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 SamplesWe used microarrays to examine the impact of AF1q/MLLT11 on the gene expression profile of CD34+CD45RA-Lin- and CD34+CD45RA+Lin- HPCs isolated from umbilical cord blood
AF1q/MLLT11 regulates the emergence of human prothymocytes through cooperative interaction with the Notch signaling pathway.
Specimen part
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 SamplesAcute myeloid leukemia (AML) is a heterogeneous group of malignancies which may be sensitive to the natural killer (NK) cell anti-tumor response. However, NK cells are frequently defective in AML. Here, we found in an exploratory cohort (n = 46) that NK-cell status at diagnosis of AML separated patients in two groups with a different clinical outcome. Patients with a deficient NK-cell profile, including reduced expression of some activating NK receptors (e.g. DNAM-1, NKp46 and NKG2D) and decreased IFN-g production, had a significantly higher risk of relapse (P = 0.03) independently of cytogenetic classification in multivariate analysis. Patients with defective NK cells showed a profound gene expression decrease in AML blasts for cytokine and chemokine signaling (e.g. IL15, IFNGR1, IFNGR2, CXCR4), antigen processing (e.g. HLA-DRA, HLA-DRB1, CD74) and adhesion molecule pathways (e.g. PVR, ICAM1). A set of 388 leukemic classifier genes defined in the exploratory cohort was independently validated in a multicentric cohort of 194 AML patients. In total, these data evidenced the interplay between NK-cells and AML blasts at diagnosis allowing an immune-based stratification of AML patients independently of clinical classifications.
Defective NK Cells in Acute Myeloid Leukemia Patients at Diagnosis Are Associated with Blast Transcriptional Signatures of Immune Evasion.
Disease, Subject
View SamplesAcute myeloid leukemia (AML) is a heterogeneous group of malignancies which may be sensitive to the natural killer (NK) cell anti-tumor response. However, NK cells are frequently defective in AML. Here, we found in an exploratory cohort (n = 46) that NK-cell status at diagnosis of AML separated patients in two groups with a different clinical outcome. Patients with a deficient NK-cell profile, including reduced expression of some activating NK receptors (e.g. DNAM-1, NKp46 and NKG2D) and decreased IFN-g production, had a significantly higher risk of relapse (P = 0.03) independently of cytogenetic classification in multivariate analysis. Patients with defective NK cells showed a profound gene expression decrease in AML blasts for cytokine and chemokine signaling (e.g. IL15, IFNGR1, IFNGR2, CXCR4), antigen processing (e.g. HLA-DRA, HLA-DRB1, CD74) and adhesion molecule pathways (e.g. PVR, ICAM1). A set of 388 leukemic classifier genes defined in the exploratory cohort was independently validated in a multicentric cohort of 194 AML patients. In total, these data evidenced the interplay between NK-cells and AML blasts at diagnosis allowing an immune-based stratification of AML patients independently of clinical classifications.
Defective NK Cells in Acute Myeloid Leukemia Patients at Diagnosis Are Associated with Blast Transcriptional Signatures of Immune Evasion.
Age, Disease, Disease stage
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 SamplesR-spondin (Rspo) signaling is crucial for stem cell renewal and tissue homeostasis in the gastrointestinal tract. In the stomach, Rspo is secreted from myofibroblasts and controls epithelial gland regeneration by inducing proliferation of Wnt-responsive Axin2+ cells in the isthmus of the gland. Infection with H. pylori results in increased expression of stromal Rspo, leading to an expansion of Axin2+ isthmus stem cells and gland hyperplasia. Lgr5+ cells in the gland base are exposed to Rspo3 but the effects of this are not well understood. Here we demonstrate that apart from its activity as a mitogen, endogenous Rspo3 regulates gene expression of Lgr5+ cells in the gastric gland base. Surprisingly, Rspo3 induces differentiation within the Lgr5+ compartment towards secretory deep mucous cells. Moreover, the Rspo3-Lgr5 axis turns out to be a stimulus of epithelial antimicrobial defense. Infection with H. pylori induces a strong antimicrobial response, with Lgr5+ cells expressing antimicrobial compounds that are secreted into the lumen in an Rspo3-dependent manner. Depletion of Lgr5+ cells or knockout of Rspo3 in myofibroblasts leads to hyper-colonization of gastric glands, including the stem cell compartment, whereas systemic application of recombinant Rspo clears H. pylori from the glands. We provide an intriguing, unexpected feature of the Rspo3-Lgr5 axis in the stomach, exhibiting antimicrobial self-protection of the gland to protect the stem cell compartment from invading pathogens. Overall design: Lgr5eGFP reporter mice were infected with H. pylori for 2 months, uninfected mice served as controls. Mice were sacrificed and isolated, sorted Lgr5eGFP+ cells from the stomach antrum were used for single cell RNAseq using the 10x genome platform.
R-spondin-3 induces secretory, antimicrobial Lgr5<sup>+</sup> cells in the stomach.
Specimen part, Cell line, Subject
View SamplesIdentification of predictive markers of response to treatment is a major objective in breast cancer. A major problem in clinical sampling is the variability of RNA templates, requiring accurate management of tumour material and subsequent analyses for future translation in clinical practice. Our aim was to establish the feasibility and reliability of high throughput RNA analysis in a prospective trial.
Importance of pre-analytical steps for transcriptome and RT-qPCR analyses in the context of the phase II randomised multicentre trial REMAGUS02 of neoadjuvant chemotherapy in breast cancer patients.
Specimen part, Disease stage
View SamplesThe aim of this study was to characterize the stroma displayed by different models of breast cancer tumors in mice. For this purpose, transcriptomic and flow cytometry analyses on murine populations were performed in a series of 25 PDXs and 2 most commonly used GEMs (MMTV-PyMT and MMTV-erBb2). Specifically, macrophages from 5 models were sorted and profiled by gene expression and phenotypically characterized by flow cytometry.
Characterization of Breast Cancer Preclinical Models Reveals a Specific Pattern of Macrophage Polarization.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic chromatin states uniquely define the developmental plasticity of murine hematopoietic stem cells.
Specimen part
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