Project description:Anaplastic Large Cell Lymphoma (ALCL) is a clinical and biological heterogeneous disease including ALK positive and ALK negative systemic forms. To discover biomarkers and/or genes involved in ALK negative ALCL pathogenesis, we applied the Cancer Outlier Profile Analysis (COPA) algorithm to a gene expression profiling data set including 249 cases of T-NHLs and normal T-cells. Ectopic co-expression of ERBB4 and COL29A1 genes was detected in 24% of ALK negative ALCL patients. RNA sequencing and 5'RNA Ligase Mediated Rapid Amplification of cDNA Ends (RLM-RACE) identified two novel ERBB4 truncated transcripts, displaying intronic Transcription Starting Sites. ERBB4 expression was confirmed at protein level by western blotting and immunohistochemistry. Moreover, by luciferase assays we defined that the expression of ERBB4 aberrant transcripts is promoted by endogenous intronic Long Terminal Repeats (LTRs). In conclusion, we identified a new subclass of ALK negative ALCL characterized by aberrant expression of ERBB4 truncated transcripts carrying intronic 5'UTRs.
Project description:Transcription factor AP-1 is constitutively activated and IRF4 drives growth and survival in ALK+ and ALK– Anaplastic Large Cell Lymphoma (ALCL). Here we demonstrate high-level expression of BATF and BATF3 in ALCL, irrespective of the ALK-status. Both BATFs bind classical AP-1 motifs and interact with in ALCL deregulated AP-1 factors. Together with IRF4, they co-occupy AP-1-IRF composite elements (AICE), differentiating ALCL from non-ALCL. Gene-specific inactivation of BATFs by CRISPR/Cas9 or siRNAs, or global AP-1 inhibition by the dominant-negative A-Fos results in ALCL growth retardation and/or cell death in vitro and in vivo. Furthermore, the AP-1-BATF module establishes TH17 / innate lymphoid cell type 3 (ILC3)-associated gene expression in ALCL, including marker genes such as AHR, IL17F, IL22, IL26, IL23R, IL18R1 and RORγt. Elevated IL-17A and IL-17F levels were detected in pretreatment sera of a subset of children and adolescents with ALK+ ALCL. Finally, pharmacological inhibition of RORC as single treatment leads to cell death in ALCL cell lines, and, in combination with the ALK inhibitor crizotinib, enforces death induction in ALK+ ALCL. Our data highlight the crucial role of AP-1 / BATFs for ALCL biology and lead to the concept that ALCL might originate from ILC3 cells.
Project description:Anaplastic large cell lymphoma (ALCL) is a peripheral T-cell lymphoma that accounts for 10–15% of all childhood lymphomas. Despite the observation that more than 90% of the cases show ALK-rearrangement resulting in aberrant ALK kinase expression, there is significant clinical, morphologic, and biological heterogeneity. To gain insight into the molecular heterogeneity within ALK-positive ALCL, we analyzed 46 ALK-positive ALCL samples by whole-exome sequencing, RNA-sequencing, and DNA methylation array analysis. Gene expression and methylation profiling consistently subclassified ALK-positive ALCL cases into two groups differentiated by ALK expression level. The ALK-low group showed enrichment pathways of the immune response and cytokine signaling and were more heavily hypermethylated than the ALK high group, which was characterized by enriched pathways of cell growth, proliferation, metabolic pathways, and large copy number change. Taken together, these findings suggest that there is molecular heterogeneity within pediatric ALK+ALCL, predicting distinct biological mechanisms that may be utilized as prognostic markers.
Project description:A "Cartes d'Identite des Tumeurs" (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net). Affymetrix UU133A gene expression data for a series of 32 cases of systemic Anaplastic Large Cell Lymphoma<br> (ALCL) and 5 ALCL cell lines; used to (1) confirm that tumors expressing Anaplastic Lymphoma Kinase (ALK+ ALCL) and ALK- ALCLs are different entities, (2) identify most significantly differentially expressed genes between ALK+ and ALK- samples, (3) generate a molecular signature of ALK- ALCL, (4) perform unsupervised analysis classifying ALCL in sub-groups related to morphology and clinical variables (e.g. disease stage and enrichment with 'early relapse' patients).<br> <br> Principal Investigator: Dr Georges DELSOL-- Centre de Physiopathologie Toulouse-Purpan CHU-Purpan -- Toulouse -- France -- Email: delsol.g@chu-toulouse.fr <br> Programme "Cartes d'identite des Tumeurs" (CIT) of the "Ligue Nationale Contre le Cancer" (LNCC)<br> Submitter: Fabien PETEL (petelf@ligue-cancer.net)
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 Lymphomas (ALCL) represent a subset of lymphomas in which the Anaplastic Lymphoma Kinase (ALK) gene is frequently fused to the NPM gene. We previously demonstrated that the constitutive phosphorylation of ALK chimeric proteins is sufficient to induce cellular transformation in vitro and in vivo, and that ALK activity is strictly required for the survival of ALK positive ALCL cells. To elucidate the signaling pathways required for ALK-mediated transformation and tumor maintenance, we analyzed the transcriptomes of multiple ALK positive ALCL cell lines abrogating their ALK-mediated signaling by inducible ALK RNA interference (RNAi) or with potent and cell permeable ALK inhibitors. Transcripts derived from the gene expression profiling (GEP) analysis uncovered a reproducible signature, which included a novel group of ALK-regulated genes. Functional RNAi screening on a set of these ALK transcriptional targets revealed that the transcription factor C/EBPb and the anti-apoptotic protein BCL2A1 are absolutely necessary to induce cell transformation and/or to sustain the growth and survival of ALK positive ALCL cells. Thus, we proved that an experimentally controlled and functionally validated GEP analysis represents a powerful tool to identify novel pathogenetic networks and validate biologically suitable target genes for therapeutic interventions. Experiment Overall Design: This series of microarray experiments contains the gene expression profiles of Anaplastic Large Cell Lymphoma (ALCL) cell lines (TS [a subclone of Sup-M2] and Su-DHL1) engineered to express ALK-A5 shRNA under a doxycycline-inducible promoter or treated with cell permeable pyrrolocarbazole-derived ALK inhibitors. A mutated ALK-A5M shRNA was used as control. Briefly, cells were transduced with pLV-DsRed-tTRKRAB, expanded, and used for transduction with pLVTH-GFP-shRNA lentiviral particles. Cells were induced with doxycycline (1 microg/ml) for 12 hours, double GFP+ DsRed+ cells selected by fluorescence-activated cell sorting. Cells expressing GFP in the absence of the inducer were removed by a second flow cytometry sorting, and expanded. shRNA expression was induced by doxycycline treatment for 72 or 84 hours. Drug treatments (300 nM), were performed in TS cells with ALK inhibitors (A2 or A3), mock compound (A1), or control diluent for 6 hours. 5 micrograms of total RNA was processed and hybridized to the Affymetrix HG-U133A chip following the manufacturer's instructions.
Project description:We present evidence to support a new model of Anaplastic Large Cell Lymphoma (ALCL) pathogenesis in which the malignancy is initiated in early thymocytes, prior to TCR rearrangement which is bypassed in NPMâ??ALK transgenic mice following Notch1 expression. In support, we show that T cell receptor (TCR) rearrangements are aberrant in some human ALCL, yielding events that would not normally be permissive for survival during T cell development. However, a TCR is required for thymic egress and subsequent development of peripheral tumors in mice yet this TCR must be downâ??regulated for Tâ??cell lymphomagenesis. Children affected by ALCL may thus harbor lymphoma-initiating cells in the thymocyte population that seeds relapse after chemotherapy. comparative genomic hybridization data from 43 human Anaplastic Large Cell Lymphoma (ALCL) samples and control samples
Project description:Deregulation of chromatin modifiers, including DNA helicases, are emerging as one of the mechanism underlying the transformation of anaplastic lymphoma kinase negative (ALK−) anaplastic large cell lymphoma (ALCL). We recently identified the DNA helicase HELLS as central for proficient ALK-ALCL proliferation and progression. By performing RNA-sequencing profiling coupled with bioinformatic prediction, we demonstrated that HELLS contributes to an appropriate cytokinesis via the transcriptional regulation of genes involved in cleavage furrow regulation in ALK- anaplastic large cell lymphoma
Project description:Anaplastic Large Cell Lymphomas (ALCL) represent a subset of lymphomas in which the Anaplastic Lymphoma Kinase (ALK) gene is frequently fused to the NPM gene. We previously demonstrated that the constitutive phosphorylation of ALK chimeric proteins is sufficient to induce cellular transformation in vitro and in vivo, and that ALK activity is strictly required for the survival of ALK positive ALCL cells. To elucidate the signaling pathways required for ALK-mediated transformation and tumor maintenance, we analyzed the transcriptomes of multiple ALK positive ALCL cell lines abrogating their ALK-mediated signaling by inducible ALK RNA interference (RNAi) or with potent and cell permeable ALK inhibitors. Transcripts derived from the gene expression profiling (GEP) analysis uncovered a reproducible signature, which included a novel group of ALK-regulated genes. Functional RNAi screening on a set of these ALK transcriptional targets revealed that the transcription factor C/EBPb and the anti-apoptotic protein BCL2A1 are absolutely necessary to induce cell transformation and/or to sustain the growth and survival of ALK positive ALCL cells. Thus, we proved that an experimentally controlled and functionally validated GEP analysis represents a powerful tool to identify novel pathogenetic networks and validate biologically suitable target genes for therapeutic interventions. Keywords: other
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.