title: Developing aptamer probes for acute myelogenous leukemia detection and surface protein biomarker discovery.
abstract: BACKGROUND
  The majority of patients with acute myelogenous leukemia (AML) still die of their disease. In order to improve survival rates in AML patients, new strategies are necessary to discover biomarkers for the detection and targeted therapy of AML. One of the advantages of the aptamer-based technology is the unique cell-based selection process, which allows us to efficiently select for cell-specific aptamers without knowing which target molecules are present on the cell surface.
  
  
  METHODS
  The NB4 AML cell line was used as the target cell population for selecting single stranded DNA aptamers. After determining the affinity of selected aptamers to leukocytes, the aptamers were used to phenotype human bone marrow leukocytes and AML cells in clinical specimens. Then a biotin-labelled aptamer was used to enrich and identify its target surface protein.
  
  
  RESULTS
  Three new aptamers were characterized from the selected aptamer pools (JH6, JH19, and K19). All of them can selectively recognize myeloid cells with Kd in the low nanomole range (2.77 to 12.37 nM). The target of the biotin-labelled K19 aptamer probe was identified as Siglec-5, a surface membrane protein in low abundance whose expression can serve as a biomarker of granulocytic maturation and be used to phenotype AML. More importantly, Siglec-5 expression can be used to detect low concentrations of AML cells in human bone marrow specimens, and functions as a potential target for leukemic therapy.
  
  
  CONCLUSIONS
  We have demonstrated a pipeline approach for developing single stranded DNA aptamer probes, phenotyping AML cells in clinical specimens, and then identifying the aptamer-recognized target protein. The developed aptamer probes and identified Siglec-5 protein may potentially be used for leukemic cell detection and therapy in our future clinical practice.
authors.forename: Mingli
authors.initials: M
authors.lastname: Yang
authors.forename: Guohua
authors.initials: G
authors.lastname: Jiang
authors.forename: Wenjing
authors.initials: W
authors.lastname: Li
authors.forename: Kai
authors.initials: K
authors.lastname: Qiu
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Carter
authors.forename: Samer Z
authors.initials: SZ
authors.lastname: Al-Quran
authors.affiliation: UF/Shands Medical Laboratory at Rocky Point, 4800 35th Drive, Gainesville, FL 32608, USA. liying@pathology.ufl.edu.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
mesh_terms: D000208:Acute Disease; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000235:genetics / Q000378:metabolism; D052157:Aptamers, Nucleotide / Q000235:genetics* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D003937:Diagnosis, Differential; D005434:Flow Cytometry; D018922:HL-60 Cells; D006801:Humans; D037102:Lectins / Q000235:genetics / Q000378:metabolism; D007951:Leukemia, Myeloid / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D015473:Leukemia, Promyelocytic, Acute / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D007962:Leukocytes / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D015203:Reproducibility of Results; D052156:SELEX Aptamer Technique / Q000379:methods; D012680:Sensitivity and Specificity
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D052157:Aptamers, Nucleotide; D014408:Biomarkers, Tumor; D004277:DNA, Single-Stranded; D037102:Lectins; D008565:Membrane Proteins; C114531:SIGLEC5 protein, human