Epigenetic changes as potential biomarkers in liver diseases induced by chronic hepatitis C virus genotype 1b infection

[N. Kokanov]

87 str.

Biologija - Biohemija i molekularna biologija / Biology - Biochemistry and Molecular Biology

Hronična infekcija virusom hepatitisa C dovodi do fibroze jetre, a potencijalno i do ciroze i hepatocelularnog karcinoma. Prevencija komplikacija bolesti se zasniva na antivirusnoj terapiji i ranoj dijagnozi. Stoga smo analizirali uticaj faktora domaćina i virusa na progresiju bolesti i odgovor na terapiju pegilovanim interferonom/ribavirinom (PEG-IFN/RBV) kod ispitanika sa hroničnom infekcijom virusom hepatitisa C genotipa 1b. Primenom PCR metode specifične za metilaciju (MSP) je ispitivan metilacioni status gena RASSF1A i p16INK4a, polimorfizam rs12979860 gena IL28B je određen esejom TaqMan, dok je automatskim sekvenciranjem analiziran mutacioni status virusnog gena C u uzorcima plazme ispitanika. Pojedinačno gledano, metilacioni status gena RASSF1A i p16INK4a, kao i amino-kiselinske izmene proteina C nisu se pokazali kao značajan biomarker odgovora na terapiju PEG-IFN/RBV i progresije bolesti. Međutim, njihova istovremena analiza sa genotipom gena IL28B je pokazala da je istovremena metilacija gena RASSF1A, odnosno gena p16INK4a i prisustvo genotipa CC gena IL28B povezana sa postizanjem stabilnog virusološkog odgovora (SVO). Takođe je utvrđeno da je istovremeno prisustvo amino-kiselinske izmene na poziciji 75 proteina C i genotipova CT/TT gena IL28B povezano sa izostankom odgovora na terapiju (BO) PEG-IFN/RBV, odnosno da je istovremeno prisustvo amino-kiselinske izmene na poziciji 91 proteina C i genotipa CC gena IL28B povezano sa postizanjem SVO. Dobijeni rezultati sugerišu da kombinovana analiza metilacionog statusa gena RASSF1A i p16INK4a, polimorfizma rs1297860 gena IL28B domaćina i amino-kiselinskih izmena proteina C virusa može pomoći u predviđanju odgovora na kombinovanu terapiju.

Chronic hepatitis C virus infection leads to liver fibrosis, and potentially to cirrhosis and hepatocellular carcinoma. Prevention of disease complications is based on antiviral therapy and early diagnosis. Therefore, we analyzed the influence of host and virus factors on disease progression and response to pegylated interferon/ribavirin (PEG-IFN/RBV) therapy in subjects with chronic hepatitis C virus genotype 1b infection. The methylation status of the RASSF1A and p16INK4a genes was investigated using the methylation-specific PCR method (MSP), the rs12979860 polymorphism of the IL28B gene was determined by the TaqMan assay, while the mutational status of the viral C gene in the plasma samples of the subjects was analyzed by automatic sequencing. Individually examined, methylation status of RASSF1A and p16INK4a genes, as well as amino-acid changes of protein C were not significant biomarkers of response to PEG-IFN/RBV therapy and disease progression. However, their simultaneous analysis with IL28B gene genotype showed that concomitant methylation of RASSF1A gene, as well as p16INK4a gene and the presence of IL28B genotype CC associated with sustained virological response (SVR). It was also determined that the simultaneous presence of an amino-acid substitutions at position 75 of protein C and CT/TT genotypes of the IL28B gene is associated with a lack of response to PEG-IFN/RBV therapy, and that the simultaneous presence of an amino-acid substitutions at position 91 of protein C and genotype CC of the IL28B gene associated with achieving SVR. The obtained results suggest that the combined analysis of the methylation status of the RASSF1A and p16INK4a genes, the rs1297860 polymorphism of the IL28B gene and the amino-acid changes of protein C can help predict the response to combined therapy.

hepatitis C virus; metilacija DNK; RASSF1A; p16INK4a; IL28B; protein C; odgovor na terapiju; progresija bolesti

hepatitis C virus; DNA methylation; RASSF1A; p16INK4a; IL28B; protein C; response to therapy; disease progression

577.2:578.5(043.3)

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