Screening and identification of an ssDNA aptamer targeting the extracellular domain of Mucin16 by CE-SELEX / 医学研究生学报

ABSTRACT

Objective CA125 has been proved to be closely related to peritoneal metastasis of gastric cancer.This study aimed to screen and identify a novel ssDNA aptamer targeting the extracellular domain of Mucin16. Methods Using capillary elec-trophoresis, we screened the aptamers targeting the synthetic peptide of the extracellular domain of Mucin16 and quantitatively deter-mined the Kd value of each cycle and the affinity of the aptamers for the synthetic peptide by CE-SELEX.Then we evaluated the ability of the obtained aptamers to target cancer cells using confocal laser imaging. Results After five cycles of screening, sequencing, af-finity determination, we obtained an ssDNA aptamer targeting the extracellular domain of Mucin16, with a Kd value of 122.7 nm and visible green fluorescent signals on the cell membrane of the human ovarian cancer cell line expressing Mucin16, but not on that of the normal hepatocytes not expressing Mucin16.This confirmed the binding ability of the aptamer to the extracellular domain of Mucin16. Conclusion A novel aptamer targeting the synthetic peptide of the extracellular domain of Mucin16 was successfully obtained by capil-lary electrophoresis, which could be used as a new agent in the diagnosis and treatment of peritoneal metastasis of gastric cancer.