title: Aptamers evolved from cultured cancer cells reveal molecular differences of cancer cells in patient samples.
abstract: BACKGROUND
  Molecular-level differentiation of neoplastic cells is essential for accurate and early diagnosis, but effective molecular probes for molecular analysis and profiling of neoplastic cells are not yet available. We recently developed a cell-based SELEX (systematic evolution of ligands by exponential enrichment) strategy to generate aptamers (designer DNA/RNA probes) as molecular probes to recognize neoplastic cells.
  
  
  METHODS
  We tested 6 cell-SELEX-generated aptamers with equilibrium dissociation constants in the nanomolar to subnanomolar range: sgd5, selected from Toledo cells, a human diffuse large-cell lymphoma cell line (B-cell), and sgc8, sgc3, sgc4, sgd2, and sgd3 from CCRF-CEM cells, a human precursor T cell acute lymphoblastic leukemia (T-ALL) cell line. Aptamers were labeled with fluorescein isothiocyanate fluorophores and then used to recognize, by flow cytometric analysis, neoplastic cells in cultured hematopoietic cell lines and clinical samples.
  
  
  RESULTS
  Aptamer sgd5 recognized only its target cells. Aptamers sgc3, sgd2, sgd3, sgc4, and sgc8, selected from a T-cell leukemia cell line, identified all of the cultured T-cell leukemia cell lines with relatively high fluorescence intensity. Aptamers sgc8, sgc3, and sgd3 showed good selectivity toward T-ALL cells and almost no binding to normal hematopoietic cells or lymphoma and myeloma cells. Selected aptamers also detected targets on the cell membranes of neoplastic cells in patient samples.
  
  
  CONCLUSIONS
  Aptamers selected against cultured neoplastic cells can effectively be used as molecular probes for recognition of neoplastic cells in patient samples. Cell-based aptamer selection can be used to generate aptamer probes to obtain molecular signatures of neoplastic cells in patient samples.
authors.affiliation: Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Dihua
authors.initials: D
authors.lastname: Shangguan
authors.forename: Zehui Charles
authors.initials: ZC
authors.lastname: Cao
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
mesh_terms: D052157:Aptamers, Nucleotide; D001854:Bone Marrow Cells / Q000166:cytology; D002051:Burkitt Lymphoma / Q000473:pathology*; D015342:DNA Probes; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000473:pathology*; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000473:pathology*; D008223:Lymphoma / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology; D009101:Multiple Myeloma / Q000473:pathology*; D015347:RNA Probes; D052156:SELEX Aptamer Technique; D014407:Tumor Cells, Cultured
chemical_list: D052157:Aptamers, Nucleotide; D015342:DNA Probes; D005456:Fluorescent Dyes; D015347:RNA Probes; D016650:Fluorescein-5-isothiocyanate