title: Use of cell-SELEX to generate DNA aptamers as molecular probes of HPV-associated cervical cancer cells.
abstract: BACKGROUND
  Disease-specific biomarkers are an important tool for the timely and effective management of pathological conditions, including determination of susceptibility, diagnosis, and monitoring efficacy of preventive or therapeutic strategies. Aptamers, comprising single-stranded or double-stranded DNA or RNA, can serve as biomarkers of disease or biological states. Aptamers can bind to specific epitopes on macromolecules by virtue of their three dimensional structures and, much like antibodies, aptamers can be used to target specific epitopes on the basis of their molecular shape. The Systematic Evolution of Ligands by EXponential enrichment (SELEX) is the approach used to select high affinity aptamers for specific macromolecular targets from among the >10(13) oligomers comprising typical random oligomer libraries. In the present study, we used live cell-based SELEX to identify DNA aptamers which recognize cell surface differences between HPV-transformed cervical carcinoma cancer cells and isogenic, nontumorigenic, revertant cell lines.
  
  
  RESULTS
  Whole-cell SELEX methodology was adapted for use with adherent cell lines (which we termed Adherent Cell-SELEX (AC-SELEX)). Using this approach, we identified high affinity aptamers (nanomolar range K(d)) to epitopes specific to the cell surface of two nontumorigenic, nontumorigenic revertants derived from the human cervical cancer HeLa cell line, and demonstrated the loss of these epitopes in another human papillomavirus transformed cervical cancer cell line (SiHa). We also performed preliminary investigation of the aptamer epitopes and their binding characteristics.
  
  
  CONCLUSIONS
  Using AC-SELEX we have generated several aptamers that have high affinity and specificity to the nontumorigenic, revertant of HPV-transformed cervical cancer cells. These aptamers can be used to identify new biomarkers that are related to carcinogenesis. Panels of aptamers, such as these may be useful in predicting the tumorigenic potential and properties of cancer biopsies and aid in the effective management of pathological conditions (diagnosis, predicted outcome, and treatment options).
authors.affiliation: Department of Environmental and Occupational Medicine, Robert Wood Johnson, Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey, United States of America.
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Graham
authors.forename: Helmut
authors.initials: H
authors.lastname: Zarbl
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D014408:Biomarkers, Tumor / Q000737:chemistry / Q000378:metabolism*; D002472:Cell Transformation, Viral; D004277:DNA, Single-Stranded / Q000737:chemistry*; D000939:Epitopes; D005260:Female; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D015335:Molecular Probes / Q000737:chemistry*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D030361:Papillomavirus Infections / Q000378:metabolism*; D052156:SELEX Aptamer Technique; D002583:Uterine Cervical Neoplasms / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D004277:DNA, Single-Stranded; D000939:Epitopes; D015335:Molecular Probes