Systemic transcriptome analysis of hepatocellular carcinoma.

Liver cancer is one of the most common malignant tumors, and most of which is hepatocellular carcinoma (HCC). We aim to study the characteristic changes of numerous genes and their roles in HCC through systematical analysis of the characteristics of expression spectrum of HCC. Firstly, we made systematic clustering of the HCC samples according to the RNAseq data from TCGA (The Cancer Genome Atlas) and newly classified HCC. Then the characteristic genes in different molecular subtypes were found out and further analyzed combing with methylation and SNP 6.0 chip. Finally, these genes were subjected to do functional annotation and abnormal signaling pathways of HCC in various molecular subtypes and were screened out. There were 3843 differential genes screened; among which, 689 genes were enriched into 13 KEGG-related pathways, and the expression of 27 and 924 genes showed positive and negative correlation to methylation level, respectively, while the expression of 43 genes showed positive correlation to variation level of copy number. The methylation degree of ZSCAN18 may be considered as a marker for prognosis evaluation, and ABHD6 could be a potential anti-oncogene.