Abstract 3014: Robust microRNA expression profiling of specific cells in complex archival tissue stained by immunohistochemistry

Abstract

Abstract Molecular diagnostics in modern pathology has been limited by the use of formalin-fixed, paraffin-embedded (FFPE) tissues in current routine diagnostic procedures due to modification and degradation of nucleic acids. In particular, molecular analysis of specific cell types potentially important for basic research and biomarker identification is largely prevented in highly complex, solid tissues routinely used in histopathology. Our objective was to establish a sensitive and robust procedure to quantify miRNA expression in specific cells from complex archival colorectal tumor tissue identified by immunohistochemistry. We combined classical immunohistochemistry and isolation of specific tissue cells by lasermicrodissection with the molecular analysis based on miRNA-preamplification and expression analysis by quantitative real-time PCR. Here we show reliable detection of miRNA expression profiles determined from limited amounts of colorectal cancer FFPE-tissues after routine staining procedure. The combination of routinely used FFPE-specimens stained by immunohistochemistry with the molecular analysis of lasermicrodissected complex tumor tissue resulted in robust miRNA expression patterns exclusively obtained from epithelial tumor cells. This approach allows for a detailed molecular analysis of cancer cells and distinct stromal cell types and their in-situ interaction in solid tumors. The methodology can therefore offer new perspectives for basic research and, by comprehensive use of present archival tissue collections linked to clinical databases, facilitate miRNA biomarker identification in defined tissue cells for future diagnostic and therapeutic strategies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3014.