title: Chromosomal aberrations in bladder cancer: fresh versus formalin fixed paraffin embedded tissue and targeted FISH versus wide microarray-based CGH analysis.
abstract: Bladder carcinogenesis is believed to follow two alternative pathways driven by the loss of chromosome 9 and the gain of chromosome 7, albeit other nonrandom copy number alterations (CNAs) were identified. However, confirmation studies are needed since many aspects of this model remain unclear and considerable heterogeneity among cases has emerged. One of the purposes of this study was to evaluate the performance of a targeted test (UroVysion assay) widely used for the detection of Transitional Cell Carcinoma (TCC) of the bladder, in two different types of material derived from the same tumor. We compared the results of UroVysion test performed on Freshly Isolated interphasic Nuclei (FIN) and on Formalin Fixed Paraffin Embedded (FFPE) tissues from 22 TCCs and we didn't find substantial differences. A second goal was to assess the concordance between array-CGH profiles and the targeted chromosomal profiles of UroVysion assay on an additional set of 10 TCCs, in order to evaluate whether UroVysion is an adequately sensitive method for the identification of selected aneuploidies and nonrandom CNAs in TCCs. Our results confirmed the importance of global genomic screening methods, that is array based CGH, to comprehensively determine the genomic profiles of large series of TCCs tumors. However, this technique has yet some limitations, such as not being able to detect low level mosaicism, or not detecting any change in the number of copies for a kind of compensatory effect due to the presence of high cellular heterogeneity. Thus, it is still advisable to use complementary techniques such as array-CGH and FISH, as the former is able to detect alterations at the genome level not excluding any chromosome, but the latter is able to maintain the individual data at the level of single cells, even if it focuses on few genomic regions.
authors: Department of Neuroscience and Biomedical Technologies, University of Milan-Bicocca, Monza, Italy.
authors: Elena
authors: E
authors: Panzeri
authors: Donatella
authors: D
authors: Conconi
authors: Laura
authors: L
authors: Antolini
authors: Serena
authors: S
authors: Redaelli
authors: Maria Grazia
authors: MG
authors: Valsecchi
authors: Giorgio
authors: G
authors: Bovo
authors: Francesco
authors: F
authors: Pallotti
authors: Paolo
authors: P
authors: Viganò
authors: Guido
authors: G
authors: Strada
authors: Leda
authors: L
authors: Dalprà
authors: Angela
authors: A
authors: Bentivegna
mesh_terms: D002467:Cell Nucleus / Q000235:genetics; D002869:Chromosome Aberrations; D055028:Comparative Genomic Hybridization / Q000379:methods*; D056915:DNA Copy Number Variations / Q000235:genetics; D005260:Female; D005557:Formaldehyde / Q000737:chemistry*; D015894:Genome, Human / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007399:Interphase / Q000235:genetics; D008297:Male; D016612:Paraffin Embedding; D016707:Tissue Fixation; D001749:Urinary Bladder Neoplasms / Q000235:genetics*
chemical_list: D005557:Formaldehyde