title: Exonuclease I manipulating primer-modified gold nanoparticles for colorimetric telomerase activity assay.
abstract: Telomerase is a widely accepted cancer biomarker. The conventional method for telomerase activity assay, the telomeric repeat amplification protocol (TRAP), is time-consuming and susceptible to contaminants. Therefore, development of simple and sensitive strategies for telomerase detection is still a challenging subject. Here we develop a highly sensitive method for telomerase detection based on primer-modified gold nanoparticles (GNPs) manipulated by exonuclease I (Exo I). In the absence of telomerase, Exo I digests the substrate nucleic acid on the surface of GNPs, inducing the GNPs' aggregation. In the presence of telomerase, the telomerase elongation products which fold into G-quadruplex are resistant to the digestion of Exo I, and protect the GNPs from aggregation. By using this method, we can detect telomerase activity in 100 HL-60 cancer cells mL(-1) by naked eyes, and the detection limit is 29 HL-60 cells mL(-1). This method is very simple and reliable, without any separation and amplification procedure. We also demonstrate the feasibility of this protocol for screening of telomerase inhibitors as anticancer agents. This method is promising to be applied in early clinical diagnosis and drug discovery.
authors.affiliation: Department of Pediatrics, The Second Hospital, Jilin University, 218 Ziqiang Street, Changchun 130041, China. Electronic address: zhang_lei@jlu.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Pediatrics, The Second Hospital, Jilin University, 218 Ziqiang Street, Changchun 130041, China.
authors.forename: Sijin
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Pediatrics, The Second Hospital, Jilin University, 218 Ziqiang Street, Changchun 130041, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.affiliation: School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, China.
authors.forename: Qingcheng
authors.initials: Q
authors.lastname: Liang
authors.affiliation: Department of Pediatrics, The Second Hospital, Jilin University, 218 Ziqiang Street, Changchun 130041, China.
authors.forename: Xingyu
authors.initials: X
authors.lastname: Song
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation*; D003124:Colorimetry / Q000295:instrumentation*; D004789:Enzyme Activation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005090:Exodeoxyribonucleases / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019098:Telomerase / Q000032:analysis* / Q000737:chemistry*
chemical_list: D009841:Oligonucleotides; D006046:Gold; D019098:Telomerase; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I
keywords: Cancer; Colorimetric; Exonuclease I; Gold nanoparticle; Telomerase