To better define cytogenetic mechanisms of CDKN2 loss at 9p21 and of DBCCR1 loss at 9q33 in bladder cancer, and to determine correlation with p53 and pRb.
These results demonstrate a role for DBCCR1 in cell cycle control, thereby supporting the hypothesis that this is the tumour suppressor gene targeted by 9q32-33 deletion in bladder cancer.
Although DBCCR1 was expressed in multiple normal human tissues including urothelium, mRNA expression was absent in 5 of 10 (50%) bladder cancer cell lines.
A panel of 4 genes (MYO3A, CA10, NKX6-2, and DBC1 or SOX11) had 81% sensitivity and 97% specificity, whereas a panel of 5 genes (MYO3A, CA10, NKX6-2, DBC1, and SOX11 or PENK) had 85% sensitivity and 95% specificity for detection of bladder cancer (area under curve = 0.939).
The DBCCR1 gene at chromosome 9q33 has been identified as a candidate tumour suppressor, which is frequently targeted by promoter hypermethylation in bladder cancer.