RESUMEN
miR-122 is the most abundant miRNA in adult human liver. To study the functions of miR-122 in liver disease, we amplified the precursor of human miR-122 gene by polymerase chain reaction (PCR) from the HepG2 genomic DNA, and then constructed miR-122 expression vector pLMP-miR-122. pLMP-miR-122 could overexpress mature miR-122 when human normal liver cells L-O2 and the hepatoma cells HepG2 were transfected with it. When HepG2 cells were co-transfected with HBV1.3 and pLMP-miR-122, we found that miR-122 could down-regulate the expression of HBs and HBe antigen. These results showed that the human liver specific miR-122 expression vector was constructed successfully, and it could regulate the replication and the expression of HBV genes. The plasmid pLMP-miR-122 will facilitate further studies of the functions of miR-122 in the development of liver virus infection diseases and HCC.