Therapeutic Silencing of MicroRNA-122 in Primates with Chronic Hepatitis C Virus Infection

Anti-MicroRNA Antiviral MicroRNAs (miRNAs) are small noncoding RNAs found in eukaryotes and viruses. They are critical regulators of a wide range of cellular processes. The highly conserved miRNA miR-122 is required for infection by hepatitis C virus (HCV), a leading cause of liver disease in humans. Present HCV treatment regimes can have serious side effects and are effective in only 50% of cases. In order to try to tackle HCV infection, Lanford et al. (p. 198 , published online 3 December) targeted miR-122 using a complementary locked nucleic acid (LNA) oligonucleotide. Treatment of chimpanzees infected by HCV with the LNA antagonist resulted in a long-term reduction of disease symptoms without the concomitant appearance of resistant strains of the virus.