Enhanced expression of vascular endothelial growth factor-A in ground glass hepatocytes and its implication in hepatitis B virus hepatocarcinogenesis

Jui Chu Yang, Chiao Fang Teng, Han Chieh Wu, Hung Wen Tsai, Huai Chia Chuang, Ting Fen Tsai, Yu Hsiang Hsu, Wenya Huang, Li Wha Wu, Ih Jen Su

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81 Citations (Scopus)

Abstract

Ground glass hepatocytes (GGH) in chronic hepatitis B virus (HBV) infection harbor HBV pre-S deletion mutants in endoplasmic reticulum (ER) and exhibit complex biologic features such as ER stress, DNA damage, and growth advantage. The presence of pre-S mutants in serum has been shown to predict the development of hepatocellular carcinoma (HCC) in HBV carriers. GGHs hence represent a potentially preneoplastic lesion. Whether a specific growth factor is overexpressed and activated in GGHs remains to be clarified. In this study, growth factor(s) up-regulated by pre-S mutants was identified using a growth factor array in HuH-7 cells. Immunohistochemistry, reverse-transcriptase polymerase chain reaction, and Western blot analysis were performed to study the participation of these genes and their signal pathways in HuH-7 cells and liver tissues. We demonstrate that vascular endothelial growth factor-A (VEGF-A) was up-regulated by pre-S mutants in HuH-7 cells and further confirmed in GGHs by immunostaining. The VEGF-A up-regulation by pre-S mutants could be suppressed by vomitoxin, an ER stress inhibitor. Furthermore, pre-S mutants-expressed HuH-7 cells exhibited activation of Akt/mTOR (mammalian target of rapamycin) signaling and increased growth advantage, which could be inhibited by VEGF-A neutralization. Consistent with this notion, enhanced expression of VEGF-A and activation of Akt/ mTOR signaling, comparable to the levels of paired HCC tissues, were also detected in HBV-related nontumorous livers. Conclusion: The enhanced expression of VEGF-A in GGHs provides potential mechanism to explain the progression from preneoplastic GGHs to HCC in chronic HBV infection.

Original languageEnglish
Pages (from-to)1962-1971
Number of pages10
JournalHepatology
Volume49
Issue number6
DOIs
Publication statusPublished - 2009 Jun 1

All Science Journal Classification (ASJC) codes

  • Hepatology

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