Home  About us  Contact
 

Number Imbalances (number + imbalance)

Distribution by Scientific Domains
Medical Sciences75%

Kinds of Number Imbalances

  • copy number imbalance
    		•

    Selected Abstracts

    A narrow deletion of 7q is common to HCL, and SMZL, but not CLL

    EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2004
    Claus Lindbjerg Andersen
    Abstract: To further characterise the genetic background of the two closely related B-lymphocytic malignancies hairy cell leukaemia (HCL), and splenic marginal zone lymphoma (SMZL) we have identified characteristic copy number imbalances by comparative genomic hybridisation (CGH). Based on these findings, areas of special interest were fine mapped, and relevant probes constructed for use in interphase-fluorescence in situ hybridisation (FISH) investigations. Thus, using the CGH data from 52 HCL and 61 SMZL patients, we identified the characteristic profiles of copy number imbalances for both diseases. These were a gain of 5q13-31 (19%) and loss of 7q22-q35 (6%) for HCL, and gain of 3q25 (28%), loss of 7q31 (16%), and gain of 12q15 (16%) for SMZL. A partial loss of 7q unsual for low-malignant B-cell diseases was found to be common to the two diseases. This loss was therefore fine mapped with BAC/PAC clones. Fine mapping revealed that in SMZL the minimal lost region covers 11.4 Mb spanning from 7q31.33 to 7q33 located between sequence tagged site (STS)-markers SHGC-3275 and D7S725. This area was distinct from the commonly deleted 7q region of myelodysplastic syndrome/acute myeloid leukaemia (MDS/AML). A FISH probe specific for the 7q region was constructed. Using this probe in an interphase-FISH investigation we showed the minimal lost 7q-region of HCL and SMZL to be one and the same. In one HCL case, this investigation furthermore showed the extent of the deleted region to be below the detection limit of CGH, whereas interphase-FISH screening of 36 chronic lymphocytic leukaemia (CLL) cases showed no deletion of the 7q area. In conclusion, we have identified characteristic profiles of copy number imbalances in HCL and SMZL and fine mapped the minimal extent of a commonly lost 7q area of special interest. We hypothesise that this region may contain (a) gene(s) important for the pathology of HCL and SMZL. [source]

    High resolution analysis of follicular lymphoma genomes reveals somatic recurrent sites of copy-neutral loss of heterozygosity and copy number alterations that target single genes,

    GENES, CHROMOSOMES AND CANCER, Issue 8 2010
    K-John J. Cheung
    A multiplatform approach, including conventional cytogenetic techniques, BAC array comparative genomic hybridization, and Affymetrix 500K SNP arrays, was applied to the study of the tumor genomes of 25 follicular lymphoma biopsy samples with paired normal DNA samples to characterize balanced translocations, copy number imbalances, and copy-neutral loss of heterozygosity (cnLOH). In addition to the t(14;18), eight unique balanced translocations were found. Commonly reported FL-associated copy number regions were revealed including losses of 1p32-36, 6q, and 10q, and gains of 1q, 6p, 7, 12, 18, and X. The most frequent regions affected by copy-neutral loss of heterozygosity were 1p36.33 (28%), 6p21.3 (20%), 12q21.2-q24.33 (16%), and 16p13.3 (24%). We also identified by SNP analysis, 45 aberrant regions that each affected one gene, including CDKN2A, CDKN2B, FHIT, KIT, PEX14, and PTPRD, which were associated with canonical pathways involved in tumor development. This study illustrates the power of using complementary high-resolution platforms on paired tumor/normal specimens and computational analysis to provide potential insights into the significance of single-gene somatic aberrations in FL tumorigenesis. © 2010 Wiley-Liss,Inc. [source]

    Order Flow Patterns around Seasoned Equity Offerings and their Implications for Stock Price Movements,

    INTERNATIONAL REVIEW OF FINANCE, Issue 1-2 2005
    SAHN-WOOK HUH
    ABSTRACT In this study, we employ order imbalance measures to provide evidence that there is cross-sectional heterogeneity in investor reactions to seasoned equity offerings (SEOs). The normally positive relation between imbalances and returns disappears for trade number imbalances but remains intact for dollar imbalances following SEOs. The return-imbalance delinkage is most pronounced for SEO stocks in which institutions (non-institutions) are net sellers (buyers). We also find that the SEO portfolio in which large institutional investors are net sellers strongly underperforms the complementary portfolio in which they are net buyers. [source]

    Geminin predicts adverse clinical outcome in breast cancer by reflecting cell-cycle progression

    THE JOURNAL OF PATHOLOGY, Issue 2 2004
    Michael A Gonzalez
    Abstract Geminin inhibits DNA replication by preventing Cdt1 from loading minichromosome maintenance (MCM) proteins onto DNA. The present study has investigated whether the frequency of geminin expression predicts clinical outcome in breast cancer. Immunohistochemistry was used first to examine geminin expression in normal and malignant breast tissue (n = 67). Correlations with cell-cycle parameters, pathological features, and clinical outcome were then determined using an invasive breast carcinoma tissue microarray (n = 165). Breast carcinomas were scanned for mutations (n = 61) and copy number imbalances (n = 241) of the geminin gene. Finally, the cell cycle distribution of geminin in breast cancer cells was investigated in vivo and in vitro. Despite a putative tumour suppressor function, it was found that increased geminin expression is a powerful independent indicator of adverse prognosis in invasive breast cancer. Both poor overall survival (p = 0.0002) and the development of distant metastases (p = 0.005) are predicted by high geminin expression, which performs better in this patient cohort than traditional factors currently used to determine prognosis and appropriate therapy. No mutations or deletions of the geminin gene and no evidence that a high frequency of protein expression is related to gene amplification were found. It is shown that geminin is expressed from S to M phase in breast carcinoma tissue and cell lines, disappearing at the metaphase,anaphase transition. While MCM proteins identify all non-quiescent cells, geminin identifies the sub-fraction that have entered S phase, but not exited mitosis, thereby indicating the rate of cell-cycle progression. It is suggested that this explains its unexpected value as a prognostic marker in breast cancer. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source]