Lmo2 is dispensable for maintenance of most Lmo2-induced murine T-cell leukemias
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ABSTRACT:
PROVIDER: PRJNA517144 | ENA |
REPOSITORIES: ENA
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Project description:Lmo2 is an oncogenic transcription factor that is a frequent target of chromosomal abnormalities in this T-cell acute lymphoblastic leukemia (T-ALL). In transgenic mouse models, overexpression of Lmo2 causes thymocyte self-renewal leading to T-cell leukemia with long latency. However, the requirement of Lmo2 for maintenance of overt leukemia is poorly understood. We found that Lyl1, a critical cofactor for Lmo2-induced leukemia, is frequently lost in cell lines derived from Lmo2-transgenic mice, raising the possibility that Lmo2 function is dispensable at this stage. To study this, we developed a Tetracycline-repressible knock-in mouse model (Vav-TRE-Lmo2), which expresses Lmo2 throughout the haematopoietic system. This led to specific effects on T-cell development and the development of T-cell leukemia with long latency, preceded by the presence of self-renewing T-cells in the thymus. Repression of Lmo2 overcame the Lmo2-induced thymocyte developmental block at the preleukemic stage and led to elimination of Lmo2-induced thymocyte self-renewal in vivo. In contrast, Lmo2 function was dispensable for the majority of overt Lmo2-induced T-cell leukemias as well as leukemia-derived cell lines, implying an evolution of oncogene addiction in the majority of T-cell leukemias. Lmo2-dependence in T-ALL was associated with an immature gene expression profile, but could not be predicted by immunophenotype or assessment of Notch pathway activation. Thus, Lmo2 can give rise to both Lmo2-depenent and –independent T-cell leukemias. The Vav-TRE-Lmo2 model should be useful to determine the molecular features associated with Lmo2-dependence, as well as the critical components of the Lmo2-induced self-renewal pathways in T-ALL.
2022-01-01 | GSE125674 | GEO
Project description:JAK2 is dispensable for maintenance of JAK2 mutant B-cell acute lymphoblastic leukemias
| PRJNA397978 | ENA
Project description:LMO2 is an oncogenic transcription factor that is frequently overexpressed due to chromosomal abnormalities in T-cell acute lymphoblastic leukemia (T-ALL). In transgenic mouse models, Lmo2 overexpression causes thymocyte self-renewal resulting in T-cell leukemia with long latency. However, the requirement for Lmo2 for leukemia maintenance is poorly understood. To study this, we developed a Tetracycline-regulated knock-in mouse model that reversibly expresses Lmo2 throughout the haematopoietic system. This led to a specific impairment of T-cell development and the development of self-renewing preleukemic stem cells (pre-LSCs) in the thymus, followed by the development of fully penetrant T-lymphoblastic leukemia resembling human T-ALL. In preleukemic mice, repression of Lmo2 overcame the LMO2-induced thymocyte developmental block, reversed Lmo2-induced gene expression changes and eliminated self-renewing pre-LSCs in vivo. In contrast, overt T-lymphoblastic leukemias arising in this model were either immature, Lmo2-dependent leukemias resembling human ETP-ALL, or mature leukemias which were Lmo2-independent. Genomic analyses identified frequent loss of tumour suppressor genes in Lmo2-independent T-ALLs. Deletion of one of these, Ikaros (Ikzf1), was sufficient to transform Lmo2-dependent tumours to Lmo2-independence. Together these results indicate an evolution of oncogene addiction in T-ALL and that loss of Ikaros can promote self-renewal of T-ALL lymphoblasts in the absence of initiating oncogenes.
2020-12-31 | GSE144035 | GEO
Project description:We used microarrays to examine what genes could be regurated by LMO2 in erythroid cells. Comparing expression profile in murine G1E-ER-GATA-1 cells treated with control and Lmo2 siRNA on Agilent array. After siRNA transfection, the cells were treated with b-estradiol for 24h to induce GATA-1-mediated erythroid maturation.
2010-09-25 | E-GEOD-24336 | biostudies-arrayexpress
Project description:We generated MLL-AF9 mediated murine leukemias that originate either from hematopoietic stem or committed progenitors cells. The luekemia stem cell fraction in these two type of leukemias shared exactly the same immunophenotype but their genetic programs differ.
2011-03-31 | GSE18483 | GEO
Project description:Zinc finger and SCAN domain-containing 10 (Zscan10, also known as Zfp206) encodes a transcription factor that has been reported to be involved in the maintenance of pluripotency in mouse embryonic stem (ES) cells. Here we generated inducible knockout ES cells for Zscan10 using the Cre-loxP system and analyzed its function. We succeeded in establishing Zscan10-null ES cells and confirmed their pluripotency by the generation of chimeric embryos. Our results clearly indicate that Zscan10 is dispensable for the ability of self-renewal and differentiation in ES cells. An inducible knockout ES cell line of Zscan10 with the Cre-loxP system was generated and gene expression was measured without Zscan10 deletion or constitutive knocked out cells. Each sample was prepared in triplicate.
2015-12-20 | E-GEOD-76143 | biostudies-arrayexpress
Project description:To identify the binding partner of LMO2 for explanation of STAT3 signal-related protein in human glioblastoma
2022-08-11 | PXD028254 | Pride
Project description:Notch signaling primarily determines T-cell fate. However, the molecular mechanisms underlying the maintenance of T-lineage potential in pre-thymic progenitors remain unclear. Here, we established two Ebf1-deficient pro-B cell lines, with and without T-lineage potential. The latter expressed lower levels of Lmo2; their potential was restored via ectopic expression of Lmo2. Conversely, the CRISPR/Cas9-mediated deletion of Lmo2 resulted in the loss of the T-lineage potential. Introduction of Bcl2 rescued massive cell death of Notch-stimulated pro-B cells without efficient LMO2-driven Bcl11a expression but was not sufficient to retain their T-lineage potential. Pro-B cells without T-lineage potential failed to activate Tcf7 due to DNA methylation; Tcf7 transduction restored this capacity. Moreover, direct binding of LMO2 to the Bcl11a and Tcf7 loci was observed. Altogether, our results highlight LMO2 as a crucial player in the survival and maintenance of T-lineage potential in T-cell progenitors via the regulation of the expression of Bcl11a and Tcf7.
2021-08-05 | GSE154472 | GEO
Project description:Activation or maintenance of a leukemia stem cell self-renewal pathway in downstream myeloid cells is an important component of AML development We generated either MLL-AF9 mediated murine leukemias that originate from committed progenitor (GMP) cells or Hoxa9/Meis1a mediated murine leukemias that originate from hematopoietic stem cells (HSC). The leukemia stem cell fraction in these two type of leukemias shared a common self-renewal pathway with normal hematopoietic stem cells. Keywords: Cell type comparison Total RNA from HSC (KLS), CMP, and GMP, and from leukemia stem cells (LGMP) was isolated and hybridized to Affymetrix expresison microarrays.
2010-03-23 | E-GEOD-20377 | biostudies-arrayexpress
Project description:Five X-linked severe combined immunodeficiency patients (SCID-X1) successfully treated with autologous bone marrow stem cells infected ex vivo with an IL2RG-containing retrovirus subsequently developed T-cell leukemia and four contained insertional mutations at LMO2. Genetic evidence also suggests a role for IL2RG in tumor formation, although this remains controversial. Here, we show that the genes and signaling pathways deregulated in murine leukemias with retroviral insertions at Lmo2 are similar to those deregulated in human leukemias with high LMO2 expression and are highly predictive of the leukemias induced in SCID-X1 patients. We also provide additional evidence supporting the notion that IL2RG and LMO2 cooperate in leukemia induction but are not sufficient and require additional cooperating mutations. The highly concordant nature of the genetic events giving rise to mouse and human leukemias with mutations at Lmo2 are an encouraging sign to those wanting to use mice to model human cancer and may help in designing safer methods for retroviral gene therapy.
| S-EPMC2679194 | biostudies-literature