Regulation of the hepatitis C virus genome replication by miR-199a.
OBJECTIVE
Hepatitis C virus (HCV) infection causes chronic hepatitis and hepatocellular carcinoma. Current anti-HCV therapies are based on interferon therapy, which is insufficiently effective. microRNAs (miRNAs) are non-coding RNAs that regulate gene expression, and they have recently been shown to play an important role in viral replication.


METHODS
An algorithm-based search for miRNAs that target the HCV genome yielded one miRNA, miR-199a, with a sequence similar to the HCV genome that is conserved among HCV genotypes.


RESULTS
Over expression of miR-199a inhibited HCV genome replication in two cells bearing replicons (replicon cell) HCV-1b or -2a, however, miRNA inhibition by specific antisense oligonucleotide (ASO) accelerated viral replication. Prior transfection of immortalized hepatocytes which were infected with serum of HCV genotype 1b and 2a-infected patients, with miR-199a reduced HCV RNA replication activity. Mutation in the miR-199a target site in the replicon reduced the effect of the miR-199a. HCV replicon RNA is accumulated to the RNA-induced silencing complex (RISC) when miR-199a was over-expressed to the replicon cell. This antiviral effect by miR-199a was independent of the interferon pathway.


CONCLUSIONS
The results of this study suggest that miR-199a directly regulates HCV replication and may serve as a novel antiviral therapy.
Murakami
Yoshiki
Y
Center for Genomic Medicine, Kyoto University, Shogoin-Kawaharacho, Kyoto, Japan. ymurakami@genome.med.kyoto-u.ac.jp
Aly
Hussein H
HH
Tajima
Atsushi
A
Inoue
Ituro
I
Shimotohno
Kunitada
K
D020413:3' Untranslated Regions / Q000235:genetics; D020121:5' Untranslated Regions / Q000235:genetics; D000465:Algorithms; D001483:Base Sequence; D002460:Cell Line; D017124:Conserved Sequence; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D016174:Hepacivirus / Q000235:genetics*; D022781:Hepatocytes / Q000166:cytology; D006801:Humans; D008099:Liver / Q000502:physiology; D035683:MicroRNAs / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D034741:RNA, Small Interfering / Q000235:genetics; D012093:Replicon / Q000235:genetics
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D035683:MicroRNAs; D034741:RNA, Small Interfering