MicroRNAs in nasopharyngeal carcinoma

Abstract

MicroRNAs (miRNAs) provide insight into both the biology and clinical behavior of many human cancers, including nasopharyngeal carcinoma (NPC). The dysregulation of miRNAs in NPC results in a variety of tumor-promoting effects. Furthermore, several miRNAs are prognostic markers for NPC. In addition to cellular miRNAs, NPC samples also often contain miRNAs encoded by Epstein-Barr virus, and these miRNAs may impact NPC biology by targeting both cellular and viral genes. Given their numerous putative roles in NPC development and progression, a thorough understanding of the impact of miRNA dysregulation in NPC is expected to shed light on useful biomarkers and therapeutic targets for the clinical management of this disease. In this review, we describe the efforts to date to identify and characterize such miRNAs in the context of NPC.

Figure 1.. MicroRNA (miRNA) biogenesis.

miRNAs are processed through a complex series of highly regulated steps in the nucleus and the cytoplasm, from transcription through to their functional roles as transcript and protein level regulators. Abbreviations: RNA Pol II, RNA polymerase type II; pri-miRNA, primary microRNA; pre-miRNA, precursor microRNA; DGCR8, Drosha-DiGeorge syndrome critical region gene 8; XPO5, nuclear export factor exportin 5; RAN, ras-related nuclear protein; GTP, guanosine tri-phosphate; AGO, Argonaute; TRBP, TAR (HIV-1) RNA-binding protein 2; PACT, protein kinase, interferon-inducible double stranded RNA; Dicer, Dicer 1 ribonuclease Type III; miR*, passenger strand from mature miRNA duplex; miRISC, microRNA RNA-induced silencing complex; P-body, processing body.