title: Single-stranded DNA aptamers that bind differentiated but not parental cells: subtractive systematic evolution of ligands by exponential enrichment.
abstract: In this paper, single-stranded (ss)DNA aptamers with capability to distinguish differentiated PC12 cells from normal PC12 cells were selected by subtractive systematic evolution of ligands by exponential enrichment (SELEX) method. Before each round of selection, randomized ssDNAs were incubated with regular PC12 cells to eliminate those that recognize the common cellular components of both differentiated and undifferentiated PC12 cells. After six rounds of cell-based selection, both of individual aptamers and aptamers of the sixth round pool were found binding to differentiated PC12 cells, but not to the parental PC12 cells. The aptamers of the starting pool showed no such binding. Sequence analysis illustrated that the amount of G content in central random region of these aptamers was much higher than that of the starting pool, which would be expected to be average. The aptamers obtained from this method were also able to identify differentiated PC12 cells from a mixture of both normal and differentiated cells. The results indicate that subtractive SELEX is a useful tool in finding ligands to specific biological markers that distinguish a subtype of cells from cells of homologous origin, such as carcinoma cells among normal epithelial tissues. Both these aptamers and their markers may play important roles in basic research and clinical diagnosis.
authors.affiliation: Beijing Institute of Basic Medical Sciences, PO Box 130(3), Beijing 100850, People's Republic of China.
authors.forename: Chenglong
authors.initials: C
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
authors.forename: Dajing
authors.initials: D
authors.lastname: Zhang
authors.forename: Hongmei
authors.initials: H
authors.lastname: Ding
authors.forename: Huixing
authors.initials: H
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Fan
authors.forename: Beifen
authors.initials: B
authors.lastname: Shen
authors.forename: Ningsheng
authors.initials: N
authors.lastname: Shao
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics*; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D008024:Ligands; D046911:Macromolecular Substances; D016716:PC12 Cells / Q000145:classification* / Q000166:cytology / Q000378:metabolism*; D051381:Rats
chemical_list: D004277:DNA, Single-Stranded; D008024:Ligands; D046911:Macromolecular Substances