title: Evolution of a gastric carcinoma cell-specific DNA aptamer by live cell-SELEX.
abstract: Aptamers have emerged as promising molecular probes for disease diagnosis and therapy. In the present study, the entire live cell-SELEX method was used to generate gastric cancer cell‑specific aptamers. Human gastric carcinoma AGS cells were used as target cells for positive selections and human normal gastric epithelial GES-1 cells as the negative cells for counter selections. The selection procedure was monitored by gel electrophoresis and flow cytometric analysis. By successive in vitro evolutions and subsequent cloning and sequencing, a gastric carcinoma cell‑specific DNA aptamer termed cy-apt 20 with minimal recognition to the controls was identified from the final enriched ssDNA 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 cancer cells. Furthermore, the targeting recognition of AGS cells was established by using 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 stained by FITC-cy-apt 20. The fluorescence intensity of AGS cells was ~6-fold over that of non-AGS cells. The present study demonstrated that the entire live cell-SELEX was simple, but effective in generating gastric cancer cell‑specific aptamers, and that the aptamer cy-apt 20 has great potential to be used for the study and diagnosis of gastric cancer.
authors.affiliation: Department of General Surgery, Nanjing Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, P.R. China.
authors.forename: Hong-Yong
authors.initials: HY
authors.lastname: Cao
authors.affiliation: Department of General Surgery, Nanjing Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, P.R. China.
authors.forename: Ai-Hua
authors.initials: AH
authors.lastname: Yuan
authors.affiliation: Department of General Surgery, Nanjing Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, P.R. China.
authors.forename: Xue-Song
authors.initials: XS
authors.lastname: Shi
authors.affiliation: Department of General Surgery, Nanjing Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of General Surgery, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, P.R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Miao
mesh_terms: D052157:Aptamers, Nucleotide / Q000138:chemical synthesis* / Q000235:genetics* / Q000627:therapeutic use; D045744:Cell Line, Tumor; D055088:Early Detection of Cancer; D056945:Hep G2 Cells; D006801:Humans; D058990:Molecular Targeted Therapy; D052156:SELEX Aptamer Technique / Q000379:methods*; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D013379:Substrate Specificity
chemical_list: D052157:Aptamers, Nucleotide