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 SamplesGene signature determination of the effect of a new bromodomain inhibitor among a representative set of leukemic cell lines
BET inhibitor OTX015 targets BRD2 and BRD4 and decreases c-MYC in acute leukemia cells.
Cell line, Compound
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 SamplesThe accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) results in the condition called ER stress which induces the unfolded protein response (UPR) which is a complex cellular process that includes changes in expression of many genes. Failure to restore homeostasis in the ER is associated with human diseases. To identify the underlying changes in gene expression in response to ER stress, we induced ER stress in human B-cells and then measured gene expression at 10 time-points. We followed up those results by studying cells from 60 unrelated people. We rediscovered genes that were known to play a role in ER stress response and uncovered several thousand genes that are not known to be involved. Two of these are VLDLR and INHBE which showed significant increase in expression following ER stress in B-cells and
Gene expression and genetic variation in response to endoplasmic reticulum stress in human cells.
Cell line, Subject, Time
View SamplesDevelopmental checkpoints in stem/progenitor cells are critical to the determination, commitment and differentiation into distinct lineages. Cancer cells often retain expression of lineage-specific checkpoint proteins, but their potential impact in cancer remains elusive. T lymphocytes mature in the thymus following a highly orchestrated developmental process that entails the successive rearrangements and expression of T-cell receptor (TCR) genes. Low affinity recognition of self-peptide/MHC complexes (self-pMHC) presented by thymic epithelial cells by the TCR of CD4+CD8+ (DP) cortical thymocytes transduces positive selection signals that ultimately shape the developing T cell repertoire. DP thymocytes not receiving these signals die by lack of stimulation whereas those that recognize self-pMHC with high affinity undergo TCR-mediated apoptosis and negative selection. In T-cell acute lymphoblastic leukaemia (T-ALL), leukaemic transformation of maturating thymocytes results from the acquisition of multiple genetic and epigenetic alterations in oncogenes and tumour suppressor genes, that disrupt the normal regulatory circuits and drive clonal expansion of differentiation-arrested lymphoblasts. We show here that TCR triggering by negatively-selecting self-pMHC prevented T-ALL development and leukaemia maintenance in mice. Induction of TCR signalling by high affinity self-pMHC or treatment with monoclonal antibodies to the CD3 signalling chain (anti-CD3) caused massive leukaemic cell death and a gene expression program resembling that of thymocyte negative selection. Importantly, anti-CD3 treatment hampered leukaemogenesis in mice transplanted with either mouse or patient-derived T-ALLs. These data provide a rationale for targeted therapy based on anti-CD3 treatment of T-ALL patients and demonstrate that endogenous developmental checkpoint proteins are amenable to therapeutic intervention in cancer cells.
Triggering the TCR Developmental Checkpoint Activates a Therapeutically Targetable Tumor Suppressive Pathway in T-cell Leukemia.
Cell line
View SamplesThe causative role of activated Hedgehog signaling in liver fibrosis was investigated in vivo.
Hepatic expression of Sonic Hedgehog induces liver fibrosis and promotes hepatocarcinogenesis in a transgenic mouse model.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MLL rearrangements impact outcome in HOXA-deregulated T-lineage acute lymphoblastic leukemia: a Children's Oncology Group Study.
Specimen part, Disease
View SamplesThe clinical and cytogenetic features associated with T-cell acute lymphoblastic leukemia (T-ALL) are not predictive of early treatment failure or relapse. We used the Affymetrix U133 Plus 2.0 chip to profile 100 newly diagnosed patients who were treated in the Children's Oncology Group (COG) T-ALL AALL0434. We performed unsupervised hierarchical clustering of 25 HOXA probe sets within the cohort of 100 T-ALL cases. We identified a cluster of 20 cases (20%) characterized by increased expression of HOXA3, 5, 7, 9, and 10. In samples with HOXA9/10 deregulation, the presence of specific molecular lesions were confirmed through a systematic review of cytogenetic databases, FISH and PCR testing, and by RNA sequence analysis. Because MLL and AF10 genes rearrangements (MLL-R, AF10-R) are hallmarks of HOXA-deregulated leukemias, we sought to identify specific genes that are enriched with these genomic abnormalities.
MLL rearrangements impact outcome in HOXA-deregulated T-lineage acute lymphoblastic leukemia: a Children's Oncology Group Study.
Specimen part, Disease
View SamplesPrevious results suggest that Bmh might inhibit the activity of the transcription factor Adr1 after binding to Adr1-dependent promoters. In a strain lacking the two major histone deacetylases, Hda1 and Rpd3 (hdac), Adr1 is bound to its target promoters recruiting what appears to be an inactive RNA ploymerase II preinitiation complex (PIC). To determine whether Bmh activity inhibits this inactive PIC and the generality of this effect on glucose-repressed gene expression, the mRNA profiles of wild type, bmh mutant, hdac mutant, and bmh hdac mutant cells grown in high glucose medium were compared.
14-3-3 (Bmh) proteins regulate combinatorial transcription following RNA polymerase II recruitment by binding at Adr1-dependent promoters in Saccharomyces cerevisiae.
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