatory cytokines in untreated AML bone marrow that was proved to promote the proliferation of leukemia cells. This inflammatory response induced an activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway in AML blasts as well as bone marrow stromal cells that also fostered leukemia proliferation. Inhibition of JAK/STAT signaling using the selective JAK1/2 inhibitor ruxolitinib resulted in significant antileukemic activity in AML in vitro which is mediated through both cell-autonomous and microenvironment-mediated mechanisms. However, in a xenograft transplantation model, monotherapy with ruxolitinib did not achieve substantial antileukemic activity, possibly suggesting a complementary function of JAK1/2 inhibition in AML.

scholarly journals The Ups and Downs of STAT Inhibition in Acute Myeloid Leukemia

Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1051
Author(s):  
Bernhard Moser ◽  
Sophie Edtmayer ◽  
Agnieszka Witalisz-Siepracka ◽  
Dagmar Stoiber
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Molecular Mechanisms ◽  
Janus Kinase ◽  
Hematopoietic Malignancy ◽  
Stat Signaling ◽  
Acute Myeloid ◽  
Stat Pathway

Aberrant Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling is implicated in the pathogenesis of acute myeloid leukemia (AML), a highly heterogeneous hematopoietic malignancy. The management of AML is complex and despite impressive efforts into better understanding its underlying molecular mechanisms, survival rates in the elderly have not shown a substantial improvement over the past decades. This is particularly due to the heterogeneity of AML and the need for personalized approaches. Due to the crucial role of the deregulated JAK-STAT signaling in AML, selective targeting of the JAK-STAT pathway, particularly constitutively activated STAT3 and STAT5 and their associated upstream JAKs, is of great interest. This strategy has shown promising results in vitro and in vivo with several compounds having reached clinical trials. Here, we summarize recent FDA approvals and current potential clinically relevant inhibitors for AML patients targeting JAK and STAT proteins. This review underlines the need for detailed cytogenetic analysis and additional assessment of JAK-STAT pathway activation. It highlights the ongoing development of new JAK-STAT inhibitors with better disease specificity, which opens up new avenues for improved disease management.

HOXB6 overexpression in murine bone marrow immortalizes a myelomonocytic precursor in vitro and causes hematopoietic stem cell expansion and acute myeloid leukemia in vivo

Blood ◽  
2005 ◽  
Vol 105 (4) ◽  
pp. 1456-1466 ◽  
Author(s):  
Neal A. Fischbach ◽  
Sofia Rozenfeld ◽  
Weifang Shen ◽  
Stephen Fong ◽  
Daniel Chrobak ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Hox Genes ◽  
Cooperative Interaction ◽  
Hematopoietic Stem ◽  
Murine Bone Marrow ◽  
Acute Myeloid

AbstractThe HOX family of homeobox genes plays an important role in normal and malignant hematopoiesis. Dysregulated HOX gene expression profoundly effects the proliferation and differentiation of hematopoietic stem cells (HSCs) and committed progenitors, and aberrant activation of HOX genes is a common event in human myeloid leukemia. HOXB6 is frequently overexpressed in human acute myeloid leukemia (AML). To gain further insight into the role of HOXB6 in hematopoiesis, we overexpressed HOXB6 in murine bone marrow using retrovirus-mediated gene transfer. We also explored structure-function relationships using mutant HOXB6 proteins unable to bind to DNA or a key HOX-binding partner, pre–B-cell leukemia transcription factor-1 (PBX1). Additionally, we investigated the potential cooperative interaction with myeloid ecotropic viral integration site 1 homolog (MEIS1). In vivo, HOXB6 expanded HSCs and myeloid precursors while inhibiting erythropoiesis and lymphopoiesis. Overexpression of HOXB6 resulted in AML with a median latency of 223 days. Coexpression of MEIS1 dramatically shortened the onset of AML. Cytogenetic analysis of a subset of HOXB6-induced AMLs revealed recurrent deletions of chromosome bands 2D-E4, a region frequently deleted in HOXA9-induced AMLs. In vitro, HOXB6 immortalized a factor-dependent myelomonocytic precursor capable of granulocytic and monocytic differentiation. These biologic effects of HOXB6 were largely dependent on DNA binding but independent of direct interaction with PBX1.

scholarly journals Drug Sensitivity Across Acute Myeloid Leukemia Subtypes Using an in Vitro Assay

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5208-5208
Author(s):  
Levanto Schachter ◽  
Irene M. Hutchins ◽  
Jill Waalen ◽  
Carol Burian ◽  
Darren Finlay ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Drug Sensitivity ◽  
In Vitro Assay ◽  
In Vitro Activity ◽  
Antileukemic Activity ◽  
Vitro Assay ◽  
Acute Myeloid

Abstract Introduction: Acute myeloid leukemia (AML) remains a challenging malignancy to treat, with high mortality despite recent advances in cancer care. The mainstay of therapy is intensive chemotherapy including anthracyclines and antimetabolites, with or without allogeneic bone marrow transplant. The standard of care has not changed significantly in decades, and treatment options are limited for patients who do not respond to induction, or who relapse. Although the genetic and molecular diversity of AML is well recognized, the effective integration of targeted therapies into treatment regimens has been difficult. The current study evaluates the in vitro activity of an array of antineoplastic agents in AML, with the goal of identifying drug sensitivity patterns that may help guide therapies based on mutational and cytogenetic profiling. Methods: 51 patients with AML were enrolled in the study from September 2013 to July 2016 under an IRB approved consenting process at Scripps Health. Samples were collected at both diagnosis and relapse if available. Both bone marrow and peripheral blood were accepted, with a requirement of significant circulating blasts if peripheral blood was used. Samples were tested for common biomarkers and cytogenetic abnormalities. 2,500 cells per well were transferred onto tissue culture treated plates. Drugs with potential antileukemic activity were added to each well in concentrations of 0.1, 1.0, and 10.0 μM. The cells were incubated with the drugs for 96 hours at 37oC. Cell viability was measured and reported as a percentage of plate-specific controls incubated with dimethylsulfoxide alone. Results: Drugs were grouped by therapeutic class. In vitro responses to anthracyclines and antimetabolites were noted across all mutational subtypes of AML. BCL-2 inhibitors and the histone deacetylase inhibitor romidepsin showed significant in vitro antileukemic activity across all subtypes. Proteasome inhibitors almost universally showed robust in vitro activity, even at the lowest drug concentration. The drug pevonedistat, a selective small-molecule inhibitor of NEDD8-activating enzyme, had significant differential activity depending on mutational status. FLT3-ITD mutations conferred sensitivity to the molecule, while mutations in NPM1 appeared to confer resistance. For the 10.0 μM concentration of pevonedistat, the average cell viability was 149.8% vs 37.3% (P=0.02) for the NPM1 mutated samples vs the FLT3-ITD mutated samples respectively. Conclusion: This in vitro assay demonstrates the ability to rapidly determine sensitivity of human AML cells to a wide variety of antileukemic drugs. Limitations include the fixed concentrations used across all medications which allowed comparisons between patients, but limits comparison of drug efficacy for an individual patient. The mechanism of some medications, such as hypomethylating agents and tretinoin, may require longer duration of exposure, thus confounding interpretation of the 96-hour viability results. Despite these limitations, we were able to find interesting patterns of responses across a wide spectrum of AML types. Anticipated applications of the assay include experimentation with novel drug combinations, directing in vivo clinical studies, and informing individualized treatment decisions in AML. Disclosures No relevant conflicts of interest to declare.

A leukemic stem cell with intrinsic drug efflux capacity in acute myeloid leukemia

Blood ◽  
2001 ◽  
Vol 98 (4) ◽  
pp. 1166-1173 ◽  
Author(s):  
Gerald G. Wulf ◽  
Rui-Yu Wang ◽  
Ingrid Kuehnle ◽  
Douglas Weidner ◽  
Frank Marini ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Myeloid Leukemia ◽  
Side Population ◽  
Fluorescence Emission ◽  
Drug Efflux ◽  
Hematopoietic Stem ◽  
Immunodeficient Mice ◽  
Acute Myeloid

The hematopoietic stem cell underlying acute myeloid leukemia (AML) is controversial. Flow cytometry and the DNA-binding dye Hoechst 33342 were previously used to identify a distinct subset of murine hematopoietic stem cells, termed the side population (SP), which rapidly expels Hoechst dye and can reconstitute the bone marrow of lethally irradiated mice. Here, the prevalence and pathogenic role of SP cells in human AML were investigated. Such cells were found in the bone marrow of more than 80% of 61 patients and had a predominant CD34low/− immunophenotype. Importantly, they carried cytogenetic markers of AML in all 11 cases of active disease examined and in 2 out of 5 cases in complete hematological remission. Comparison of daunorubicin and mitoxantrone fluorescence emission profiles revealed significantly higher drug efflux from leukemic SP cells than from non-SP cells. Three of 28 SP cell transplants generated overt AML-like disease in nonobese diabetic–severe combined immunodeficient mice. Low but persistent numbers of leukemic SP cells were detected by molecular and immunological assays in half of the remaining mice. Taken together, these findings indicate that SP cells are frequently involved in human AML and may be a target for leukemic transformation. They also suggest a mechanism by which SP cells could escape the effects of cytostatic drugs and might eventually contribute to leukemia relapse.

scholarly journals 7-Ketocholesterol Promotes Oxiapoptophagy in Bone Marrow Mesenchymal Stem Cell from Patients with Acute Myeloid Leukemia

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 482 ◽  
Author(s):  
Jessica Liliane Paz ◽  
Debora Levy ◽  
Beatriz Araujo Oliveira ◽  
Thatiana Correia de Melo ◽  
Fabio Alessandro de Freitas ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cholesterol Oxidation ◽  
Specific Cell ◽  
Hematopoietic Stem ◽  
Shh Pathway ◽  
Number Of Cells ◽  
Acute Myeloid

7-Ketocholesterol (7-KC) is a cholesterol oxidation product with several biological functions. 7-KC has the capacity to cause cell death depending on the concentration and specific cell type. Mesenchymal stem cells (MSCs) are multipotent cells with the ability to differentiate into various types of cells, such as osteoblasts and adipocytes, among others. MSCs contribute to the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases, such as leukemia, to a yet unknown extent. Here, we describe the effect of 7-KC on the death of bone marrow MSCs from patients with acute myeloid leukemia (LMSCs). LMSCs were less susceptible to the death-promoting effect of 7-KC than other cell types. 7-KC exposure triggered the extrinsic pathway of apoptosis with an increase in activated caspase-8 and caspase-3 activity. Mechanisms other than caspase-dependent pathways were involved. 7-KC increased ROS generation by LMSCs, which was related to decreased cell viability. 7-KC also led to disruption of the cytoskeleton of LMSCs, increased the number of cells in S phase, and decreased the number of cells in the G1/S transition. Autophagosome accumulation was also observed. 7-KC downregulated the SHh protein in LMSCs but did not change the expression of SMO. In conclusion, oxiapoptophagy (OXIdative stress + APOPTOsis + autophagy) seems to be activated by 7-KC in LMSCs. More studies are needed to better understand the role of 7-KC in the death of LMSCs and the possible effects on the SHh pathway.

scholarly journals SETDB1 mediated histone H3 lysine 9 methylation suppresses MLL-fusion target expression and leukemic transformation

Haematologica ◽  
2019 ◽  
Vol 105 (9) ◽  
pp. 2273-2285 ◽  
Author(s):  
James Ropa ◽  
Nirmalya Saha ◽  
Hsiangyu Hu ◽  
Luke F. Peterson ◽  
Moshe Talpaz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Target Genes ◽  
Critical Role ◽  
High Expression ◽  
Leukemia Cells ◽  
Biological Impact ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Epigenetic regulators play a critical role in normal and malignant hematopoiesis. Deregulation, including epigenetic deregulation, of the HOXA gene cluster drives transformation of about 50% of acute myeloid leukemia. We recently showed that the Histone 3 Lysine 9 methyltransferase SETDB1 negatively regulates the expression of the pro-leukemic genes Hoxa9 and its cofactor Meis1 through deposition of promoter H3K9 trimethylation in MLL-AF9 leukemia cells. Here, we investigated the biological impact of altered SETDB1 expression and changes in H3K9 methylation on acute myeloid leukemia. We demonstrate that SETDB1 expression is correlated to disease status and overall survival in acute myeloid leukemia patients. We recapitulated these findings in mice, where high expression of SETDB1 delayed MLL-AF9 mediated disease progression by promoting differentiation of leukemia cells. We also explored the biological impact of treating normal and malignant hematopoietic cells with an H3K9 methyltransferase inhibitor, UNC0638. While myeloid leukemia cells demonstrate cytotoxicity to UNC0638 treatment, normal bone marrow cells exhibit an expansion of cKit+ hematopoietic stem and progenitor cells. Consistent with these data, we show that bone marrow treated with UNC0638 is more amenable to transformation by MLL-AF9. Next generation sequencing of leukemia cells shows that high expression of SETDB1 induces repressive changes to the promoter epigenome and downregulation of genes linked with acute myeloid leukemia, including Dock1 and the MLL-AF9 target genes Hoxa9, Six1, and others. These data reveal novel targets of SETDB1 in leukemia that point to a role for SETDB1 in negatively regulating pro-leukemic target genes and suppressing acute myeloid leukemia.

scholarly journals Gpr44 Mediates the Selenium-Dependent Anti-Leukemic Effect in Acute Myeloid Leukemia

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1835-1835
Author(s):  
Fenghua Qian ◽  
Fenghua Qian ◽  
Diwakar Tukaramrao ◽  
Jiayan Zhou ◽  
Nicole Palmiero ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Murine Model ◽  
Myeloid Leukemia ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Pparγ Agonist ◽  
Acute Myeloid

Abstract Objectives The relapse of acute myeloid leukemia (AML) remains a significant concern due to persistent leukemia stem cells (LSCs) that are not targeted by existing therapies. LSCs show sensitivity to endogenous cyclopentenone prostaglandin J (CyPG) metabolites that are increased by dietary trace element selenium (Se), which is significantly decreased in AML patients. We investigated the anti-leukemic effect of Se supplementation in AML via mechanisms involving the activation of the membrane-bound G-protein coupled receptor 44 (Gpr44) and the intracellular receptor, peroxisome proliferator-activated receptor gamma (PPARγ), by endogenous CyPGs. Methods A murine model of AML generated by transplantation of hematopoietic stem cells (HSCs- WT or Gpr44−/−) expressing human MLL-AF9 fusion oncoprotein, in the following experiments: To investigate the effect of Se supplementation on the outcome of AML, donor mice were maintained on either Se-adequate (Se-A; 0.08–0.1 ppm Se) or Se-supplemented (Se-S; 0.4 ppm Se) diets. Complete cell counts in peripheral blood were analyzed by hemavet. LSCs in bone marrow and spleen were analyzed by flow cytometry. To determine the role of Gpr44 activation in AML, mice were treated with Gpr44 agonists, CyPGs. LSCs in bone marrow and spleen were analyzed. Mice transplanted with Gpr44−/- AML cells were compared with mice transplanted with wild type AML cells and the progression of the disease was followed as above. To determine the role of PPARγ activation in AML, PPARγ agonist (Rosiglitazone, 6 mg/kg, i.p, 14 d) and antagonist (GW9662, 1 mg/kg, i.p. once every other day, 7 injections) were applied to Se-S mice transplanted with Gpr44−/- AML cells and disease progression was followed. Results Se supplementation at supraphysiological levels alleviated the disease via the elimination of LSCs in a murine model of AML. CyPGs induced by Se supplementation mediate the apoptosis in LSCs via the activation of Gpr44 and PPARγ. Conclusions Endogenous CyPGs produced upon supplementation with Se at supraphysiological levels improved the outcome of AML by targeting LSCs to apoptosis via the activation of two receptors, Gpr44 and PPARg. Funding Sources NIH DK 07,7152; CA 175,576; CA 162,665. Office of Dietary Supplements, USDA Hatch funds PEN04605, Accession # 1,010,021 (KSP, RFP).

scholarly journals Acute myeloid leukemia–induced remodeling of the human bone marrow niche predicts clinical outcome

2020 ◽  
Vol 4 (20) ◽  
pp. 5257-5268
Author(s):  
Yiyang Chen ◽  
Lina Marie Hoffmeister ◽  
Yasmin Zaun ◽  
Lucas Arnold ◽  
Kurt Werner Schmid ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Survival Rate ◽  
Clinical Outcome ◽  
Myeloid Leukemia ◽  
Bone Marrow Niche ◽  
Dependent Manner ◽  
Hematopoietic Stem ◽  
Acute Myeloid ◽  
First Diagnosis

Abstract Murine models of myeloid neoplasia show how leukemia infiltration alters the hematopoietic stem cell (HSC) niche to reinforce malignancy at the expense of healthy hematopoiesis. However, little is known about the bone marrow architecture in humans and its impact on clinical outcome. Here, we dissect the bone marrow niche in patients with acute myeloid leukemia (AML) at first diagnosis. We combined immunohistochemical stainings with global gene expression analyses from these AML patients and correlated them with clinical features. Mesenchymal stem and progenitor cells (MSPCs) lost quiescence and significantly expanded in the bone marrow of AML patients. Strikingly, their HSC- and niche-regulating capacities were impaired with significant inhibition of osteogenesis and bone formation in a cell contact–dependent manner through inhibition of cytoplasmic β-catenin. Assessment of bone metabolism by quantifying peripheral blood osteocalcin levels revealed 30% lower expression in AML patients at first diagnosis than in non-leukemic donors. Furthermore, patients with osteocalcin levels ≤11 ng/mL showed inferior overall survival with a 1-year survival rate of 38.7% whereas patients with higher osteocalcin levels reached a survival rate of 66.8%. These novel insights into the human AML bone marrow microenvironment help translate findings from preclinical models and detect new targets which might pave the way for niche-targeted therapies in AML patients.

Selective Ablation of Acute Myeloid Leukemia Using Antibody-Targeted Chemotherapy: A Phase I Study of an Anti-CD33 Calicheamicin Immunoconjugate

Blood ◽  
1999 ◽  
Vol 93 (11) ◽  
pp. 3678-3684 ◽  
Author(s):  
E.L. Sievers ◽  
F.R. Appelbaum ◽  
R.T. Spielberger ◽  
S.J. Forman ◽  
D. Flowers ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
High Rate ◽  
Leukemic Cells ◽  
Antitumor Antibiotic ◽  
Dose Escalation Study ◽  
Hematopoietic Stem ◽  
Selective Ablation ◽  
Acute Myeloid

Abstract Leukemic blast cells express the CD33 antigen in most patients with acute myeloid leukemia (AML), but this antigen is not expressed by hematopoietic stem cells. We conducted a study to determine whether normal hematopoiesis could be restored in patients with AML by selective ablation of cells expressing the CD33 antigen. In a dose escalation study, 40 patients with relapsed or refractory CD33+ AML were treated with an immunoconjugate (CMA-676) consisting of humanized anti-CD33 antibody linked to the potent antitumor antibiotic calicheamicin. The capacity of leukemic cells to efflux 3,3’-diethyloxacarbocyanine iodide (DiOC2) was used to estimate pretreatment functional drug resistance. Leukemia was eliminated from the blood and marrow of 8 (20%) of the 40 patients; blood counts returned to normal in three (8%) patients. A high rate of clinical response was observed in leukemias characterized by low dye efflux in vitro. Infusions of CMA-676 were generally well tolerated, and a postinfusion syndrome of fever and chills was the most common toxic effect. Two patients who were treated at the highest dose level (9 mg/m2) were neutropenic >5 weeks after the last dose of CMA-676. These results show that an immunoconjugate targeted to CD33 can selectively ablate malignant hematopoiesis in some patients with AML.

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