Primary application study in early diagnosis of bladder cancer by survivin molecular beacons

OBJECTIVES To develop a sensitive method for the detection of bladder cancer cells in the urine castoff cells of patients with bladder cancer, we examined the feasibility of using molecular beacon (MB) probes specific for tumor-specific survivin mRNA. METHODS MBs are single-stranded oligonucleotide hybridization probes that form a stem-and-loop structure and have high sensitivity and specificity. Western blot analysis showed that a high level of survivin gene expression is detected in human bladder cancer 5637 and J82 cell lines but not in normal human prostate fibroblast cells. These cell lines were incubated with survivin MBs, and the fluorescence intensity was examined in those cells using a fluorescence microscope. RESULTS We found that survivin MBs could detect expression of the survivin gene and generated fluorescent signals in the cancer cells. However, the fluorescence signal was not detected in the normal prostate fibroblast cells. The green fluorescent signal was present in the exfoliated cells of patients with bladder cancer but not in the healthy adult after incubating with survivin MBs. CONCLUSIONS Our results have demonstrated that the survivin MB is a specific and sensitive molecular probe for detecting bladder cancer cells and urine castoff cells of patients with bladder cancer. It has great potential for the development of a clinical diagnostic procedure for the early detection of bladder cancer and follow-up after surgery.