Project description:CRLF2-rearranged acute lymphoblastic leukemia (ALL) is associated with poor clinical outcomes. Although JAK1/2 is activated in this type of ALL, treatment with JAK1/2 inhibitors is insufficient in inhibiting cell growth and inducing apoptosis. BCL6 upregulation upon JAK inhibition may account for this insufficiency. Therefore, we compared gene expression changes of two CRLF2-rearranged ALL cell lines, MHH-CALL-4 and MUTZ-5, treated with either ruxolitinib(a JAK1/2 inhibitor), FX1(a BCL6 inhibitor), their combination, or control.
Project description:Chromosomal aneuploidy and translocations are hallmarks of acute lymphoblastic leukemia (ALL), but many patients lack a recurring chromosomal alteration. Here we report a recurring interstitial deletion of the pseudoautosomal region 1 of chromosomes X and Y in B-progenitor ALL that results in the expression of a novel fusion that juxtaposes the first non-coding exon of P2RY8 to the coding region of the CRLF2 (cytokine receptor like factor 2, or thymic stromal lymphopoietin receptor) gene. The P2RY8-CRLF2 fusion was identified in 7% of B-ALL cases, and was very common in ALL associated with Down syndrome (55% of cases) and was associated with the presence of JAK mutations. The P2RY8-CRLF2 fusion results in increased expression of CRLF2, a lymphoid signaling molecule that forms a heterodimeric complex with interleukin receptor 7 alpha. These findings identify a novel recurring chromosomal alteration in B-ALL, and suggest that perturbed CRLF2-mediated signaling is a key event in leukemogenesis in these cases. Profiling of tumor acquired DNA copy number alterations in 2 patients with Down syndrome associated B-progenitor acute lymphoblastic leukemia. Matched tumor and normal DNA was used for each array hybridization in each case.
Project description:We quantitatively evaluated H2Bub and H3K79me2 epigenetic marks genome wide in a KMT2A rearranged B lineage acute lymphoblastic leukemia cell line after treatment with bortezomib over a 6 hour time course by ChIP-Rx. We identified rapid and concordant depletion of these epigenetic marks within two hours. To look at gene expression changes, RNA sequencing was performed on KMT2A rearranged B lineage acute lymphoblastic leukemia patient samples in the presence and absence of bortezomib exposure.
Project description:Enhancer activity and RUNX1 binding was studied using ChIP-seq in mixed lineage leukemia t(4;11) rearranged acute lymphoblastic leukemia upon inhibition of the WEE1 kinase.
Project description:Deregulated expression of cytokine receptor gene, CRLF2, is involved in lymphoid transformation in B-cell precursor acute lymphoblastic leukemia We report two novel, cryptic chromosomal abnormalities in precursor B-cell acute lymphoblastic leukemia (BCP-ALL): a translocation, either t(X;14)(p22;q32) or t(Y;14)(p11;q32), in 33 patients and an interstitial deletion, either del(X)(p22.33p22.33) or del(Y)(p11.32p11.32), in 64 patients, involving the pseudoautosomal region (PAR1) of the sex chromosomes. The incidence of these abnormalities was 5% in childhood ALL (0.8% with the translocation, 4.2% with the deletion). Patients with the translocation were older (median age 16 years), whilst the patients with the deletion were younger (median age 4 years). The two abnormalities result in deregulated expression of the cytokine receptor, cytokine receptor-like factor 2, CRLF2 (also known as thymic stromal-derived lymphopoietin receptor, TSLPR). Over-expression of CRLF2 was associated with activation of the JAK-STAT pathway in cell lines and transduced primary B-cell progenitors, sustaining their proliferation and indicating a causal role of CRLF2 over-expression in lymphoid transformation. In Down Syndrome (DS) ALL and two non DS BCP-ALL cell lines, CRLF2 deregulation was associated with mutations of the JAK2 pseudokinase domain suggesting oncogenic cooperation, as well as highlighting a link between non DS ALL and JAK2 mutations. Keyword(s): Global copy number analysis using Agilent oligonucleotide arrays DNA copy number analysis of 16 acute lymphoblastic leukaemia samples (13 diagnostic, 1 diagnostic and relapse pair and 2 cell-lines) was performed using Agilent 244K and 105K custom microarrays. These samples were hybridised against gender matched reference DNA.
Project description:We evaluated the efficacy of proteolysis-targeting chimeras (PROTACs) directed against Janus kinases. Solving the structure of FDA-approved type I JAK inhibitors ruxolitinib and baricitinib bound to the JAK2 JH1 tyrosine kinase domain enabled the rational design and optimization of Cereblon (CRBN)-directed JAK PROTACs utilizing multiple derivatives of JAK inhibitors, linkers and CRBN-specific molecular glues. The resulting JAK PROTACs were evaluated for target degradation by proteomic approaches, and activity tested in CRLF2-rearranged cell line and xenograft models of ALL.
Project description:DS-ALL is a highly heterogeneous disease with predominance of an aberrant exp. of CRLF2 cooperating with mutated JAK2 Acute lymphoblastic pediatric leukemia specimens of Down's syndrome are examined for gene expression profiles and specific genetic aberrations. Gene expression profiling and specific genetic variation analysis identify novel pathways involved in DS-ALL pathogenesis.
Project description:Deregulated expression of cytokine receptor gene, CRLF2, is involved in lymphoid transformation in B-cell precursor acute lymphoblastic leukemia We report two novel, cryptic chromosomal abnormalities in precursor B-cell acute lymphoblastic leukemia (BCP-ALL): a translocation, either t(X;14)(p22;q32) or t(Y;14)(p11;q32), in 33 patients and an interstitial deletion, either del(X)(p22.33p22.33) or del(Y)(p11.32p11.32), in 64 patients, involving the pseudoautosomal region (PAR1) of the sex chromosomes. The incidence of these abnormalities was 5% in childhood ALL (0.8% with the translocation, 4.2% with the deletion). Patients with the translocation were older (median age 16 years), whilst the patients with the deletion were younger (median age 4 years). The two abnormalities result in deregulated expression of the cytokine receptor, cytokine receptor-like factor 2, CRLF2 (also known as thymic stromal-derived lymphopoietin receptor, TSLPR). Over-expression of CRLF2 was associated with activation of the JAK-STAT pathway in cell lines and transduced primary B-cell progenitors, sustaining their proliferation and indicating a causal role of CRLF2 over-expression in lymphoid transformation. In Down Syndrome (DS) ALL and two non DS BCP-ALL cell lines, CRLF2 deregulation was associated with mutations of the JAK2 pseudokinase domain suggesting oncogenic cooperation, as well as highlighting a link between non DS ALL and JAK2 mutations. Keyword(s): Global copy number analysis using Agilent oligonucleotide arrays