scholarly journals Heterogeneous disease-propagating stem cells in juvenile myelomonocytic leukemia

2019 ◽  
Author(s):  
Eleni Louka ◽  
Benjamin Povinelli ◽  
Alba Rodriguez Meira ◽  
Gemma Buck ◽  
Neil Ashley ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Single Cell ◽  
Rna Sequencing ◽  
Childhood Leukemia ◽  
Clonal Evolution ◽  
Juvenile Myelomonocytic Leukemia ◽  
Hematopoietic Stem ◽  
Activating Mutations ◽  
Myelomonocytic Leukemia

AbstractJuvenile Myelomonocytic Leukemia (JMML) is a poor prognosis childhood leukemia usually caused by germline or somatic RAS-activating mutations. The cellular hierarchy in JMML is poorly characterized, including the identity of leukemia stem cells (LSCs). FACS and single-cell RNA-sequencing reveal marked heterogeneity of JMML hematopoietic stem/progenitor cells (HSPCs), including an aberrant Lin-CD34+CD38-CD90+CD45RA+ population. Single-cell HSPC index-sorting and clonogenic assays show that (1) all somatic mutations can be backtracked to the phenotypic HSC compartment with RAS-activating mutations as a “first hit”, (2) mutations are acquired with both linear and branching patterns of clonal evolution and (3) mutant HSPCs are present after allogeneic HSC transplant before molecular/clinical evidence of relapse. Stem cell assays reveal inter-patient heterogeneity of JMML-LSCs which are present in, but not confined to, the phenotypic HSC compartment. RNA-sequencing of JMML-LSCs reveals upregulation of stem cell and fetal genes (HLF, MEIS1, CNN3, VNN2, HMGA2) and candidate therapeutic targets/biomarkers (MTOR, SLC2A1, CD96) paving the way for LSC-directed disease monitoring and therapy in this disease.

scholarly journals Heterogeneous disease-propagating stem cells in juvenile myelomonocytic leukemia

2021 ◽  
Vol 218 (2) ◽  
Author(s):  
Eleni Louka ◽  
Benjamin Povinelli ◽  
Alba Rodriguez-Meira ◽  
Gemma Buck ◽  
Wei Xiong Wen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Single Cell ◽  
Rna Sequencing ◽  
Childhood Leukemia ◽  
Clonal Evolution ◽  
Juvenile Myelomonocytic Leukemia ◽  
Hematopoietic Stem ◽  
Ras Pathway ◽  
Myelomonocytic Leukemia

Juvenile myelomonocytic leukemia (JMML) is a poor-prognosis childhood leukemia usually caused by RAS-pathway mutations. The cellular hierarchy in JMML is poorly characterized, including the identity of leukemia stem cells (LSCs). FACS and single-cell RNA sequencing reveal marked heterogeneity of JMML hematopoietic stem/progenitor cells (HSPCs), including an aberrant Lin−CD34+CD38−CD90+CD45RA+ population. Single-cell HSPC index-sorting and clonogenic assays show that (1) all somatic mutations can be backtracked to the phenotypic HSC compartment, with RAS-pathway mutations as a “first hit,” (2) mutations are acquired with both linear and branching patterns of clonal evolution, and (3) mutant HSPCs are present after allogeneic HSC transplant before molecular/clinical evidence of relapse. Stem cell assays reveal interpatient heterogeneity of JMML LSCs, which are present in, but not confined to, the phenotypic HSC compartment. RNA sequencing of JMML LSC reveals up-regulation of stem cell and fetal genes (HLF, MEIS1, CNN3, VNN2, and HMGA2) and candidate therapeutic targets/biomarkers (MTOR, SLC2A1, and CD96), paving the way for LSC-directed disease monitoring and therapy in this disease.

scholarly journals Despite mutation acquisition in hematopoietic stem cells, JMML-propagating cells are not always restricted to this compartment

Leukemia ◽  
2019 ◽  
Vol 34 (6) ◽  
pp. 1658-1668
Author(s):  
Aurélie Caye ◽  
Kevin Rouault-Pierre ◽  
Marion Strullu ◽  
Elodie Lainey ◽  
Ander Abarrategi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Myeloproliferative Neoplasm ◽  
Juvenile Myelomonocytic Leukemia ◽  
Integrated Analysis ◽  
Cell Phenotype ◽  
Hematopoietic Stem ◽  
Activating Mutations ◽  
Colony Forming Assay ◽  
Myelomonocytic Leukemia

AbstractJuvenile myelomonocytic leukemia (JMML) is a rare aggressive myelodysplastic/myeloproliferative neoplasm of early childhood, initiated by RAS-activating mutations. Genomic analyses have recently described JMML mutational landscape; however, the nature of JMML-propagating cells (JMML-PCs) and the clonal architecture of the disease remained until now elusive. Combining genomic (exome, RNA-seq), Colony forming assay and xenograft studies, we detect the presence of JMML-PCs that faithfully reproduce JMML features including the complex/nonlinear organization of dominant/minor clones, both at diagnosis and relapse. Further integrated analysis also reveals that although the mutations are acquired in hematopoietic stem cells, JMML-PCs are not always restricted to this compartment, highlighting the heterogeneity of the disease during the initiation steps. We show that the hematopoietic stem/progenitor cell phenotype is globally maintained in JMML despite overexpression of CD90/THY-1 in a subset of patients. This study shed new lights into the ontogeny of JMML, and the identity of JMML-PCs, and provides robust models to monitor the disease and test novel therapeutic approaches.

scholarly journals Stem cell origins of JMML

2021 ◽  
Vol 218 (2) ◽  
Author(s):  
Sriram Sundaravel ◽  
Ulrich Steidl
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Progenitor Cell ◽  
Therapeutic Targets ◽  
Leukemia Stem Cells ◽  
Juvenile Myelomonocytic Leukemia ◽  
Hematopoietic Stem ◽  
Cell Compartments ◽  
Myelomonocytic Leukemia

In this issue of JEM, Louka et al. (https://doi.org/10.1084/jem.20180853) report that leukemia stem cells lie within the phenotypic hematopoietic stem cell and progenitor cell compartments in juvenile myelomonocytic leukemia (JMML). Furthermore, they identify several candidate biomarker/therapeutic targets, such as CD96 and SLC2A1, that are of translational significance in JMML.

scholarly journals The results of hematopoietic stem cell transplantation in patients with juvenile myelomonocytic leukemia at the Russian Children’s Clinical Hospital

2019 ◽  
Vol 6 (2) ◽  
pp. 20-29
Author(s):  
E. V. Machneva ◽  
V. V. Konstantinova ◽  
Yu. V. Skvortsova ◽  
А. E. Burya ◽  
N. V. Sidorova ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Hematopoietic Stem Cell ◽  
Juvenile Myelomonocytic Leukemia ◽  
Hematopoietic Stem ◽  
Free Survival ◽  
Myelomonocytic Leukemia

Relevance. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only effective treatment method for the majority of patients with juvenile myelomonocytic leukemia (JMML). The authors of the article presented the experience of conducting HSCT in patients with JMML in the Russian Children’s Clinical Hospital.Materials and methods. 55 HSCT for the period from 2003 to 2019 were performed in forty-two patients with JMML. 14 (33.3 %) patients from a related HLA-identical donor were given primary HSCT, 1 (2.4 %) from a related 9/10 HLA-compatible, 16 (38.1 %) – from unrelated HLA-identical, 6 (14.3 %) – from unrelated 9/10 HLA-compatible, 5 (11.9 %) – from haploidentical. The source of hematopoietic stem cells (HSC) in primary HSCT for 22 (52.4 %) patients was bone marrow (BM), for 13 (31.0 %) – peripheral blood stem cells (PBSC), for 4 (9.5 %) – cord blood (CB), for 3 (7.1 %) – BM in combination with CB. Twenty-two (52.4 %) patients received a myeloablative busulfan-containing conditioning regimen, 20 (47.6 %) – treosulfan-containing.Results. The overall survival (OS) of patients for the entire observation period was 53 ± 8.3 %; transplantation lethality (TL) – 21.2 ± 6.8 %, relapse-free survival (RFS) – 72.0 ± 7.7 %, event-free survival (EFS) – 49.4 ± 7.8 %. The factors negatively influencing the results of HSCT in patients with JMML were the progression of the underlying disease at the time of HSCT, incomplete compatibility of the HSC donor, the use of CB as a source of HSC.Conclusion. Indicators of OS, RFS, EFS patients with JMLL after HSCT are low. The reasons for treatment failure are TL, graft failure and relapse after transplantation. To improve the results of treatment of patients with JMML, careful selection of the donor and the source of HSC, the maximum possible reduction in the toxicity of conditioning regimens is necessary.

scholarly journals Development of an allele-specific minimal residual disease assay for patients with juvenile myelomonocytic leukemia

Blood ◽  
2008 ◽  
Vol 111 (3) ◽  
pp. 1124-1127 ◽  
Author(s):  
Sophie Archambeault ◽  
Nikki J. Flores ◽  
Ayami Yoshimi ◽  
Christian P. Kratz ◽  
Miriam Reising ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Stem Cell Transplantation ◽  
Peripheral Blood ◽  
Residual Disease ◽  
Juvenile Myelomonocytic Leukemia ◽  
Hematopoietic Stem ◽  
Allele Specific ◽  
Myelomonocytic Leukemia

AbstractJuvenile myelomonocytic leukemia is an aggressive and frequently lethal myeloproliferative disorder of childhood. Somatic mutations in NRAS, KRAS, or PTPN11 occur in 60% of cases. Monitoring disease status is difficult because of the lack of characteristic leukemic blasts at diagnosis. We designed a fluorescently based, allele-specific polymerase chain reaction assay called TaqMAMA to detect the most common RAS or PTPN11 mutations. We analyzed peripheral blood and/or bone marrow of 25 patients for levels of mutant alleles over time. Analysis of pre–hematopoietic stem-cell transplantation, samples revealed a broad distribution of the quantity of the mutant alleles. After hematopoietic stem-cell transplantation, the level of the mutant allele rose rapidly in patients who relapsed and correlated well with falling donor chimerism. Simultaneously analyzed peripheral blood and bone marrow samples demonstrate that blood can be monitored for residual disease. Importantly, these assays provide a sensitive strategy to evaluate molecular responses to new therapeutic strategies.

Rapid Cyclosporine Tapering and Isotretinoin Usage after Unrelated Donor Hematopoietic Stem Cell Transplantation in Juvenile Myelomonocytic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5188-5188
Author(s):  
Keon Hee Yoo ◽  
Soo Hyun Lee ◽  
Ki Woong Sung ◽  
Hong Hoe Koo ◽  
Hye Lim Jung
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Complete Remission ◽  
Stem Cell Transplantation ◽  
Acute Gvhd ◽  
Juvenile Myelomonocytic Leukemia ◽  
Hematopoietic Stem ◽  
Differentiating Agent ◽  
Myelomonocytic Leukemia ◽  
Disease Free

Abstract Juvenile myelomonocytic leukemia (JMML) is a rare type of childhood leukemias, and allogeneic hematopoietic stem cell transplantation (HSCT) is known to be the only way to cure the disease. Unfortunately, relapse is still the most frequent cause of treatment failure after transplant in JMML. We investigated the feasibility of inducing graft versus leukemia (GVL) effect and the use of a differentiating agent even after unrelated HSCT in children with JMML. Seven consecutive patients with JMML underwent unrelated HSCT at a median age of 17 months. The sources of grafts were bone marrows (n=3) or HLA 1- or 2-antigen mismatched cord bloods (n=4). Only 3 of the 7 patients were in complete remission before transplantation. Intravenous busulfan, cyclophosphamide, and etoposide were used as preparative agents except in one who was conditioned with TBI-based regimen. Cyclosporine was used universally for GVHD prophylaxis with additional use of short-term methotrexate in bone marrow transplants and of methyl-prednisolone in cord blood transplants. Cyclosporine was tapered rapidly from around 1 month post-HSCT and isotretinoin (75–100 mg/m2/day) was used in selected patients who have any risk factors of relapse. Cyclosporine blood levels were 247.8±91.1, 146.6±104.2, and 88.8±52.6 ng/mL at 1, 2, and 3 months post-transplant, respectively. There was no grade 3 or 4 acute GVHD and only 2 patients developed grade 2 acute GVHD which was improved without additional treatment. Chronic GVHD was developed in 3 (1 limited, 2 extensive) of the evaluable 5 patents, which was all resolved after combined use of immune suppressive agents. Initial chimeric status analysis at 1 month revealed complete donor chimerism (CC) in 4 patients, mixed chimerism (MC) in 2 and autologous recovery (AR) in one. One of the patients with MC and the one with AR were in disease-free status. One patient whose chimeric status changed from CC to MC eventually relapsed. One patient with initial MC with residual disease turned to CC with complete remission. Another patient with initial MC but with no evidence of disease is on treatment with isotretinoin without relapse for 3 months even with persistent MC. The patient with AR relapsed early after transplant. Five patients are alive relapse-free and disease-free with a median follow-up of 16 months after transplant. The Kaplan-Meier probability of event-free survival was 66.7%. We suggest that GVL induction strategy with concomittant use of a differentiating agent might have a role to suppress leukemic relapse in JMML.

Development of two cytogenetically abnormal clones from multipotential hematopoietic stem cells in a patient with juvenile myelomonocytic leukemia

2005 ◽  
Vol 29 (9) ◽  
pp. 1069-1072 ◽  
Author(s):  
Satoshi Matsuzaki ◽  
Kazuyuki Matsuda ◽  
Jun Miki ◽  
Yozo Nakazawa ◽  
Kazuo Sakashita ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Juvenile Myelomonocytic Leukemia ◽  
Hematopoietic Stem ◽  
Myelomonocytic Leukemia
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