Expression profiling reveals dysregulation of cellular cytoskeletal genes in HBx-induced hepatocarcinogenesis.

Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing, PR, China.
Cancer biology & therapy (Impact Factor: 3.29). 06/2007; 6(5):668-74. DOI: 10.4161/cbt.6.5.3955
Source: PubMed

ABSTRACT The molecular mechanisms underlying hepatitis B virus encoded HBx protein-mediated tumorigenesis are not fully understood. In order to gain a better view of the effects of HBx on transcriptional regulation and hepatocarcinogenesis, the expression profiles of liver and tumor tissues from 6- and 18-month-old p21-HBx transgenic and control mice were monitored using oligo microarrays. Data analysis demonstrated that 42 genes were deregulated in both 6- and 18-month-old HBx transgenic mouse tissues. Gene ontology assisted analysis classified these genes into functionally related clusters that encode proteins related to metabolism, signal transduction, transcription regulation and stress responses. Among them, cytoskeletal genes, including microtubule genes tubulinbeta2 (Tubb2), tubulinbeta3 (Tubb3) and tubulinbeta6 (Tubb6), intermediate filament genes periplakin, keratin 8 (K8) and keratin 18 (K18) and actingamma1 (Actg1), were closely clustered and upregulated in liver tissues. These results were validated by semi-quantitative RT-PCR in both mouse and human HCC tissues. The upregulation of K8 and K18 was only detected in p21-HBx but not p21-HBsAg liver tissues, suggesting that the global change in the expression of cellular cytoskeletal genes was correlated with the expression of HBx transgene. These findings propose for the first time that systemic dysregulation of cellular cytoskeletal genes is involved in HBx-induced hepatocarcinogenesis.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although the activation of Ras pathway is frequently observed in human hepatocellular carcinoma (HCC), the in vivo role of Ras activation in HCC initiation and progression is underdetermined. To test the consequence of Kras activation in hepatocyte, we generated a hepatocyte-specific Kras(G12D) transgenic mouse strain and observed spontaneous development of HCC in these mice. Remarkably, HBV X protein (HBx) expression significantly promotes the formation and malignant progression of Kras(G12D)-driven HCC as shown with the accelerated tumor onset, the increased tumor burden and the more poorly differentiated lesions. At the cellular level, concomitant expression of Kras(G12D) and HBx results in a robust increase in hepatocellular proliferation. We reveal that the Akt, MAPK, p53 and TGF-β pathways are deregulated in the Kras(G12D)-driven HCCs. Also, the dysregulation is more pronounced in the HCCs developed in Kras(G12D) and HBx double transgenic mice. In addition, the altered expressions of β-catenin, CD44 and E-cadherin are only observed in the Kras(G12D) and HBx double transgenic mice. These results demonstrate a crucial role of Ras activation in hepatocellular carcinogenesis and the functional synergy between Kras(G12D) and HBx in HCC initiation and progression. The novel genetic mouse models that closely recapitulate the histopathologic progression and molecular alterations of human HCC may potentially facilitate the future therapeutic studies.Oncogene advance online publication, 11 November 2013; doi:10.1038/onc.2013.468.
    Oncogene 11/2013; · 7.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Transcriptional regulatory network (TRN) is used to study conditional regulatory relationships between transcriptional factors and genes. However few studies have tried to integrate genomic variation information such as copy number variation (CNV) with TRN to find causal disturbances in a network. Intrahepatic cholangiocarcinoma (ICC) is the second most common hepatic carcinoma with high malignancy and poor prognosis. Research about ICC is relatively limited comparing to hepatocellular carcinoma, and there are no approved gene therapeutic targets yet.
    PLoS ONE 01/2014; 9(6):e98653. · 3.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate cytokeratin 8 (CK8) overexpression during hepatitis C virus (HCV) infection and its pathogenesis, and the effect of ectopic CK8 expression on hepatoma cell lines. We successfully established an in vitro HCV cell culture system (HCVcc) to investigate the different expression profiles of CK8 in Huh-7-HCV and Huh-7.5-HCV cells. The expression of CK8 at the mRNA level was determined by real-time polymerase chain reaction (RT-PCR). The expression of CK8 at the protein level was evaluated by Western blotting. We then constructed a eukaryotic expression combination vector containing the coding sequence of human full length CK8 gene. CK8 cDNA was amplified by reverse transcription-PCR and inserted into pEGFP-C1 and the positive clone pEGFP-CK8 was obtained. After confirming the sequence, the recombinant plasmid was transfected into SMMC7721 cells with lipofectamine2000 and CK8 expression was detected using inverted fluorescence microscopy, RT-PCR and Western blotting. Besides, we identified biological function of CK8 on SMMC7721 cells, including cell proliferation, cell cycle and apoptosis detection. RT-PCR showed that the expression level of CK8 in Huh-7-HCV and Huh-7.5-HCV cells was 2.88 and 2.95 times higher than in control cells. Western blot showed that CK8 expression in Huh-7-HCV and Huh-7.5-HCV cells was 2.53 and 3.26 times higher than that in control cells, respectively. We found that CK8 at mRNA and protein levels were both significantly increased in HCVcc. CK8 was up-regulated in SMMC7721 cells. CK8 expression at the mRNA level was significantly upregulated in SMMC7721/pEGFP-CK8 cells. CK8 expression in SMMC7721/ pEGFP-CK8 cells was 2.69 times higher than in SMMC7721 cells, and was 2.64 times higher than in SMMC7721/pEGFP-C1 cells. CK8 expression at the protein level in SMMC7721/pEGFP-CK8 cells was 2.46 times higher than in SMMC7721 cells, and was 2.29 times higher than in SMMC7721/pEGFP-C1 cells. Further analysis demonstrated that forced expression of CK8 slowed cell growth and induced apoptosis of SMMC7721 cells. CK8 up-regulation might have a functional role in HCV infection and pathogenesis, and could be a promising target for the treatment of HCV infection.
    World Journal of Gastroenterology 10/2013; 19(37):6178-6187. · 2.55 Impact Factor


Available from