Non-coding RNAs in hepatitis C-induced hepatocellular carcinoma:Dysregulation and implications for early detection,diagnosis and therapy

Hepatitis C virus(HCV)infection is one of main causes of hepatocellular carcinoma(HCC)and the prevalence of HCV-associated HCC is on the rise worldwide.It is particularly important and helpful to identify potential markers for screening and early diagnosis of HCC among high-risk individuals with chronic hepatitis C,and to identify target molecules for the prevention and treatment of HCV-associated-HCC.Small noncoding RNAs,mainly microRNAs(miRNAs),and long non-coding RNAs(lncRNAs)with size greater than 200nucleotides,are likely to play important roles in a variety of biological processes,including development and progression of HCC.For the most part their underlying mechanisms of action remain largely unknown.In recent years,with the advance of high-resolution of microarray and application of next generation sequencing techniques,a significant number of non-coding RNAs(ncRNAs)associated with HCC,particularly caused by HCV infection,have been found to be differentially expressed and to be involved in pathogenesis of HCVassociated HCC.In this review,we focus on recent studies of ncRNAs,especially miRNAs and lncRNAs related to HCV-induced HCC.We summarize those ncRNAs aberrantly expressed in HCV-associated HCC and highlight the potential uses of ncRNAs in early detection,diagnosis and therapy of HCV-associated HCC.We also discuss the limitations of recent studies,and suggest future directions for research in the field.miRNAs,lncRNAs and their target genes may represent new candidate molecules for the prevention,diagnosis and treatment of HCC in patients with HCV infection.Studies of the potential uses of miRNAs and lncRNAs as diagnostic tools or therapies are still in their infancy.     

Antibodies against mitochondrial dehydrogenase complexes in primary biliary cirrhosis

Antimitochondrial antibodies, serological hallmarks of primary biliary cirrhosis, recently were found to be directed against the E2 subunits of mitochondrial dehydrogenase complexes (pyruvate, branched-chain ketoacid, and alpha-ketoglutarate dehydrogenases). The objectives of this study were to extend these findings and to determine whether purified immunoglobulin from the sera of patients with primary biliary cirrhosis inhibit activity of these dehydrogenase complexes in vitro. Sera were examined from 14 patients with primary biliary cirrhosis (13 mitochondrial antibody positive), 23 with rheumatic diseases and 30 with chronic active hepatitis (all 53 positive for mitochondrial antibodies by indirect immunofluorescence), 10 with alcoholic liver disease, and 5 normal controls. Antibodies against pyruvate dehydrogenase, branched-chain alpha-ketoacid dehydrogenase and alpha-ketoglutarate dehydrogenase complexes were detected by immunoblot and quantified by enzyme-linked immunosorbent assay. Of the 14 serum samples obtained from patients with primary biliary cirrhosis, 13, 11, and 2 samples tested positive by immunoblot for the E2 subunits of pyruvate, branched-chain ketoacid, and alpha-ketoglutarate dehydrogenase, respectively. In contrast, samples from subjects with rheumatic diseases, chronic active hepatitis, and alcoholic liver disease and control subjects tested negative for these antibodies. Serum immunoglobulin G with high titers of mitochondrial antibodies showed concentration-dependent inhibition of activity of the dehydrogenase complexes, and close correlation (r = 0.917, n = 13) was observed between inhibitory activity against pyruvate dehydrogenase complex and the reciprocal titer of immunoglobulin against this complex. These data suggest that such autoantibodies, besides serving as diagnostic markers for primary biliary cirrhosis, may have a pathogenic role by their ability to inhibit important mitochondrial enzymes.