Description
An increasing number of non-coding RNAs (ncRNAs) are implicated in various human diseases including cancer; however ncRNA transcriptome of hepatocellular carcinoma (HCC) remains largely unexplored. We use CAGE (Cap Analysis of Gene Expression) to comprehensively map transcription start sites (TSSs) across different etiologies of human HCC as well as mouse HCC, with particular emphasis on ncRNAs distant from protein-coding genes. We find thousands of significantly up-regulated distal ncRNAs in HCC tumors compared to their matched non-tumors, which are as many as protein-coding genes. Moreover, we identify many LTR retroviral promoters activated in HCC tissues and expressed in a subfamily-specific manner, which account for approximately 20% of the up-regulated distal ncRNAs. The transcripts derived from LTRs, determined by 3'' RACE, are multi-exon nuclear ncRNAs typically 0.5-2kb in length. This study sheds light on ncRNA transcriptome of human and mouse HCC. Overall design: Expression profiles using CAGE for 37 mouse HCC. The human data are archived at dbGaP (phs000885.v1.p1). An umbrella BioProject has been created to associate the GEO and dbGaP BioProjects: PRJNA278792