Strong Activation of Retroviral LTRs in HCC

The ncRNA transcriptome of human hepatocellular carcinoma (HCC) is largely unexplored. We used CAGE to characterize transcription start sites across different etiologies of human HCCs with emphasis on ncRNAs. Here we report that retroviral LTR promoters, expressed in healthy tissues such as testis and placenta but not liver, are widely activated in HCC. Despite HCC heterogeneity, a subset of LTR-derived ncRNAs were more than 10-fold up-regulated in the vast majority of samples. HCCs with a high LTR activity mostly had a viral etiology, were less differentiated and showed higher risk of recurrence. CAGE enabled us to build a promoter map for HCC, which uncovers a new layer of complexity in HCC genomics.]]>
The samples used in this study are derived from French Liver Cancer Biobanks Network, a join effort from eight liver centers in France to collect tissue samples from hepatocellular carcinomas and liver disease, according to the recommendations for Biological Resources Centers (BRC) released by the Organisation for Economic Cooperation and Development (OECD).]]>