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:The mechanisms underlying the pathogenesis of the constitutively active tyrosine kinase nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) expressing anaplastic large cell lymphoma are not completely understood. Here we show using an integrated phosphoproteomic and metabolomic strategy that NPM-ALK induces a metabolic shift toward aerobic glycolysis, increased lactate production, and biomass production. The metabolic shift is mediated through the anaplastic lymphoma kinase (ALK) phosphorylation of the tumor-specific isoform of pyruvate kinase (PKM2) at Y105, resulting in decreased enzymatic activity. Small molecule activation of PKM2 or expression of Y105F PKM2 mutant leads to reversal of the metabolic switch with increased oxidative phosphorylation and reduced lactate production coincident with increased cell death, decreased colony formation, and reduced tumor growth in an in vivo xenograft model. This study provides comprehensive profiling of the phosphoproteomic and metabolomic consequences of NPM-ALK expression and reveals a novel role of ALK in the regulation of multiple components of cellular metabolism. Our studies show that PKM2 is a novel substrate of ALK and plays a critical role in mediating the metabolic shift toward biomass production and tumorigenesis.
Research is published:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3739039/
Project description:Anaplastic large-cell lymphoma (ALCL) makes up approximately 15% of paediatric non-Hodgkin's lymphomas of childhood. The vast majority of them is associated with the t(2;5)(p23;q35) translocation that results in the expression of a hybrid oncogenic tyrosine kinase, NPM-ALK. In order to investigate ALCL biological characteristics we used transcriptional profiling approach. Genome-wide gene expression profiling, performed on 23 paediatric ALCL and 12 reactive lymph nodes specimens, showed two novel ALCL subgroups based on their NPM-ALK expression levels (named (ALK low and ALK high). Gene set enrichment analysis revealed, in ALK low samples, a positive enrichment of genes involved in the Interleukin signaling pathway, whereas we found increased expression of genes related to cell cycle progression and division in ALK high tumour samples, such as Aurora Kinase A (AURKA) and B (AURKB). Growth inhibition was observed upon administration of AURKA and AURKB inhibitors Alisertib and Barasertib and it was associated with perturbation of the cell cycle and induction of apoptosis. In conclusion we identified two novel ALCL subgroups, which display unique biological characteristics suggesting sensitivity to distinct targeted therapies.
Project description:To examine the existence of lymphoma initiating cells, we used an anaplastic large cell lymphoma mouse model. Established NPM-ALK+ lymphomas contained a heterogeneous cell composition ranging from mature T-cells to undifferentiated hematopoietic stem cells. To investigate the underlying mechanisms and activated pathways of lymphoma initiating cells we used gene expression analyses. These analyses unmasked stem-cell-like transcriptional regulation exclusively of the DN3/DN4 lymphoma T-cell subpopulation.
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 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: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. 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:Total RNA was extracted from primary T cell lymphoma that spontaneously developed in either NPM-ALK or NPM-ALK/WASP-deficent transgenic mice
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