Telomerase activity detection in cancer cells via primer extension-mediated fluorescence enhancement of silver nanoclusters

Abstract

Telomerase is a potentially sensitive biomarker for early cancer diagnosis and prognosis. The development of effective methods for telomerase activity detection is important and desirable. In this study, inspired by the tunable fluorescence properties of DNA-templated AgNCs, which can be enhanced by a guanine-rich DNA sequence in proximity, a new fluorescence strategy for telomerase activity detection was proposed. In the presence of active telomerase extracted from cancer cells, repeats of a guanine-rich DNA sequence (TTAGGG) could be generated by telomerase-catalyzed extension of the primer, and fluorescence enhancement of AgNCs could be triggered by the hybridization of the extended product with the template DNA of AgNCs. The results demonstrated that the proposed method was sensitive to telomerase activity, could discriminate cancer cells from normal cells, held satisfactory potential for cancer diagnosis and could be applied to the telomerase inhibition assay. Thus, we believe that this developed method is applicable to a wide variety of fields including biochemical sensing, molecular biology and biomedicine.