Project description:Arrested bone marrow (BM) lymphoid cell differentiation underlies the emergence of the most common childhood cancer, acute lymphoblastic leukemia (ALL). Recurrent genetic lesions often directly involve transcription factors (TFs), such as ETV6 and RUNX1 found in the most common ALL translocation.
Project description:Arrested bone marrow (BM) lymphoid cell differentiation underlies the emergence of the most common childhood cancer, acute lymphoblastic leukemia (ALL). Recurrent genetic lesions often directly involve transcription factors (TFs), such as ETV6 and RUNX1 found in the most common ALL translocation. Here, we studied differential gene expression in ETV6-RUNX1 primary ALL samples and the REH cell line using single cell RNA-seq (scRNA-seq). Submitter declares that the raw data will be deposited in EGA due to patient privacy concerns. The raw data can be accessed at https://www.ebi.ac.uk/ega/studies/EGAS00001004374
Project description:Single cell characterization of arrested B-lymphoid differentiation and leukemic cell states in ETV6-RUNX1-positive pediatric leukemia
Project description:Analysis of gene signatures in WT+Ctrl vs WT+ETV6-RUNX1, Btg1-/- and Btg1-/-+ETV6-RUNX1 in cKit+Ter119- fetal liver-derived hematopoietic progenitor cells (FL-HPCs). The Btg1-/-+ETV6-RUNX1 FL-HPCs display a strong increase in proliferation compared to WT+ETV6-RUNX1. Total RNA otained from WT+Ctrl, WT+ETV6-RUNX1, Btg1-/-+Ctrl and Btg1-/-+ETV6-RUNX1 FL-HPCs cells that were cultured for 12 days in expansion medium.
Project description:ETV6-RUNX1 is a first-hit mutation in childhood B cell precursor acute lymphoblastic leukaemia. ETV6-RUNX1 is a fusion protein which inherits the DNA-binding runt domain from RUNX1. Here we performed chromatin precipitation for native RUNX1 and ETV6-RUNX1 using RUNX1 antibodies and specifically for the ETV6-RUNX1 fusion using a V5-tag pull down.
Project description:Analysis of gene signatures in WT+Ctrl vs WT+ETV6-RUNX1, Btg1-/- and Btg1-/-+ETV6-RUNX1 in cKit+Ter119- fetal liver-derived hematopoietic progenitor cells (FL-HPCs). The Btg1-/-+ETV6-RUNX1 FL-HPCs display a strong increase in proliferation compared to WT+ETV6-RUNX1.
Project description:Genetic hits in the gene regulatory network underlie arrested lymphoid cell differentiation and emergence of the most common childhood cancer, acute lymphoblastic leukemia (ALL). Here, we aimed to understand what alterations in the lymphoid gene expression program arise in leukemias carrying the common translocation t12;21, fusing the ETV6 and RUNX1 genes. We compared normal B-lineage differentiation and in vivo leukemic cell states at diagnosis and during chemotherapy using single cell RNA-sequencing (scRNA-seq) and several complementary genomics assays. We show that noisy gene expression of critical pre-BCR signaling pathway genes arises as a consequence of ETV6-RUNX1-mediated repression of intronic enhancers. Furthermore, our analysis implicated the genome-wide association study hit ELK3 among high activity transcription factors in leukemic cell states. The accompanying gene expression changes were found to associate with natural killer cell inactivation and depletion in the leukemic immune microenvironment. Moreover, our results suggest that the abundance of G1 cell cycle state at diagnosis and lack of differentiation-associated regulatory network changes represent features of chemoresistance during induction chemotherapy. Finally, we show that selective inhibitors of ETS-transcription factors could dramatically reduce cell viability. In summary, our results provide a detailed picture of gene regulatory defects in leukemic bone marrow, disclosing mechanistic insight on the role of gene expression noise and suggesting new treatment strategies targeting the active regulatory network.
Project description:ETV6-RUNX1 is associated with childhood B-cell acute lymphoblastic leukemia (B-ALL), but the consequence of ETV6-RUNX1 expression on cell lineage decision during B-cell leukemogenesis remains largely evasive. Clinically silent ETV6-RUNX1 preleukemic clones are frequently found in neonatal cord blood, but only a few carriers develop B-ALL as a result of the acquisition of secondary postnatal genetic hits, like KDM5C or PAX5 loss. However, understanding the mechanism involved in this transformation would advance the development of non-toxic prophylactic interventions to preleukemic carriers. Using genetic lineage tracing, we have examined the capacity of ETV6-RUNX1 in instructing a B-cell malignant phenotype. Restricted Cre-mediated activation of ETV6-RUNX1 from the endogenous Etv6 locus into B-cell precursors does not trigger B-ALL development. Similarly, concomitant transient ETV6-RUNX1 expression in hematopoietic progenitors close to restricted Cre-mediated introduction of second hit (Kdm5c loss) in B-cells fail to induce B-ALL. In contrast, targeting ETV6-RUNX1 in hematopoietic progenitors was required to induce leukemia. These mice develop either T-ALL or B-ALL, suggesting that the nature of the second hit may define tumor cell identity during ETV6-RUNX1 leukemogenesis. In order to uncover a potential exclusive effect of the second hit in establishing the leukemic phenotype, we next showed that the introduction of the second hit, either Kdm5c or Pax5 loss, to the ETV6-RUNX1 preleukemic clone confers the tumor B-cell identity without need of environmental infection exposure. The resulting B-ALLs clustered according to the second-hit by RNA sequencing (RNA-Seq) analysis. Together these results provide a novel paradigm for the generation of tumor B cells through ETV6-RUNX1 in vivo where the second hit confers the tumor cell-identity to the ETV6-RUNX1 preleukemic clone. These findings could be relevant to develop new therapeutic approaches to prevent disease development.
Project description:Overwhelming evidence indicates that long non-coding RNAs have essential roles in tumorigenesis. Nevertheless, their expression and role in pediatric B-cell precursor acute lymphoblastic leukemia has not been extensively explored. Here, we conducted a comprehensive analysis of the long non-coding RNA transcriptome in ETV6/RUNX1 positive BCP-ALL, one of the most frequent subtypes of pediatric leukemia. An ETV6/RUNX1 expression signature was established, consisting of 596 lncRNAs (434 up and 162 down) using expression analysis of a series of primary patient samples. Subsequently, RNA sequencing from BCP-ALL cell lines and shRNA-mediated silencing of ETV6/RUNX1, illustrated that lnc-NKX2-3-1, lnc-TIMM21-5, lnc-ASTN1-1 and lnc-RTN4R-1 are bona fide ETV6/RUNX1 targets and could serve as novel biomarkers of this prevalent subtype of human leukemia.