Functional Analysis of microRNA in Multiple Myeloma

MicroRNAs (miRNAs) are short non coding RNAs that regulate the gene expression and play a relevant role in physiopathological mechanisms such as development, proliferation, death, and differentiation of normal and cancer cells. Recently, abnormal expression of miRNAs has been reported in most of solid or hematopoietic malignancies, including multiple myeloma (MM), where miRNAs have been found deeply dysregulated and act as oncogenes or tumor suppressors. Presently, the most recognized approach for definition of miRNA portraits is based on microarray profiling analysis. We here describe a workflow based on the identification of dysregulated miRNAs in plasma cells from MM patients based on Affymetrix technology. We describe how it is possible to search miRNA putative targets performing whole gene expression profile on MM cell lines transfected with miRNA mimics or inhibitors followed by luciferase reporter assay to analyze the specific targeting of the 3'untranslated region (UTR) sequence of a mRNA by selected miRNAs. These technological approaches are suitable strategies for the identification of relevant druggable targets in MM.