Whole genome expression data from human urinary bladder cancer

At diagnosis approximately 75% of bladder urothelial carcinomas are non muscle invasive bladder cancers (Ta, T1 and Tis), 20% are muscle invasive bladder cancer (T2-T4) and 5% are already metastatic. Non muscle invasive bladder cancers are characterized by tumor recurrence in 60% to 85% of cases and, therefore, long-term followup is needed. The current standard methods to detect and monitor bladder cancer are cystoscopy and cytology. Cystoscopy is an invasive method and cytology is hampered by low sensitivity, especially for low grade tumors. So there is need to develop reliable and noninvasive methods to detect and predict bladder cancer biological behavior. So we have performed high density oligonucleotide microarray for discovery of new molecular markers to diagnose and predict the outcome of bladder cancer. Under an ethical guideline of Chhatrapati Shahuji Maharaj Medical University, India histologically confirmed seven bladder cancer patients were recruited from Department of Urology, Chhatrapati Shahuji Maharaj Medical University, Lucknow, India. Total RNA was extracted from tumor biopsies and hybridized on affymetrix Human Gene ST 1.1 array to determine differentially expressed genes in urinary bladder cancer with muscle invasion in comparison of normal human urinary bladder.