Metaphase and array comparative genomic hybridization: unique copy number changes and gene amplification of medulloblastomas in South America

2006 ◽  
Vol 170 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Maisa Yoshimoto ◽  
Jane Bayani ◽  
Paulo A.S. Nuin ◽  
Nasjla S. Silva ◽  
Sergio Cavalheiro ◽  
...  
2009 ◽  
Vol 31 (1) ◽  
pp. 31-39
Author(s):  
Arno Kuijper ◽  
Antoine M. Snijders ◽  
Els M. J. J. Berns ◽  
Vibeke Kuenen-Boumeester ◽  
Elsken van der Wall ◽  
...  

Breast phyllodes tumour (PT) is a rare fibroepithelial tumour. The genetic alterations contributing to its tumorigenesis are largely unknown. To identify genomic regions involved in pathogenesis and progression of PTs we obtained genome-wide copy number profiles by array comparative genomic hybridization (CGH).DNA was isolated from fresh-frozen tissue samples. 11 PTs and 3 fibroadenomas, a frequently occurring fibroepithelial breast tumour, were analyzed. Arrays composed of 2464 genomic clones were used, providing a resolution of ~1.4 Mb across the genome. Each clone contains at least one STS for linkage to the human genome sequence.No copy number changes were detected in fibroadenomas. On the other hand, 10 of 11 PT (91%) showed DNA copy number alterations. The mean number of chromosomal events in PT was 5.5 (range 0–16) per case. A mean of 2.0 gains (range 0–10) and 3.0 losses (range 0–9) was seen per case of PT. Three cases showed amplifications. DNA copy number change was not related to PT grade. We observed recurrent loss on chromosome 1q, 4p, 10, 13q, 15q, 16, 17p, 19 and X. Recurrent copy number gain was seen on 1q, 2p, 3q, 7p, 8q, 16q, 20.In this study we used array CGH for genomic profiling of fibroepithelial breast tumours. Whereas most PT showed chromosomal instability, fibroadenomas lacked copy number changes. Some copy number aberrations had not previously been associated with PT. Several well-known cancer related genes, such as TP53 and members of the Cadherin, reside within the recurrent regions of copy number alteration. Since copy number change was found in all benign PT, genomic instability may be an early event in PT genesis.


Blood ◽  
2006 ◽  
Vol 107 (6) ◽  
pp. 2477-2485 ◽  
Author(s):  
Weiyi Chen ◽  
Jane Houldsworth ◽  
Adam B. Olshen ◽  
Gouri Nanjangud ◽  
Seeta Chaganti ◽  
...  

Abstract To identify, in high-resolution regions of DNA, the copy number changes associated with outcome in patients with diffuse large B-cell lymphoma (DLBCL), a disease with an approximately 50% mortality rate, we performed array comparative genomic hybridization (array-CGH) on specimens from 64 patients with newly diagnosed DLBCL treated with anthracycline-based chemotherapy. For the entire cohort, 55 commonly gained/lost regions, ranging in size from less than 1 Mbp to entire chromosomes, were identified using 1- to 2-Mbp and 2- to 4-Mbp resolution BAC arrays. Copy number changes of 9 minimal regions significantly correlated with overall survival, of which 6 were 10 Mbp or smaller. On multivariate analysis, loss of chromosomes 2 (2.4-4.1 Mbp) and 16 (33.8-35.6 Mbp) were found to be prognostic indicators of poor survival, independent of clinical features routinely used to predict outcome. Loss of chromosome 1 (78.2-79.1 Mbp) was predictive of good outcome. For a subset of 55 specimens classified according to cell-of-origin expression signature subtype, gain of chromosome 12 (45.4-53.8 Mbp) was found to be significantly associated with the germinal center B-cell-like DLBCL subtype. Overall, array-CGH identified relatively small genomic regions associated with outcome, which, along with follow-up expression studies, may reveal target genes important in DLBCL clinical behavior. (Blood. 2006;107:2477-2485)


2001 ◽  
Vol 22 (3) ◽  
pp. 159-163 ◽  
Author(s):  
Kowan J. Jee ◽  
Young Tak Kim ◽  
Kyu Rae Kim ◽  
Yan Aalto ◽  
Sakari Knuutila

DNA copy number changes were studied by comparative genomic hybridization on 10 tumor specimens of squamous cell carcinoma of cervix obtained from Korean patients. DNA was extracted from paraffin‐embedded sections after removal of non‐malignant cells by microdissection technique. Copy number changes were found in 8/10 tumors. The most frequent changes were chromosome 19 gains (n=6) and losses on chromosomes 4 (n=4), 5 (n=3), and 3p (n=3). A novel finding was amplification in chromosome arm 9p21‐pter in 2 cases. Gains in 1, 3q, 5p, 6p, 8q, 16p, 17, and 20q and losses at 2q, 6q, 8p, 9q, 10p, 11, 13, 16q, and 18q were observed in at least one of the cases.


Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5269-5278 ◽  
Author(s):  
O Monni ◽  
H Joensuu ◽  
K Franssila ◽  
S Knuutila

We studied DNA copy number changes in diffuse large B-cell lymphoma using comparative genomic hybridization analysis on 20 primary tumors and on 12 recurrent tumors excised after chemotherapy or radiotherapy. Twenty-nine (91%) of the cases showed abnormal copy number karyotypes. Chromosomal regions at X (41%), 1q (38%), 7 (31%), 3 (24%), 6p (21%), 11 (21%), 12 (21%), and 18 (21%) were most frequently gained, and the most common losses involved 6q (38%), X (21%), 1p (14%), and 8p (10%). High-level amplifications were observed at 6p23-ter, 10p12–14, 17p1l.2, 18q21-ter, and Xq22-ter, all but 18q appearing only in the recurrent tumors. Gains (median, 2; range, 0 to 10) were more frequent than losses (median, 1; range, 0 to 7; P = .0004). The median number of aberrations found in the recurrent tumors (6.5) was greater than that in the primary tumors (2; P = .01). The copy number changes found in the recurrent tumors were more random than those found in the primary tumors, which were mainly located in the most frequently affected regions. Our findings are in line with those observed using conventional cytogenetic analysis, but especially novel high-level amplifications were detected. Southern blot analysis showed BCL2 amplification, but not translocation t(14;18)(q32;q21), in cases in which a gain at 18q was detected by comparative genomic hybridization, which strongly suggests that, in addition to translocation, gene amplification is another mechanism for the overexpression of the BCL2 protein.


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