A "Cartes d'Identite des Tumeurs" (CIT) project from the french Ligue Nationale Contre le Cancer (<a href="http://cit.ligue-cancer.net" target="_blank">http://cit.ligue-cancer.net</a>). 104 samples; Affymetrix U133A micro-arrays.<br></br> <br></br> Ninety two patients with T-ALL were diagnosed and treated at Saint-Louis hospital, Paris. Seven patients were studied at diagnosis and relapse (total 99 T-ALL samples). There were 56 children (median age 9 years old; range 1 to 16), and 36 adults (median age 27; range 17 to 66). Informed consent was obtained from the patients and/or relatives. T-ALL diagnosis was based on morphological and immunophenotypical criteria using flow cytometry and an extended monoclonal antibody panel.<br></br> <br></br> Using a combination of molecular cytogenetic and large-scale expression analysis in human T-ALL, we identified and characterized a new recurrent chromosomal translocation, targeting the major homeobox gene cluster HOXA and the TCRB locus. Specific quantitative PCR analysis showed that the expression of the whole HOXA gene cluster was dramatically dysregulated in the HOXA-rearranged cases, and also in MLL and CALM-AF10-related T-ALL cases, strongly suggesting that HOXA genes are oncogenic in these leukemias. Inclusion of HOXA-translocated cases in a general molecular portrait of 92 T-ALL based on large-scale expression analysis shows that this rearrangement defines a new homogeneous subgroup, which shares common biological networks with the TLX1 and TLX3-related cases. Since T-ALLs derive from T-cell progenitors, expression profiles of the distinct T-ALL subgroups were analyzed with respect to those of normal human thymic sub-populations. Inappropriate utilization or perturbation of specific molecular networks involved in thymic differentiation was detected. Moreover, we found a significant association between T-ALL oncogenic subgroups and ectopic expression of a limited set of genes, including several developmental genes, namely HOXA, TLX1, TLX3, NKX3-1, SIX6 and TFAP2C. These data strongly support the view that the abnormal expression of developmental genes, including the prototypical homeobox genes HOXA, is critical in T-ALL oncogenesis.<br></br> <br></br> Project Leader: <br></br> FranC'ois Sigaux<br></br> Institut Universitaire d'Hematologie<br></br> Hopital Saint Louis, Paris, France<br></br> <br></br> Data submission:<br></br>Fabien Petel
HOXA genes are included in genetic and biologic networks defining human acute T-cell leukemia (T-ALL).
Sex, Age, Specimen part, Disease, Disease stage, Subject
View SamplesCyclin D3 is critical hematopoiesis and loss of cyclin D3 leads to resistance to transformation of bone marrow progenitors by Notch1-IC.
Therapeutic targeting of the cyclin D3:CDK4/6 complex in T cell leukemia.
Specimen part, Cell line
View SamplesMultiple myeloma (MM) is a currently incurable malignancy of antibody-secreting plasma cells. Long non-coding RNAs (lncRNAs) have been recognised as an important class of regulatory molecules which are increasingly implicated in tumorigenesis. While recent studies have demonstrated changes in expression of lncRNAs in MM, the functional significance and molecular pathways downstream of these changes remain poorly characterised. In this study we have performed CRISPR-mediated deletion of the locus encoding the lncRNA Colorectal Neoplasia Differentially Expressed (CRNDE), a known oncogenic lncRNA that is overexpressed in plasma cells of MM patients and is a marker of poor prognosis. We found that CRISPR-mediated deletion of the CRNDE locus in MM cells decreases proliferation and adhesion properties, increases sensitivity to Dexamethasone and reduces tumour growth in an in vivo xenograft model. Transcriptomic profiling in CRNDE-deleted MM cells demonstrated that CRNDE activates expression of a number of genes previously implicated in the aetiology of MM, including IL6R. We further demonstrate that deletion of the CRNDE locus diminishes IL6 signalling and proliferative responses in MM cells. Altogether this study reveals the IL6 signalling pathway as a novel mechanism by which CRNDE impacts upon MM cell growth and disease progression.
The long non-coding RNA CRNDE regulates growth of multiple myeloma cells via an effect on IL6 signalling.
Cell line
View SamplesThe NOTCH1 signaling pathway directly links extracellular signals with transcriptional responses in the cell nucleus and plays a critical role during T-cell development and in the pathogenesis over 50% of human T-cell lymphoblastic leukemia (T-ALL) cases. However, little is known about the transcriptional programs activated by NOTCH1. Using an integrative systems biology approach we show that NOTCH1 controls a feed-forward loop transcriptional network that promotes cell growth. Inhibition of NOTCH1 signaling in T-ALL cells led to a reduction in cell size and elicited a gene expression signature dominated by downregulated biosynthetic pathway genes. By integrating gene expression array and ChIP-on-chip data, we show that NOTCH1 directly activates multiple biosynthetic routes and induces c-MYC gene expression. Reverse engineering of regulatory networks from expression profiles showed that NOTCH1 and c-MYC govern two directly interconnected transcriptional programs containing common target genes that together regulate the growth of primary T-ALL cells. These results identify c-MYC as an essential mediator of NOTCH1 signaling and integrate NOTCH1 activation with oncogenic signaling pathways upstream of c-MYC.
NOTCH1 directly regulates c-MYC and activates a feed-forward-loop transcriptional network promoting leukemic cell growth.
No sample metadata fields
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is an aggressive type of blood cancer resulting from malignant transformation of T-cell precursors. Several oncogenes, including the 'T-cell leukemia homeobox 1' TLX1 (HOX11) transcription factor, have been identified as early driver events that cooperate with other genetic aberrations in leukemic transformation of progenitor T-cells. The TLX1 controlled transcriptome in T-ALL has been investigated extensively in the past in terms of protein-coding genes, but remains unexplored thus far at the level of long non-coding RNAs (lncRNAs), the latter renown as well-established versatile and key players implicated in various cancer hallmarks. In this study, we present the first extensive analysis of the TLX1 regulated transcriptome focusing on lncRNA expression patterns. We present an integrative analysis of polyA and total RNA sequencing of ALL-SIL lymphoblasts with perturbed TLX1 expression and a primary T-ALL patient cohort (including 5 TLX1+ and 12 TLX3+ cases). We expanded our initially presented dataset of TLX1 and H3K27ac ChIP data in ALL-SIL cells (Durinck et al., Leukemia, 2015) with H3K4me1, H3K4me3, and ATAC-seq data to accurately define (super-) enhancer marked lncRNAs and assigned potential functional annotations to candidate TLX1-controlled lncRNAs through an in silico guilt-by-association approach. Our study paves the way for further functional analysis of selected lncRNAs as potential novel therapeutic targets for a precision medicine approach in the context of T-ALL. Overall design: polyA+ RNA-seq data was generated for a primary T-ALL patient cohort
A comprehensive inventory of TLX1 controlled long non-coding RNAs in T-cell acute lymphoblastic leukemia through polyA+ and total RNA sequencing.
Subject
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is an aggressive type of blood cancer resulting from malignant transformation of T-cell precursors. Several oncogenes, including the 'T-cell leukemia homeobox 1' TLX1 (HOX11) transcription factor, have been identified as early driver events that cooperate with other genetic aberrations in leukemic transformation of progenitor T-cells. The TLX1 controlled transcriptome in T-ALL has been investigated extensively in the past in terms of protein-coding genes, but remains unexplored thus far at the level of long non-coding RNAs (lncRNAs), the latter renown as well-established versatile and key players implicated in various cancer hallmarks. In this study, we present the first extensive analysis of the TLX1 regulated transcriptome focusing on lncRNA expression patterns. We present an integrative analysis of polyA and total RNA sequencing of ALL-SIL lymphoblasts with perturbed TLX1 expression and a primary T-ALL patient cohort (including 5 TLX1+ and 12 TLX3+ cases). We expanded our initially presented dataset of TLX1 and H3K27ac ChIP data in ALL-SIL cells (Durinck et al., Leukemia, 2015) with H3K4me1, H3K4me3, and ATAC-seq data to accurately define (super-) enhancer marked lncRNAs and assigned potential functional annotations to candidate TLX1-controlled lncRNAs through an in silico guilt-by-association approach. Our study paves the way for further functional analysis of selected lncRNAs as potential novel therapeutic targets for a precision medicine approach in the context of T-ALL. Overall design: Total RNA-seq data was generated for the T-ALL cell line ALL-SIL upon TLX1 knockdown
A comprehensive inventory of TLX1 controlled long non-coding RNAs in T-cell acute lymphoblastic leukemia through polyA+ and total RNA sequencing.
Cell line, Subject
View SamplesT-cell acute lymphoblastic leukemia (T-ALL) is mostly characterized by specific chromosomal abnormalities, some occurring in a mutually exclusive manner possibly delineating specific T-ALL subgroups. One subgroup, including MLL-rearranged, CALM-AF10 or inv(7)(p15q34) cases, is characterized by elevated expression of HOXA genes. Using a gene expression based clustering analysis of 67 T-ALL cases with recurrent molecular genetic abnormalities and 25 samples lacking apparent aberrations, we identified 5 new cases with elevated HOXA levels. Using array-CGH, a cryptic and recurrent deletion, del(9)(q34.11q34.13), was exclusively identified in 3 of these 5 cases. This deletion results in a conserved SET-NUP214 fusion product, that was also identified in the T-ALL cell line LOUCY. SET-NUP214 binds in the promoter regions of specific HOXA genes, where it may interact with CRM1 and DOT1L leading to the transcriptional activation of HOXA genes. Targeted inhibition of SET-NUP214 by siRNA abolished expression of HOXA genes, inhibited proliferation and induced differentiation in LOUCY but not in other T-ALL lines. We conclude that SET-NUP214 may contribute to the pathogenesis of T-ALL by enforcing T-cell differentiation arrest.
The recurrent SET-NUP214 fusion as a new HOXA activation mechanism in pediatric T-cell acute lymphoblastic leukemia.
No sample metadata fields
View SamplesGenetic studies in T-cell acute lymphoblastic leukemia have uncovered a remarkable complexity of oncogenic and loss-of-function mutations. Amongst this plethora of genetic changes, NOTCH1 activating mutations stand out as the most frequently occurring genetic defect, identified in more than 50% of T-cell acute lymphoblastic leukemias, supporting an essential driver role for this gene in T-cell acute lymphoblastic leukemia oncogenesis. In this study, we aimed to establish a comprehensive compendium of the long non-coding RNA transcriptome under control of Notch signaling. For this purpose, we measured the transcriptional response of all protein coding genes and long non-coding RNAs upon pharmacological Notch inhibition in the human T-cell acute lymphoblastic leukemia cell line CUTLL1 using RNA-sequencing. Similar Notch dependent profiles were established for normal human CD34+ thymic T-cell progenitors exposed to Notch signaling activity in vivo. In addition, we generated long non-coding RNA expression profiles (array data) from GSI treated T-ALL cell lines, ex vivo isolated Notch active CD34+ and Notch inactive CD4+CD8+ thymocytes and from a primary cohort of 15 T-cell acute lymphoblastic leukemia patients with known NOTCH1 mutation status. Integration of these expression datasets with publically available Notch1 ChIP-sequencing data resulted in the identification of long non-coding RNAs directly regulated by Notch activity in normal and malignant T-cell context. Given the central role of Notch in T-cell acute lymphoblastic leukemia oncogenesis, these data pave the way towards development of novel therapeutic strategies that target hyperactive Notch1 signaling in human T-cell acute lymphoblastic leukemia. Overall design: CUTLL1 cell lines were treated with Compound E (GSI) or DMSO (solvent control). Cells were collected 12 h and 48 h after treatment. This was performed for 3 replicates. RNA-sequencing was performed on these samples.
The Notch driven long non-coding RNA repertoire in T-cell acute lymphoblastic leukemia.
No sample metadata fields
View SamplesGenetic studies have shown that human T-ALLs can be divided into subgroups that are characterized by unique gene expression signatures and relate to stages of T-cell differentiation at which the leukemic cells arrest. Each molecular subgroup has characteristic genetic abnormalities that cause aberrant activation of specific T-ALL transcription factor oncogenes, including LYL1/MEF2C, HOXA, TLX1, TLX3 and TAL1/LMO2. Notably, the recently described Early T-cell Precursor ALL (ETP-ALL) patients have leukemic cells that show an early block in T-cell differentiation and significantly overlap with LYL1-positive T-ALL and MEF2C-dysregulated immature T-ALL. We studied the gene expression profiles of 64 primary T-ALL samples and found a high BCL-2 expression in immature T-ALL patients compared to patients belonging to other subgroups.
ABT-199 mediated inhibition of BCL-2 as a novel therapeutic strategy in T-cell acute lymphoblastic leukemia.
Specimen part
View SamplesTo identify novel oncogenic pathways in T-cell acute lymphoblastic leukemia (T-ALL), we combined expression profiling of 117 pediatric patient samples and detailed molecular cytogenetic analyses including the Chromosome Conformation Capture on Chip (4C) method. Two T-ALL subtypes were identified that lacked rearrangements of known oncogenes. One subtype associated with cortical arrest, expression of cell cycle genes and ectopic NKX2-1 or NKX2-2 expression for which rearrangements were identified. The second subtype associated with immature T-cell development and high expression of the MEF2C transcription factor as consequence of rearrangements of MEF2C, transcription factors that target MEF2C or MEF2C-associated cofactors. We propose NKX2-1, NKX2-2 and MEF2C as T-ALL oncogenes that are activated by various rearrangements.
Integrated transcript and genome analyses reveal NKX2-1 and MEF2C as potential oncogenes in T cell acute lymphoblastic leukemia.
Specimen part
View Samples