ABSTRACT
Acute myeloid leukemia is driven by leukemic stem cells which can be identified by cross lineage expression or arrest of differentiation compared to normal hematopoietic stem cells. Self-renewal and lack of differentiation are also features of stem cells and have been associated with the expression of embryonic genes. The aim of our study was to evaluate the expression of embryonic antigens (OCT4, NANOG, SOX2, SSEA1, SSEA3) in hematopoietic stem cell subsets (CD34+CD38- and CD34+CD38+) from normal bone marrows and in samples from acute myeloid leukemia patients. We observed an upregulation of the transcription factors OCT4 and SOX2 in leukemic cells as compared to normal cells. Conversely, SSEA1 protein was downregulated in leukemic cells. The expression of OCT4, SOX2, and SSEA3 was higher in CD34+CD38- than in CD34+CD38+ subsets in leukemic cells. There was no correlation with biological characteristics of the leukemia. We evaluated the prognostic value of marker expression in 69 patients who received an intensive treatment. The rate of complete remission was not influenced by the level of expression of markers. Overall survival was significantly better for patients with high SOX2 levels, which was unexpected because of the inverse correlation with favorable genetic subtypes. These results prompt us to evaluate the potential role of these markers in leukemogenesis and to test their relevance for better leukemic stem cell identification.
Subject(s)
Biomarkers, Tumor/biosynthesis , Fucosyltransferases/biosynthesis , Leukemia, Myeloid, Acute/drug therapy , Lewis X Antigen/biosynthesis , Octamer Transcription Factor-3/biosynthesis , SOXB1 Transcription Factors/biosynthesis , ADP-ribosyl Cyclase 1/genetics , Adult , Aged , Antigens, CD34/genetics , Bone Marrow Cells/metabolism , Cell Differentiation/genetics , Embryonic Stem Cells/metabolism , Embryonic Stem Cells/pathology , Female , Flow Cytometry , Gene Expression Regulation, Neoplastic/drug effects , Hematopoietic Stem Cells/drug effects , Hematopoietic Stem Cells/pathology , Humans , Immunophenotyping , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Male , Middle Aged , PrognosisABSTRACT
Patients with Core-Binding Factor (CBF) and NPM1-mutated acute myeloid leukemia (AML) can be monitored by quantitative PCR after having achieved first complete remission (CR) to detect morphologic relapse and drive preemptive therapy. How to best manage these patients is unknown. We retrospectively analyzed 303 patients with CBF and NPM1-mutated AML, aged 18-60 years, without allogeneic hematopoietic cell transplantation (HCT) in first CR, with molecular monitoring after first-line intensive therapy. Among these patients, 153 (51%) never relapsed, 95 (31%) had molecular relapse (53 received preemptive therapy and 42 progressed to morphologic relapse at salvage therapy), and 55 (18%) had upfront morphologic relapse. Patients who received preemptive therapy had higher OS than those who received salvage therapy after having progressed from molecular to morphologic relapse and those with upfront morphologic relapse (three-year OS: 78% vs. 51% vs. 51%, respectively, P = 0.01). Preemptive therapy included upfront allogeneic HCT (n = 19), intensive chemotherapy (n = 21), and non-intensive therapy (n = 13; three-year OS: 92% vs. 79% vs. 58%, respectively, P = 0.09). Although not definitive due to the non-randomized allocation of patients to different treatment strategies at relapse, our study suggests that molecular monitoring should be considered during follow-up to start preemptive therapy before overt morphologic relapse.
ABSTRACT
Direct cell-cell contact between haematopoietic progenitor cells (HPCs) and their cellular microenvironment is essential to maintain 'stemness'. In cancer biology, focal adhesion (FA) proteins are involved in survival signal transduction in a wide variety of human tumours. To define the role of FA proteins in the haematopoietic microenvironment of myelodysplastic syndromes (MDS), CD73-positive mesenchymal stromal cells (MSCs) were immunostained for paxillin, pFAK [Y(397)], and HSP90α/ß and p130CAS, and analysed for reactivity, intensity and cellular localisation. Immunofluorescence microscopy allowed us to identify qualitative and quantitative differences, and subcellular localisation analysis revealed that in pathological MSCs, paxillin, pFAK [Y(397)], and HSP90α/ß formed nuclear molecular complexes. Increased expression of paxillin, pFAK [Y(397)], and HSP90α/ß and enhanced nuclear co-localisation of these proteins correlated with a consistent proliferative advantage in MSCs from patients with refractory anaemia with excess blasts (RAEB) and negatively impacted clonogenicity of HPCs. These results suggest that signalling via FA proteins could be implicated in HPC-MSC interactions. Further, because FAK is an HSP90α/ß client protein, these results suggest the utility of HSP90α/ß inhibition as a target for adjuvant therapy for myelodysplasia.
Subject(s)
Focal Adhesions/metabolism , Mesoderm/pathology , Myelodysplastic Syndromes/metabolism , Paxillin/metabolism , Stromal Cells/pathology , Adult , Aged , Aged, 80 and over , Crk-Associated Substrate Protein/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Focal Adhesions/pathology , HSP90 Heat-Shock Proteins/metabolism , Humans , Mesoderm/metabolism , Middle Aged , Myelodysplastic Syndromes/pathology , Stromal Cells/metabolismABSTRACT
Acute myeloid leukemias (AMLs) are hematologic malignancies with varied molecular and immunophenotypic profiles, making them difficult to diagnose and classify. High-dimensional analysis algorithms might increase the utility of multicolor flow cytometry for AML diagnosis and follow-up. The objective of the present study was to assess whether a Compass database-guided analysis can be used to achieve rapid and accurate diagnoses. We conducted this study to determine whether this method could be employed to pilote the genetic and molecular tests and to objectively identify different-from-normal (DfN) patterns to improve measurable residual disease follow-up in AML. Three Compass databases were built using Infinicyt 2.0 software, including normal myeloid-committed hematopoietic precursors (n = 20) and AML blasts harboring the most frequent recurrent genetic abnormalities (n = 50). The diagnostic accuracy of the Compass database-guided analysis was evaluated in a prospective validation study (125 suspected AML patients). This method excluded AML associated with the following genetic abnormalities: t(8;21), t(15;17), inv(16), and KMT2A translocation, with 92% sensitivity [95% confidence interval (CI): 78.6%-98.3%] and a 98.5% negative predictive value (95% CI: 90.6%-99.8%). Our data showed that the Compass database-guided analysis could identify phenotypic differences between AML groups, representing a useful tool for the identification of DfN patterns.
ABSTRACT
Molecular tests have become an indispensable tool for the diagnosis and prognosis of hematological malignancies and are subject to accreditation according to the International Standard ISO 15189. National standardization of these techniques is essential to ensure that patients throughout France benefit from the same care. We report here on the experience of the GBMHM (Groupe des Biologistes Moléculaires des Hémopathies Malignes). By organizing External Evaluation of Quality (EEQ) programs and training meetings, the GBMHM has contributed to improvement and standardization of molecular tests in 64 French laboratories. A retrospective analysis of the quality-control results of 11 national campaigns spanning 10 years was performed for the 3 most frequently prescribed tests: BCR-ABL1, JAK2 V617F, and lymphoid clonality. For each test, particular attention was placed on comparing methodologies and their evolution throughout the period. The establishment of the BCR-ABL1, JAK2 V617F, and lymphoid clonality EEQ programs and the associated training meetings have initiated a process of collective standardization concerning the methods of implementation (JAK2 V617F) and the interpretation and formulation of results (lymphoid clonality). In addition, it resulted in objective improvement in technical performance (BCR-ABL1). Our evaluation of the impact of these EEQ programs demonstrates that it is possible to obtain reproducible values across different laboratories in France by applying national recommendations. To our knowledge, this is the first publication that evaluates the impact of a national quality assurance program on improving molecular results in hematology.
ABSTRACT
Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the presence of BCR-ABL1 transcript as a result of reciprocal translocation between chromosome 9 and 22. The most common transcripts subtypes are e13a2 (b2a2) and e14a2 (b3a2). The prognostic impact of the type of BCR-ABL1 transcript has been the subject of controversies over time. In the imatinib era, several studies have suggested a deeper and faster response in patients expressing e14a2. However, the impact on response after first line therapy with a second-generation tyrosine kinase inhibitor, nilotinib, is unknown. We retrospectively evaluated 118 patients newly diagnosed with chronic phase CML and treated frontline with nilotinib inside or outside clinical trial in five French centers. Only patients expressing e14a2 or e13a2 transcripts alone were analyzed. At baseline, 55.3% expressed e14a2, 44.7% expressed e13a2. The median age was 51 years and median follow-up was 49 months. Relative risks of CML at diagnosis were similar according to the ELTS score (p = .87). Complete hematological response and complete cytogenetic response rates were similar among groups. Patients expressing e14a2 transcripts compared to e13a2 transcripts had deeper and faster molecular responses, when considering MMR (100% vs 84.1%, p = .007) with a median time of 6.7 and 17.1 months or MR4.5 (100% vs 59.9%, p = .005) with a median time of 39.7 and 70.9 months, respectively. A sustained treatment free remission was observed in 10/10 patients with e14a2 versus 1/3 with e13a2 transcript (p = .04). In conclusion, even treated with nilotinib first line, patients with chronic phase CML expressing BCR-ABL1 e13a2 transcript have a lower rate of deep molecular responses.
ABSTRACT
Chronic myelomonocytic leukemia (CMML) is a myelodysplastic/myeloproliferative neoplasm, characterized by persistent monocytosis and dysplasia in at least one myeloid cell lineage. This persistent monocytosis should be distinguished from the reactive monocytosis which is sometimes observed in a context of infections or solid tumors. In 2015, Selimoglu-Buet et al. observed an increased percentage of classical monocytes (CD14+/CD16- >94%) in the peripheral blood (PB) of CMML patients. In this study, using multiparametric flow cytometry (MFC), we assessed the monocytic distribution in PB samples and in bone marrow aspirates from 63 patients with monocytosis or CMML suspicion, and in seven follow-up blood samples from CMML patients treated with hypomethylating agents (HMA). A control group of 12 healthy age-matched donors was evaluated in parallel in order to validate the analysis template. The CMML diagnosis was established in 15 cases in correlation with other clinical manifestations and biological tests. The MFC test for the evaluation of the repartition of monocyte subsets, as previously described by Selimoglu-Buet et al. showed a specificity of 97% in blood and 100% in marrow samples. Additional information regarding the expression of intermediate MO2 monocytes percentage improved the specificity to 100% in blood samples allowing the screening of abnormal monocytosis. The indicative thresholds of CMML monocytosis were different in PB compared to BM samples (classical monocytes >95% for PB and >93% for BM). A decrease of monocyte levels in PB and BM, along with a normalization of monocytes distribution, was observed after treatment in 4/7 CMML patients with favorable evolution. No significant changes were observed in 3/7 patients who did not respond to HMA therapy and also presented unfavorable molecular prognostic factors at diagnosis (ASXL1, TET2, and IDH2 mutations). Considering its simplicity and robustness, the monocyte subsets evaluation by MFC provides relevant information for CMML diagnosis.
ABSTRACT
Embryonic stem cells typically show properties of long-term self-renewal and lack of differentiation. When appropriately stimulated, they are able to differentiate into all cell lineages, and lose their self-renewal characteristics. These properties are controlled by a series of genes encoding several transcription factors, including OCT4, the product of POU5F1 gene. OCT4 is expressed in germ cell tumors but also aberrantly in cancers developing in differentiated tissues. In a previous study, we observed a high expression of OCT4 in acute myeloid cell lines and primary cells, regardless of the acute myeloid leukemia (AML) subtype. In this study, we investigated the putative oncogenic role of OCT4 in proliferation and differentiation arrest. OCT4 expression was assessed in a panel of myeloid cell lines, together with clonogenic and proliferation properties, before and after differentiation in the presence of retinoic acid (RA). Same experiments were performed under short hairpin RNA (shRNA)-mediated OCT4 inhibition. In the presence of RA, we observed a decrease of OCT4 expression, associated with a loss of clonogenic and proliferation capacities, cell cycle arrest, and upregulation of p21, in HL60, NB4, KASUMI, and Me-1 cell lines. This effect was absent in the KG1a cell line, which did not differentiate. Downregulation of OCT4 by shRNA resulted in the same pattern of differentiation and loss of proliferation. Although KG1a did not differentiate, a decrease in proliferation was observed. Our findings suggest that OCT4 is implicated in the differentiation arrest at least in some types of AML, and that it also plays a role in cell proliferation through different oncogenic mechanisms. OCT4 might be a potential new target for antileukemic treatments.
Subject(s)
Leukemia, Myeloid, Acute/pathology , Octamer Transcription Factor-3/metabolism , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , Cell Differentiation/drug effects , Cell Line, Tumor , Cell Lineage/drug effects , Cell Proliferation/drug effects , Cell Transformation, Neoplastic , Down-Regulation/drug effects , Genes, Homeobox/drug effects , Humans , Tretinoin/pharmacologyABSTRACT
Purpose: Azacitidine inhibits DNA methyltransferases, including DNMT1, and is currently the standard of care for patients with higher-risk myelodysplastic syndrome (HRMDS) or low blast count acute myeloid leukemia (AML).Experimental Design: The expression of 754 miRNAs was compared in azacitidine-resistant and azacitidine-sensitive myelodysplastic syndrome cells. We investigated the role of differentially expressed miRNAs on DNMT1 expression and azacitidine resistance in vitro We next evaluated anti-DNMT1 miRNA expression in pretreatment bone marrow samples derived from 75 patients treated with azacitidine for HRMDS or AML.Results: Seven miRNAs, including 5 that in silico targeted the DNMT1 3' UTR, were repressed in azacitidine-resistant cells in which DNMT1 protein levels were significantly higher. Ectopic anti-DNMT1 miRNA expression decreased DNMT1 expression and increased azacitidine sensitivity, whereas specific inhibition of endogenous anti-DNMT1 miRNAs increased DNMT1 expression and triggered azacitidine resistance. In patients treated with azacitidine, decreased expression of anti-DNMT1 miRNAs was associated with poor outcome. miR-126* had the strongest prognostic impact. Patients with miR-126*low myelodysplastic syndrome had significantly lower response rates (P = 0.04) and higher relapse rates (P = 0.03), as well as shorter progression-free (PFS; P = 0.004) and overall survival (OS; P = 0.004). Multivariate analysis showed that age, miR-126* expression, and revised International Prognostic Scoring System risk independently predicted PFS and OS. In 15 patient samples collected over time, decreased miRNA expression levels were associated with secondary resistance.Conclusions: A decreased expression of anti-DNMT1 miRNAs might account for azacitidine resistance in HRMDS and AML, and measuring miRNA expression before and during treatment might help predict primary or secondary azacitidine resistance. Clin Cancer Res; 23(12); 3025-34. ©2016 AACR.
Subject(s)
DNA (Cytosine-5-)-Methyltransferase 1/genetics , Leukemia, Myeloid, Acute/drug therapy , MicroRNAs/genetics , Myelodysplastic Syndromes/drug therapy , Aged , Aged, 80 and over , Azacitidine/administration & dosage , Disease-Free Survival , Drug Resistance, Neoplasm/genetics , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Male , Middle Aged , Myelodysplastic Syndromes/genetics , Myelodysplastic Syndromes/pathology , Prognosis , Signal TransductionABSTRACT
In AML, approximately one-third of expressed genes are abnormally spliced, including aberrant TET2 exon 2 expression. In a discovery cohort (n=99), TET2 exon 2 skipping (TET2E2S) was found positively associated with a significant reduction in the cumulative incidence of relapse (CIR). Age, cytogenetics, and TET2E2S were independent prognostic factors for disease-free survival (DFS), and favorable effects on outcomes predominated in cytogenetic normal (CN)-AML and younger patients. Using the same cutoff in a validation cohort of 86 CN-AML patients, TET2E2Shigh patients were found to be younger than TET2low patients without a difference in the rate of complete remission. However, TET2E2Shigh patients exhibited a significantly lower CIR (p<10-4). TET2E2S and FLT3-ITD, but not age or NPM1 mutation status were independent prognostic factors for DFS and event-free survival (EFS), while TET2E2S was the sole prognostic factor that we identified for overall survival (OS). In both the intermediate-1 and favorable ELN genetic categories, TET2E2S remained significantly associated with prolonged survival. There was no correlation between TET2E2S status and outcomes in 34 additional AML patients who were unfit for IC. Therefore our results suggest that assessments of TET2 exon 2 splicing status might improve risk stratification in CN-AML patients treated with IC.
Subject(s)
DNA-Binding Proteins/genetics , Leukemia, Myeloid, Acute/genetics , Proto-Oncogene Proteins/genetics , Age Factors , Cytogenetics , Dioxygenases , Disease-Free Survival , Exons , Female , Humans , Leukemia, Myeloid, Acute/mortality , Male , Middle Aged , Nucleophosmin , Prognosis , Risk Assessment , fms-Like Tyrosine Kinase 3/geneticsABSTRACT
In addition to spliceosome gene mutations, oncogene expression and drug resistance in AML might influence exon expression. We performed exon-array analysis and exon-specific PCR (ESPCR) to identify specific landscapes of exon expression that are associated with DEK and WT1 oncogene expression and the resistance of AML cells to AraC, doxorubicin or azacitidine. Data were obtained for these five conditions through exon-array analysis of 17 cell lines and 24 patient samples and were extended through qESPCR of samples from 152 additional AML cases. More than 70% of AEUs identified by exon-array were technically validated through ESPCR. In vitro, 1,130 to 5,868 exon events distinguished the 5 conditions from their respective controls while in vivo 6,560 and 9,378 events distinguished chemosensitive and chemoresistant AML, respectively, from normal bone marrow. Whatever the cause of this effect, 30 to 80% of mis-spliced mRNAs involved genes unmodified at the whole transcriptional level. These AEUs unmasked new functional pathways that are distinct from those generated by transcriptional deregulation. These results also identified new putative pathways that could help increase the understanding of the effects mediated by DEK or WT1, which may allow the targeting of these pathways to prevent resistance of AML cells to chemotherapeutic agents.
Subject(s)
Alternative Splicing/genetics , Antineoplastic Agents/pharmacology , Drug Resistance, Neoplasm/genetics , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Aged , Anthracyclines/pharmacology , Azacitidine/pharmacology , Cell Line, Tumor , Chromosomal Proteins, Non-Histone/metabolism , Cytarabine/pharmacology , Doxorubicin/pharmacology , Exons/genetics , Gene Expression Profiling , HEK293 Cells , Humans , Male , Middle Aged , Oncogene Proteins/metabolism , Oncogenes/genetics , Poly-ADP-Ribose Binding Proteins , RNA Interference , RNA, Small Interfering/genetics , WT1 Proteins/metabolismABSTRACT
Over recent years, the development of molecular biology techniques has improved the hematological diseases diagnostic and follow-up. Consequently, these techniques are largely used in the biological screening of these diseases; therefore the Hemato-oncology molecular diagnostics laboratories must be actively involved in the accreditation process according the ISO 15189 standard. The French group of molecular biologists (GBMHM) provides requirements for the implementation of quality assurance for the medical molecular laboratories. This guideline states the recommendations for the pre-analytical, analytical (methods validation procedures, quality controls, reagents), and post-analytical conditions. In addition, herein we state a strategy for the internal quality control management. These recommendations will be regularly updated.
Subject(s)
Accreditation/standards , Hematologic Neoplasms/pathology , Laboratories/standards , Molecular Biology/standards , France , Humans , Laboratory Personnel/education , Laboratory Personnel/standards , Quality Assurance, Health Care , Quality Control , Reproducibility of ResultsABSTRACT
CXCR4, receptor of the chemokine SDF-1 (stromal cell-derived factor 1) plays a major role in the normal hematopoiesis but also in the biology of the leukaemic cell. This receptor is expressed on the surface of blasts and is a key molecule in "the anchoring" of the leukaemic stem cell (LSC) within the bone marrow niche. The interactions of the LSC with the bone marrow microenvironment promote survival signals and drug resistance. Recent flow cytometry analyses reported that CXCR4 expression levels have a major prognostic impact in acute myeloid leukaemia (AML). CXCR4 expression is associated with poor prognosis and can be useful to stratify patients, according to their phenotype, in order to establish risk-adapted strategies. Newly diagnosed AML are now routinely stratified according to molecular markers which guide prognosis and treatment. Many leukaemia are composed of multiples subclones with differential susceptibility to treatment and specific targeted therapies are missing. Despite therapeutic improvements for the treatment of AML, long term survival remains poor. Targeting CXCR4 is a novel promising approach of therapy. CXCR4 antagonists are used in combination with chemotherapy in preclinical and clinical studies. This review summarises our current knowledge regarding the key role of CXCR4 in AML and discusses how targeting this pathway could provide an interesting approach to eradicate the LSC.
Subject(s)
Chemokine CXCL12/physiology , Leukemia, Myeloid, Acute , Molecular Targeted Therapy/methods , Receptors, CXCR4/physiology , Animals , Cell Movement/physiology , Cell Proliferation , Clinical Trials as Topic , Granulocyte Colony-Stimulating Factor/administration & dosage , Granulocyte-Macrophage Colony-Stimulating Factor/administration & dosage , Hematopoietic Stem Cell Mobilization/methods , Hematopoietic Stem Cells/cytology , Humans , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Mice , Prognosis , Receptors, CXCR/metabolism , Receptors, CXCR4/antagonists & inhibitors , Signal Transduction , Tumor Microenvironment/physiologySubject(s)
Clonal Evolution , Myeloablative Agonists/therapeutic use , Nuclear Proteins/genetics , Sarcoma, Myeloid/genetics , Stem Cell Transplantation , Biopsy , DNA Mutational Analysis , Humans , Male , Middle Aged , Nucleophosmin , Remission Induction , Sarcoma, Myeloid/diagnosis , Sarcoma, Myeloid/pathology , Sarcoma, Myeloid/therapy , Skin/pathology , Transplantation, HomologousABSTRACT
Myelodysplastic syndromes are characterized by a high risk of evolution into acute myeloid leukaemia which can involve activation of signalling pathways. As the chaperone heat shock protein 90 (HSP90) has a key role in signal transduction, we investigated its role in the pathogenesis and evolution of myelodysplastic syndromes. Expressions of HSP90 and signalling proteins clients (phosphorylated-AKT (pAKT), Focal Adhesion Kinase (FAK) and phosphorylated-FAK (pFAK)), were assessed in bone marrow mononuclear and CD34-positive (CD34+) cells from 177 patients with myelodysplasia. Effects of HSP90 inhibition were also evaluated in 39 samples. The levels of all proteins studied were significantly higher in patients with high grade disease, than those with low grade myelodysplastic syndrome or chronic myelomonocytic leukaemia. High levels of HSP90, FAK, pFAK and pAKT were associated with shorter survival and increased risk of progression into acute leukaemia. A down regulation of pFAK and pAKT and increased apoptosis was observed in mononuclear and CD34+ cells after 12 hours of incubation with 17-AAG. In conclusion, our data suggest the implication of HSP90 and FAK and AKT activation in the pathogenesis of myelodysplastic syndromes with excess of blasts and evolution to leukaemia. Moreover this signalling network could be a therapeutic target through HSP90 inhibition.