title: An exonuclease I hydrolysis assay for evaluating G-quadruplex stabilization by small molecules.
abstract: Telomere length homeostasis is a prerequisite for the generation and growth of cancer. In >85% cancer cells, telomere length is maintained by telomerase that add telomere repeats to the end of telomere DNA. Because the G-rich strand of telomere DNA can fold into G-quadruplex that inhibits telomerase activity, stabilizing telomere quadruplex by small molecules is emerging as a potential therapeutic strategy against cancer. In these applications, the specificity of small molecules toward quadruplex over other forms of DNA is an important property to ensure no processes other than telomere elongation are interrupted. The evaluating assays currently available more or less have difficulty identifying or distinguishing quadruplex-irrelevant effect from quadruplex stabilization. Here, we describe an exonuclease I hydrolysis assay that evaluates quadruplex stabilization by DNA-interacting compounds, discriminates inhibitory effect from different sources and helps determine the optimal compound concentration.
authors.affiliation: Laboratory of Biochemistry and Biophysics, College of Life Sciences, Wuhan University, Wuhan 430072, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yao
authors.forename: Quan
authors.initials: Q
authors.lastname: Wang
authors.forename: Yu-hua
authors.initials: YH
authors.lastname: Hao
authors.forename: Zheng
authors.initials: Z
authors.lastname: Tan
mesh_terms: D002227:Carbazoles / Q000494:pharmacology; D002232:Carbocyanines / Q000494:pharmacology; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005090:Exodeoxyribonucleases / Q000378:metabolism*; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism; D011166:Porphyrins / Q000494:pharmacology; D011726:Pyridinium Compounds / Q000494:pharmacology; D013053:Spectrophotometry; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000737:chemistry* / Q000378:metabolism
chemical_list: C486012:3,6-bis(1-methyl-4-vinylpyridium)carbazole diiodide; D002227:Carbazoles; D002232:Carbocyanines; D009841:Oligonucleotides; D011166:Porphyrins; D011726:Pyridinium Compounds; C018919:3,3'-diethyloxadicarbocyanine; C021096:tetra(4-N-methylpyridyl)porphine; D006147:Guanine; D004247:DNA; D019098:Telomerase; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I