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 Lymphoma (ALCL) is a mature T-cell lymphoma that can present as a systemic or primary cutaneous disease. Systemic ALCL represents 2-5% of adult lymphoma but up to 30% of all pediatric cases. Two subtypes of systemic ALCL are currently recognized on the basis of the presence of a translocation involving the Anaplastic Lymphoma Kinase ALK gene. Despite considerable progress, several questions remain open regarding the pathogenesis of both ALCL subtypes. To investigate the molecular pathogenesis and to assess the relationship between the ALK(+) and ALK(-)ALCL subtypes, we performed a genome-wide DNA profiling using high density, single nucleotide polymorphism (SNP) arrays (SNP-array) on a series of 63 cases and seven cell lines. The commonest lesions were losses at 17p13 and at 6q21, encompassing the TP53 and PRDM1 genes respectively. The latter gene, coding for BLIMP1, was inactivated by multiple mechanisms, more frequently, but not exclusively, in ALK(-)ALCL. In vitro and in vivo experiments showed that that PRDM1 is a tumor suppressor gene in ALCL models, likely acting as an anti-apoptotic agent. Losses of TP53 and/or PRDM1 were present in 52% of ALK(-)ALCL, and in 29% of all ALCL cases with a clinical implication. Genomic profiling of Anaplastic Large Cell Lymphoma
Project description:Global proteomics profiling of anaplastic large cell lymphoma cell lines DEL, SU-DHL-1 (ALK+), Mac-1, Mac-2A (ALK-) as well as Hodgkin lymphoma cell lines L-428, L-540, L-1236 and HDLM-2.
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:The aim was to dissect molecular changes in histone and non-histone protein acetylation dynamics following the genetic or pharmacological inhibition of HDAC activity in a model of Anaplastic Large Cell Lymphoma (ALCL), a T cell non-Hodgkin lymphoma, predominantly found in children and adolescents.
Project description:Aberrant DNA methylation patterns of malignant cells allow for the study of the tumor phenotype and behavior, and can be used for tumor classification. Here, we describe the genome-wide DNA methylation signatures of NPM-ALK positive and negative anaplastic large cell lymphoma (ALCL). Differences in DNA methylation of tumor cells compared to normal T cells concern pathways that are implicated in T cell development and function and reveal a close relationship to distinct developmental stages of thymocytes. We find DNA hypomethylation in regulatory regions that are enriched for conserved transcription factor binding motifs, such as AP1. Our results suggest a direct relationship of oncogenic signaling with epigenetic modifications via transcription factor induction and occupancy.
Project description:Anaplastic Large Cell Lymphoma (ALCL) is a mature T-cell lymphoma that can present as a systemic or primary cutaneous disease. Systemic ALCL represents 2-5% of adult lymphoma but up to 30% of all pediatric cases. Two subtypes of systemic ALCL are currently recognized on the basis of the presence of a translocation involving the Anaplastic Lymphoma Kinase ALK gene. Despite considerable progress, several questions remain open regarding the pathogenesis of both ALCL subtypes. To investigate the molecular pathogenesis and to assess the relationship between the ALK(+) and ALK(-)ALCL subtypes, we performed a genome-wide DNA profiling using high density, single nucleotide polymorphism (SNP) arrays (SNP-array) on a series of 63 cases and seven cell lines. The commonest lesions were losses at 17p13 and at 6q21, encompassing the TP53 and PRDM1 genes respectively. The latter gene, coding for BLIMP1, was inactivated by multiple mechanisms, more frequently, but not exclusively, in ALK(-)ALCL. In vitro and in vivo experiments showed that that PRDM1 is a tumor suppressor gene in ALCL models, likely acting as an anti-apoptotic agent. Losses of TP53 and/or PRDM1 were present in 52% of ALK(-)ALCL, and in 29% of all ALCL cases with a clinical implication.
Project description:We performed DNA methylation (HELP) and gene expression profiling in 69 samples of diffuse large B cell lymphoma (DLBCL). First, by gene expression, two molecular subtypes of DLBCL termed as germinal center B cell-like (GCB) and activated B cell-like (ABC) DLBCL were assigned to the 69 DLBCL cases. Then, we performed supervised analysis using HELP data and defined DNA methylation signature differentiating 2 subgroups of DLBCLs. Keywords: DNA methylation profiling
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.