Project description:We compared the transcriptome of E47-/- and E2a/-Lef1F/F leukemia lines 72 hours after transduction with MigR1 or MigR1-Cre. The GFP+ populations were isolated by flow cytometric sorting
Project description:Microarray data of mouse primary E2A-PBX1 leukemias and preleukemia cells were compared to wild-type B-cell progenitor cells Aberrant activation of signaling pathways has been linked to leukemogenesis, however, little is known about cell signaling perturbations induced by fusion transcription factors. To address this, we interrogated activated signaling pathways in a comparative analysis of mouse and human leukemias expressing the chimeric fusion protein E2A-PBX1, which is present in 5-7% of pediatric and 50% of pre-B-cell receptor (preBCR+) ALL. We describe here signaling network remodeling by E2A-PBX1 in pre-B-ALL, which results in hyperactivation of PLCγ2. Depletion of PLCγ2 reduced proliferation of mouse and human ALLs, including E2A-PBX1 leukemias, and increased disease-free survival after secondary transplantation. E2A-PBX1 binds and activates the transcription of its target genes ZAP70, SYK and LCK, which encode kinases upstream of PLCγ2. Efficient shRNA-mediated depletion of the respective upstream kinases decreased cell proliferation and phosphorylated levels of PLCγ2 (pPLCγ2). Pairwise compound knockdown of ZAP70, SYK or LCK showed additive effects on cell growth inhibition, providing a rationale for combination therapy. Inhibition of SYK, LCK and SFK with small molecule inhibitors, including dasatinib, was highly effective in reducing pPLCγ2 and inhibiting proliferation of preBCR+ leukemias in vitro and in vivo. Combination small molecule inhibition of SYK, LCK and SFK showed promising preclinical efficacy for preBCR+/E2A-PBX1+ leukemias. These studies demonstrate that E2A-PBX1 induces signaling pathway perturbations upstream of PLCγ2, which render leukemias amenable to targeted therapeutic inhibition.
Project description:To investigate gene targets of the E-proteins HEB and E2A during the CD4+CD8+ double positive (DP) stage of T cell development. We examined E-protein function by simultaneous removal of both HEB (Tcf12) and E2A (Tcfe2a) genes at the DP stage. This was done by crossing mice containing HEB floxed and E2A floxed alleles to a CD4Cre background (Tcf12f/fTcfe2af/fCD4Cre mice). Microarray analysis was used to compare gene expression in HEB and E2A double deficient DP thymocytes (Cre+) to Cre- control DP thymocytes. Keywords: genetic modification
Project description:Human B cell lineage acute lymphoblastic leukemia (ALL) cells carrying MLL-AF4 (SEM; BEL) and E2A-PBX1 (697) gene rearrangements were transduced with the mouse ecotropic receptor to permit subsequent entry of retroviral BCR-ABL1 GFP and GFP empty vectors (EV) pseudotyped with murine ecotropic envelope. GFP expression was measured by flow cytometry. Transductions with BCR-ABL1 GFP and GFP empty vectors (EV) were performed in the presence and absence of 2 mmol/l Imatinib (TKI). Washout of Imatinib in one series of experiments is indicated with an arrow. To study gene expression changes in MLL-AF4 and E2A-PBX1 B cell lineage ALL cells that were transduced with empty vectors (EV), BCR-ABL1 GFP in the presence of Imatinib (BCR-ABL1 OFF), washout of Imatinib (BCR-ABL1 ON) and subsequent re-addition of Imatinib, microarray analyses were performed.
Project description:Hematopoietic conditional knockout (cKO) of Phf6 in a mouse retroviral-HoxA9 AML model led to increased transplantability and accumulation of a c-Kit+ Ly6C- population that we termed the 'Leukemia Initiating Cell-Enriched' (LIC-e) population. We performed bulk ATAC-Seq on the LIC-e population sort purified 4 days after transduction of Ctrl (Vav-Cre/+, Phf6 +/Y) or cKO (Vav-Cre/+, Phf6 flox/Y) marrow retrovirally transduced with HoxA9.
Project description:Background: E2A, encoded by the TCF3 gene locus, belongs to the E protein transcription factor family, which also includes HEB (TCF12) and E2-2 (TCF4), has been suggested to play an important role in leukemogenesis. However, far less is known about the function of E2A in cell-fate regulation of hESCs. Therefore, further understanding of E2A in self-renewal and differentiation of embryonic stem cells may be influenced. Methods: The mRNA profiles of wildtype and E2A knockout embryonic stem cells were generated by RNA-seq technique, in triplicate for each group, using IIIumina Hiseq 2500. Results: A comprehensive human transcriptome map of wild type and E2A knockout embryonic stem cells was provided. Function enrichment, network characteristics and disease association of the differentially expressed genes were analyzed. Conclusion: The dataset could serve as a baseline resource for investigating the potential effects and mechanism of E2A in embryonic stem cells.