Preliminary study of diagnostic utility of molecular beacons in bladder cancer

To investigate the feasibility of molecular beacons (MBs) for screening urine samples from patients with suspected bladder cancer. Our previous study showed that MBs could detect bladder cancer cells and cells shed in the urine from patients with bladder cancer.

Samples from 35 patients with bladder cancer and 35 healthy adults were initially evaluated. Cyanine 3-labeled MBs linked to a survivin mRNA probe were used to detect exfoliative cells in urine. Exfoliative cytology, enzyme-linked immunosorbent assay, and Western blotting of the tissues were used to confirm the MB results. We then evaluated the urine samples from 187 patients with suspected bladder cancer. All 187 patients also underwent cystoscopy.

In the initial cohort evaluated, MBs detected cancerous cells in 28 (80%) of the 35 patients with confirmed bladder cancer. Survivin protein was detected by Western blotting in 25 (71.4%) of the 35 patients. The sensitivity and specificity of enzyme-linked immunosorbent assay was 54.3% (20 of 35) and 68.6% (24 of 35), respectively. In a large group of patients with suspected bladder cancer, the sensitivity of MBs was 77.3% (85 of 110) and the specificity was 76.6% (59 of 77) compared with the cystoscopy data. Differences in the protein levels between the tumor grades and stages were not significant.

Our results have demonstrated that it is feasible to detect survivin mRNA in the exfoliated cells in urine using MBs. With further development, MBs could be used in a noninvasive clinical diagnostic procedure for the early detection of bladder cancer and postoperative follow-up.