Abstract 1819: Fecal RNA test using microRNA expressions of exfoliated colonocytes for colorectal cancer screening

Abstract Background & Aims: To reduce the mortality rate of colorectal cancer (CRC), the development of a screening test for its early diagnosis is needed. We have been developing new CRC screening methods by applying molecular biological tools to exfoliated colonocytes. As part of this development, we have reported in the last few years the fecal RNA test using CRC-related gene expression analysis for CRC screening. In this study, we conducted microRNA (miRNA) expression analysis in exfoliated colonocytes isolated from feces for CRC screening. Methods: We initially analyzed CRC-related oncogenic miRNAs (miR-17-92, miR-21, and miR-135) in CRC tissue and exfoliated colonocytes. We subsequently selected other oncogenic miRNAs for CRC detection using TaqMan MicroRNA Array v3.0 (corresponds to miRBase release 14). We finally analyzed all oncogenic miRNA expressions in colonocytes isolated from feces from 197 CRC patients and 119 healthy volunteers by quantitative real-time PCR. Results: miR-17-92, miR-21, and miR-135 showed a significantly higher expression in CRC tissue than in normal tissue. The overall sensitivity of miRNA expression analysis in the exfoliated colonocytes was 74.1% (146/197, 95% CI; 67.4-80.1) and the specificity was 79.0% (94/119, 95% CI; 70.6-85.9). Because the sensitivity and specificity using CRC-related oncogenic miRNA expressions were relatively low, we selected 12 miRNAs as candidates of CRC detection using TaqMan MicroRNA Array v3.0. Conclusions: We have indentified suitable miRNAs for CRC detection in exfoliated colonocytes. Additionally, we report the overall sensitivity and specificity of miRNA expression analysis in exfoliated colonocytes using these oncogenic miRNAs in this annual meeting. miRNA expression analysis of colonocytes isolated from feces may be useful for CRC screening. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1819. doi:10.1158/1538-7445.AM2011-1819