ABSTRACT
Objective To investigate the methods of screening specific aptamers for (EpCAM)Gpositive prostate cancer (PCa)cells by cellGSELEX technique.Methods A random DNA library was designed to screen EpCAMGspecific DNA aptamers from human prostate cancer cells expressing EpCAM molecule by cellGSELEX technique.After 12 rounds of in vitro screening,DNA products were cloned and sequenced.Flow cytometry and cellular immunofluorescence were used to detect the specific binding ability of aptamers to target cells.Results Two aptamers of Ep1 and Ep2 were selected.Both of them could specifically bind to EpCAMGpositive cancer cells LNCap,PCG3 ,DU1 45 , and HEK293T cells transfected with target molecule.The binding rates of Ep1 were 61.0%,74.3%,5 9.1% and 60.3%.The binding rates of Ep2 were 65.1%,77.8%,54.2% and 58.3%.Neither of them could bind to HEK293T cells transfected with empty vector with the binding rate of 5.4% in Ep1 and 3.3% in Ep2,respectively.Flow cytometry analysis and confocal images indicated that the EpCAM aptamers could specifically recognize human PCa cells expressing EpCAM,but could not bind to EpCAMGnegative cells.Conclusion EpCAM aptamers derived from cellGSELEX technology can recognize and bind to EpCAMGpositive PCa cells specifically,which may provide new ideas for the specific diagnosis and targeted therapy of prostate cancer,and lay an experimental basis for the other specific diagnosis and treatment schemes of malignant tumors.