Micro RNA : Potential biomarker for cancer diagnosis and prognosis

MicroRNAs (miRs, miRNAs) are small non-coding RNAs that regulate gene expression. Studies have demonstrated that miRNAs are not only found intracellularly, but also detectable outside cells, including various body fluids (i.e. serum, plasma, saliva, urine, milk and tears). Approximately 90% of extracellular miRNAs are packaged with proteins and 10% are wrapped in small membranous particles (i.e. exosomes, micro vesicles and apoptotic bodies). Numerous studies have indicated that the level and composition of these extracellular /circulating miRNAs correlate well with disease conditions, including cancer, such as Lung cancer, Breast cancer