Project description:Proteogenomic analysis and genomic profiling, RNA-sequencing, and mass spectrometry-based analysis of High hyperdiploid childhood acute lymphoblastic leukemia.
Project description:Proteogenomic analysis and genomic profiling, RNA-sequencing, and mass spectrometry-based analysis of High hyperdiploid childhood acute lymphoblastic leukemia.
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:We identified germline single nucleotide polymorphisms (SNPs) associated with childhood acute lymphoblastic leukemia (ALL) and its subtypes. Using the Affymetrix 500K Mapping array and publicly available genotypes, we identified 18 SNPs whose allele frequency differed (P<1x10-5) between a pediatric ALL population (n=317) and non-ALL controls (n=17,958). Six of these SNPs differed (P≤0.05) in allele frequency among four ALL subtypes. Two SNPs in ARID5B not only differed between ALL and non-ALL groups (rs10821936, P=1.4x10-15, odds ratio[OR]=1.91; rs10994982, P=5.7x10-9, OR=1.62) but also distinguished B-hyperdiploid ALL from other subtypes (rs10821936, P=1.62 x10-5, OR=2.17; rs10994982, P=0.003, OR 1.72). These ARID5B SNPs also distinguished B-hyperdiploid ALL from other subtypes in an independent validation cohort (n=124 children with ALL) (P=0.003 and P=0.0008, OR 2.45 and 2.86, respectively) and were associated with methotrexate accumulation and gene expression pattern in leukemic lymphoblasts. We conclude that germline genomic variations affect susceptibility to and characteristics of specific ALL subtypes. We used microarrays to detail the global program of gene expression in primary leukemic blasts cells from children diagnosed with acute lymphoblastic leukemia.
Project description:Gene expression profiling (GEP) can reveal characteristic signatures associated with distinct biologic subtypes of acute lymphoblastic leukemia (ALL). We performed GEP on Down syndrome (DS) and comparison non-Down syndrome (NDS) ALL cases to identify biologic differences between these groups. Ficoll-enriched, cryopreserved diagnostic bone marrow samples were obtained from patients with newly diagnosed B-precursor acute lymphoblastic leukemia.
Project description:Lymphoblastic lymphoma (LBL) is one of the most frequent occurring pediatric non-Hodgkin lymphomas. In the WHO classification scheme pediatric LBL is considered to be the same disease entity as pediatric acute lymphoblastic leukemia (ALL). However, it is unclear whether the genetic basis of pediatric LBL development is similar to that of pediatric ALL. We performed genome-wide analyses of copy number aberrations in 12 T-LBL and 7 precursor B-cell LBL pediatric cases using high-resolution SNP-based array CGH. Similar to what previously has been found in T-ALLs, T-LBLs exhibited recurrent deletions of the CDKN2A locus, occurring in 92% of the cases. Additionally, we detected deletions of RB1 (16%), duplications of MYB (16%) and an amplification of ABL1 in one case. These results show that, similar to T-ALL, the genomic alterations in T-LBL predominantly target genes involved in cell cycle progression. The majority of precursor B-cell LBLs was characterized by high-hyperdiploidy (71%), and showed high resemblance with high-hyperdiploid precursor B-cell ALLs. These results show that, similar to T-ALL, the genomic alterations in T-LBL predominantly target genes involved in cell cycle progression and that high-hyperdiploidy is a commen event in B-LBL. Taken together, our data suggest that pediatric LBLs and ALLs exhibit similar genomic abnormalities within confined immunophenotypic and cytogenetic subgroups, but that the representations of these subgroups differs between the two entities. Copy number detection was performed using CNAG2.0 software, Reference genomes are included in this data set Keywords: comparative genome hybridization
Project description:The presence of supernumerary chromosomes is the only abnormality shared by all patients diagnosed with high-hyperdiploid B cell acute lymphoblastic leukemia (HD-ALL). Despite being the most frequently diagnosed pediatric leukemia, the lack of clonal molecular lesions and complete absence of appropriate experimental models have impeded the elucidation of HD-ALL leukemogenesis. Here, we report that for 23 leukemia samples isolated from moribund Eμ-Ret mice, all were characterized by non-random chromosomal gains, involving combinations of trisomy 9, 12, 14, 15, and 17. With a median gain of three chromosomes, leukemia emerged after a prolonged latency from a preleukemic B cell precursor cell population displaying more diverse aneuploidy. Transition from preleukemia to overt disease in Eμ-Ret mice is associated with acquisition of heterogeneous genomic abnormalities affecting the expression of genes implicated in pediatric B-ALL. The development of abnormal centrosomes in parallel with aneuploidy renders both preleukemic and leukemic cells sensitive to inhibitors of centrosome clustering, enabling targeted in vivo depletion of leukemia-propagating cells. This study reveals the Eμ-Ret mouse to be a novel tool for investigating HD-ALL leukemogenesis, including supervision and selection of preleukemic aneuploid clones by the immune system and identification of vulnerabilities that could be targeted to prevent relapse.
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)