Characterization of Extramedullary Acute Myeloid Leukemia – Results of the AML96 Trial

Abstract Abstract 2154 Background: Myeloid Sarcoma (MS) is defined as an extramedullary mass composed of myeloid blasts occurring at an anatomical site other than the bone marrow. Furthermore, the term extramedullary manifestation (EM) is applied if it accompanies overt acute myeloid leukemia (AML) and represents non-effacing tissue infiltration. EM is reported to correspond often to the skin but can affect almost every site of the body. The prognosis of MS or EM has been discussed controversially in the past. EM at diagnosis of AML is generally thought to be a rare event. However, data defining the prevalence of EM at diagnosis of AML and its prognostic value are missing. The aim of this analysis was to provide data for estimating the prevalence of EM at diagnosis of AML and to determine its relevance by including clinical and laboratory data from patients being treated in the prospective AML96 trial of the Study Alliance Leukemia (SAL) study group. Patients and Methods: A total of 326 patients with AML (age 17 – 83 years) and EM were treated within the AML96 trial with a median follow up of 8.8 years (95% CI, 8.4 to 9.3 years). All patients received double induction chemotherapy. Consolidation therapy contained high-dose cytosine arabinoside and for patients ≤ 60 years of age the option of autologous or allogeneic hematopoietic stem cell transplantation (HSCT). Logistic regression analyses were used to identify prognostic variables for CR rates. The method of Kaplan-Meier was used to estimate OS and EFS. Confidence interval (CI) estimation for the survival curves was based on the cumulative hazard function using the Greenwood's formula for the SE estimation. Survival distributions were compared using the log rank test. Results: 17% of the AML patients entered into the AML96 trial were diagnosed with EM. In 313 of the 326 patients (96%) EM was evident at diagnosis. The majority of patients with EM were diagnosed with de novo AML (84%, n=273), whereas gingival infiltration (51%, n=166) displayed the main EM of AML with CNS involvement being less common (4%, n=14). The majority of patients had a cytogenetic intermediate risk profile (71%, n=221) with a total of 172 patients (56%) harboring a normal karyotype. Patients with EM had a statistically significant lower median CD34-positivity of bone marrow blasts, higher percentage of FAB subtypes M4 and M5, higher WBC counts and LDH at diagnosis and higher percentage of NPM1 mutations compared to those patients without EM (all p<.001). When comparing achievement of CR between patients with EM to patients without EM, no statistical difference between these two groups was observed. Analysis according to the NPM1/FLT3-ITD mutation status revealed highest 5-year-OS (37%, 95% CI: .24 - .508) and 5-year-EFS (36%, 95% CI: .224 - .448) in the NPM1-mut/FLT3-wt group and lowest 5-year-OS (12%, 95% CI: 0 - .261) and 5-year-EFS (4%, 95% CI: 0 - .124) in the NPM1-wt/FLT3-ITD group, p=.007 and p=.001, respectively. Of the 49 relapsed patients with EM who had a NPM1-mutation at diagnosis 48 deceased despite of intensified relapse therapies. Conclusions: This analysis represents the largest study so far investigating the impact of EM AML. Patients with EM AML have distinct differences from AML patients without EM regarding their clinical and molecular characteristics at diagnosis. However these differences do not translate into differences in response to induction chemotherapy. Compared to patients without EM, survival analysis revealed differences according to the NPM1/FLT3-ITD mutation status which is also described for patients without EM AML. However, the prognosis for patients with EM who harbor a mutated NPM1 the prognosis at relapse seems to be dismal. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Multidrug-Related Protein 1 (MRP1) Polymorphisms rs129081, rs212090, and rs212091 Predict Survival In Acute Myeloid Leukemia

Blood ◽

10.1182/blood.v122.21.2580.2580 ◽

2013 ◽

Vol 122 (21) ◽

pp. 2580-2580 ◽

Cited By ~ 1

Author(s):

Desiree Kunadt ◽

Christian Dransfeld ◽

Maria Schmiedgen ◽

Michael Kramer ◽

Christoph Röllig ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Induction Chemotherapy ◽

Significant Influence ◽

Myeloid Leukemia ◽

Conflicts Of Interest ◽

Npm1 Mutation ◽

Significant Difference ◽

Impact On Treatment ◽

Acute Myeloid

Abstract Background ABCB1 (=MDR1, multidrug resistance protein 1) single nucleotide polymorphisms (SNPs) were shown to have a significant impact on therapy outcome in patients with acute myeloid leukemia (AML). Furthermore, an independent significant impact on treatment response and patient survival of SNPs in the genes for ABCC4 (MRP4), ABCC5 (MRP5) and ABCC11 (MRP8) related SNPs has also been demonstrated. In contrast, therapeutic strategies trying to modulate the anthracycline efflux of these transporters have failed in most clinical trials so far. Recently, higher dosages of daunorubicin used during induction chemotherapy have been associated with a better outcome in certain subgroups of AML patients. Hence, in times of individual diagnostic genetic analyses available as point-of-care diagnostics, the goal of this study was to further investigate whether SNPs in ABC-transporter genes, which are responsible for anthracycline efflux, have an independent impact on treatment outcome. Patients and Methods DNA samples were obtained from bone marrow aspirates of 160 Caucasian patients with newly diagnosed AML as part of the prospective AML2003 trial (NCT00180102). The cohort solely consisted of patients with a normal karyotype, based on conventional G-banding, minimizing false results in case of gain or loss of chromosomal material. All patients received double induction chemotherapy with daunorubicin and cytarabine. After DNA extraction, quantitative real time PCR was performed, using a total of 49 SNP assays investigating SNPs of seven different ABC genes. The identification of the corresponding SNPs was performed in an in silico analysis using the NIH dbSNP database and HapMap while statistical univariate and multivariate analyses were performed using SPSS. Results We detected three ABCC1 (MRP1) SNPs: rs129081 (CACCCC[C/G]ACTCCA), rs212090 (TTACTG[A/T]TCCCAC), and rs212091 (ACCTTA[A/G]AGAACA) with a significant influence on disease-free survival (DFS) or overall survival (OS), respectively. Patients carrying the homozygous rs129081 GG-SNP had a significant longer 5-year OS and 5-year DFS compared to the homozygous wildtype CC and heterozygous CG patients (OS: 68% [GG] vs. 40% [CC] vs. 64%, [CG], p=.035; DFS: 64% vs. 35% vs. 50%, p=.01). SNP rs212090 revealed a statistically significant difference in DFS when comparing homozygous alleles TT and AA (wildtype), 40% vs. 68%, p=.021. SNP rs212091 showed a significant difference concerning OS, with homozygous SNP GG leading to worse OS (0% vs. wildtype AA 64% vs. heterozygous AG 59%, p=.006). Again, there was a significant difference in DFS between both homozygous alleles AA (wildtype) and GG (55% vs. 0%, p=.018). Furthermore, there were no significant differences of standard clinical and laboratory baseline characteristics, FLT3-ITD mutation, or NPM1-mutation status, or chemotherapeutic toxicities. In order to exclude false positive findings of SNPs conferred as a result of leukemic transformation, we obtained saliva germline DNA from patients in complete remission who were treated by chemoconsolidation and performed a confirmatory analysis with the investigated SNPs, including rs129081, rs212090, and rs212091. Here, all SNPs were shown to be expressed in germline DNA in remission and bone marrow samples at diagnosis alike. The multivariate models for rs129081, rs212090 (TT), rs212091(AG), and rs212091(AA) revealed significances of p=.024, p=.029, p=.042, and p=.017 respectively for DFS but not for OS (except for rs212091[AA]). After adjustment for a false discovery rate of 5% still a trend towards the association of the SNPs and DFS could be seen. Therefore, more research is necessary to strengthen this evidence. Conclusion In this study we found a significant influence of rs129081, rs212090, and rs212091 SNPs (ABCC1, MRP1) on survival in AML in univariate analyses. Interestingly, these polymorphisms were not associated with other AML specific characteristics at diagnosis and were shown to be expressed in germline DNA and AML DNA alike. Hence, we suggest a prognostic effect of these SNPs which might be responsible for differential anthracycline susceptibility. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Inhibition of HDAC8 Reactivates p53 and Abrogates Leukemia Stem Cell Activity in CBFβ-SMMHC Associated Acute Myeloid Leukemia

Blood ◽

10.1182/blood.v124.21.363.363 ◽

2014 ◽

Vol 124 (21) ◽

pp. 363-363

Author(s):

Jing Qi ◽

Qi Cai ◽

Sandeep Singh ◽

Ling Li ◽

Hongjun Liu ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Bone Marrow Cells ◽

Conflicts Of Interest ◽

Cell Activity ◽

Disease Free Survival ◽

Hematopoietic Stem ◽

The Impact ◽

Acute Myeloid

Abstract The inv(16)-created CBFβ-SMMHC fusion protein inhibits differentiation of hematopoietic stem and progenitor cells (HSPCs) and creates pre-leukemic populations predisposed to acute myeloid leukemia (AML) transformation. However, the molecular mechanism underlying the leukemogenic function of CBFβ-SMMHC has been elusive. Given the low TP53 mutation rate in AML, alternative mechanisms disrupting p53 function are expected. We showed thatCBFβ-SMMHC impairs p53 acetylation and p53 target gene activation through formation of an aberrant protein complex with p53 and HDAC8 (Blood, 120: A772; 122(21): 224). We now show that CBFβ-SMMHC binds to p53 and HDAC8 independently through distinct regions and that HDAC8 mediates the deacetylation of p53 associated with CBFβ-SMMHC. In addition, we generated mice carrying a floxed Hdac8 (Hdac8f) allele and crossed with Cbfb56M/+/Mx1-Cre (Kuo YH et al, Cancer Cell 2006). Deletion of Hdac8 signifiacntly (p<0.0001) reduced the incidence of AML and prolonged disease-free survival. Pharmacologic inhibition of HDAC8 activity with HDAC8-selective inhibitors (HDAC8i) reactivates p53 and selectively induces apoptosis of inv(16)+ AML CD34+ cells while sparing normal HSPCs. To test the effect of HDAC8i on LSC engraftment and leukemia-initiating capacity, we generated Cbfb56M/+/Mx1-Cre mice with a Cre-reporter line expressing tdTomato fluorescence protein following Cre-mediated recombination. AML cells (dTomato+/cKit+) treated with HDAC8i (22d) ex vivo showed reduced engraftment (p=0.025) and enhanced survival (p=0.025) in transplanted mice. To examine whether HDAC8i 22d treatment affects the engraftment capacity on surviving cells, we transplanted equal number (2 x 106) of AML cells treated with either 22d or vehicle in another cohort of mice (n=4). We show that HDAC8i 22d treatment reduced the engraftment of dTomato+/cKit+ AML cells and enhanced survival, suggesting that the engraftment capacity is altered in addition to reducing AML cell survival. We next performed preclinical studies to determine the efficacy of in vivo administration of HDAC8i 22d. AML transplanted mice were randomized into two groups, one group treated with vehicle and the other treated with HDAC8i 22d for 2 weeks. Flow cytometry analysis revealed significantly reduced frequency (p=0.0097) and number (p=0.0101) of dTomato+/cKit+ AML cells in the bone marrow and spleen of 22d treated mice compared to vehicle treated group. To further assess the impact on LSC activity, we transplanted bone marrow cells from these treated mice into secondary recipients and analyzed for AML engraftment. Significant reduction in the frequency (p<0.0001) and the number (p=0.0006) of dTomato+/cKit+ AML cells was observed in the bone marrow and spleen. Furthermore, HDAC8i 22d treated transplants showed no signs of leukemia while vehicle treated transplants are moribund with aggressive AML. These results indicate that HDAC8 inhibition by 22d treatment effectively eliminates engraftment and leukemia-initiating capacity of AML LSCs. In conclusion, our studies identify a novel post-translational p53-inactivating mechanism and demonstrate selective HDAC8 inhibition as a promising approach to target inv(16)+ AML LSCs. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Prognostic Significance of FLT3/ITD Mutation in AML1/ETO-Associated Acute Myeloid Leukemia.

Blood ◽

10.1182/blood.v110.11.3493.3493 ◽

2007 ◽

Vol 110 (11) ◽

pp. 3493-3493 ◽

Cited By ~ 1

Author(s):

Yeo-Kyeoung Kim ◽

Hee-Nam Kim ◽

Il-Kwon Lee ◽

Soo-Mee Bang ◽

Deog-Yeon Jo ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Induction Chemotherapy ◽

Relapse Rate ◽

Myeloid Leukemia ◽

Fusion Gene ◽

Npm1 Mutation ◽

Response To Chemotherapy ◽

Significant Difference ◽

Acute Myeloid

Abstract Background: AML1-ETO fusion gene in acute myeloid leukemia (AML) usually predicts a good response to chemotherapy with a high remission rate and a relatively long median survival. An internal tandem duplication of the FLT3 gene (FLT3/ITDs) is known to be associated with poor outcome after standard induction chemotherapy in AML patients with normal cytogenetics. However, this mutation is reported to be rarely found in cases with AML1/ETO positive and it remains a matter of debate as to whether these mutations play an independent role in the prognosis of AML patients with AML1/ETO fusion gene. Aims: To determine the prevalence and the prognostic role of FLT3/ITD in patients with AML1/ETO positive AML. Methods: FLT3/ITD and NPM1 mutation status was evaluated by performing DNA polymerase chain reaction assays on 39 bone marrow samples obtained at initial diagnosis from the patients with AML1/ETO fusion gene positive AML. GeneScan analysis was performed to confirm the FLT3/ITD mutation and to measure mutant levels. Results: Of total 39 patients, 11 patients (28.2%) demonstrated the aberrant FLT3/ITD mutations. The median age of patients was 40 years (range, 17–75 years). There were 24 males (61.5%) and 15 females (38.5%). There was no statistically significant difference in age, gender, leukocyte count, hemoglobin level, platelet count and percentage of peripheral or bone marrow blasts between the patients with or without FLT3/ITD. No NPM1 mutation was found in these AML Patients. To analyze the response to or outcome of therapy, we evaluated 34 patients who received intensive induction chemotherapy containing cytarabine. In univariate analysis, there was no significant difference in complete response rate (FLT3/ITD+: 100% vs. FLT3/ITD−: 95.6%, p = 0.48). However, the presence of FLT3/ITD was associated with higher relapse rate in these patients (FLT3/ITD+: 72.7% vs. FLT3/ITD−: 27.3%, p = 0.01).Significant shorter leukemic-free survival (LFS) was observed in patients with FLT3/ITD compared with those without FLT3/ITD (6.9±1.0 ms vs. 18.9±10.9 ms, p = 0.01), but there was no statistical significance in overall survival (OS) (10.6±0.6 ms vs. 16.5± NA ms, p = 0.56). Conclusions: This study demonstrates that the presence of FLT3/ITD mutations is a significantly higher relapse rate and shorter LFS in AML1/ETO positive patients. Therefore, a stratified treatment plan such as stem cell transplantation may be warranted for the AML1/ETO positive AML harvoring FLT3/ITD mutation.

Download Full-text

A “canonical” Npm1 mutation Knock-in Mouse Model Revealed Subtle but Definitive Myeloid Expansion with Poor HSC Niche Interaction

Blood ◽

10.1182/blood.v118.21.762.762 ◽

2011 ◽

Vol 118 (21) ◽

pp. 762-762

Author(s):

Wen-Chien Chou ◽

Shiu-Huey Chou ◽

Ji-Shain Chiou ◽

Bor-Sheng Ko ◽

Shu-Wha Lin ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Amino Acid ◽

Mouse Model ◽

Myeloid Leukemia ◽

Peptide Sequence ◽

Protein Accumulation ◽

Hematopoietic Stem ◽

Npm1 Mutation ◽

Acute Myeloid

Abstract Abstract 762 Nucleophosmin (NPM1) is a ubiquitous multifunctional phosphoprotein, which has nucleocytoplasmic shuttling activity. Somatic mutations in NPM1 gene result in cytoplasmic dislocation of NPM1 (NPM1c) and are frequently associated with acute myeloid leukemia (AML). The pathogenetic effects of mutated NPM1 protein have been explored by animal models including transgenic or “humanized” knock-in mouse models. Here, we demonstrate the first “canonical” mouse Npm1 mutant knock-in model. Different from the previously report of humanized NPM1 mutant knock-in model, we inserted TCTG after nucleotide c.857 of murine Npm1 coding sequence (c.854–857dupTCTG), a pattern identical to human NPM1 mutation, without any “humanized” sequence. This mutation caused a shift of peptide sequence from WQWRKSL* (amino acid 286–292) to LCLAVEEISLRKGFKQFEIFCLHFCNS* (amino acid 285 to 311), a pattern mildly different from the change in human NPM1 mutation, but is still predicted to generate a nuclear export signal. NPM1c+ genotype and protein accumulation in cytoplasm were confirmed with PCR and immunocytochemistry, respectively. We found that the homozygous NPM mutant (NPMc+/c+) mice were embryonic lethal before E10.5 day, while hetrozygote (NPMwt/c+) mice survived and were fertile, and born with Mendelian ratio. Most NPMwt/c+ mice had normal hematologic parameters and remained disease-free, however, these mice developed a delayed-onset aberration on the distribution of granulocyte-monocye progenitors (GMP), monocytes, and B lymphocytes in blood, spleen, and bone marrow. Colony forming unit assay showed normal hematopoietic development of marrow hematopoietic stem cells (HSC), but poor cobblestone formation while HSCs contacted with stroma microenvironment in NPMwt/c+ mice, suggesting the NPMc mutant may affect the ability of HSCs on contact signal expression. Three (12.5%) of 24 NPMwt/c+ mice developed leukocytosis and splenomegaly mimicking myeloproliferative neoplasm of human. Microscopic examination showed panmyelosis of the bone marrow and existence of hematopoiesis in the spleen. In addition, the immune activities of NPMwt/c+ mice's splenocytes and thymocytes with mitogen stimulation were decreased. In summary, our “canonical” NPMwt/c+ mouse model demonstrated subtle but definitive phenotypes in hematopoietic cells and provided insight into the pathogenesis of NPM1 mutation in human acute myeloid leukemia. A second hit may be necessary for the development of AML in NPMwt/c+ mice since no AML was detected in these mice till 20 months of age. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Deep learning detects acute myeloid leukemia and predicts NPM1 mutation status from bone marrow smears

Leukemia ◽

10.1038/s41375-021-01408-w ◽

2021 ◽

Author(s):

Jan-Niklas Eckardt ◽

Jan Moritz Middeke ◽

Sebastian Riechert ◽

Tim Schmittmann ◽

Anas Shekh Sulaiman ◽

...

Keyword(s):

Bone Marrow ◽

Acute Myeloid Leukemia ◽

Deep Learning ◽

Myeloid Leukemia ◽

Operating Characteristic ◽

Image Data ◽

Npm1 Mutation ◽

Mutation Status ◽

Inter Observer Variability ◽

Acute Myeloid

AbstractThe evaluation of bone marrow morphology by experienced hematopathologists is essential in the diagnosis of acute myeloid leukemia (AML); however, it suffers from a lack of standardization and inter-observer variability. Deep learning (DL) can process medical image data and provides data-driven class predictions. Here, we apply a multi-step DL approach to automatically segment cells from bone marrow images, distinguish between AML samples and healthy controls with an area under the receiver operating characteristic (AUROC) of 0.9699, and predict the mutation status of Nucleophosmin 1 (NPM1)—one of the most common mutations in AML—with an AUROC of 0.92 using only image data from bone marrow smears. Utilizing occlusion sensitivity maps, we observed so far unreported morphologic cell features such as a pattern of condensed chromatin and perinuclear lightening zones in myeloblasts of NPM1-mutated AML and prominent nucleoli in wild-type NPM1 AML enabling the DL model to provide accurate class predictions.

Download Full-text

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

Blood ◽

10.1182/blood.v98.4.1166 ◽

2001 ◽

Vol 98 (4) ◽

pp. 1166-1173 ◽

Cited By ~ 240

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.

Download Full-text

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

Cells ◽

10.3390/cells8050482 ◽

2019 ◽

Vol 8 (5) ◽

pp. 482 ◽

Cited By ~ 5

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.

Download Full-text

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

Haematologica ◽

10.3324/haematol.2019.223883 ◽

2019 ◽

Vol 105 (9) ◽

pp. 2273-2285 ◽

Cited By ~ 4

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.

Download Full-text

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

Current Developments in Nutrition ◽

10.1093/cdn/nzaa067_062 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 1835-1835

Author(s):

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).

Download Full-text

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

Blood Advances ◽

10.1182/bloodadvances.2020001808 ◽

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.

Download Full-text