Inhibition of Inflammatory Signaling in Pax5 Mutant Cells Mitigates B-cell leukemogenesis against leukemia
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PROVIDER: PRJNA646739 | ENA |
REPOSITORIES: ENA
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Project description:We used microarrays to investigate gene expression changes in healthy and leukemic cells from Pax5+/- and IL6+/-;Pax5+/- mice in CF and SPF housing conditions. PAX5 is one of the most frequently mutated genes in B-cell acute lymphoblastic leukemia (B-ALL), and children with inherited preleukemic PAX5 mutations are at a higher risk of developing the disease. Abnormal profiles of inflammatory markers can be detected in neonatal blood spot samples of children who later developed B-cell precursor B-ALL. However, how inflammatory signals contribute to B-ALL development is unclear. Here, we demonstrate that Pax5 loss results in the enhanced production of the inflammatory cytokine interleukin-6 (IL-6), which appears to act in an autocrine fashion to promote leukemia growth. In vivo genetic downregulation of IL-6 in Pax5 mutant mice retards B-cell leukemogenesis. In vivo pharmacologic inhibition of IL-6 with a neutralizing IL-6 antibody in Pax5 mutant mice with B-ALL clears leukemic cells. This exciting novel IL 6 signaling paradigm identified in mice was also substantiated in humans. Altogether, our studies establish aberrant IL6 expression caused by Pax5 loss as a hallmark of Pax5-dependent B-ALL and the IL6 as a therapeutic vulnerability for B-ALL characterized by PAX5 loss.
2020-07-17 | GSE154589 | GEO
Project description:PAX5 is one of the most frequently mutated genes in B-cell acute lymphoblastic leukemia (B-ALL), and children with inherited preleukemic PAX5 mutations are at a higher risk of developing the disease. Abnormal profiles of inflammatory markers have been detected in neonatal blood spot samples of children who later developed B-ALL. However, how inflammatory signals contribute to B-ALL development is unclear. Here, we demonstrate that Pax5 heterozygosis, in the presence of infections, results in the enhanced production of the inflammatory cytokine interleukin-6 (IL-6), which appears to act in an autocrine fashion to promote leukemia growth. Furthermore, in vivo genetic downregulation of IL-6 in these Pax5 heterozygous mice retards B-cell leukemogenesis, and in vivo pharmacologic inhibition of IL-6 with a neutralizing antibody in Pax5 mutant mice with B-ALL clears leukemic cells. Additionally, this novel IL-6 signaling paradigm identified in mice was also substantiated in humans. Altogether, our studies establish aberrant IL6 expression caused by Pax5 loss as a hallmark of Pax5-dependent B-ALL and the IL6 as a therapeutic vulnerability for B-ALL characterized by PAX5 loss.
| S-EPMC7644722 | biostudies-literature
Project description:We used microarrays to investigate gene expression changes in bone marrow B220+ cells from Pax5+/- and wild-type mice after ruxolitinib treatment during 2 weeks. Preventing development of B cell acute lymphoblastic leukemia (B-ALL), a disease with devastating effects in children, is a longstanding and unsolved challenge in medicine. In humans and mice, germline alterations in the Pax5 gene can lead to B-ALL. Preclinical studies have shown that this malignant transformation only occurs under an immune stress through the accumulation of secondary mutations in the JAK/STAT pathway. Here we describe that transient oral administration of ruxolitinib, a drug targeting the JAK/STAT pathway, can mitigate the risk of B-ALL in Pax5+/- mice. Although exposure to infection strongly potentiates leukemogenesis, the development of B-ALL was significantly impeded by transient in vivo treatment of Pax5+/- mice with ruxolitinib early in life (p-value=0.0332). These findings provided the first in vivo evidence for an effective preventive strategy for B-ALL development in genetically predisposed mice.
2021-07-02 | GSE179182 | GEO
Project description:To examine the role of PAX5 alterations in leukemogenesis, we performed mutagenesis screens of mice heterozygous for a loss-of-function Pax5 allele. Both chemical and retroviral mutagenesis resulted in a significantly increased penetrance and reduced latency of leukemia, with a shift to B-lymphoid lineage. We observed a range of maturation of lymphoid tumors, and genomic profiling identified a high frequency of secondary genomic mutations, deletions and retroviral insertions targeting B-lymphoid development, including Pax5, and additional genes and pathways known to be mutated in ALL, including tumor suppressors, Ras and JAK-STAT signaling. These results support the notion that loss-of-function of PAX5 is a central event in leukemogenesis and contributes to the arrest in lymphoid maturation characteristic of this disease. Moreover, we validate the role of mutations in additional pathways and demonstrate that sequential acquisition of genetic alterations is required for establishment of leukemia.
2015-04-10 | GSE67611 | GEO
Project description:PAX5, a transcription factor essential for B-cell development, has been found as a frequent target of abnormalities in B-Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) cases, showing point mutations, deletions, as well as translocations with several partner genes. We identified four novel PAX5 fusion partner genes by performing a screening on BCP-ALL cases with 9p rearrangements. Copy Number Variation analysis of translocated samples showed that few significant cooperative genetic lesions are present in addition to the translocation event, suggesting that it might have a primary role in leukemogenesis.
2015-03-02 | E-MTAB-2416 | biostudies-arrayexpress
Project description:PAX5-JAK2 has recently been identified as a novel recurrent fusion gene in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) but the function of the encoded chimeric protein has not yet been characterized in detail. Herein we show that the PAX5-JAK2 chimera, which consists of the DNA-binding paired domain of PAX5 and the active kinase domain of JAK2, is a nuclear protein that has the ability to bind to wild-type PAX5 target loci. Moreover, our data provide compelling evidence that PAX5-JAK2 functions as nuclear catalytically active kinase that autophosphorylates and in turn phosphorylates and activates downstream STATs in an apparently non-canonical mode. The chimeric protein also enables cytokine-independent growth of Ba/F3 cells and, therefore, possessing transforming potential. Importantly, the kinase activity of PAX5-JAK2 can be efficiently blocked by JAK2 inhibitors rendering it a potential target for therapeutic intervention. Together, our data show that PAX5-JAK2 simultaneously deregulates the PAX5 downstream transcriptional program and activates the JAK-STAT signaling cascade, and thus, by interfering with these two important pathways, may promote leukemogenesis.
2014-12-29 | GSE56449 | GEO
Project description:PAX5, one of nine members of the mammalian paired box (PAX) family of transcription factors, plays an important role in B cell development. Approximately one-third of individuals with pre-B acute lymphoblastic leukemia (ALL) acquire heterozygous inactivating mutations of PAX5 in malignant cells, and heterozygous germline loss-offunction PAX5 mutations cause autosomal dominant predisposition to ALL. At least in mice, Pax5 is required for pre-B cell maturation, and leukemic remission occurs when Pax5 expression is restored in a Pax5-deficient mouse model of ALL. Together, these observations indicate that PAX5 deficiency reversibly drives leukemogenesis. PAX5 and its two most closely related paralogs, PAX2 and PAX8, which are not mutated in ALL, exhibit overlapping expression and function redundantly during embryonic development. However, PAX5 alone is expressed in lymphocytes, while PAX2 and PAX8 are predominantly specific to kidney and thyroid, respectively. We show that forced expression of PAX2 or PAX8 complements PAX5 loss-of-function mutation in ALL cells as determined by modulation of PAX5 target genes, restoration of immunophenotypic and morphological differentiation, and, ultimately, reduction of replicative potential. Activation of PAX5 paralogs, PAX2 or PAX8, ordinarily silenced in lymphocytes, may therefore represent a novel approach for treating PAX5-deficient ALL. In pursuit of this strategy, we took advantage of the fact that, in kidney, PAX2 is upregulated by extracellular hyperosmolarity. We found that hyperosmolarity, at potentially clinically achievable levels, transcriptionally activates endogenous PAX2 in ALL cells via a mechanism dependent on NFAT5, a transcription factor coordinating response to hyperosmolarity. We also found that hyperosmolarity upregulates residual wild type PAX5 expression in ALL cells and modulates gene expression, including in PAX5-mutant primary ALL cells. These findings specifically demonstrate that osmosensing pathways may represent a new therapeutic target for ALL and more broadly point toward the possibility of using gene paralogs to rescue mutations driving cancer and other diseases.
2018-09-11 | GSE109860 | GEO
Project description:PAX5 transduction of Pax5-/- pro-B cells
| PRJNA414096 | ENA
Project description:Pax5 controls B-cell commitment, development and immunity by repressing B-lineage-inappropriate genes and activating B-cell-specific genes. In addition to the N-terminal DNA-binding paired domain, Pax5 contains a conserved octapeptide, partial homeodomain and C-terminal sequences with transactivating and inhibitory potential. To understand how the C-terminal domains of Pax5 contribute to the repression and activation function of Pax5, we performed Pax5 pulldown combined with mass spectrometry to identify coactivator or corepressor complexes that bind to the C-terminal regions of Pax5.
2023-08-24 | PXD040424 | Pride
Project description:Using integrated genomic analysis of 1.988 childhood and adult cases, we describe a revised taxonomy of B-cell acute lymphoblastic leukemia, which incorporates 23 subtypes defined by chromosomal rearrangements, sequence mutations, or heterogeneous genomic alterations. Two subtypes have frequent alterations of the B lymphoid transcription factor gene PAX5. One, PAX5alt, has diverse PAX5 alterations, and a second subtype is defined by a single mutation, PAX5 P80R. We show that P80R impairs B lymphoid development and promotes the development of B-ALL in vivo. These results demonstrate the utility of transcriptome sequencing to classify B-ALL and reinforce the central role of PAX5 as a checkpoint in B lymphoid maturation and leukemogenesis.
| EGAS00001003266 | EGA