Small RNA proteome as disease biomarker: An incognito treasure of clinical utility

Abstract The discovery of small non-coding RNAs such as microRNAs (miRNAs), small interfering RNAs (siRNAs), and PIWI-interacting RNAs (piRNAs) in recent years has divulged as the powerful regulators of gene expression as riboregulators. In order to execute the silencing function, these tiny RNAs require physical association with their respective protein partners, the Argonaute (AGO) family of proteins. Over the decades, tremendous progress has been made to understand the function of AGO proteins in various cellular processes such as in translational regulation, RNA interference by guiding the small RNAs, and maintenance of stem cell self-renewal. However, relatively little is known about their role in human diseases and their potential use as a biomarker for early diagnosis of various deadly disease including cancer. In this chapter, we have reviewed the association of two major AGO protein families, AGO2 and PIWI, the functional partner of miRNAs and piRNAs, respectively, as well as their other associated accessory proteins in various diseases, and have tried to unveil whether these can serve as potential disease biomarkers or not.