Use of serum-circulating miRNA profiling for the identification of breast cancer biomarkers.

MicroRNAs (miRNAs) are important regulatory molecules involved in disease pathogenesis. miRNAs are very stable in bodily fluids and can be detected in serum, plasma, saliva, and urine, among other fluids. Several studies have demonstrated the usefulness of serum miRNAs as potential biomarkers for detecting and monitoring cancer progression. Here, we describe in detail the experiment protocol we used to profile miRNA expression in the serum of breast cancer patients, including RNA extraction from serum, RT-qPCR quantification, and analysis of the deregulated miRNAs. Detection of circulating miRNAs may be a useful, noninvasive diagnostic tool for breast cancer.