Label-free, PCR-free chip-based detection of telomerase activity in bladder cancer cells

Bladder cancer is one of the most common cancers in Worldwide. The determination of urinary telomerase activity is a promising tool for the diagnosis of bladder carcinoma owing to the high rate of expression of telomerase in cancer cells. Typical assay for telomerase activity is the telomeric repeat amplification protocol (TRAP) based on polymerase chain reaction (PCR) amplification. However, TRAP assay is susceptible to PCR-derived artifacts and requires time-consuming procedure, expensive equipments and reagents. To develop a new method for telomerase activity assay that is fast, simple, and cost-effective, we have examined a silicon-based microring resonator biosensor to detect label-free, PCR-free telomerase activity using telomerase extracted from two bladder cancer cell lines, J-82 and HT-1376, in a buffer solution and spiked urine. With telomerase primer immobilized microring resonator sensor system, we successfully demonstrate the detection of telomerse extracted from as little as 10 cells/mu L and 100 cells/mu L in buffer and urine, respectively. Especially, the results represented here is the first demonstration of the detection of telomerase activity in human urine on the chip-based system. From the results, we expect that the silicon photonic microring resonator system can provide a powerful tool for cost-effective and sensitive telomerase activity detection in urinary bladder cancer. (C) 2013 Elsevier B.V. All rights reserved.