Viral miRNAs role as diagnostic, prognostic biomarkers for cancer and infectious diseases

The discovery of viral miRNAs (v-miRNAs) by Pfeffer et al. followed by unraveling their spectacular biological roles in gene regulation signifies the miRNA-mediated regulation in host-pathogen interactions. The v-miRNAs regulate viral as well as cellular gene expression, driving viral survival, carcinogenesis, and escaping host's innate and adaptive immune responses. Besides gene regulation, these v-miRNA molecules make some invaluable potential as diagnostic and prognostic biomarkers, proving the particular miRNAs signatures as diagnosing the viral infections as well as viral-induced carcinogenesis. Their differential expressions in different stages of the diseases in the same individual could make them as a potential biomarker for the disease identification and prognosis. The advent of different techniques in identifying the tissue and/or circulating miRNAs eased the identification of v-miRNAs in different pathological conditions and merits them in monitoring viral disease progression, carcinogenesis, and tumor growth. The circulating and/or exosomal v-miRNAs provides the possibilities for less or noninvasive and more specific method of detections. In this chapter, we outline the suitability of v-miRNAs as biomarkers in clinical diagnosis, disease prognosis, management, and treatment of cancer and/or infectious diseases with the recent developments in the methods of detecting and quantifying them. Further, we discussed the prospect of v-miRNAs as a diagnostic or prognostic marker(s) in clinical diagnosis and their possibility to become the targets for the therapeutic interventions.