Microrna In Biofluid As Robust Biomarkers For Cancer

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA microRNAs constitute a class of small cellular RNAs (typically 19-23 nt) that function as post-transcriptional regulators of gene expression. Current estimates indicate that more than one third of the human cellular transcriptome is regulated by this small class of RNA (∼2000 miRNA). The study of extracellular microRNAs and their potential as pathophysiological markers has greatly expanded in the last couple of years. microRNAs have been shown to be actively exported from tissues into the circulation through a variety of mechanisms including exosome and microvesicle transport, and complexing with RNA binding proteins or HDL. The high relative stability of microRNAs in common clinical source materials (FFPE blocks, plasma, serum, urine, saliva, etc.) and the ability of microRNA expression profiles to accurately classify discrete tissue types and specific disease states have positioned microRNAs as promising new biomarkers for diagnostic application in cancer. We have applied Exiqons highly sensitive LNA™-based qPCR platform for detection of microRNAs, which has enabled microRNA profiling in biofluids where levels are extremely low. The platform uses a single RT reaction to conduct full miRNome profiling and allows high-throughput profiling of microRNAs without the need for pre-amplification. Thousands of biofluid samples including serum/plasma and urine have been profiled to determine normal reference ranges for circulating microRNAs as well as to identify biomarkers of disease. Extensive data qualification and analysis methods have been developed and are central parameters to secure high quality data from biofluids. The methods can quickly and robustly be applied in biomarker discovery and validation projects. We will present examples from our collaborative cancer diagnostic projects. Also we have developed a new exosome enrichment method and will present a comparison of microRNA profiles obtained with this method to profiles obtained with different commercial available exosome isolation methods and standard profiles of whole plasma and serum. Citation Format: Thorarinn Blondal, Anni Thomsen, Jorg Krummheyer, Peter Mouritzen, Ditte Andreasen, Maria Theilum, Jan Stenvang, Claus L. Andersen, Hans J. Nielsen, Nils Brunner. MicroRNA in biofluid as robust biomarkers for cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5233. doi:10.1158/1538-7445.AM2014-5233