(116w) Application of Aptamers for Cancer Diagnostics

The overall goal of this research is to create a quantification strategy to measure serum levels of cancer biomarker proteins in solution. This is accomplished through the use of molecular barcode labeled aptamers. Aptamers are single stranded RNA molecules that bind specifically to molecular targets, and with high affinity[1]. A molecular barcode is a short sequence of nucleotides (~20 long), serving as a unique identifier of the specific protein analyte. The aptamer is introduced into a solution containing the protein. Upon protein binding, the aptamer goes through a structure rearrangement to expose the barcode sequence. These can then be hybridized and detected with oligonucleotide microarrays synthesized with barcode complementary sequences. Protein concentrations in solution can therefore be determined with the existing microarray platform. The concentration of the three protein targets-haptoglobin, fibrinogen, and CRP can be used as indicators of liver cancer. The blood serum concentration of the three proteins rises with the onset of cancer. Protein detection by this method has potential for a diagnostic as well as a monitor for the effectiveness of cancer interventions. The amount of protein can be quantified in the blood serum pre- and post treatment, which allows physicians to determine if the treatment was successful, and to what degree.