DBCCR1 (deleted in bladder cancer chromosomal region 1) has been reported as the gene functionally affected by frequent loss of 9q32-33 in transitional cell carcinomas of the urinary bladder.
Vascular endothelial growth factor (VEGF), a positive regulator of angiogenesis, plays a pivotal role in tumor angiogenesis and shows a high expression in almost all known tumors, including transitional cell carcinoma (TCC) of the bladder.
TRAP activity was positive in 100% of high grade urothelial carcinoma compared to low grade and 92% positive in invasive tumors compared to non invasive tumors. hTERT protein was detected in 75.4% of bladder cancer cases; there was a significant increase in the number of positive cases in schistosomal urothelial carcinoma and SCC compared to control and non schistosomal urothelial carcinoma (p<0.01 for each). hTERT was positive in 100% of high grade and invasive TCC. sFas was detected in 64.6% in bladder cancer cases; there was a significant increase in the number of positive cases in SCC compared to control and non-schistosomal urothelial carcinoma.
CD99 protein expression was determined by immunohistochemical staining in a series of 100 cases of transitional cell carcinomas (TCC) and 35 cases of normal urinary bladder tissues, and the methylation status of CD99 gene promoter was studied by using methylation-specific PCR and DNA sequencing.
Thymosin β4 was highly expressed in the hepatic cells in the normal adult liver, duct, and acinar cells in pancreas, and muscle cells in the heart and also expressed highly in certain tumor cells, including osteosarcoma, colon adenocarcinoma, esophageal squamous cell carcinoma, kidney and urinary bladder transitional carcinoma, lung cancer, and liver cancer.
FGFR3 appears to be the most frequently mutated oncogene in transitional cell carcinoma; its mutation is strongly associated with low tumor grade, early stage, and low recurrence rate, which confer a better overall prognosis.
BRCA1-associated high-grade serous carcinomas had more frequent Solid, pseudoEndometrioid, and Transitional cell carcinoma-like morphology (SET features) (P=0.0045), higher mitotic indexes (P=0.012), more TILs (P=0.034), and either geographic or comedo necrosis (P=0.034).