STAT3 couples activated tyrosine kinase signaling to the oncogenic core transcriptional regulatory circuitry of anaplastic large cell lymphoma [ChIP-seq]
Ontology highlight
ABSTRACT: Anaplastic large cell lymphoma (ALCL) is an aggressive, CD30+ T-cell lymphoma of children and adults. ALK fusion transcripts or mutations in the JAK-STAT pathway are observed in most ALCL tumors, but the mechanisms underlying tumorigenesis are not fully understood. Here we show that dysregulated STAT3, together with a core transcriptional regulatory circuit consisting of BATF3–IRF4–IKZF1, co-occupies gene enhancers to establish an oncogenic transcription program and maintain the malignant state of ALCL. Critical downstream targets of this network in ALCL cells include the proto-oncogene MYC, which requires active STAT3 to facilitate high levels of MYC transcription. The activity of this auto-regulatory transcription loop is reinforced by MYC binding to the enhancer regions associated with STAT3 and each of the core regulatory transcription factors. These findings provide new insights for understanding how dysregulated signaling pathways hijack cell-type-specific transcriptional machinery to drive tumorigenesis and create therapeutic vulnerabilities in genetically defined tumors.
Project description:Anaplastic large cell lymphoma (ALCL) is an aggressive, CD30+ T-cell lymphoma of children and adults. ALK fusion transcripts or mutations in the JAK-STAT pathway are observed in most ALCL tumors, but the mechanisms underlying tumorigenesis are not fully understood. Here we show that dysregulated STAT3, together with a core transcriptional regulatory circuit consisting of BATF3–IRF4–IKZF1, co-occupies gene enhancers to establish an oncogenic transcription program and maintain the malignant state of ALCL. Critical downstream targets of this network in ALCL cells include the proto-oncogene MYC, which requires active STAT3 to facilitate high levels of MYC transcription. The activity of this auto-regulatory transcription loop is reinforced by MYC binding to the enhancer regions associated with STAT3 and each of the core regulatory transcription factors. These findings provide new insights for understanding how dysregulated signaling pathways hijack cell-type-specific transcriptional machinery to drive tumorigenesis and create therapeutic vulnerabilities in genetically defined tumors.
Project description:Anaplastic large cell lymphoma (ALCL) is an aggressive, CD30+ T-cell lymphoma of children and adults. ALK fusion transcripts or mutations in the JAK-STAT pathway are observed in most ALCL tumors, but the mechanisms underlying tumorigenesis are not fully understood. Here we show that dysregulated STAT3, together with a core transcriptional regulatory circuit consisting of BATF3–IRF4–IKZF1, co-occupies gene enhancers to establish an oncogenic transcription program and maintain the malignant state of ALCL. Critical downstream targets of this network in ALCL cells include the proto-oncogene MYC, which requires active STAT3 to facilitate high levels of MYC transcription. The activity of this auto-regulatory transcription loop is reinforced by MYC binding to the enhancer regions associated with STAT3 and each of the core regulatory transcription factors. These findings provide new insights for understanding how dysregulated signaling pathways hijack cell-type-specific transcriptional machinery to drive tumorigenesis and create therapeutic vulnerabilities in genetically defined tumors.
Project description:Anaplastic large cell lymphoma (ALCL) is a main type of T cell lymphomas and comprises three distinct entities: systemic ALK+, systemic ALK- and cutaneous ALK- ALCL. Little is known about their pathogenesis and their cellular origin, and morphological and immunophenotypical overlap exists between ALK- ALCL and classical Hodgkin lymphoma (cHL). We conducted gene expression profiling of microdissected lymphoma cells of ALK+ and ALK- systemic ALCL, cutaneous ALCL and cHL, and of eight subsets of normal T and NK cells. The analysis supports a derivation of ALCL from activated T cells, but the lymphoma cells acquired a gene expression pattern hampering an assignment to a CD4+, CD8+ or CD30+ T cell origin. Indeed, ALCL display a general down-modulation of T cell characteristic molecules. All ALCL types show significant expression of NFκB target genes and upregulation of genes involved in oncogenesis (e.g. EZH2). Surprisingly few genes are differentially expressed between systemic and cutaneous ALK- ALCL despite their different clinical behaviour, and between ALK- ALCL and cHL despite their different cellular origin. ALK+ ALCL are characterized by expression of genes regulated by pathways constitutively activated by ALK. This study provides multiple novel insights into the molecular biology and pathogenesis of ALCL.
Project description:Anaplastic large cell lymphoma (ALCL) is a mature T cell neoplasm that often expresses the CD4+ T cell surface marker. (It usually harbors the t(2;5) (p23;q35) translocation, leading to the ectopic expression of NPM-ALK, a chimeric tyrosine kinase. We demonstrated that in vitro transduction of normal human CD4+ T lymphocytes with NPM-ALK results in their immortalization and malignant transformation. The tumor cells displayed morphological and immunophenotypical characteristics of primary patient–derived anaplastic large cell lymphomas. Cell growth, proliferation, and survival were strictly dependent on NPM-ALK activity and include activation of the key factors STAT3 and DNMT1 and expression of CD30 (the hallmark of anaplastic large-cell lymphoma). Implantation of NPM-ALK–transformed CD4+ T lymphocytes into immunodeficient mice resulted in the formation of tumors indistinguishable from patients’ anaplastic large cell lymphomas. Integration of “Omic” data revealed that NPM-ALK–transformed CD4+ T lymphocytes and primary NPM-ALK+ ALCL biopsies share similarities with early T cell precursors. Of note, these NPM-ALK+ lymphoma cells overexpress stem cell regulators (OCT4, SOX2, and NANOG) and HIF2A, which is known to affect hematopoietic precursor differentiation and NPM-ALK+ cell growth. Altogether, for the first time our findings suggest that NPM-ALK could restore progenitor-like features in mature CD30+ peripheral CD4+ T cells, in keeping with a thymic progenitor-like pattern.
Project description:Systemic anaplastic large cell lymphoma (ALCL) is an aggressive T-cell lymphoma comprising ALK-positive (ALK+) and ALK-negative (ALK−) as well as breast implant-associated (BIA)-ALCL. The prognosis for ALCL, ALK− in particular is poor, and already in second line there is an unmet medical need for effective treatment options. To identify genes defining ALCL cell state and dependencies, we here started by an unbiased characterization of super-enhancer regions by genome-wide H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq). We identified, in addition to known key regulators, the AP-1 transcription factor member BATF3 and IL-2 receptor (IL2R) components among the genes with most extensively H3K27-acetylated regulatory regions. Consistently, specific and high-level expression of the IL-2R subunits, IL-2Rα, IL-2Rβ and IL-2Rγ in ALCL correlate with BATF3 expression. Confirming a regulatory link, expression of IL-2R subunits decreases following BATF3 knockout, and BATF3 is recruited to AP-1 sites in IL2R regulatory regions. Functionally, IL-2, IL-15 and Neo-2/15, a hyper-stable IL-2/IL-15 mimic, accelerate growth of ALCL cells and activate STAT1, STAT5 and ERK, but not STAT3. In line, strong IL-2Rα expression in ALCL patients is linked to more aggressive clinical presentation. Finally, we demonstrate highly efficient killing of ALCL cells by an IL-2Rα-targeting antibody-drug conjugate in vitro and in vivo. Our results highlight the importance of the BATF3/IL-2R module for ALCL biology and identify IL-2Rα as the target of a promising treatment strategy for ALCL.
Project description:Systemic anaplastic large cell lymphoma (ALCL) is an aggressive T-cell lymphoma comprising ALK-positive (ALK+) and ALK-negative (ALK−) as well as breast implant-associated (BIA)-ALCL. The prognosis for ALCL, ALK− in particular is poor, and already in second line there is an unmet medical need for effective treatment options. To identify genes defining ALCL cell state and dependencies, we here started by an unbiased characterization of super-enhancer regions by genome-wide H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq). We identified, in addition to known key regulators, the AP-1 transcription factor member BATF3 and IL-2 receptor (IL2R) components among the genes with most extensively H3K27-acetylated regulatory regions. Consistently, specific and high-level expression of the IL-2R subunits, IL-2Rα, IL-2Rβ and IL-2Rγ in ALCL correlate with BATF3 expression. Confirming a regulatory link, expression of IL-2R subunits decreases following BATF3 knockout, and BATF3 is recruited to AP-1 sites in IL2R regulatory regions. Functionally, IL-2, IL-15 and Neo-2/15, a hyper-stable IL-2/IL-15 mimic, accelerate growth of ALCL cells and activate STAT1, STAT5 and ERK, but not STAT3. In line, strong IL-2Rα expression in ALCL patients is linked to more aggressive clinical presentation. Finally, we demonstrate highly efficient killing of ALCL cells by an IL-2Rα-targeting antibody-drug conjugate in vitro and in vivo. Our results highlight the importance of the BATF3/IL-2R module for ALCL biology and identify IL-2Rα as the target of a promising treatment strategy for ALCL.
Project description:Chicken MarekM-bM-^@M-^Ys disease (MD) is a unique naturally occurring model for human herpesvirus-induced lymphomas that over-express the M-bM-^@M-^\HodgkinM-bM-^@M-^Ys disease antigenM-bM-^@M-^] (TNFRSF-8; CD30) on the lymphomaM-bM-^@M-^Ys neoplastically-transformed cells. We used transcriptomics, proteomics, computational systems biology and reductionist molecular biology to identify the differences between the CD30(hi) lymphoma cells and the non-transformed CD30(lo) MD lymphoma cells. We propose specific mechanisms of neoplastic transformation, genetic resistance to lymphomagenesis and impact of lymphoma microenvironment on CD30(hi) cell development. We demonstrate that: a) in situ, CD30(lo) cells are pre-neoplastic and we identify the proteome involved in transformation as well as potential mechanisms that may be controlled by MDV oncogene Meq; b) MD herpesvirus, (via its Meq oncogene) can drive a feed forward loop that induces CD30 transcription and overexpression, increased CD30 signaling, which then activates NFM-NM-:B and, in turn, increases Meq transcription; c) Meq transcriptional repression or activation from the CD30 promoter generally correlates with a polymorphism in the CD30 promoter between MD-resistant and -susceptible chicken genotypes and so a herpesvirus has evolved to utilize NFM-NM-:B as a direct transcriptional activator for its oncogene. A dual color, balanced design was carried on eight sorted lymphoma cells from white leghorn chickens infected with MDV GA/22 strain. Each of two sample types, CD30(hi) and CD30(lo) cells, includes four biological replicates for total RNA extraction and labeling. A Dye swap was used in four biological repeats of CD30(hi) to CD30(lo) cells comparison. Background subtracted signal intensities were collected from 4 arrays and normalized for data analysis.
Project description:Peripheral T-cell lymphomas (PTCL) are aggressive diseases with poor response to chemotherapy and dismal survival. Identification of effective strategies to target PTCL biology represents an urgent need. Here we report that PTCL are sensitive to transcription-targeting drugs, and, in particular, to THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7). The STAT-signaling pathway is highly vulnerable to THZ1 even in PTCL cells that carry the activating STAT3 mutation Y640F. In mutant cells, CDK7 inhibition decreases STAT3 chromatin binding and expression of highly transcribed target genes like MYC, PIM1, MCL1, CD30, IL2RA, CDC25A and IL4R. In surviving cells, THZ1 decreases the expression of STAT-regulated anti-apoptotic BH3 family members MCL1 and BCL-XL sensitizing PTCL cells to BH3 mimetic drugs. Accordingly, the combination of THZ1 and the BH3 mimetic obatoclax improves lymphoma growth control in a primary PTCL ex vivo culture and in two STAT3-mutant PTCL xenografts, delineating a potential targeted agent-based therapeutic option for these patients.
Project description:Chicken Marek’s disease (MD) is a unique naturally occurring model for human herpesvirus-induced lymphomas that over-express the “Hodgkin’s disease antigen” (TNFRSF-8; CD30) on the lymphoma’s neoplastically-transformed cells. We used transcriptomics, proteomics, computational systems biology and reductionist molecular biology to identify the differences between the CD30(hi) lymphoma cells and the non-transformed CD30(lo) MD lymphoma cells. We propose specific mechanisms of neoplastic transformation, genetic resistance to lymphomagenesis and impact of lymphoma microenvironment on CD30(hi) cell development. We demonstrate that: a) in situ, CD30(lo) cells are pre-neoplastic and we identify the proteome involved in transformation as well as potential mechanisms that may be controlled by MDV oncogene Meq; b) MD herpesvirus, (via its Meq oncogene) can drive a feed forward loop that induces CD30 transcription and overexpression, increased CD30 signaling, which then activates NFκB and, in turn, increases Meq transcription; c) Meq transcriptional repression or activation from the CD30 promoter generally correlates with a polymorphism in the CD30 promoter between MD-resistant and -susceptible chicken genotypes and so a herpesvirus has evolved to utilize NFκB as a direct transcriptional activator for its oncogene.
Project description:Small subsets of B cells in the germinal center (GC) and in extrafollicular regions of lymph nodes express the activation marker CD30. Very little is known about the specific features of these cells and their relationship to the CD30-expressing Hodgkin and Reed/Sternberg (HRS) cells of Hodgkin lymphoma. Phenotypic and immunoglobulin V gene analyses revealed that CD30+ GC B lymphocytes represent typical GC B cells, and that CD30+ non-GC B cells are mostly post-GC B cells. However, despite these seemingly distinct identities, both CD30+ subsets share an unexpectedly large overlap in specific transcriptome patterns, and are strikingly different from bulk GC B cells and classical memory and plasma cells, respectively. A main common feature of these CD30+ B cells is a strong MYC signature. CD30+ GC B cells appear to represent the recently described MYC+ GC B cell subset of recirculating centrocytes at the stage of centroblast transition. CD30+ non-GC B cells rather represent highly activated and proliferating memory B cells, differentiating into plasma cells. Notably, CD30+ B cells were more similar in their transcriptome patterns to HRS cells than any other B cell subset investigated, suggesting that HRS cells may either derive from CD30+ B cells or acquired a similar activation signature. In comparison to CD30+ B cells and other lymphomas, HRS cells show a remarkable downregulation of genes regulating cell cycle, genomic stability and polyploidity, providing a potential explanation for the genomic instability and multinuclearity of HRS cells.