Browsing by Author "Jin, Shiow-Lian Catherine"

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Hepatitis B virus X antigen and aflatoxin B1 synergistically cause hepatitis, steatosis and liver hyperplasia in transgenic zebrafish
(2013)
Lu, Jeng-Wei
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Yang, Wan-Yu
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Lin, Yueh-Min
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Jin, Shiow-Lian Catherine
;
Yuh, Chiou-Hwa
Aflatoxin B1 (AFB1) and the hepatitis B virus X antigen (HBx) are linked to the formation of liver diseases and hepatocellular carcinoma (HCC). The aim of this study was to investigate the synergistic effects between HBx and AFB1 in causing liver disorders using a transgenic zebrafish animal model. Histopathology, Periodic acid-Schiff (PAS) staining, Sirius red staining, TdT-mediated dUTP Nick End Labeling (TUNEL) assay, immunohistochemistry, and quantitative reverse transcriptase-polymerase chain reaction (Q-RT-PCR) were used to examine the livers of the HBx transgenic fish injected with AFB1. We found that HBx and AFB1 synergistically promoted steatosis as indicated by histopathological examinations and the increased expression of lipogenic factors, enzymes, and genes related to lipid metabolism. Moreover, treatment of AFB1 in HBx transgenic fish accelerated the development of liver hyperplasia and enhanced the expression of cell cycle related genes. PCNA was co-localized with active caspase 3 protein expression in HBx zebrafish liver samples and human HBV positive HCC samples by double fluorescence immuno-staining. Finally, we found that in human patients with liver disease, significant glycogen accumulated in the inflammation, cirrhosis stage, and all cases of hepatocellular and cholangiocellular carcinoma showed a moderate cytoplasmic accumulation of glycogen. Our data demonstrated a synergistic effect of AFB1 and HBx on the regulation of lipid metabolism related genes and cell cycle/division-related genes which might contribute to enhanced steatosis and hyperplasia at 5.75 months. (C) 2013 Elsevier GmbH. All rights reserved.
Liver-Specific Expressions of HBx and src in the p53 Mutant Trigger Hepatocarcinogenesis in Zebrafish
(2013-10-09)
Lu, Jeng-Wei
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Yang, Wan-Yu
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Tsai, Su-Mei
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Lin, Yueh-Min
;
Chang, Pen-Heng
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.
Overexpression of Endothelin 1 Triggers Hepatocarcinogenesis in Zebrafish and Promotes Cell Proliferation and Migration through the AKT Pathway
(2014-01-08)
Lu, Jeng-Wei
;
Liao, Chung-Yi
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Yang, Wan-Yu
;
Lin, Yueh-Min
;
Jin, Shiow-Lian Catherine
Hepatocarcinogenesis commonly involves the gradual progression from hepatitis to fibrosis and cirrhosis, and ultimately to hepatocellular carcinoma (HCC). Endothelin 1 (Edn1) has been identified as a gene that is significantly up-regulated in HBx-induced HCC in mice. In this study, we further investigated the role of edn1 in hepatocarcinogenesis using a transgenic zebrafish model and a cell culture system. Liver-specific edn1 expression caused steatosis, fibrosis, glycogen accumulation, bile duct dilation, hyperplasia, and HCC in zebrafish. Overexpression of EDN1 in 293T cells enhanced cell proliferation and cell migration in in vitro and xenotransplantation assays and was accompanied with up-regulation of several cell cycle/proliferation- and migration-specific genes. Furthermore, expression of the unfolded protein response (UPR) pathway-related mediators, such as spliced XBP1, ATF6, IRE1, and PERK, was also up-regulated at both the RNA and protein levels. In the presence of an EDN1 inhibitor or an AKT inhibitor, these increases were diminished and the EDN1-induced migration ability also was disappeared, suggesting that the EDN1 effects act through activation of the AKT pathway to enhance the UPR and subsequently activate the expression of downstream genes. Additionally, p-AKT is enhanced in the edn1 transgenic fish compared to the GFP-mCherry control. The micro RNA miR-1 was found to inhibit the expression of EDN1. We also observed an inverse correlation between EDN1 and miR-1 expression in HCC patients. In conclusion, our data suggest that EDN1 plays an important role in HCC progression by activating the PI3K/AKT pathway and is regulated by miR-1.