A catalytic DNA probe with stem-loop motif for human T47D breast cancer cells

Abstract

In vitro selection methods allow for isolation of DNAzymes (catalytic DNAs) from random DNA pools. Here we describe a fluorogenic DNAzyme, LYF5, isolated using a double-random selection approach: a random DNA pool was selected against a complex molecular mixture derived from a breast cancer cell line, T47D. LYF5 specifically indicates the T47D breast cancer cell line with high sensitivity. After sequence optimization, the second-generation DNAzyme, 2G-LYF5, exhibited an approximately 2-fold higher cleavage percentage. Finally, we have determined that the intramolecular stem-loop motif plays a crucial role in 2G-LYF5 activity. Our findings underscore the capability of singlestranded DNA molecules to perform highly sophisticated functions that are amenable to the development of diagnostic tests for early identification of breast cancer. 2015