Detection and Quantification of MicroRNAs in Laser-Microdissected Formalin-Fixed Paraffin-Embedded Breast Cancer Tissues

MicroRNAs (miRNAs) are a class of small endogenous non-coding RNAs that regulate gene expression post-transcriptionally through targeting protein-coding mRNAs for cleavage or translational repression, and thus play key roles in cellular fate-determinant pathways. Both profiling and functional studies demonstrated derangement of miRNA repertoire in many human cancers, including breast tumours. Discovery of miRNAs provided new insights into cancer pathogenesis and led the scientific community to approach novel diagnostic and therapeutic strategies in cancer management. Research in this field is increasing, and the potential for miRNAs being used in clinical settings emphasises the need for high-throughput and sensitive detection techniques. In this chapter, techniques for the analysis of miRNA expression in laser-microdissected formalin-fixed paraffin-embedded breast cancer tissues are discussed.