The transcripts of SFRP1,CEP63 and EIF4G2 genes are frequently downregulated in transitional cell carcinomas of the bladder.

Objective: The aim of the present study was to identify differentially expressed genes that might be associated with the phenotype of superficial and invasive bladder cancer.

Methods: Differential display reverse transcriptase PCR (DDRT-PCR) was used to compare the expression pattern between normal bladder tissue and 4 groups of transitional cell carcinomas of the bladder regarding clinical stage and grade.

Results: We were able to identify 72 different transcripts, of which 57 (79%) showed homology to known genes, 12 (17%) to hypothetical proteins and 3 (4%) to human expressed sequence tags. Among the differentially expressed genes, SFRP1,CEP63 and EIF4G2 were further validated by quantitative RT-PCR in a series of 50 transitional cell carcinomas. Overall, the transcripts of these three genes were shown to be downregulated in the bladder tumors analyzed. In accordance with the DDRT-PCR results, the SFRP1 transcripts were shown to be downregulated in 90% (45/50) of the bladder tumors as compared with the normal bladder tissue. Although EIF4G2 and CEP63 transcripts exhibited three different expression patterns, downregulation was found in about 50% of the cases analyzed. In addition, downregulation of both CEP63 and EIF4G2 gene transcription was associated with invasive tumors.

Conclusion: The use of DDRT-PCR analysis to compare expression patterns among different subgroups of bladder tumors allowed us to identify a significant number of genes implicated in different cellular pathways that, when up- or downregulated, might play a role in the tumorigenic process of the bladder.