Abstract

Aptamers have emerged as promisingmolecular probes for disease diagnosis and therapy. In the present study, theentire live cell-SELEX method was used to generate gastric cancer cell‑specific aptamers. Human gastric carcinoma AGS cells were used astarget cells for positive selections and human normal gastric epithelial GES-1cells as the negative cells for counter selections. The selection procedure wasmonitored by gel electrophoresis and flow cytometric analysis. By successive invitro evolutions and subsequent cloning and sequencing, a gastric carcinomacell‑specific DNA aptamer termed cy-apt 20with minimal recognition to the controls was identified from the final enrichedssDNA pool. Flow cytometry binding assays revealed that cy-apt 20 had a >70%binding rate to AGS cells and <30% binding affinity to non-gastric cancercells. Furthermore, the targeting recognition of AGS cells was established byusing minimal doses of FITC-cy-apt 20 that continued for a long period of time.As visualized by fluorescence imaging, the majority of AGS cells were stainedby FITC-cy-apt 20. The fluorescence intensity of AGS cells was ~6-fold overthat of non-AGS cells. The present study demonstrated that the entire livecell-SELEX was simple, but effective in generating gastric cancer cell‑specific aptamers, and that the aptamer cy-apt 20 has greatpotential to be used for the study and diagnosis of gastric cancer.