Project description:Comparison of copy number variations of acute myeloid leukemia mononuclear cells and the given cell types collected during complete remission of the acute myeloid leukemia
Project description:Acute myeloid leukemia (AML) is a heterogeneous disease in respect of molecular aberrations and prognosis. We used gene expression profiling of 562 patients treated in the German AMLCG 1999 trial to develop a gene signature that predicts survival in AML. Analysis of 562 samples (140 HGU-133plus2; 422 HGU-133A; 422 HGU-133B) from adult patients with acute myeloid leukemia (AML).
Project description:The outcome of treating chronic myeloid leukemia (CML) with imatinib mesylate (IM) is inferior when therapy is commenced in late chronic or accelerated phase as compared to early chronic phase. This may be attributed to additional genomic alterations that accumulate during disease progression. We sought to identify such lesions in patients showing suboptimal response to IM by performing array-CGH analysis on 39 sequential samples from 15 CML patients. Seventy-four cumulative copy number alterations (CNAs) consisting of 35 losses and 39 gains were identified. Alterations flanking the ABL1 and BCR genes on chromosomes 9 and 22, respectively, were the most common identified lesions with 5 patients losing variable portions of 9q34.11 proximal to ABL1. Losses involving 1p36, 5q31, 17q25, Y and gains of 3q21, 8q24, 22q11, Xp11 were among other recurrent lesions identified. Aberrations were also observed in individual patients, involving regions containing known leukemia-associated genes; CDKN2A/2B, IKZF1, RB1, TLX1, AFF4. CML patients in late stages of their disease, harbor pre-existing and evolving sub-microscopic CNAs that may influence disease progression and IM response.
Project description:Except for the well-known association with Down syndrome, there is little information on the genetic factors predisposing to acute myeloid leukemia. Germinal gene copy-number variations may represent risk factors for the disease. To identify copy number variants present in both normal and leukemic cells, we compared the Comparative Genomic Hybridization profiles of the blasts and healthy cells (CD3+ cells or peripheral lymphocytes during remission) of 13 patients (SET-A) and the blasts of a further 12 normal-karyotype acute myeloid leukemia patients (SET-B) for which only blasts DNA were available.
Project description:Identification of Acquired Copy Number Alterations and Uniparental Disomies in Cytogenetically Normal Acute Myeloid Leukemia Using High-Resolution Single Nucleotide Polymorphism Analysis Recent advances in genome-wide single nucleotide polymorphism (SNP) analyses have revealed previously unrecognized microdeletions and uniparental disomy (UPD) in a broad spectrum of human cancers. As acute myeloid leukemia (AML) represents a genetically heterogeneous disease, this technology might prove helpful especially for cytogenetically normal AML (CN-AML) cases. Thus, we performed high-resolution SNP analyses in 157 adult cases of CN-AML. Regions of acquired UPD were identified in 12% of cases and most frequently affected chromosomes 6p, 11p, and 13q. Notably, acquired UPD was invariably associated with mutations in NPM1 or CEBPA that impair hematopoietic differentiation (P=0.008), suggesting that UPDs may preferentially target genes that are essential for proliferation and survival of hematopoietic progenitors. Acquired copy number alterations (CNAs) were detected in 49% of cases with losses found in two or more cases affecting e.g. chromosome bands 3p13-p14.1 and 12p13. Furthermore, we identified two cases with a cryptic t(6;11) as well as several non-recurrent aberrations pointing to leukemia relevant regions. With regard to clinical outcome, there appeared to be an association between UPD 11p and UPD 13q cases with overall survival. These data demonstrate the potential of high-resolution SNP analysis for identifying genomic regions of potential pathogenic and clinical relevance in AML.
Project description:Background: MicroRNAs are regulators of gene expression, mainly functioning by decreasing mRNA levels of their multiple targets. Deregulated microRNA expression has been shown for acute myeloid leukemia, a disease also characterized by altered gene expression associated with distinct genomic aberrations such as nucleophosmin (NPM1) mutations. To further illuminate the role of deregulated microRNA and gene expression in cytogenetically normal acute myeloid leukemia with NPM1 mutation, we performed an integrative analysis of microRNA and mRNA expression data sets. Design and Methods: Both microRNA and gene expression profiles were measured in a cohort of 43 adult acute myeloid leukemia patient samples (n=42 cytogenetically normal, n=1 del7q; median age 46 years [range 23-60]) of known NPM1 mutation status (n=23 mutated, n=20 wild-type) and data integratively analyzed. Putative microRNA-mRNA interactions were validated by quantitative RT-PCR, Western Blot and luciferase reporter assays. For selected microRNAs, sensitivity of microRNA-overexpressing cells to cytarabine treatment was tested by FACS viability and cell proliferation assays. Results: Our integrative approach of analyzing both microRNA and gene expression profiles in parallel resulted in a refined list of putative target genes affected by NPM1 mutation-associated microRNA deregulation. Of 177 putative microRNA - target mRNA interactions, we could identify and validate 77 novel candidates with known or potential implication in leukemogenesis, such as IRF2-miR-20a, KIT-miR-20a and MN1-miR-15a. Furthermore, our data showed that deregulated expression of tumor suppressor microRNAs such as miR-29a and miR-30c might contribute to the sensitivity to cytarabine, which is observed in NPM1-mutated acute myeloid leukemia. Conclusions: Overall, our observations highlight that integrative data analysis approaches can improve insights into leukemia biology, and lead to the identification of novel microRNA - target gene interactions of potential relevance for acute myeloid leukemia treatment. MicroRNA and gene expression profiles were measured in a cohort of 43 adult (42 cytogenetically normal and 1 del7q) acute myeloid leukemia patient samples of known NPM1 mutation status (n=23 mutated, n=20 wild-type). This submission represents the mRNA expression component of the study. The miRNA expression data will be deposited as supplementary information along with the accompanying manuscript.
Project description:Copy number and LOH analysis was performed for 56 chronic myeloid leukemia cases obtained from 23 CML cases obtained atchronic phase, accelerated phase, blast crisis, or remission. All caseswere genotyped with Affymetrix 250k Sty and Nsp arrays. Keywords: Acute leukemia, BCR-ABL1, chronic myeloid leukemia, copy number analysis, loss-of-heterozygosity, genomics *** Due to privacy concerns, the primary SNP array data is no longer available with unrestricted access. Individuals wishing to obtain this data for research purposes may request access using the Web links below. ***