title: DNA aptamers as molecular probes for colorectal cancer study.
abstract: BACKGROUND
  Understanding the molecular features of specific tumors can increase our knowledge about the mechanism(s) underlying disease development and progression. This is particularly significant for colorectal cancer, which is a heterogeneous complex of diseases developed in a sequential manner through a multistep carcinogenic process. As such, it is likely that tumors with similar characteristics might originate in the same manner and have a similar molecular behavior. Therefore, specific mapping of the molecular features can be potentially useful for both tumor classification and the development of appropriate therapeutic regimens. However, this can only be accomplished by developing high-affinity molecular probes with the ability to recognize specific markers associated with different tumors. Aptamers can most easily meet this challenge based on their target diversity, flexible manipulation and ease of development.
  
  
  RESULTS
  Using a method known as cell-based Systematic Evolution of Ligands by Exponential enrichment (cell-SELEX) and colorectal cancer cultured cell lines DLD-1 and HCT 116, we selected a panel of target-specific aptamers. Binding studies by flow cytometry and confocal microscopy showed that these aptamers have high affinity and selectivity. Our data further show that these aptamers neither recognize normal colon cells (cultured and fresh), nor do they recognize most other cancer cell lines tested.
  
  
  CONCLUSIONS
  The selected aptamers can identify specific biomarkers associated with colorectal cancers. We believe that these probes could be further developed for early disease detection, as well as prognostic markers, of colorectal cancers.
authors.affiliation: Department of Chemistry, Department of Physiology and Functional Genomics, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Kwame
authors.initials: K
authors.lastname: Sefah
authors.forename: Ling
authors.initials: L
authors.lastname: Meng
authors.forename: Dalia
authors.initials: D
authors.lastname: Lopez-Colon
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Jimenez
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
mesh_terms: D052157:Aptamers, Nucleotide; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000378:metabolism; D045744:Cell Line, Tumor; D002874:Chromosome Mapping; D015179:Colorectal Neoplasms / Q000235:genetics*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007700:Kinetics; D008024:Ligands; D018613:Microscopy, Confocal / Q000379:methods; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D011485:Protein Binding; D052156:SELEX Aptamer Technique / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D014408:Biomarkers, Tumor; D008024:Ligands; D015335:Molecular Probes