Genomic copy number alterations in bladder urothelial carcinoma: similarities and differences between biopsy samples and cancer stem-like cells.
Bladder cancer is the fourth most common cancer in men and the eighth in women in both incidences and mortality and over 90% of bladder tumors are transitional cell carcinomas (TCCs). More than 70% are low-grade (LG) non-infiltrating (NI) cancers at diagnosis, but 60-80% of them recur at least one time and 10-20% progress in stage and grade. On the other hand, about 20% of tumors show muscle invasion (IN) and have a poor prognosis with <50% survival after 5 years. It appears increasingly clear that the two types of tumors originate through at least two different pathways of tumor development and progression even at the level of genetic alterations, and probably arise from distinct progenitor types. In this study we initially used conventional chromosome analysis on TCC biopsies with different histotypes (LG vs HG) in order to detect rough differences between them. Then, we performed aCGH analysis on 10 HG and 10 LG tumors providing an overview of CNAs. Finally, we made a comparison of the overall CNAs in 16 biopsies and their respective CSCs isolated from them. The overall data indicate that LG diverge from HG regarding their respective genomic profile even in the early stage of tumorigenesis; moreover, it has been identified a subgroup of LG samples in which the tendency to loss of genomic regions is significantly higher (up to 14 times). These findings provide valuable information to deeper studying TCC carcinogenesis and in the clinic for the identification of patients who will benefit from a more aggressive therapy. ==fine abstract==