Screening and identification of specific markers for bladder transitional cell carcinoma from urine urothelial cells with suppressive subtractive hybridization and cDNA microarray

Abstract

Objective: The objective of this study was to screen and identifydifferentially expressed genes in invasive bladder transitional cellcarcinoma (BTCC).Methods: Voided urine samples were collected from consecutivepatients with BTCC and patients under surveillance for bladdercancer recurrence; voided urine samples from patients with nonmalignantdiseases served as control. We identified the differentiallyexpressed genes by comparing urine samples of bladdercarcinoma to that of the control group with suppressive subtractivehybridization (SSH) and cDNA microarray. The differentiallyexpressed genes were verified by quantitative real-time polymerasechain reaction (QPCR).Results: From the 762 white colonies, a total of 449 positive cloneswere obtained in which 112 were found to be upregulated in BTCC.Sequencing and homology analysis were performed for these 112clonies. The detection rates of some known genes (including IGF-1, human telomerase reverse transcriptase [hTERT], bladder cancerspecific nuclear matrix protein 4 [BLCA-4] and homeobox A13[HOXA13]) for BTCC at the Ta, T1 and >T1 stages were 48%, 90%and 100%, respectively, with a specificity of 85%. The test specificitywas 80% for the 30 control patients with urinary tract infections. Thecombination of BLCA-4 and HOXA13 could distinguish betweenlow- and high-grade tumours, with specificity and sensitivity of 80%.Conclusion: We successfully constructed a reliable SSH library ofBTCC and found that combination detection insulin-like growthfactor 1 (IGF-1), hTERT, BLCA-4 and HOXA13 genes could helpto evaluate BTCC at different stages.