Ground glass hepatocyte (GGH) represents a histological hallmark of chronic hepatitis B virus infection and contains surface antigens in the endoplasmic reticulum (ER). Several types of GGHs are recognized at different hepatitis B virus replicative stages. The recent identification of pre-S mutants from GGHs encourages us to investigate whether different GGHs may harbor specific mutants and exhibit differential biological activities. In this study, we applied laser capture microdissection to isolate specific GGHs from a total of 50 samples on eight resected liver specimens. The surface genes in two major types of GGHs were analyzed. Type I GGHs expressed an inclusion-like pattern of hepatitis B surface antigens and harbored mutants with deletions over pre-S1 region, whereas type II GGHs, distributed in clusters and emerged at late replicative phase, contained mutants with deletions over pre-S2 region that defines a cytotoxic T lymphocyte (CTL) immune epitope, and may represent an immune escape mutant. Transfection of pre-S mutants in Huh7 revealed decreased syntheses of middle and small S proteins with accumulation of large surface antigen in ER, which in turn led to the activation of ER stress response with differential activities for different mutants. This study therefore demonstrates that different GGHs may contain specific mutants and exhibit differential biological activities.

The discovery of "ground glass" hepatocytes (GGH) that contain hepatitis B virus (HBV) surface antigens by Hadziyannis and Popper in 1973 represents a historical landmark in the pathology of chronic HBV infection. Different types of GGH have been correlated to the expression patterns of surface/core antigens and the stages of virus replication. The original two types (designated types I & II) of GGH were found to contain specific pre-S mutants with deletions over either pre-S1 or pre-S2 regions, respectively. Type II GGH consistently harbor pre-S2 deletion mutants, which can escape from immune attack and grow preferentially to form clusters. Both types of pre-S mutants can induce endoplasmic reticulum (ER) stress and oxidative DNA damage. The pre-S2 mutants, albeit inducing a weaker level of ER stress signals, could additionally initiate ER stress-independent retinoblastoma/ adenovirus E2 promoter binding factor/cyclin A signaling through their interaction with c-Jun activation domain binding protein 1 to degrade p27, illustrating the growth advantage of type II GGH. The combined effects of genomic instability and the proliferation of hepatocytes harboring pre-S mutants could potentially lead to hepatocarcinogenesis over the decades of chronic HBV infection. The presence of pre-S mutants in sera was reported to carry a high risk of developing hepatocellular carcinoma (HCC). Furthermore, transgenic mice harboring pre-S2 mutant plasmids have been shown to develop a dysplastic change of hepatocytes and HCC. Therefore, in addition to being a histological marker of chronic HBV infection, GGH, particularly type II GGH, may represent the preneoplastic lesions of HBV-related HCC.

Mounting evidence supports the involvement of HBV and its gene products in the multistep progression of liver tumorigenesis. 2 A protein-designated HBx has been extensively studied; the data reveal a role of the protein as a transactivator involved in cell growth, apoptosis, DNA damage signals, mitogen-activated protein kinase, and JAK/STAT signaling pathways. 3 Recently, the large surface protein (LHBs) and a C-terminally truncated middle surface protein (MHBs t ) have likewise been recognized as transactivators that share the same mechanism for transcriptional activation. 4,5 This group of activators may trigger a protein kinase C-dependent activation of the c-Raf-1/mitogen-activated protein kinase 2 signal transduction cascade, resulting in the activation of transcription factors such as activator protein 1 and nuclear factor B. The functional activity of these activators is dependent on the cytoplasmic orientation of the pre-S2 region of MHBs t and LHBs that is also related to their intracellular retention. 6,7 Besides the MHBs t , we have previously identified a mutant Abbreviations: ⌬S2-LHBs, mutant with a deletion in the pre-S2 region of the large surface protein; HBV, hepatitis B virus; ER, endoplasmic reticulum; HCC, hepatocellular carcinoma; GGH, ground glass hepatocyte; cDNA, complementary DNA; HH4, nontransformed human hepatocyte cell line; BFA, brefeldin A; VT, vomitoxin; PCNA, proliferating cell nuclear antigen; CDK, From the

Ground glass hepatocytes (GGH) in chronic hepatitis B virus (HBV) infection harbor HBVpre-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

BACKGROUND:The recurrence of hepatocellular carcinoma (HCC) after hepatectomy is a serious event. It has been demonstrated that different ground-glass hepatocyte (GGH) patterns harbor specific hepatitis B virus (HBV) pre-S deletion mutants and represent preneoplastic lesions in chronic HBV infection. In the current study, the authors investigated whether a specific GGH pattern in nontumorous liver tissues was associated with the recurrence of HBVrelated HCC after surgery. METHODS: Clinicopathologic data from 82 patients with HBV-related HCC were reviewed. GGH patterns were assessed on hematoxylin and eosin-stained sections. Tissue hepatitis B surface antigen (HBsAg) expression was evaluated by immunohistochemical staining. Serum profiles of pre-S status, viral load, and HBV genotype were determined and correlated with clinical recurrence and survival after surgery. RESULTS: The results indicated that the clustered pattern of GGHs or HBsAg expression was associated significantly with decreased local recurrence-free survival (LRFS) during a mean follow-up of 46.4 months (P<.001). This biomarker was comparable to or better than the prognostic value of other parameters, such as multifocal tumors (P ¼ .022), satellite nodules (P ¼ .005), small cell dysplasia (P ¼ .045), or elevated viral load (P ¼ .027), to predict recurrent HCC. Multivariate analysis also revealed that type II GGHs, which expressed marginal HBsAg and consistently clustered in nodules, were independent variables associated with LRFS (P<.001) and overall survival (P ¼ .003). CONCLUSIONS: The current results indicated that the assessment of GGH patterns or HBsAg expression in nontumorous liver tissues provides an easily recognized, new risk marker for the recurrence of HBV-related HCC after hepatic resection. Cancer 2011;117:2951-60.