Project description:Discovery of novel recurrent mutations and rearrangements in early T-cell precursor acute lymphoblastic leukaemia by whole genome sequencing
Project description:PAX5, a transcription factor essential for B-cell development, has been found as a frequent target of abnormalities in B-Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) cases, showing point mutations, deletions, as well as translocations with several partner genes. We identified four novel PAX5 fusion partner genes by performing a screening on BCP-ALL cases with 9p rearrangements. Copy Number Variation analysis of translocated samples showed that few significant cooperative genetic lesions are present in addition to the translocation event, suggesting that it might have a primary role in leukemogenesis.
Project description:Whole transcriptome RNA-seq of pediatric infant (<1year of aget at diagnosis) patients affected by B-cell precursor Acute Lymphoblastic leukemia (BCP-ALL). The aim of the study is to identify fusion gene rearrangements involved in childhood leukemia, using Next Generation Sequencing (NGS)
Project description:Targeted RNA-seq of pediatric infant (<1year of age at diagnosis) patients affected by B-cell precursor Acute Lymphoblastic leukemia (BCP-ALL). The aim of the study is to identify fusion gene rearrangements involved in childhood leukemia, using a custom targeted panel for RNA analysis by NGS.
Project description:Acute lymphoblastic leukaemia with early T-cell precursor immunophenotype (ETP ALL) is a highly aggressive subtype of ALL of unknown aetiology. To gain insights into the genetic basis of this disease, we performed whole genome sequencing of tumour and normal DNA of 12 children with ETP ALL. Analysis of structural and sequence variants in this discovery cohort, and mutation recurrence screening in a panel of 51 ETP and 43 non ETP ALL samples identified a high frequency of activating mutations in genes regulating cytokine receptor and Ras signalling, including IL7R, NRAS, KRAS, FLT3, BRAF, JAK1 and JAK3 in ETP ALL. Moreover, we identified multiple new targets of mutation in including GATA3, EP300, RUNX1, DNM2, ECT2L, HNRNPA1 and HNRNPR, as well as genes known to be mutated in T-ALL, including NOTCH1, PHF6, and WT1.. Five of 12 ETP ALL cases harboured novel chromosomal translocations, several of which accompanied complex multichromosomal rearrangements and resulted in the expression of chimeric in-frame fusion genes disrupting hematopoietic regulators, including ETV6-INO80D, NAP1L1-MLLT10 and RUNX1-EVX1. These results indicate that although ETP ALL is genetically heterogeneous, activation of Ras and cytokine receptor signalling distinguishes this disease from non-ETP ALL. These findings suggest that targeting this pathway may improve the currently dismal outcome of this disease. Gene expression profiling of an extended panel of childhood B-lineage and T-lineage acute lymphoblastic leukemia samples was performed using Affymetrix U133A arrays.
Project description:Acute lymphoblastic leukaemia with early T-cell precursor immunophenotype (ETP ALL) is a highly aggressive subtype of ALL of unknown aetiology. To gain insights into the genetic basis of this disease, we performed whole genome sequencing of tumour and normal DNA of 12 children with ETP ALL. Analysis of structural and sequence variants in this discovery cohort, and mutation recurrence screening in a panel of 51 ETP and 43 non ETP ALL samples identified a high frequency of activating mutations in genes regulating cytokine receptor and Ras signalling, including IL7R, NRAS, KRAS, FLT3, BRAF, JAK1 and JAK3 in ETP ALL. Moreover, we identified multiple new targets of mutation in including GATA3, EP300, RUNX1, DNM2, ECT2L, HNRNPA1 and HNRNPR, as well as genes known to be mutated in T-ALL, including NOTCH1, PHF6, and WT1.. Five of 12 ETP ALL cases harboured novel chromosomal translocations, several of which accompanied complex multichromosomal rearrangements and resulted in the expression of chimeric in-frame fusion genes disrupting hematopoietic regulators, including ETV6-INO80D, NAP1L1-MLLT10 and RUNX1-EVX1. These results indicate that although ETP ALL is genetically heterogeneous, activation of Ras and cytokine receptor signalling distinguishes this disease from non-ETP ALL. These findings suggest that targeting this pathway may improve the currently dismal outcome of this disease. Gene expression profiling of an extended panel of childhood B-lineage and T-lineage acute lymphoblastic leukemia samples was performed using Affymetrix U133A arrays.
Project description:<p>Few genetic drivers of children with hyperdiploid precursor B-cell acute lymphoblastic leukemia (ALL) have been identified to date. In an effort to detect novel genomic rearrangements that could be promoting leukemogenesis in this subset of patients, we sequenced ribosomal RNA-depleted transcriptomes isolated from 5 hyperdiploid acute lymphoblastic leukemia samples. In addition to looking for novel genomic rearrangements, we also sought to identify transcripts that could be created as a result of a novel posttranscriptional process. Surprisingly, we identified transcripts created as the result of exon circularization. The results of our studies are present in the paper "Circular RNAs Are the Predominant Transcript Isoform from Hundreds of Human Genes in Diverse Cell Types" published in PLoS ONE (PMID: <a href="http://www.ncbi.nlm.nih.gov/pubmed/22319583" target="_blank">22319583</a>).</p>
Project description:Interleukin-7 receptor α (encoded by IL7R) is essential for lymphoid development. Whether acute lymphoblastic leukemia (ALL)-related IL7R gain-of-function mutations can trigger leukemogenesis remains unclear. Here, we demonstrate that lymphoid-restricted mutant IL7R, expressed at physiological levels in conditional knock-in mice, establishes a pre-leukemia stage in which B-cell precursors display self-renewal ability, initiating precursor B-ALL that resembles PAX5 P80R or Ph-like human leukemia. Full transformation associates with transcriptional upregulation of oncogenes such as Myc or Bcl2, downregulation of tumor suppressors such as Ikzf1 or Arid2, and major IL-7R signaling upregulation (involving both JAK/STAT5 and PI3K/mTOR), required for leukemia cell viability. Accordingly, maximal signaling drives full penetrance and early leukemia onset in homozygous IL7R mutant animals. Notably, we identify 2 transcriptional subgroups in mouse and human Ph-like ALL, and show that dactolisib and sphingosine-kinase inhibitors are novel treatment avenues for IL-7R-related cases. Our model, a unique resource to explore the pathophysiology and therapeutic vulnerabilities of B-ALL, demonstrates that IL7R can initiate this malignancy.
Project description:We report the design and implementation of a "breakpoint analysis" pipeline to discover novel gene fusions by tell-tale transcript level or genomic DNA copy number transitions occurring within genes. We use this method to prioritize candidate rearrangements from high density array CGH datasets as well as exon-resolution expression microarrays. We mine both publicly available data as well as datasets generated in our laboratory. Several gene fusion candidates were chosen for further characterization, and corresponding samples were profiled using paired end RNA sequencing to discover the identity of the gene fusion. Using this approach, we report the discovery and characterization of novel gene fusions spanning multiple cancer subtypes including angiosarcoma, pancreatic cancer, anaplastic astrocytoma, melanoma, breast cancer, and T-cell acute lymphoblastic leukemia. Taken together, this study provides a robust approach for gene fusion discovery, and our results highlight a more widespread role of fusion genes in cancer pathogenesis. Breakpoint analysis for the discovery of novel gene fusions across human cancers