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DNA Copy Number Changes (dna + copy_number_change)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Quantitative microsatellite analysis to delineate the commonly deleted region 1p22.3 in mantle cell lymphomas

GENES, CHROMOSOMES AND CANCER, Issue 10 2006
Asha Balakrishnan
The molecular pathogenesis of mantle cell lymphomas (MCL), a subset of B-cell non-Hodgkin's lymphomas with a poor prognosis, is still poorly understood. In addition to the characteristic primary genetic alteration t(11;14)(q13;q32), several further genetic changes are present in most cases. One of the most frequent genomic imbalances is the deletion of 1p22.1,p31.1 observed in nearly one-third of MCL cases. This might indicate the presence of tumor suppressor gene(s) in this critical region of deletion. Quantitative microsatellite analysis (QuMA) is a real-time PCR-based method to detect DNA copy number changes. Since QuMA has the resolving power to detect subtle genomic alterations, including homozygous deletions, this may help to identify candidate tumor suppressor genes from deleted regions. To gain more insight into the molecular pathogenesis of MCL, QuMA was performed on genomic DNA from 57 MCL cases. Eight microsatellite loci mapping to the chromosomal region 1p22.3 were analyzed. Losses were observed in 51 of the 57 (,89.5%) samples. Two cases showed a homozygous deletion at the locus containing the gene SH3GLB1, which plays a key role in Bax-mediated apoptosis. Two hotspots with copy number losses were detected at chromosomal localizations 85.4 and 86.6 Mb encompassing BCL10 and CLCA2. Both the genes seem to be attractive candidates to study tumor suppressor function in MCL. This article contains Supplementary material available at http://www.interscience.wiley.com/jpages/1045,2257/suppmat. © 2006 Wiley-Liss, Inc. [source]

DNA copy number changes in carcinoma in pleomorphic adenoma of the salivary gland: A comparative genomic hybridization study

PATHOLOGY INTERNATIONAL, Issue 8 2002
Takashi Morio
Pleomorphic adenoma is the most common benign tumor of the salivary glands and is rarely associated with concurrent epithelial malignancy, which is designated as carcinoma in pleomorphic adenoma (CPA). Genetic abnormalities potentially related to the development of CPA have not been fully investigated. We analyzed DNA copy number changes in each of the adenomatous and carcinomatous components of seven CPA by comparative genomic hybridization using DNA extracted from microdissected tissues of formalin-fixed, paraffin-embedded tumor samples. Carcinomatous components of CPA showed multiple DNA copy number changes at 1,18 different genomic sites (mean 13 sites). Adenomatous components displayed less frequent DNA copy number changes (0,13 sites; mean, 5). In both components, the majority of the changes were gains. The most common recurrent gains in carcinomatous components were seen at 6q (four cases in each), whereas gains at 13q1,2 and 15q1 were most frequently detected in adenomatous components (three cases in each). In five CPA, the same chromosomal regions were involved in the DNA copy number changes detected in both components. Our data suggest that an accumulated or increased number of chromosomal changes including 6q abnormalities may be associated with the development of carcinomatous components in a subset of CPA. [source]

A case of adult T-cell leukaemia/lymphoma characterized by multiplex-fluorescence in situ hybridization, comparative genomic hybridization, fluorescence in situ hybridization and cytogenetics

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2001
X. Mao
Adult T-cell leukaemia/lymphoma (ATLL) is a neoplasm of mature helper (CD4) T lymphocytes. Little is known, however, about the chromosome aberrations associated with the pathogenesis of this malignancy. Using molecular cytogenetic techniques we, therefore, investigated a 44-year-old man who had a 7-year history of ATLL with cutaneous involvement mimicking primary cutaneous T-cell lymphoma. Conventional cytogenetics revealed gross chromosomal changes with chromosome numbers ranging from 71 to 82. There were structural abnormalities of chromosomes 7 and 9, partial deletions of chromosomes 1, 3, 5 and 6, and loss of chromosomes 2, 4, 9, 11,14, 21 and 22. Multiplex-fluorescence in situ hybridization (M-FISH) identified two derivative chromosomes, der(6)t(6;7)(q16;q21) and der(7)t(6;7)(q16;q21)ins(6;12)(q2?;?), and a deletion of chromosome 1p. Conventional FISH confirmed the M-FISH findings. Comparative genomic hybridization of the blood revealed gains of DNA copy number at 1q12,25, 6p24,25, 9p23, 16p13,q13, 17q11,21, 19p13 and 20q13 and loss at 11p15 while lymph nodes showed gains at 3p22,24, 3q27,29, 7q36 and 15q26 and losses at 2p24,25, 2q37, 10p14,15, 11p15, 13q33,34 and 16p13.3. No DNA copy number changes were seen in a skin lesion. These results show the extent of genetic abnormalities within this malignancy. [source]