Abstract

No validated micro(mi) RNA diagnostic test currently exist for the diagnostic screening of colon cancer (CC). MiRNAs are good candidates for markers for cancer diagnosis, prognosis or response to therapy. Profiles of miRNA expression differ between normal tissues and tumor types, and evidence suggests that miRNA expression profiles cluster similar tumor types together more accurately than expression profiles of protein-coding mRNA genes. A small number of miRNAs can differentiate cancer from normal, and miRNAs in stool remain mostly intact for detection We first carried a microarray study on immunocaptured stool colonocytes on 15 subjects and selected a panel of 14 preferentially expressed mature miRNAs associated with colon cancer (12 Up-Regulated, miR-19a, miR-20a, miR-21, miR-31, miR-34a, miR-96, miR-106a, miR-133a, miR-135b, miR-206, miR-224 and miR-302; and 2 Down-Regulated, miR-143 and miR-145). We then used absolute quantitative digital PCR on these 15 stool samples from stages 0-4 using a chip based Absolute Quant Studio™ 3D Digital PCR Applied Biosystem 3D instrument, using 96 well plates.