Telomerase is extensively expressed in various cancer cells and recognized as a target for cancer drug discovery. In the present study, a simple and amplification-free fluorescence assay based on polyamidoamine starburst dendrimer (PAMAM dendrimer)-activated paper device is proposed for sensitive detection of telomerase activity through hybridization of Cy5 modified single strand DNA probes with telomerase extension products. The paper substrate is fabricated by hand drawing according to a template, which is low cost, instrument free and easy operation. PAMAM is rich in amino groups on its surface and employed to immobilize the telomerase substrate (TS) primer. Highly sensitive detection of telomerase activity in HeLa cell lysate of 10 cells is achieved since the PAMAM dendrimer-activated paper surface can provide high density of binding sites for immobilization of TS primer. The experimental results also demonstrate that the assay can be employed to evaluate telomerase activity levels of various cell lines and screen telomerase inhibitors.

端粒酶在各种癌细胞中广泛表达，并被认为是癌症药物发现的靶标。在本研究中，提出了一种基于聚酰胺酰胺星暴树枝状大分子（PAMAM树枝状大分子）活化的纸装置的简单且无扩增的荧光测定方法，用于通过Cy5修饰的单链DNA探针与端粒酶延伸产物的杂交来灵敏检测端粒酶活性。纸质基板是根据模板手工绘制而成的，成本低，无需仪器，操作简便。PAMAM在其表面上富含氨基，可用于固定端粒酶底物（TS）引物。由于PAMAM树枝状大分子活化的纸表面可提供高密度的结合位点用于固定TS引物，因此可对10个细胞的HeLa细胞裂解物中的端粒酶活性进行高度灵敏的检测。实验结果还证明该测定法可用于评估各种细胞系的端粒酶活性水平并筛选端粒酶抑制剂。