REVIEW ARTICLE: HCV IMPACTON THE PATTERN OF CIRC-RNAEXPRESSION IN HCV RELATED HCC

Circular RNAs (circRNAs) are a class of non-coding RNAs with a circular, covalent structure, which are highly conserved, stable unique molecules found in eukaryotic cells. The most notable character of circRNAs is their high stability in biological systems which is a key factor in their potential for use in a variety of RNA-focused medical applications. Despite the fact that circRNAs have a wide range of biological roles and regulatory functions, their circular structure and sequence overlap with their linear mRNA counterparts make it difficult to research them in depth. Furthermore, little is known about their function in viral infections and in immune responses.Since circRNAs have been found to be involved in a number of viral infections (including hepatitis B virus infection and human papilloma virus infection), their significance in viral infections is being more recognized in the last years.In this review, we aimed to provide a broad basis and overview on the biogenesis, significance and regulatory roles of circRNAs in the context of viral hepatitis C virus (HCV) infection, and HCV related hepatocellular carcinoma. Owing to the fact that the chronic HCV infection is the leading cause of HCC in the western countries especially Egypt. HCV can act directly on cell signaling pathways to promote HCC by inhibiting tumor suppressor genes or by causing activation of signaling pathways that up-regulate growth and division. Because viruses frequently manipulate cellular pathways to control viral gene expression, cellular and viral circRNA landscapes in virus-infected cells are altered. Studying the contribution of circRNAs in these pathways may give valuable information in the pathogenesis of HCC caused by HCV or in finding more reliable therapeutic approaches.