miRNA Characterization from the Extracellular Vesicles

Cancer cells and cancer associated stromal cells co-evolve secrete extracellular vesicles to the surrounding regions and regulate several processes involved in cancer metastasis. miRNAs have been known to be mediators of cancer progression and metastasis. miRNAs consist of short noncoding RNA. miRNAs are stable in extracellular fluids such as serum, plasma and urine. miRNAs are secreted by cells in normal and diseased conditions. miRNAs signatures have been identified specific to certain disease conditions. Therefore they are valuable biomarkers for different diseases. In our study we identified certain miRNAs, miR-409-3p and miR-409-5p, which were secreted by activated stromal fibroblast cells and were taken up by cancer cells to induce explosive tumor growth, through activation of epithelial to mesenchymal transition of cancer cells. Here we describe a procedure to determine miRNAs (miR-409-3p and miR-409-5p) in extracellular vesicles, which were secreted by prostate cancer stromal cells expressing miR-409. In this procedure, conditioned media from the stromal fibroblasts was used to extract the vesicular fraction. RNA was purified from the vesicular fraction, and specific miRNA was reverse transcribed and quantitated using real-time PCR assay.