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.


CONCLUSIONS
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.
Buim
Marcilei E
ME
Departamento de Radiologia, Disciplina de Oncologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Soares
Fernando A
FA
Sarkis
Alvaro S
AS
Nagai
Maria Aparecida
MA
D000328:Adult; D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000235:genetics*; D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis; D015536:Down-Regulation; D039603:Eukaryotic Initiation Factor-4G / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics*; D012334:RNA, Neoplasm / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D014158:Transcription, Genetic; D001743:Urinary Bladder / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000235:genetics*; D000094742:Secreted Frizzled-Related Proteins
D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004273:DNA, Neoplasm; D039603:Eukaryotic Initiation Factor-4G; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; C508298:CEP63 protein, human; C491300:EIF4G2 protein, human; C117636:SFRP1 protein, human; D000094742:Secreted Frizzled-Related Proteins