BACKGROUNDMicroRNAs (miRNAs) are highly conserved small non-coding RNAs of 18 - 25 nucleotides (nt) that mediate post-transcriptional gene regulation. Hepatitis B virus (HBV) can cause either acute or chronic hepatitis B, and is a high risk factor for liver cirrhosis and hepatocellular carcinoma. Some mammalian viruses have been shown to modulate the expression of host cellular miRNAs. However, interactions between the HBV and the host cellular miRNAs are largely unknown.

METHODSmiRNA microarray and Northern blotting analysis were used to compare the expression profile of cellular miRNAs of a stable HBV-expressing cell line HepG2.2.15 and its parent cell line HepG2. mRNA microarray assay and the miRanda program were used to predict the miRNA targets. A flow cytometric assay was further used to investigate the expression of human leukocyte antigen (HLA)-A.

RESULTSEighteen miRNAs were differentially expressed between the two cell lines. Among them, eleven were up-regulated and seven were down-regulated in HepG2.2.15 cells. Northern blotting analysis confirmed that the expression of miR-181a, miR-181b, miR-200b and miR-146a were up-regulated and the expression of miR-15a was down-regulated, which was in consistent with the results of the microarray analysis. Furthermore, some putative miRNA targets were predicted and verified to be linked with mRNA expression. The 3'-UTR of HLA-A gene had one partially complementary site for miR-181a and miR-181a might down-regulate the expression of HLA-A.

CONCLUSIONHBV replication modulates the expression of host cellular miRNAs, which may play a role in the pathogenesis of HBV-related liver diseases.

Blotting, Northern ; Cell Line, Tumor ; metabolism ; virology ; Flow Cytometry ; Gene Expression Profiling ; Gene Expression Regulation ; HLA-A Antigens ; metabolism ; Hepatitis B virus ; growth & development ; physiology ; Humans ; MicroRNAs ; genetics ; Oligonucleotide Array Sequence Analysis

Adenine ; analogs & derivatives ; therapeutic use ; Adult ; Drug Resistance, Viral ; genetics ; Female ; Gene Amplification ; Genotype ; Hepatitis B virus ; genetics ; Hepatitis B, Chronic ; drug therapy ; Humans ; Male ; Middle Aged ; Mutation ; Organophosphonates ; therapeutic use ; RNA-Directed DNA Polymerase ; genetics ; Reverse Transcriptase Inhibitors ; therapeutic use ; Tenofovir

BACKGROUND/AIMS: A recent study reported that entecavir had inferior efficacy in nucleos(t)ide analogue (NA)-experienced chronic hepatitis B (CHB) patients compared to NA-naïve patients. We sought to compare the efficacy of tenofovir disoproxil fumarate (TDF) in NA-experienced and NA-naïve CHB patients. METHODS: We retrospectively enrolled 252 consecutive patients who had a serum hepatitis B virus (HBV) DNA level greater than 2,000 IU/mL at the initiation of TDF treatment and who received TDF for at least 6 months. Complete virologic suppression (CVS) was defined as undetectable serum HBV DNA. We generated a multivariate Cox proportional-hazard model to examine predictive factors that were independently associated with time to CVS. RESULTS: The mean age of patients was 48.2 years, and the cohort included 181 NA-naïve patients and 71 NA-experienced patients. The median duration of TDF treatment was 14.4 (interquartile range, 9.5-17.8) months. A total of 167 (92.3%) of 181 NA-naïve patients achieved CVS, and 60 (84.5%) of 71 NA-exposed patients achieved CVS. Forty-nine (89.1%) of 55 patients who previously took an NA aside from adefovir and 11 (68.8%) of 16 adefovir-experienced patients achieved CVS. In multivariable analysis, previous adefovir exposure significantly influenced time to CVS (hazard ratio, 0.37; 95% confidence interval, 0.19-0.72; P=0.003), after adjusting for HBeAg positivity, baseline HBV DNA level and cirrhosis. CONCLUSIONS: Tenofovir had inferior efficacy in adefovir-experienced CHB patients compared to NA-naïve patients. The response of patients with previous adefovir exposure to TDF monotherapy should be monitored closely.
Cohort Studies ; DNA ; Fibrosis ; Hepatitis B ; Hepatitis B e Antigens ; Hepatitis B virus ; Hepatitis B, Chronic* ; Hepatitis, Chronic* ; Humans ; Retrospective Studies ; Tenofovir*