scholarly journals Synoptic Diagnostics of Myeloproliferative Neoplasms: Morphology and Molecular Genetics

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3528
Author(s):  
Dominik Nann ◽  
Falko Fend
Keyword(s):  
Bone Marrow ◽  
Myeloproliferative Neoplasms ◽  
Molecular Medicine ◽  
Differential Diagnoses ◽  
Trephine Biopsy ◽  
Prognostic Information ◽  
Molecular Features ◽  
Cell Counts ◽  
Myeloid Neoplasms ◽  
Molecular Studies

The diagnosis of a myeloid neoplasm relies on a combination of clinical, morphological, immunophenotypic and genetic features, and an integrated, multimodality approach is needed for precise classification. The basic diagnostics of myeloid neoplasms still rely on cell counts and morphology of peripheral blood and bone marrow aspirate, flow cytometry, cytogenetics and bone marrow trephine biopsy, but particularly in the setting of Ph− myeloproliferative neoplasms (MPN), the trephine biopsy has a crucial role. Nowadays, molecular studies are of great importance in confirming or refining a diagnosis and providing prognostic information. All myeloid neoplasms of chronic evolution included in this review, nowadays feature the presence or absence of specific genetic markers in their diagnostic criteria according to the current WHO classification, underlining the importance of molecular studies. Crucial differential diagnoses of Ph− MPN are the category of myeloid/lymphoid neoplasms with eosinophilia and gene rearrangement of PDGFRA, PDGFRB or FGFR1, or with PCM1-JAK2, and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). This review focuses on morphological, immunophenotypical and molecular features of BCR-ABL1-negative MPN and their differential diagnoses. Furthermore, areas of difficulties and open questions in their classification are addressed, and the persistent role of morphology in the area of molecular medicine is discussed.

Clinical Implications for Patients with Low JAK2V617F Allele Burden

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1745-1745
Author(s):  
Marguerite Vignon ◽  
Dorota Jeziorowska ◽  
Pierre Hirsch ◽  
Ollivier Legrand ◽  
Nicole Casadevall ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Clinical Phenotype ◽  
Myeloproliferative Neoplasms ◽  
Kinase Domain ◽  
Jak2 Mutation ◽  
Allele Burden ◽  
Vein Thrombosis ◽  
Myeloid Neoplasms ◽  
Exon 10 ◽  
Jak2v617f Allele Burden

Abstract Abstract 1745 In classical Philadelphia-negative myeloproliferative neoplasms (MPN), JAK2V617F is considered as a driver mutation when the threshold of 1% JAK2V617F/JAK2total allele burden is reached. However a lower ratio is sometimes detected with highly sensitive assays. We investigated the clinical significance of such minor clones by describing the characteristics of 27 patients with a low JAK2V617F allele burden ranging from 0.1% to 0.99%. Material and Methods A commercially available quantitative ASO-PCR assay of 0.1% sensitivity (MutaQuant® kit, Ipsogen) was used. Two thousand five hundred consecutive blood samples were sent to our lab for JAK2V617F mutation between 2009 and 2012. Total blood DNA was extracted by an automated standardized procedure (Qiasymphony®, Qiagen). All samples were tested in duplicate. The 27 samples of our cohort were controlled using a second assay of 0.01% sensitivity (Larsen et al, BJH 2007). Thirty samples from healthy donors were also tested. High resolution melting curve (HRM) analysis of JAK2 exon 14 ruled out the possibility of an additional mutation hampering the annealing of a primer. Patients with a known classical MPN clinical phenotype were also tested for JAK2 exons 12–17 (entire pseudo-kinase domain) or for MPL exon 10 depending on the context. Results Laboratory Findings Among the 2500 samples, 735 (29.4%) were positive above 1%, 27 (1.1%) had low JAK2V617F allele burden ranging from 0.12 to 0.99%. The patient with the lowest ratio (0.12%) was not confirmed by the second assay and therefore was excluded from the study. This allowed the median to settle at 0.40%. No associated mutations were found in the JAK2 pseudo-kinase domain in patients with polycythemia vera (PV) and in MPL exon 10 in patients with essential thrombocytosis (ET) and primary myelofibrosis (PMF). Healthy patients were all tested JAK2V617F negative. Clinical Aspects The cohort included 19 men and 7 women ranging from 28 to 95 years of age (median 63 years old). Two patients had secondary acute myeloid leukaemia following JAK2V617F positive MPN indicating the presence of residual JAK2V617F cells and the negativity of the myeloblastic population. Thirteen patients (50%) had a classical MPN with a median ratio of 0.36%: 7 ET, 5 PV and 1 PMF according to WHO 2008 criteria. However a bone marrow biopsy was available for only two patients (1 ET, 1 PMF). None of them had received pegylated interferon alpha-2a. Four patients had a prior history of thrombosis: two strokes, one pulmonary embolism, two portal vein thrombosis (PVT). For one PV patient, a 6 months follow-up blood and bone marrow sample confirmed a low allele burden in the same range (0.4%) and in vitro Epo-independant erythroid colonies were observed. Five patients had other chronic myeloid neoplasms (two myelodysplastic/myeloproliferative neoplasms, one chronic eosinophilic leukaemia, one chronic myeloid leukaemia, one refractory anaemia with ring sideroblasts). Among these five, four had an abnormal karyotype. We did not observe any thrombotic event in these patients. We cannot conclude on hematological diagnosis for the last six patients: four patients were screened for JAK2 mutation because of PVT. One patient had chronic polycythemia in a context of alcohol and tobacco abuse. One patient had homozygous hemochromatosis with a normal haemoglobin level in spite of repeated phlebotomies. Discussion In this single centre study low JAK2V617F allele burden represented 1% of all samples sent for JAK2V617F study and 3.5% of JAK2V617F positive patients. Seventeen patients (65%) had classical MPN or splanchnic vein thrombosis. To our knowledge PV patients with such low JAK2V617F allele burden have not been reported in the absence of associated JAK2 pseudo-kinase domain mutation. A larger screen for cooperating mutations responsible for the PV phenotype is under process. In the context of other chronic myeloid neoplasms, the JAK2V617F mutation is thought to belong to a more complex clonal architecture mostly implicating chromatin remodeling genes. Here, the presence of a JAK2 mutation could argue in favour of clonal haematopoiesis. In conclusion the clinical phenotype of low JAK2V617F patients overlaps with classical JAK2V617F MPN. The technical implications might be challenging for molecular diagnostic platforms. More data are needed to further characterize these patients. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Large Granular Lymphocyte Expansion in Myeloid Diseases and Bone Marrow Failure Syndromes: Whoever Seeks Finds

2021 ◽  
Vol 11 ◽  
Author(s):  
Bruno Fattizzo ◽  
Valentina Bellani ◽  
Raffaella Pasquale ◽  
Juri Alessandro Giannotta ◽  
Wilma Barcellini
Keyword(s):  
Bone Marrow ◽  
Clonal Selection ◽  
Myeloproliferative Neoplasms ◽  
Bone Marrow Failure ◽  
Pure Red Cell Aplasia ◽  
Lymphoid Cells ◽  
Myeloid Neoplasms ◽  
Bone Marrow Failure Syndromes ◽  
Clonal Origin ◽  
Clinical Conditions

Large granular lymphocytes (LGL) are lymphoid cells characterized by either a T-cell or a natural killer phenotype whose expansion may be reactive to toxic, infectious, and neoplastic conditions, or result from clonal selection. Recently, the higher attention to LGL clones led to their detection in many clinical conditions including myeloid neoplasms and bone marrow failures. In these contexts, it is still unclear whether LGL cells actively contribute to anti-stem cell autoimmunity or are only a reaction to dysplastic/leukemic myelopoiesis. Moreover, some evidence exists about a common clonal origin of LGL and myeloid clones, including the detection of STAT3 mutations, typical of LGL, in myeloid precursors from myelodysplastic patients. In this article we reviewed available literature regarding the association of LGL clones with myeloid neoplasms (myelodysplastic syndromes, myeloproliferative neoplasms, and acute myeloid leukemias) and bone marrow failures (aplastic anemia and pure red cell aplasia, PRCA) focusing on evidence of pathogenic, clinical, and prognostic relevance. It emerged that LGL clones may be found in up to one third of patients, particularly those with PRCA, and are associated with a more cytopenic phenotype and good response to immunosuppression. Pathogenically, LGL clones seem to expand after myeloid therapies, whilst immunosuppression leading to LGL depletion may favor leukemic escape and thus requires caution.

scholarly journals Clinicohematological study of spectrum of myeloproliferative neoplasms in a tertiary care hospital

2020 ◽  
Vol 11 (3) ◽  
pp. 3710-3718
Author(s):  
Sonal Gupta ◽  
Sujata R. Kanetkar
Keyword(s):  
Bone Marrow ◽  
High Risk ◽  
Tertiary Care Hospital ◽  
Risk Group ◽  
Myeloproliferative Neoplasms ◽  
Tertiary Care ◽  
Care Hospital ◽  
Trephine Biopsy ◽  
Maximum Serum ◽  
Hasford Score

Myeloproliferative neoplasms (MPNs) are a group of disorders of hematopoietic stem cells which were initially recognised by William Dameshek in 1951. Objectives of the study were to diagnose and classify cases of myeloproliferative neoplasms according to 2016 revision of WHO classification of myeloid neoplasms and acute leukaemias, to study various haematological parameters of cases of MPNs (Peripheral smear findings, bone marrow aspirate and trephine biopsy) and their clinical manifestations, to record the cytogenetic/molecular genetic abnormalities of the cases and to categorise CML patients according to Hasford Risk Score as a predictor of prognosis. This study was a prospective study carried out in the Department of Pathology of a tertiary care hospital over two years from June 2016 to September 2018. The study included a total of 41 cases of MPNs. The cases of CMLs were diagnosed on peripheral blood findings, Bone marrow aspiration, Trephine biopsy Serum LDH and uric acid. CML was the most common MPN encountered (37/41; 90.24%) in the present study. Maximum serum LDH elevation was observed in CML cases with a mean value of 1396.6 U/L. Of the 37 CML cases, as per Hasford score, 17 cases were categorised into a low-risk group, 17 cases into an intermediate-risk group and 3 cases into a high-risk group. In the present study of Hasford score in CML cases, it was found that it helps in making a better-informed decision about the adaption of alternative high-risk treatment, and was of value in oncology practice.

scholarly journals rs2431697, a Polymorphism of Mir-146a, Is a Precozing Marker of Progression to Secondary Myelofibrosis: New Epigenetic Regulation of Jak/Stat3 Signaling

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3072-3072
Author(s):  
Francisca Ferrer Marin ◽  
Ana Belen F Arroyo ◽  
Beatriz Bellosillo ◽  
Lurdes Zamora ◽  
Ana Kerguelen Fuentes ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Research Funding ◽  
Molecular Mechanisms ◽  
Myeloproliferative Neoplasms ◽  
Critical Role ◽  
Expression Levels ◽  
Stat3 Signaling ◽  
Cell Counts ◽  
Secondary Myelofibrosis ◽  
Lower Expression

Abstract Introduction: Transformation to secondary myelofibrosis (MF) occurs as part of the natural history of polycythemia vera (PV) and essential thrombocythemia (ET), the two more indolent Ph-negative myeloproliferative neoplasms (MPN). Once transformed, survival is remarkably shorted. Chronic inflammation plays a critical role in the progression of MPN, driving clonal expansion toward end stage disease. Importantly, MPN are characterized by the production of inflammatory cytokines, by both malignant and non-malignant clone. Inflammation and cancer share a common pathway, i.e. NF-κB. Interestingly, miR-146a regulates TLR/NF-κB pathway through the inhibition of its targets, IRAK1 and TRAF6, decreasing the production of cytokines. Based on: i) miR-146a-/- mice develop an MF-like phenotype with aging; and ii) miR-146a polymorphism (miRSNPs) rs2431697, influences its expression levels (50% decrease in TT individuals); we hypothesized that lower miR-146a-5p levels associated to this miRSNPs may result in high risk to develop MF. Objective: To evaluate the association of rs2431697 with MF transformation and to study the molecular mechanisms beyond this association. Methods: We genotyped rs2431697 in 938 patients (312 MF, 299 PV, and 327 ET) recruited from 13 tertiary Spanish institutions belonging to GEMFIN and 600 controls. The levels of miR-146a and IRAK1 were evaluated by qRT-PCR in total blood RNA of homozygous patients (TT=30, CC=25) with PV or ET and in healthy subjects (TT=7, CC=7). In miR-146a-/- mice, 2 and 9 months old, we evaluated spleen size and cellularity: degree of fibrosis in bone marrow (H&E and silver staining); and STAT3 and pSTAT3 in granulocytic lysates by western blot. Results: Association analysis, taken controls as reference, showed that TT genotype (associated in the literature with low levels of mir-146a) is associated to MF with an OR of 1.36 (1.01-1.82, p=0.04). Among MF patients, the subgroup with the greatest differences was the one of secondary MF (OR = 1.47, CI: 0.98-2.20) (Table 1 a,b). Next, we compared the genetic frequencies of rs2431697 SNPs between the secondary MF patients and the population in risk. Confirming our hypothesis, we observed an enrichment of TT genotype in the post-PV/TE MF group (n=132) compared to the PV+TE group (n=626) (OR=1.51; p<0.05), Table 1c. In patients with PV or true-ET (WHO criteria) and known clinical follow-up (n=243), excluding pre-fibrotic MF, 8.6% were transformed. The median time to transformation was 27 years, being significantly shorter in patients with PV (vs. ET); homozygous for JAK2V617F; and in TT carriers (vs. TC+CC) (Figure 1A). The mayor differences were seen at early time points (Wilconxon test, p=0.001). In fact, 7 out of 10 TT patients who progress to MF, did so in the first 10 years after diagnosis (70%) as compared with 2 out of 11 CC/CT patients (18%).Both groups (TT and TC+CC) were similar in age, sex, cell counts, initial diagnosis (PV/ET), driver mutations and fibrosis grade 1. In the multivariate analysis, TT genotype remained statistically significative [OR 2.87; CI: 1.19-6.94; p=0.019], independently of phenotype (PV/ET) or V617F allele burden. Both in JAK2 mutated and wild type patients, the time to progression to secondary MF was significantly shorter among TT patients (p=0.027) (Figure 1B). Moreover, TT genotype helped to categorize the risk of progression to MF independently of the driver mutation (JAK2 or CALR) or JAK2 burden allele (p=0.06) (Figure 1C). Consistently, TT patients showed a trends towards a lower expression of miR-146a (p=0.08) and higher IRAK1 (p=0.07) with a significant correlation between both (p<0.01). Finally, we evaluated the association between the JAK-STAT3 and TLR/NF-κB pathways in mice miR-146a-/-. We observed higher total STAT3 and pSTAT3 expression levels in miR-146a-/- than in WT mice (Figure 1D). This increase correlated with aging, and were associated with the appearance of splenomegaly, extramedular hematopoyesis and bone marrow fibrosis at 9 months of age (Figure 1E). Conclusion: rs2431697-TT is an independent marker of early progression to secondary MF. The lower expression of miR-146a that this SNP confers is associated with an increase in JAK-STAT3 signaling. Our findings include, for the first time, miR-146a in the MPN signaling pathways. Thus, miR-146a, modulating the activation of NF-kB-IRAK1, could indirectly regulates JAK-STAT3 signalling. CINC424AES05T Disclosures Ferrer Marin: Novartis: Consultancy, Research Funding; Incyte: Consultancy. Hernandez Boluda:Incyte: Consultancy; Novartis: Consultancy. García Gutiérrez:Incyte: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Research Funding, Speakers Bureau. Gómez-Casares:Bristol-Myers Squibb: Speakers Bureau; Incyte: Speakers Bureau; Novartis: Speakers Bureau. Besses:Novartis: Honoraria, Research Funding; Shire: Honoraria.

scholarly journals Clinical Discernment, Bone Marrow, and Molecular Diagnostics Are Equally Important to Solve the Phenotypic Mimicry among Subtypes of Myeloproliferative Neoplasms

Reports ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 27
Author(s):  
Susann Schulze ◽  
Nadia Jaekel ◽  
Christin Le Hoa Naumann ◽  
Anja Haak ◽  
Marcus Bauer ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Clinical Judgment ◽  
Systemic Mastocytosis ◽  
Myeloproliferative Neoplasms ◽  
Accurate Diagnosis ◽  
Molecular Techniques ◽  
Driver Mutations ◽  
Therapeutic Consequences ◽  
Molecular Features ◽  
Disease Entities

The 2016 WHO classification integrates clinical, bone marrow (BM)-morphology, and molecular features to define disease entities. This together with the advancements in molecular detection and standardization of BM features enable an accurate diagnosis of myeloproliferative neoplasms (MPN) in the majority of patients. Diagnostic challenges remain due to phenotypic mimicry of MPN, failing specificity of BM-morphology, and the fact that phenotype-driver mutations, such as JAK2V617F, are not exclusive to a particular MPN, and their absence does not preclude any of these. We present a series of cases to illustrate themes to be considered in complex cases of MPN, such as triple-negative (TN)-MPN or MPN-unclassifiable (MPN-U). Eleven patients labelled as TN-MPN or MPN-U were included. Serum tryptase and NGS were part of a systematic/sequential multidisciplinary evaluation. Results were clustered into four categories based on diagnostic entities and/or how these diagnoses were made: (A) With expanding molecular techniques, BCR-ABL1 and karyotyping should not be missed; (B) systemic mastocytosis is underdiagnosed and often missed; (C) benign non-clonal disorders could mimic MPN; and (D) NGS could prove clonality in some “TN”-MPN cases. The prognostic/therapeutic consequences of an accurate diagnosis are immense. In TN-MPN or MPN-U cases, a multidisciplinary re-evaluation integrating molecular results, BM-morphology, and clinical judgment is crucial.

scholarly journals Triple-Negative Essential Thrombocythemia: Clinical-Pathological and Molecular Features. A Single-Center Cohort Study

2021 ◽  
Vol 11 ◽  
Author(s):  
Daniele Cattaneo ◽  
Giorgio Alberto Croci ◽  
Cristina Bucelli ◽  
Silvia Tabano ◽  
Marta Giulia Cannone ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Essential Thrombocythemia ◽  
Triple Negative ◽  
Clinical Laboratory ◽  
Myeloproliferative Neoplasms ◽  
Primary Myelofibrosis ◽  
Molecular Profile ◽  
Single Center ◽  
Driver Genes ◽  
Molecular Features

Lack of demonstrable mutations affecting JAK2, CALR, or MPL driver genes within the spectrum of BCR-ABL1-negative myeloproliferative neoplasms (MPNs) is currently referred to as a triple-negative genotype, which is found in about 10% of patients with essential thrombocythemia (ET) and 5–10% of those with primary myelofibrosis (PMF). Very few papers are presently available on triple-negative ET, which is basically described as an indolent disease, differently from triple-negative PMF, which is an aggressive myeloid neoplasm, with a significantly higher risk of leukemic evolution. The aim of the present study was to evaluate the bone marrow morphology and the clinical-laboratory parameters of triple-negative ET patients, as well as to determine their molecular profile using next-generation sequencing (NGS) to identify any potential clonal biomarkers. We evaluated a single-center series of 40 triple-negative ET patients, diagnosed according to the 2017 WHO classification criteria and regularly followed up at the Hematology Unit of our Institution, between January 1983 and January 2019. In all patients, NGS was performed using the Illumina Ampliseq Myeloid Panel; morphological and immunohistochemical features of the bone marrow trephine biopsies were also thoroughly reviewed. Nucleotide variants were detected in 35 out of 40 patients. In detail, 29 subjects harbored one or two variants and six cases showed three or more concomitant nucleotide changes. The most frequent sequence variants involved the TET2 gene (55.0%), followed by KIT (27.5%). Histologically, most of the cases displayed a classical ET morphology. Interestingly, prevalent megakaryocytes morphology was more frequently polymorphic with a mixture of giant megakaryocytes with hyperlobulated nuclei, normal and small sized maturing elements, and naked nuclei. Finally, in five cases a mild degree of reticulin fibrosis (MF-1) was evident together with an increase in the micro-vessel density. By means of NGS we were able to identify nucleotide variants in most cases, thus we suggest that a sizeable proportion of triple-negative ET patients do have a clonal disease. In analogy with driver genes-mutated MPNs, these observations may prevent issues arising concerning triple-negative ET treatment, especially when a cytoreductive therapy may be warranted.

Clinical and Biological Implications of CUX1 Mutations in Myeloid Neoplasms

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3156-3156
Author(s):  
Mai Aly ◽  
Naoko Hosono ◽  
Przychodzen Bartlomiej ◽  
Hideki Makishima ◽  
Nagata Yasunobu ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Lower Risk ◽  
Somatic Mutations ◽  
Myeloproliferative Neoplasms ◽  
Loss Of Function ◽  
Wild Type ◽  
Advisory Committees ◽  
Molecular Features ◽  
Myeloid Neoplasms ◽  
Normal Cytogenetics

Abstract Recurrent somatic mutations of CUX1 are described in myeloid neoplasms. CUX1 is located at chromosome 7q22.1; -7/del(7q) involving CUX1 locus are common abnormalities in myelodysplastic syndromes (MDS). Mutations and loss of heterozygosity involving CUX1 have been also described in breast, lung and uterine cancers. Preliminary functional studies, lack of a mutational hotspot and coincidental deletions suggest loss of function/hypomorphic consequences of these molecular defects. CUX1 (p200), contains 4 evolutionarily conserved DNA-binding domains, including 3 CUT repeats and a CUT homeodomain. Functionally, CUX1 regulates many genes involved in DNA replication and chromosome segregation. Cell-based assays have established a role for CUX1 in the control of cell-cycle progression, cell motility, and invasion .The objective of this study is to assess the molecular context and clinical significance of CUX1 mutations and deletions in myeloid neoplasms. We analyzed a subset of 1478 patients [24% lower-risk MDS, 17% higher-risk MDS, 22% primary (p)AML, 14% secondary AML, 14% MDS/myeloproliferative neoplasms (MPN) and 9% MPN] for the presence of CUX1 mutations and deletions. No CUX1 mutations were found in core binding factor AML. We correlated the presence of these lesions with clinical parameters, cytogenetic abnormalities, and molecular features including clonal architecture and associated somatic mutations. Copy number variation and their boundaries were analyzed by Single Nucleotide Polymorphism (SNP) arrays and mutations by multiamplicon deep sequencing utilizing a panel targeting 60 most commonly mutated genes in myeloid neoplasms. In total cohort 4 % of patients had CUX1 mutations and 6% had locus deletions (affecting ch 7q commonly deleted region: 7q22.1) including 90% of del (7q) cases. Expression of CUX1 is significantly lower in AML with -7/del(7q) compared to AML with normal cytogenetics (p<.00001) and also in MDS with -7/del(7q) compared tohealthy controls (p=.004). Additionally, decreased expression of CUX1 was found in 15% of MDS and 8% of AML patients without -7/del(7q) or related mutations. Cases with lower expression had worse OS compared to patients with higher expression (p=.002). In terms of configuration, most mutations were heterozygous, 5% of mutations were hemizygous and 4% were homozygous (due to UPD). Among 75 somatic CUX1mutations; 72% were missense, 20% where frame shift and 8% where non sense. CUX1 mutations were associated with either lower-risk MDS (p=.0001) and pAML (p=.04) while deletions involving the CUX1 locus were significantly related to higher-risk MDS (p=.05). Heterozygous CUX1 mutations were more commonly associated with normal cytogenetics (p=.01). Patients with -7/del(7q) frequently represented del(5q) (p=.04) and thrombocytopenia (p=.001). The OS of patients with CUX1 mutations was shorter (p=.04) as was that of patients with CUX1/deletions (p=.02) when compared to wild type. We subsequently studied the molecular background of CUX1 alterations. CUX1 mutations (vs. wild type) were associated with TET2 (31% vs. 14%, p=.006), ASXL1 (29% vs. 9%, p=.0005), BCOR (28% vs. 8%, p=.0004), and cohesion mutations (26%, vs. 5%, p=.0005), while NPM1 mutations showed the reverse relationship (1% vs. 7%, p=.03). RAS and CUX1 mutations were mutually exclusive (0% vs. 6%, p=.03). When we analyzed clonal hierarchy in the context of CUX1 mutations; dominant CUX1 mutations (24%; mean VAF=49%); were accomplished by ASXL1 (21%) and SRSF2 (14%) mutations which were the most common secondary events in this context. Phenotypically, dominant CUX1 mutations were associated with MDS/MPN (42%) and MDS (33%). 14% of CUX1 mutant cases did not harbor any other alterations and were not associated with a discernable phenotype. Secondary CUX1 lesions (62%; mean VAF=22%) were found in the context of dominant TET2 mutations (16%). The pathomorphologic context of secondary CUX1 mutation did not differ from that of primary lesions. AML seemed to be underrepresented (p=.006) and MPN overrepresented (p=.019) among dominant CUX1 mutant cases. In conclusion, CUX1 lesions including locus deletions with haploinsuffciency, mutations and a fraction of cases with decreased CUX1 expression can be encountered in MDS and related neoplasms, chiefly AML. CUX1 dysfunction is associated with poor survival likely due to its distinct molecular background. Disclosures Makishima: The Yasuda Medical Foundation: Research Funding. Sekeres:Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Clinical, Hematologic, Biologic and Molecular Characteristics of Patients with Myeloproliferative Neoplasms and a Chronic Myelomonocytic Leukemia-Like Phenotype

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1891
Author(s):  
Sonja Heibl ◽  
Bettina Gisslinger ◽  
Eva Jäger ◽  
Agnes Barna ◽  
Michael Gurbisz ◽  
...  
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Myeloproliferative Neoplasm ◽  
Jak2 V617f ◽  
Primary Myelofibrosis ◽  
Chronic Myelomonocytic Leukemia ◽  
Molecular Characteristics ◽  
Molecular Features ◽  
Cell Counts ◽  
Myelomonocytic Leukemia

Patients with a myeloproliferative neoplasm (MPN) sometimes show a chronic myelomonocytic leukemia (CMML)-like phenotype but, according to the 2016 WHO classification, a documented history of an MPN excludes the diagnosis of CMML. Forty-one patients with an MPN (35 polycythemia vera (PV), 5 primary myelofibrosis, 1 essential thrombocythemia) and a CMML-like phenotype (MPN/CMML) were comprehensively characterized regarding clinical, hematologic, biologic and molecular features. The white blood cell counts in MPN/CMML patients were not different from CMML patients and PV patients. The hemoglobin values and platelet counts of these patients were higher than in CMML but lower than in PV, respectively. MPN/CMML patients showed myelomonocytic skewing, a typical in vitro feature of CMML but not of PV. The mutational landscape of MPN/CMML was not different from JAK2-mutated CMML. In two MPN/CMML patients, development of a CMML-like phenotype was associated with a decrease in the JAK2 V617F allelic burden. Finally, the prognosis of MPN/CMML (median overall survival (OS) 27 months) was more similar to CMML (JAK2-mutated, 28 months; JAK2-nonmutated 29 months) than to PV (186 months). In conclusion, we show that patients with MPN and a CMML-like phenotype share more characteristics with CMML than with PV, which may be relevant for their classification and clinical management.

scholarly journals Inhibiting Glutamine Metabolism with CB-839 Reduces Erythrocytosis in MPN Mice

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3585-3585
Author(s):  
MARC Usart ◽  
Shivam Rai ◽  
Nils Hansen ◽  
Alexandre Guy ◽  
Jan Stetka ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Oxidative Phosphorylation ◽  
Aminolevulinic Acid ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Jak2 V617f ◽  
Metabolic Reprogramming ◽  
Glutamine Metabolism ◽  
Vehicle Group ◽  
Cell Counts

Abstract Metabolic reprogramming is one of the hallmarks of cancer, as these rapidly dividing cells need to adapt their metabolism to cope with an increased energy demand. We have previously showed that in mouse models of myeloproliferative neoplasms (MPN), JAK2-mutant cells display metabolic alterations, including increased oxidative phosphorylation and glycolysis. The glutamine-glutamate-alphaKetoglutarate (aKG) axis, besides fueling the Krebs cycle and anabolic processes, contributes to the synthesis of the heme precursor 5-aminolevulinic acid (5-ALA), thus making glutaminolysis a potential target for MPN therapy. Here, we examined the effects of pharmacological inhibition of the conversion of glutamine to glutamate by glutaminase 1 by Telaglenastat (CB-839) in a mouse model of JAK2-V617F driven MPN. We performed competitive transplantations of bone marrow co-expressing JAK2-V617F with a GFP-reporter and wildtype mice in a 1:10 mixture into lethally irradiated mice. At 8 weeks post-transplantation, the mice developed MPN phenotype and were randomized into 4 treatment arms. They were then treated for 6 weeks with vehicle, CB-839, 3PO (6-phosphofructo-2-kinase inhibitor) and the combination of CB-839 + 3PO. We found that hemoglobin levels were significantly reduced in CB-839 treated mice and were fully normalised in mice that received a combination of CB-839 + 3PO (Fig. 1A). Other peripheral blood cell counts did not change (not shown). Hypoglycemia was noted in the vehicle group, as previously described, but an increase in blood glucose levels was seen already after one week of treatment with CB-839. 3PO alone had less impact on hypoglycemia and mice receiving CB-839 + 3PO had similar values to CB-839 alone (Fig. 1A). In line with these findings, splenomegaly was also reduced (Fig. 1A). To characterise the changes in metabolic activity, we determined the metabolic profiles of unfractionated bone marrow (BM) cells using seahorse assays. As expected, basal and maximal glycolysis and oxidative phosphorylation were higher in vehicle treated MPN cells than cells from wildtype controls. However, when BM cells from CB-839 or CB-839 + 3PO groups were examined, they displayed a strong downmodulation of both glycolysis and oxidative phosphorylation, indicating that chronic exposure to CB-839 reprograms the metabolic machinery by reducing not only the basal glycolytic and respiratory levels, but also the maximal capacity (Fig. 1B). Glutamine is the primary source of aKG needed to produce the heme precursor 5-ALA, and hemoglobin synthesis consumes the majority of ATP in erythroid progenitors. We therefore hypothesize that 5-ALA shortage caused by CB-839 limits hemoglobin production, leading to reduced catabolic activity and drop in ATP demand. To evaluate this model, we examined the stages of erythroid differentiation from vehicle or treated mice. Early and intermediate erythroid cells were enriched at the expense of later stages in CB-839 and CB-839+3PO treatment arms (Fig. 1C). The accumulation of erythroid precursors at the stage before hemoglobin is assembled supports the hypothesis that targeting glutamine usage impairs excessive erythropoiesis by limiting hemoglobinization rate. Our data show that inhibiting glutaminolysis ameliorated MPN phenotype and that the combination with the glycolytic inhibitor 3PO was able to induce complete hematological response. Since CB-839 is already in clinical trials for other cancers, our data suggest that it could also be tested for treatment of patients with polycythemia vera. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

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