PO-337 Preliminary observations: array-comparative genomic hybridization as a high-throughput approach against bladder cancer

Introduction Bladder cancer (BC) starts when urinary bladder cells grow abnormally. It is a solid tumour with high recurrence rates. BC is the eight tumour with the highest mortality and the sixth one with the highest incidence in the worldwide. Since the prognostic tools currently available have limitations and acquired changes in specific genes are thought to be significant in the development of bladder tumours, we needed to improve the research in this field of genetic changes associated with the BC. The aim of this study was the characterisation of the genomic profile of bladder tumours using the array-Comparative Genomic Hybridization (aCGH) technique. Material and methods Bladder tumour samples were acquired from 28 patients when they were submitted a transurethral resection of bladder tumour (TURBT). The aCGH was done using an Agilent oligonucleotide microarray 4 × 180K. Bladder tissue samples from non-cancer donors are used as controls. Histopathological information from the patients was analysed and clinical data registered. Results and discussions A few genomic imbalances were verified, using aCGH – a whole genome technique. In these preliminary outcomes, we did not observe a pattern of chromosomal alterations, as, we did not find imbalances in more than 20% of patients. Moreover, the chromosomes with more frequent copy number losses were 1, 6, 10, 13, 20, 21, 22 and X and the chromosomes with more frequent copy number gains were 1, 11, 13, 18 and 21. Additionally, the sizes of aberrations detected for the same chromosome were often variable between patients. Conclusion This approach allowed us to identify altered chromosomal regions in bladder cancer comparing to normal tissues. In this way, is possible to map fundamental genes related to disease initiation and progression. The correlation between molecular and clinical-pathological data will be fundamental to identify recognised biomarkers with possible diagnostic and prognostic interest.