Abstract
Deficient DNA repair capacity is associated with genetic lesions accumulation and susceptibility to carcinogenesis. MicroRNAs (miRNAs) are small non-coding RNAs that regulate various cellular pathways including DNA repair. Here we hypothesized that the existence of HBV products may interfere with cellular nucleotide excision repair (NER) through microRNA-mediated gene regulation. We found that NER was impaired in HepG2.2.15 cells, a stable HBV-expressing cell line, compared with its parental cell line HepG2. Altered miRNA expression profile, in particular the significant upregulation of miR-192, was observed in HepG2.2.15 cells. Additionally, ERCC3 and ERCC4, two key factors implicated in NER, were identified as targets of miR-192 and over-expressing miR-192 significantly inhibited cellular NER. These results indicated that persistent HBV infection might trigger NER impairment in part through upregulation of miR-192, which suppressed the levels of ERCC3 and ERCC4. It provides new insight into the effect of chronic HBV infection on NER and genetic instability in cancer.