Liver-specific expressions of HBx and src in the p53 mutant trigger hepatocarcinogenesis in zebrafish

• Published in: PloS one 2013-10, Vol.8 (10), p.e76951
• Main Authors: Lu, Jeng-Wei, Yang, Wan-Yu, Tsai, Su-Mei, Lin, Yueh-Min, Chang, Pen-Heng, Chen, Jim-Ray, Wang, Horng-Dar, Wu, Jen-Leih, Jin, Shiow-Lian Catherine, Yuh, Chiou-Hwa
• Format: Article
• Language: English
• Subjects: Activation; AKT protein; Animal genetic engineering; Animals; Animals, Genetically Modified; Apoptosis - genetics; Biomarkers, Tumor - metabolism; Cancer; Cancer screening; Carcinogenesis - genetics; Carcinoma, Hepatocellular - genetics; Carcinoma, Hepatocellular - metabolism; Carcinoma, Hepatocellular - pathology; Cell cycle; Cell Cycle - genetics; Danio rerio; Development and progression; Drug screening; Enzyme Activation - genetics; Etiology; Extracellular signal-regulated kinase; Fatty liver; Fibrosis; Gene Expression; Gene regulation; Genes; Genetic aspects; Glucose metabolism; Glycogen; Glycogen - metabolism; Health aspects; Hepatitis; Hepatitis B; Hepatitis B virus; Hepatocellular carcinoma; Humans; Hyperplasia; Hyperplasia - genetics; Kinases; Lipid metabolism; Lipogenesis - genetics; Liver; Liver - metabolism; Liver - pathology; Liver cancer; Liver Neoplasms - genetics; Liver Neoplasms - metabolism; Liver Neoplasms - pathology; Metabolism; Molecular chains; Mutation; Myc protein; Neoplasm Metastasis; Organ Specificity; p53 Protein; Physiological aspects; Proliferating Cell Nuclear Antigen - metabolism; Protein-tyrosine kinase; Proteins; Recombinant Fusion Proteins - genetics; Rodents; Signal Transduction - genetics; src-Family Kinases - genetics; Steatosis; Synergistic effect; Synergistic effects; Trans-Activators - genetics; Transgenic; Tumor proteins; Tumor Suppressor Protein p53 - genetics; Tumorigenesis; Tyrosine; Vascular endothelial growth factor; Viruses; Zebrafish; Zebrafish - genetics; Zebrafish - metabolism
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0076951

Hepatocarcinogenesis is a multistep process that starts from fatty liver and transitions to fibrosis and, finally, into cancer. Many etiological factors, including hepatitis B virus X antigen (HBx) and p53 mutations, have been implicated in hepatocarcinogenesis. However, potential synergistic effects between these two factors and the underlying mechanisms by which they promote hepatocarcinogenesis are still unclear. In this report, we show that the synergistic action of HBx and p53 mutation triggers progressive hepatocellular carcinoma (HCC) formation via src activation in zebrafish. Liver-specific expression of HBx in wild-type zebrafish caused steatosis, fibrosis and glycogen accumulation. However, the induction of tumorigenesis by HBx was only observed in p53 mutant fish and occurred in association with the up-regulation and activation of the src tyrosine kinase pathway. Furthermore, the overexpression of src in p53 mutant zebrafish also caused hyperplasia, HCC, and sarcomatoid HCC, which were accompanied by increased levels of the signaling proteins p-erk, p-akt, myc, jnk1 and vegf. Increased expression levels of lipogenic factors and the genes involved in lipid metabolism and glycogen storage were detected during the early stages of hepatocarcinogenesis in the HBx and src transgenic zebrafish. The up-regulation of genes involved in cell cycle regulation, tumor progression and other molecular hallmarks of human liver cancer were found at later stages in both HBx and src transgenic, p53 mutant zebrafish. Together, our study demonstrates that HBx and src overexpression induced hepatocarcinogenesis in p53 mutant zebrafish. This phenomenon mimics human HCC formation and provides potential in vivo platforms for drug screening for therapies for human liver cancer.