Functional heterogeneity exceeds genetic heterogeneity in chronic myelomonocytic leukemia
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE114115 | GEO | 2020/04/14
REPOSITORIES: GEO
Similar Datasets
Project description:<p>Hematopoietic stem cell (HSC) mutations can result in clonal hematopoiesis (CH) with heterogeneous clinical outcomes. Here, we investigated how the cell state preceding <em>Tet2</em> mutation impacts the pre-malignant phenotype. Using an inducible system for clonal analysis of myeloid progenitors, we found that the epigenetic features of clones at similar differentiation status were highly heterogeneous and functionally responded differently to <em>Tet2</em> mutation. Cell differentiation stage also influenced <em>Tet2</em> mutation response indicating that the cell of origin's epigenome modulates clone-specific behaviors in CH. Molecular features associated with higher risk outcomes include <em>Sox4</em> that sensitized cells to <em>Tet2</em> inactivation, inducing dedifferentiation, altered metabolism and increasing the <em>in vivo</em> clonal output of mutant cells, as confirmed in primary GMP and HSC models. Our findings validate the hypothesis that epigenetic features can predispose specific clones for dominance, explaining why identical genetic mutations can result in different phenotypes.</p>
1970-01-01 | MTBLS9914 | MetaboLights
Project description:Chronic myelomonocyticleukemia (CMML) is a clinically heterogeneous stem cell malignancy with overlapping features of myelodysplasiaand myeloproliferation. CMML is further subclassified according to percentage of leukemic blasts present in blood or bone marrow, reflecting its intrinsic tendency to progression towards acute myeloid leukemia. Over 90% of CMML patients carry founding mutations in epigenetic and/or splicing genes, which typically involve the primitive stem cell compartment. Thus, transcriptional dysregulation at the stem cell level is likely fundamental to disease onset and progression. However, the critical early hematopoietic stem and progenitor cell (HSPC) subpopulation has not been studied in CMML. We performed single cell RNA sequencing on>6,800 Lin-CD34+CD38-primitive HSPCs from seven CMML patients and three healthy controls. We found substantial inter-and intra-patient heterogeneity, with CMML stem cells displaying distinct transcriptional programs, differentiation potential and cellular signaling pathway priming. Pseudotime analyses revealed that CMML-1/CMML-2 HSPCs have distinct cellular trajectories, indicating that transformation events initiate early within the hematopoietic hierarchy and suggesting against a simple linear clonal evolution dynamic in acute leukemic transformation. We further identified several transcription factors uniquely active in distinct sample subsets. Together our findings provide novel insights into the CMML stem cell compartment, revealing an unexpected degree of transcriptional and subclonal heterogeneity and highlighting early mediators of disease initiation and transformation, of potential translational importance
2020-08-03 | E-MTAB-8884 | biostudies-arrayexpress
Project description:Genomic studies in chronic myeloid malignancies, including myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS) and MPN/MDS, have identified common mutations in genes encoding signaling, epigenetic, transcription and splicing factors. Analysis of 18 of these genes in a cohort of 224 chronic myelomonocytic leukemias (CMML), which is the most frequent MPN/MDS, identified at least one mutated gene in 95% of the patients, with some of the mutations affecting the disease phenotype. The number of mutated genes negatively affected progression-free and overall survival in multivariate analysis. Analysis of sorted progenitors indicated an early amplification of the CMML clone at the CD34+/CD38- stage of hematopoiesis, together with a premature granulomonocytic differentiation skewing. We interrogated the clone architecture by mutation-specific discrimination analysis of single-cell-derived colonies. The genetic classification of individual colonies allowed a designation of sub-clones and the assembly of putative evolutionary trees, indicating a linear acquisition of the studied mutations. Analysis of matched pre- and post-treatment samples demonstrated clonal persistence with limited and selective elimination of sub-clones. The disease was characterized by an amplification of multipotent and common myeloid progenitors in the CD34+ compartment, both fractions showing increased granulomonocytic differentiation at the expense of erythroid progenitors, contrasting with normal granulomonocytic progenitors. Altogether, early amplification of the leukemic clone and increased granulomonocytic differentiation of early progenitors may account for the specificity of CMML among myeloid neoplasms. This experiment correspond to the analysis of gene expression profiles in total CD34+ cells from the peripheral blood of 15 patients (Chronic Myelomonocytic Leukemia) and 4 healthy controls.
2013-01-17 | E-MTAB-1044 | biostudies-arrayexpress
Project description:Current strategies to target RNA splicing mutant myeloid cancers propose disruption of normal splicing activity by targeting the splicing apparatus therapeutically. This approach is only modestly sensitizing and is also toxic to non-mutant bearing wild-type cells. To explore potentially exploitable genetic interactions with spliceosome mutations, we combined data mining and functional screening for synthetic lethal interactions with an Srsf2P95H/+ mutation. Analysis of mis-splicing events in a series of both human and murine SRSF2P95H mutant samples across multiple myeloid diseases (AML, MDS, CMML) was first performed to identify conserved mis-splicing events. From this analysis, we identified that the DNA repair and cell cycle pathways were overrepresented within the conserved mis-spliced transcript sets. In parallel, to functionally define pathways essential for survival and proliferation Srsf2P95H/+ cells, we performed a genome-wide pooled CRISPR loss of function screen using Hoxb8 immortalised R26-CreERki/+ Srsf2P95H/+ and R26-CreERki/+ Srsf2+/+ cell lines. We assessed for loss of sgRNA representation at three timepoints: immediately after Srsf2P95H/+ activation, and at one week and two weeks post Srsf2P95H/+ mutation. Pathway analysis demonstrated that the DNA damage response and cell cycle pathways were amongst the top synthetic lethal pathways with Srsf2P95H/+ mutation., Based on the loss of guide RNAs targeting Cdk6, we identified that Palbocilib, a CDK6 inhibitor, showed preferential sensitivity in Srsf2P95H/+ cell lines and in primary non-immortalised lin-cKIT+Sca-1+ cells compared to wild type controls. Our data strongly suggest that cell cycle and DNA damage response pathways are required for Srsf2P95H/+ cell survival, and that Palbociclib could be an alternative therapeutic option for targeting SRSF2 mutant myeloid cancers.
2021-09-15 | GSE165505 | GEO
Project description:Current strategies to target RNA splicing mutant myeloid cancers propose disruption of normal splicing activity by targeting the splicing apparatus therapeutically. This approach is only modestly sensitizing and is also toxic to non-mutant bearing wild-type cells. To explore potentially exploitable genetic interactions with spliceosome mutations, we combined data mining and functional screening for synthetic lethal interactions with an Srsf2P95H/+ mutation. Analysis of mis-splicing events in a series of both human and murine SRSF2P95H mutant samples across multiple myeloid diseases (AML, MDS, CMML) was first performed to identify conserved mis-splicing events. From this analysis, we identified that the DNA repair and cell cycle pathways were overrepresented within the conserved mis-spliced transcript sets. In parallel, to functionally define pathways essential for survival and proliferation Srsf2P95H/+ cells, we performed a genome-wide pooled CRISPR loss of function screen using Hoxb8 immortalised R26-CreERki/+ Srsf2P95H/+ and R26-CreERki/+ Srsf2+/+ cell lines. We assessed for loss of sgRNA representation at three timepoints: immediately after Srsf2P95H/+ activation, and at one week and two weeks post Srsf2P95H/+ mutation. Pathway analysis demonstrated that the DNA damage response and cell cycle pathways were amongst the top synthetic lethal pathways with Srsf2P95H/+ mutation., Based on the loss of guide RNAs targeting Cdk6, we identified that Palbocilib, a CDK6 inhibitor, showed preferential sensitivity in Srsf2P95H/+ cell lines and in primary non-immortalised lin-cKIT+Sca-1+ cells compared to wild type controls. Our data strongly suggest that cell cycle and DNA damage response pathways are required for Srsf2P95H/+ cell survival, and that Palbociclib could be an alternative therapeutic option for targeting SRSF2 mutant myeloid cancers.
2021-09-15 | GSE165504 | GEO
Project description:Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic disorder with heterogeneous clinical, morphological and genetic characteristics. Clonal cytogenetic abnormalities are found in 20-30% of patients with CMML. Patients with low risk cytogenetic features (normal karyotype and isolated loss of Y chromosome) account for approximately 80% of CMML patients and often fall into the low risk categories of CMML prognostic scores. SNP-A were performed in 82 CMML patients with low risk karyotypes and uninformative results for conventional G-banding cytogenetics (CC).
2015-12-01 | GSE67460 | GEO
Project description:Mutations in spliceosomal genes are commonly found in patients with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). These mutations occur at highly restricted amino acid residues and perturb normal splice site and exon recognition. Spliceosomal mutations are always heterozygous and rarely co-occur with one another, suggesting that cells may only tolerate a partial deviation from normal splicing activity. To test this hypothesis, we generated mice with inducible hemizygous expression of the commonly occurring SRSF2P95H mutation in the hematopoietic system. These mice rapidly developed lethal bone marrow failure upon activation of the Srsf2P95H mutation with concomitant deletion of the wildtype Srsf2 allele, demonstrating that Srsf2-mutant cells depend on the wildtype Srsf2 allele for survival. We next tested whether spliceosomal-mutant leukemias display greater sensitivity to pharmacologic splicing inhibition induced by the small molecule E7107. Treatment of isogenic murine leukemias as well as patient-derived xenograft (PDX) AMLs showed significant reductions in leukemic burden specifically in samples carrying spliceosomal mutations. Collectively, these data provide genetic and pharmacologic evidence that leukemias with spliceosomal mutations are preferentially susceptible to additional splicing perturbations in vivo compared with wildtype counterparts. Modulation of spliceosome function may provide a novel therapeutic avenue in genetically defined subsets of MDS/AML patients. We created an isogenic murine leukemia model by retroviral overexpression of the MLL-AF9 fusion oncogene in Vav-Cre Srsf2+/+ or Vav-Cre Srsf2P95H/+ BM cells followed by transplantation into lethally irradiated recipient mice. In order to determine the mechanistic origins of the Srsf2 mutant-selective effects of E7107, we analyzed transcriptional changes after five consecutive days of E7107 or vehicle treatment in vivo. GFP+ Cd11b+ cells were purified from the BM of recipient mice exactly three hours after the last dose of E7107 and were subjected to paired-end 2x50bp RNA-seq. For the knock-in/knock-out experiments, we generated inducible, hemizygous Srsf2P95H mice to study the effects of wildtype Srsf2 deletion with concomitant activation of the Srsf2P95H allele. Mx1-cre Srsf2fl/+ mice were crossed to Srsf2P95H/+ mice to generate Srsf2 wildtype (Mx1-cre Srsf2+/+), Srsf2 heterozygous knockout (Mx1-Cre Srsf2+/-), Srsf2 heterozygous P95H mutant (Mx1-Cre Srsf2P95H/+), and Srsf2 hemizygous P95H mutant (Mx1-Cre Srsf2P95H/-) mice, which were subjected to single-end 101bp RNA-seq.
2016-03-31 | E-GEOD-74064 | biostudies-arrayexpress
Project description:<p>Although multi-agent combination chemotherapy is curative in a significant fraction of childhood acute lymphoblastic leukemia (ALL) patients, 20% of cases relapse and most die due to chemo-refractory disease. Here we used whole-exome and whole-genome sequencing to analyze the mutational landscape and pattern of clonal evolution at relapse in pediatric ALL cases. These analyses showed that ALL relapses originate from a common ancestral precursor clone of the diagnosis and relapsed populations and frequently harbor mutations implicated in chemotherapy resistance. RAS-MAPK pathway activating mutations in NRAS, KRAS and PTPN11 were present in 24/55 (44%) cases in our series. Notably, while some cases showed emergence of RAS mutant clones at relapse, in others, RAS mutant clones present at diagnosis were replaced by RAS wild type populations. Mechanistically, functional dissection of mouse and human wild type Kras and mutant Kras (Kras G12D) isogenic leukemia cells demonstrated induction of methotrexate resistance, but also improved response to vincristine, in mutant Kras- expressing lymphoblasts. These results identify chemotherapy driven selection as a central mechanism of leukemia clonal evolution and pave the road for the development of tailored personalized therapies for the treatment of relapsed ALL. </p>
| phs001072 | dbGaP
Project description:We have generated M-bM-^@M-^\reprogrammableM-bM-^@M-^] transgenic mice that ubiquitously express the four Yamanaka factors in an inducible manner. Transitory induction of the transgene results in multiple teratomas emerging from a variety of organs, thus indicating that full reprogramming into iPSCs can occur in vivo. By performing bone marrow transplant experiments, we demonstrate that both hematopoietic cells, as well as non-hematopoietic cells can be reprogrammed in vivo. Remarkably, reprogrammable mice also present circulating iPSCs in the bloodstream (in vivo-iPSCs) with all the expected properties of bona fide iPSCs. Moreover, in contrast to in vitro-iPSCs or embryonic stem cells (ESCs), in vivo-iPSCs have an increased capacity to undergo trophectoderm lineage differentiation, which suggests that in vivo-iPSCs are more plastic or primitive than in vitro-generated iPSCs or ESCs. 6 clones of in vivo-generated iPSCs, 5 indendent clones of in vitro-generated iPSCs, and 3 clones of established ESCs
2013-09-12 | E-GEOD-48364 | biostudies-arrayexpress
Project description:Understanding the contribution of abnormal genetic and epigenetic programs to acute myeloid leukemia (AML) is necessary for the integrated design of targeted therapies. To investigate this, we determined the effect of epigenetic reprogramming on leukemic behavior by generating induced pluripotent stem cells (iPSCs) from AML patient samples harboring MLL rearrangements. AML-derived iPSCs (AML-iPSCs) retained leukemic mutations, but reset leukemic DNA methylation/gene expression patterns and lacked leukemic potential. However, when differentiated into hematopoietic cells, AML-iPSCs reacquired the ability to give rise to leukemia in vivo and reestablished leukemic methylation/gene expression patterns, including an aberrant MLL signature, indicating that epigenetic reprogramming was insufficient to eliminate leukemic behavior. In one case, we identified distinct AML-iPSC KRAS mutant and wildtype subclones that demonstrated differential growth properties and therapeutic susceptibilities, predicting KRAS wildtype clonal relapse due to increased cytarabine resistance. Increased cytarabine resistance was further observed in a cohort of KRAS wildtype MLL-rearranged AML samples, demonstrating the utility of AML-iPSCs in predicting subclonal relapse and facilitating clonal targeting in AML. This SuperSeries is composed of the SubSeries listed below.
2016-11-14 | GSE89778 | GEO