Integrating transcriptome and metabolomics analyses of hepatocellular carcinoma to discover novel biomarkers and drug targets

Background: Hepatocellular carcinoma (HCC) ranks sixth in incidence and third in mortality among all cancers. Chronic infection by hepatitis B and C viruses are the predominant risk factors for HCC, but other factors related to metabolic disorders including diabetes and obesity are also involved. Methods: Ten male HCC patients with chronic HBV infection were included in this study. Primary HCC tissues were obtained from all study participants following liver resection. Normal tissues that were simultaneously collected served as the controls and were defined as tissue at least 5 cm from the tumor edge. Tissues were subjected to untargeted metabolomics and transcriptome analyses. Results: We identified 31 and 41 differentially expressed metabolites (DEMs) in positive and negative ion modes, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that 15 DEMs were enriched in ABC transporters, nine in purine metabolism, eight in central carbon metabolism in cancer, and seven in biosynthesis of amino acids. Regarding the transcriptome analysis, 1,224 significantly up-regulated and 887 down-regulated RNAs were found. KEGG pathway analysis revealed that the most significantly enriched pathways were metabolic pathways. Integrated analysis showed seven pathways that were highly activated in HCC tissues including PI3K/Akt, ABC transporters, caffeine metabolism, carbon metabolism, biosynthesis of amino acids, arginine biosynthesis, alanine, aspartate, and glutamate metabolism. Conclusion: Some DEMs could be biomarkers or therapeutic targets for HCC. Moreover, we found that MAGEB2 was significantly elevated in HCC tissues for the first time, and its association with HCC needs to be explored by functional studies.