Expression of GP73, a resident Golgi membrane protein, in viral and nonviral liver disease

Significance of expression of Golgi glycoprotein 73 in hepatocellular carcinoma

AIM: To investigate the expression of Golgi glycoprotein 73 (GP73) in hepatocellular carcinoma (HCC) tissues and to analyze its relationship with the clinicopathological features of HCC.

METHODS: Seventy-five hepatocellular carcinoma specimens and matched tumor-adjacent specimens were collected. Immunohistochemistry was used to determine the expression of GP73 in the above specimens. The correlation of GP73 expression with the clinicopathological features and prognosis was analyzed.

RESULTS: The positive rate of GP73 expression in HCC tissues was significantly higher than that in adjacent tissues (χ² = 73.60, P < 0.001). The expression of GP73 was associated with Edmondson pathological grade, TNM stage and vascular invasion (P < 0.001), but not with the patient's gender, age, hepatitis B surface antigen (HBsAg), cirrhosis, α-fetoprotein (AFP), portal vein thrombosis or tumor number (P > 0.05). Kaplan-Meier analysis showed that HCC patients with high GP73 expression had lower median survival time than those with low GP73 expression (χ² = 28.72, P < 0.05). Univariate analysis showed that AFP level > 20 ng/mL, TNM stage, and GP73 expression were poor prognostic factors for patients with HCC (P < 0.05). Multivariate analysis found that GP73 expression was an independent prognostic factor for HCC (P = 0.07).

CONCLUSION: The expressions of GP73 is high in HCC tissues, which might be associated with tumor malignant behavior and prognosis of HCC patients.

Serum gp73 is also a biomarker for diagnosing cirrhosis in population with chronic HBV infection

OBJECTIVES

To clarify the role of Golgi membrane glycoprotein 73 (gp73) in evaluating the progression of chronic hepatitis B virus (HBV) infection.

DESIGN AND METHODS

Participants included 958 controls, 421 chronic hepatitis B, 944 hepatic cirrhosis, and 127 hepatocellular carcinoma (HCC) patients. All the patients, with the exception of the controls, were diagnosed HBsAg positive. Serum biomarkers, including gp73, alpha-fetoprotein (AFP), alpha-l-fucosidase, and Lens culinaris agglutinin-reactive fraction of AFP, were determined.

RESULTS

The patients with Hepatic cirrhosis gp73 levels over 150 ng/mL had an odds ratio of 3.21 (95% CI: 2.07-5.00). In hepatic cirrhosis patients, serum gp73 correlated with the Child-Pugh score. gp73 is a marker for diagnosing cirrhosis in the hepatitis populations. When the cut-off was set at 75.5 ng/mL, the sensitivity, specificity, and AUC were 75.6% (95% CI: 71.30%-79.62%), 60.3% (95% CI: 56.95%-63.63%) and 0.72 (95% CI: 0.69-0.75), respectively.

CONCLUSION

The variation trend of gp73 in chronic liver disease may indicate that monitoring of serum gp73 is helpful to diagnose cirrhosis in population with chronic HBV infection.

Effect of GP73 silencing on proliferation and apoptosis in hepatocellular cancer

AIM: To investigate the roles of Golgi protein (GP) 73 in the regulation of cell proliferation and apoptosis.

METHODS: Stealth RNAi targeting GP73 gene sequence was used to silence its expression in Hep G2 cells and Bel7402 cells. Stealth RNAi effects were assessed by reverse transcriptase polymerase chain reaction and ELISA. Cell proliferation assay and cell cycle analysis were assessed by MTT assay and flow cytometry. Apoptosis was assessed by flow cytometry and transmission electron microscopy. Apoptosis-related proteins were assessed by western immunoblot analysis.

RESULTS: Stealth RNAi targeting GP73 gene sequence markedly reduced the expression of GP73 gene. The reduction of GP73 in Hep G2 cells and Bel7402 cells inhibited cell proliferation and induced apoptosis, however, terminal apoptosis occurred in Hep G2 cells, but early apoptosis occurred in Bel7402 cells. Reduced expression of GP73 gene might lead to a reduction in Bcl-2/Bax ratio, an increase in cytochrome c, but a reduction in capase-3.

CONCLUSION: GP73 might play an important role in proliferation and apoptosis in hepatocellular carcinoma cells.

Expression of GOLPH2 is associated with the progression of and poor prognosis in gastric cancer

Golgi phosphoprotein 2 (GOLPH2) has been associated with the development and progression of various human cancers. The aims of this study were to investigate the relationship between GOLPH2 and gastric cancer (GC) progression and explore the clinical significance of GOLPH2 in GC. GOLPH2 expression was examined in four pairs of primary GC tissues and the adjacent non-cancerous tissues from the same patients, using immunohistochemistry (IHC), quantitative PCR and western blotting. Furthermore, GOLPH2 protein expression was analyzed in 10 normal gastric tissues and 385 clinicopathologically characterized cases of GC by IHC. Statistical analyses were performed to determine the prognostic and diagnostic associations. GOLPH2 mRNA and protein expression were both markedly upregulated in GC tissues, compared with the paired adjacent non-cancerous tissues. The Chi-square test and Spearman analysis revealed a significant correlation between GOLPH2 expression and clinical stage, T classification, lymph node metastasis, metastasis and venous invasion. Patients with a higher GOLPH2 expression had a shorter overall survival (OS), compared to patients with lower GOLPH2 expression. Notably, our results suggested that GOLPH2 is associated with the development and progression of GC. Therefore, additional studies focusing on the potential of GOLPH2 as a novel therapeutic target in GC are required.

The predictive value of Golgi protein 73 in differentiating benign from malignant liver tumors

Introduction

In the work up of primary solid liver lesions it is essential to differentiate correctly between benign and malignant tumors, such as hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC) respectively. A promising new marker to detect HCC is Golgi Protein 73 (GP73). Studies comparing patients with HCC and cirrhosis with normal controls suggested that GP73 is specific for patients with HCC; however, patients with other liver tumors were not included. We therefore studied the predictive value of GP73 in differentiating between solid benign and malignant liver tumors.

Materials and Methods

This study included 264 patients: 88 patients with HCC, 88 with hepatocellular adenoma (HCA), and 88 with focal nodal hyperplasia (FNH). A blood sample was collected from each patient to measure GP73 levels using a quantitative ELISA assay and differences in outcome between subgroups were compared. The receiver operating characteristic (ROC) curve, sensitivity and specificity of GP73 were calculated and compared to alpha-fetoprotein (AFP) levels.

Results

When comparing malignant and benign liver tumors the area under ROC was 0.701 and 0.912 for GP73 and AFP respectively. Test characteristics revealed a sensitivity of 60% for GP73 and 65% for AFP; in addition the specificity was 77% for GP73 and 96% for AFP.

Conclusion

Although the literature suggests that GP73 is a valuable serum marker in patients with HCC, the serum concentration may also be increased in patients with solid benign liver tumors. Therefore, a GP73 assay is less suitable for discriminating between primary malignant and benign tumors of the liver.

Evaluation of α-fetoprotein-L3 and Golgi protein 73 detection in diagnosis of hepatocellular carcinoma

Aim of the study

Hepatocellular carcinoma (HCC) is common throughout the world. Most HCCs are diagnosed at an advanced stage. There is an urgent need to find new methods for screening and surveillance of individuals at risk for HCC. The aim of this study was to evaluate serum α-fetoprotein (AFP)-L3 and serum Golgi protein 73 (GP73) detection in diagnosis of HCC with different AFP concentration.

Material and methods

One hundred and eighty one patients were involved, including 102 with HCC and 79 with benign liver disease. The serum AFP-L3 and GP73 was measured by a liquid-phase binding assay and quantitative enzyme-linked immunosorbent assay, respectively.

Results

Of the 102 HCC patients, 53 were positive for AFP, 77 were positive for AFP-L3, and 79 were positive for GP73. The maximum area under the curve for AFP-L3% and for GP73 was significantly different from the AUC of 0.5525 for total AFP (p < 0.01). AFP-L3% was not detected for AFP < 20 ng/ml. However, elevated GP73 was detected in 87.50% of the patients. In the HCC patients with total AFP 20–400 ng/ml, elevated AFP-L3 was detected in 26 patients, whereas in 23 patients elevated GP73 could be detected. In the HCC patients with a total AFP > 400 ng/ml, AFP-L3% > 10% was present in 96.23%, and GP73 was detected in 87.50%.

Conclusions

The determination of AFP-L3% and GP73 in combination with AFP can increase the sensitivity and specificity in diagnosis of HCC. α-fetoprotein-L3% and GP73, in combination with AFP, are useful biomarkers to confirm the diagnosis of HCC.

GP73 is upregulated by hepatitis C virus (HCV) infection and enhances HCV secretion

Hepatitis C virus (HCV) is a major cause of chronic liver disease. However, little is known about the details of its assembly and secretion. Golgi-related proteins have been recently proven to have a key function in HCV secretion. Golgi protein 73 (GP73), a resident Golgi membrane protein, is a potential serum biomarker for the diagnosis of liver diseases and hepatocellular carcinoma. Previous studies have demonstrated the upregulation of GP73 in the liver samples and sera of HCV-infected patients. However, the function and regulatory mechanism of GP73 in HCV infection at the cellular level remain unknown. In this study, we examined the expression level of GP73 in HCV infected cells and its effect on HCV life cycle in cell culture systems. Both the protein expression and mRNA levels of GP73 significantly increased in HCV subgenomic replicon-harboring cells and HCV-infected cells, which imply that GP73 was upregulated by HCV infection. HCV production was significantly enhanced when GP73 was overexpressed, but dramatically inhibited when GP73 was silenced. However, the overexpression and knockdown of GP73 showed no evident effect on the entry, protein translation, RNA replication, and assembly of HCV, which indicates that GP73 enhanced the secretion process. Moreover, the coiled-coil domain of GP73 was required to increase HCV secretion. GP73 increased and interacted with apolipoprotein E, an identified host factor that assists in HCV secretion. These results demonstrate the critical function of GP73 in HCV secretion and provide new insights into the therapeutic design of antiviral strategies.

GP73, a new marker for diagnosing HBV-ACLF in population with chronic HBV infections

Although Golgi protein 73 (GP73) has been widely evaluated for diagnosing hepatocellular carcinoma (HCC) and other liver diseases in recent decade, its serum profile of patients with hepatitis B virus (HBV)-associated acute-on-chronic liver failure (HBV-ACLF) is still unknown. This study was designed to evaluate the serum levels of GP73 in patients with HBV-ACLF. The participants included 200 apparently healthy controls; 200 patients with chronic hepatitis B (CHB); 200 patients with HCC; 210 patients with HBV-ACLF, in which 29 HBV-ACLF patients were followed up for 3 months. All patients were Hepatitis B virus surface antigen (HBsAg) positive. The concentrations of GP73 in patients with HBV-ACLF (285.3 ± 128.5 ng/mL) were markedly higher than those HCC patients (159.1 ± 105.8 ng/mL), CHB patients (64.65 ± 44.99 ng/mL), and healthy controls (35.37 ± 12.41 ng/mL). When the cut-off value was set at 182.1 ng/mL, the sensitivity and specificity of HBV-ACLF diagnosis were 77.62% (95% confidence interval [CI]: 71.37%-83.07%) and 95.50% (95% CI: 92.27%-98.26%), respectively. If serum GP73 concentration was still above 361.6 ng/mL after 14 days of follow-up, the patient's prognosis may be depressed. Serum GP73 may be used to diagnosis HBV-ACLF in population with chronic HBV infections.

CXCL10 decreases GP73 expression in hepatoma cells at the early stage of hepatitis C virus (HCV) infection

Golgi protein 73 (GP73), which is up-regulated in hepatocellular carcinoma (HCC), has recently been identified as a novel serum marker for HCC diagnosis. Several reports also noted the increased levels of GP73 expression in chronic liver disease in patients with acute hepatitis of various etiologies, chronic Hepatitis C virus (HCV) infection and alcoholic liver disease. The molecular mechanisms of GP73 expression in HCV related liver disease still need to be determined. In this study, we aimed to evaluate the effect of HCV infection on GP73 expression. GP73 was highly expressed in Huh7, Hep3B, 293T and HUVEC cells, and was low-expressed in HepG2 cells. HCV infection led to down-regulation of GP73 in Huh7 and HepG2/CD81 cells at the early stage of infection. CXCL10 decreased GP73 expression in Huh7 and HepG2 cells. Up-regulation of GP73 was noted in hepatocytes with cytopathic effect at advanced stage of HCV infection, and further research is needed to determine the unknown factors affecting GP73 expression. In conclusion, our study provided additional evidence for the roles of GP73 in liver disease.

Evaluation of circulating Transforming growth factor-beta1, Glypican-3 and Golgi protein-73 mRNAs expression as predictive markers for hepatocellular carcinoma in Egyptian patients

Hepatocellular carcinoma (HCC) incidence is fast-growing especially in countries highly prevalent with viral hepatitis. Its poor prognosis has driven the research toward the discovery of sensitive markers for early detection. We investigated the usefulness of serum Transforming growth factor-beta1 (TGF-β1), Glypican-3 (GPC3), and Golgi protein-73 (GP73) mRNAs as early biomarkers in HCC Egyptian patients chronically infected with hepatitis C virus (HCV) in comparison with serum alpha-fetoprotein (AFP). Using semi-quantitative RT-PCR and densitometry analysis, circulating TGF-β1, GPC3, and GP73 mRNAs expressions were estimated in 15 healthy adults, 15 chronic HCV (CHC) patients and 25 HCC patients. Serum GP73 expression percentage in HCC group was significantly higher than controls (100 vs. 40 %, P ≤ 0.001) and when compared to elevated serum AFP levels (100 vs. 36 %, P ≤ 0.001). TGF-β1 and GP73 expression means were also higher in HCC patients than controls and CHC patients (P < 0.05). GPC3 expression showed higher frequency in CHC patients compared to HCC group (80 vs. 28 %, P = 0.0016). According to the study cutoffs, serum TGF-β1 and GP73 mRNAs showed 60 and 96 % sensitivities for HCC diagnosis with 100 and 95 % specificities, respectively. Furthermore, elevated GP73 mRNA expression levels in early HCC were significantly increased compared to those of TGF-β1 mRNA and to high serum AFP (92.3 vs. 53.8 and 23.1 %; P = 0.03 and 0.0004, respectively). In conclusion, circulating TGF-β1 and GP73 mRNAs could be useful biomarkers for HCV-induced HCC diagnosis. Moreover, serum GP73 mRNA is sensitive for early cancer detection than AFP and TGF-β1 mRNA. However, these results need further validation studies.

Gradually increased Golgi protein 73 expression in the progression of benign liver diseases to precancerous lesions and hepatocellular carcinoma correlates with prognosis of patients

AIM

Serum Golgi protein 73 (sGP73) is a novel biomarker for hepatocellular carcinoma (HCC). However, there are few reports on the pattern of GP73 expression in the progression of benign liver diseases to precancerous lesions and HCC. This study aimed to investigate GP73 expression and its correlation with clinicopathological parameters.

METHODS

Tissue GP73 (tGP73) levels were detected in specimens of group A (n = 186) including HCC, peritumoral tissue (PTL), high/low-grade hepatic atypical hyperplasia (AH), chronic hepatitis B (CHB) and normal controls (NC) by immunohistochemistry, and GP73 expression in group B (n = 159) and group C (n = 16) were detected by reverse transcription polymerase chain reaction and western blot, respectively. sGP73 levels were detected in subjects of group D (n = 287) by enzyme-linked immunoassay.

RESULTS

GP73 expression increased gradually from NC, CHB, PTL to high-grade AH and HCC at both protein and mRNA levels (P < 0.05), while sGP73 in the HCC group was lower than in the liver cirrhosis (LC) group (P < 0.001). Both tGP73 and sGP73 levels were negatively associated with tumor size and tumor-node-metastasis stage, and tGP73 levels were positively associated with tumor differentiation. The high-tGP73 group showed significantly better overall and disease-free survival than the low-tGP73 group (P = 0.008, P = 0.018). Multivariate analysis revealed that the tGP73 level was an independent prognostic factor for HCC, but not sGP73.

CONCLUSION

GP73 expression pattern suggests that the regulatory mechanism of GP73 is related to the progression of chronic liver diseases. Furthermore, a high level of tGP73 is a favorable prognostic factor for HCC.

Serum GP73 is complementary to AFP and GGT-II for the diagnosis of hepatocellular carcinoma

Golgi protein 73 (GP73) is a resident Golgi type II transmembrane protein that has been reported to markedly increase in chronic liver disease, particularly in hepatocellular carcinoma (HCC). However, it remains unclear as to whether serum GP73 represents a reliable serum marker for the diagnosis of HCC. The aim of the present study was to evaluate the diagnostic value of serum GP73 in patients with HCC and to determine the diagnostic accuracy of measuring serum GP73 in combination with α-fetoprotein (AFP) and γ-glutamyl transferase isoenzyme II (GGT-II) in HCC. Serum GP73 was detected using a time-resolved fluorescence immunological assay (TRFIA) and enzyme-linked immunosorbent assay (ELISA) in 79 HCC cases, including 16 liver cirrhosis, 30 chronic hepatitis and 28 healthy individuals. The correlation between serum GP73 and tumor size and HCC grading was analyzed and the complementary diagnostic value of serum GP73, AFP and GGT-II was evaluated. TRFIA was established for the detection of serum GP73 and was sensitive and reproducible. The expression levels of serum GP73 were markedly higher in the patients with HCC when compared with those of the individuals with liver cirrhosis and chronic hepatitis or the healthy individuals. According to the receiver operating characteristic (ROC) curve, diagnostic sensitivity and specificity for HCC with a cut-off value of 78.1 ng/l were 73.4 and 79.0%, respectively. However, no correlation was identified among serum GP73 and tumor size or grading, and no correlations were identified among serum GP73, AFP and GGT-II. The diagnostic sensitivities for HCC, as detected by TRFIA of GP73, AFP and GGT-II, were 73.4, 55.6 and 68.4%, respectively, and the specificities were 80.0, 86.7 and 97.1%, respectively. The combined determination of these markers increased the diagnostic sensitivity to 96.3% for HCC. TRFIA functions as a sensitive and replicable assay for the detection of serum GP73. The levels of serum GP73 were significantly higher in the HCC group when compared with the individuals with benign liver diseases. Serum GP73 may serve as a potential independent diagnostic candidate for HCC and the combined determination of serum GP73, AFP and GGT-II may increase the diagnostic efficiency of HCC.

Expression of GOLM1 correlates with prognosis in human hepatocellular carcinoma

BACKGROUND

Serum Golgi membrane protein 1 (GOLM1) is a novel biomarker for hepatocellular carcinoma (HCC). However, few studies have investigated the relationship between GOLM1 protein expression and clinicopathologic features in HCC patients. The aim of this study was to investigate the expression of GOLM1 in human HCC and its correlation with clinicopathologic parameters.

METHODS

Clinicopathologic data were obtained through a detailed retrospective review of the medical records of 193 patients with HCC who had undergone surgical resection between 1990 and 2006 at the Taipei Veterans General Hospital. Another 120 HCC tissue samples provided by the Taiwan Liver Cancer Network were used as validation cohort. Immunohistochemical staining was used to determine the expression of GOLM1 in archived formalin-fixed, paraffin-embedded tissue specimens.

RESULTS

GOLM1 expression was significantly higher in resected HCC tumor tissues than in corresponding normal liver tissues (p < 0.01). After a median follow-up of 51 months, multivariate analysis showed that portal vein invasion (hazard ratio [HR], 1.515; 95 % confidence interval [95 % CI], 1.008-2.277; p = 0.046) and high GOLM1 protein expression (HR, 1.696; 95 % CI, 1.160-2.479; p = 0.006) were independent prognostic factors for poor overall survival. High GOLM1 protein expression still significantly correlates with worse overall survival as well as disease-free survival in the validation cohort (p < 0.001 and p = 0.002).

CONCLUSIONS

Overexpression of GOLM1 is associated with poor prognosis in human HCC.

GP73 is down-regulated in gastric cancer and associated with tumor differentiation

Background

Golgi protein 73 (GP73) is a type II Golgi transmembrane protein. It is over-expressed in several cancers, including hepatocellular carcinomas, bile duct carcinomas, lung cancer and prostate cancer. However, there are few reports of GP73 in gastric cancer. This study is aimed at investigating the expression of GP73 and its relationship with clinical pathological characters in gastric cancer.

Methods

GP73 mRNA level was determined by quantitative real-time RT-PCR in 41 pairs of matched gastric tumorous tissues and adjacent non-tumorous mucosal tissues. Western blotting was also performed to detect the GP73 protein level. GP73 protein expression was analyzed by immunohistochemistry in 52 clinically characterized gastric cancer patients and 10 non-tumorous gastric mucosal tissue controls.

Results

The mRNA and protein level of GP73 were significantly down-regulated in gastric tumorous tissues compared with the non-tumorous mucosal tissues. In non-tumorous mucosa, strong diffuse cytoplasmic staining can be seen in cells located at the surface of the glandular and foveolar compartment; while in tumorous tissues, the staining was much weaker or even absent, and mainly in a semi-granular dot-like staining pattern. The expression level of GP73 protein was associated with patients’ gender and tumor differentiation.

Conclusions

GP73 was normally expressed in non-tumorous gastric mucosa and down-regulated in gastric cancer. Its expression in gastric cancer was correlated with tumor differentiation.

Diagnostic value of immunohistochemical staining of GP73, GPC3, DCP, CD34, CD31, and reticulin staining in hepatocellular carcinoma

It has been reported that Golgi protein-73 (GP73), glypican-3 (GPC3), and des-γ-carboxy prothrombin (DCP) could serve as serum markers for the early detection of hepatocellular carcinoma (HCC). This study aimed to evaluate a panel of immunostaining markers (including GP73, GPC3, DCP, CD34, and CD31) as well as reticulin staining to distinguish HCC from the mimickers. Our results revealed that CD34 immunostaining and reticulin staining were highly sensitive for the diagnosis of HCC. A special immunoreaction pattern of GP73--a diffuse coarse-block pattern in a perinuclear region or a concentrated cluster-like or cord-like pattern in a certain part of the cytoplasm--was observed in HCC cells, in contrast to the cytoplasmic fine-granular pattern in surrounding non-tumor cells and non-malignant nodules. This coarse-block pattern correlated significantly with less differentiated HCC. In comparison, GPC3 displayed a good advantage in diagnosing well-differentiated HCC. In our study, DCP and CD31 showed little diagnostic value for HCC as an immunostaining marker. When GP73, GPC3, and CD34 were combined, the specificity improved to 96.6%. Our findings demonstrate for the first time that the immunohistochemical panel of GP73, GPC3, and CD34 as well as reticulin staining is highly specific for the pathological diagnosis of HCC.

Interleukin-6 and oncostatin M are elevated in liver disease in conjunction with candidate hepatocellular carcinoma biomarker GP73

The Golgi phosphoprotein GP73 is elevated in the circulation of individuals with a diagnosis of hepatocellular carcinoma. Its usefulness as a biomarker of HCC is questioned, since it has also been reported to be elevated in the circulation of people with liver cirrhosis. Regulation of GP73 by inflammatory cytokines is therefore of interest. The interleukin-6 (IL-6) family cytokines were tested for effects on GP73 mRNA and/or protein levels in human hepatoblastoma HepG2 cells. Levels of GP73 mRNA and protein were up-regulated in HepG2 cells following treatment with either proinflammatory cytokine IL-6 or the related cytokine oncostatin M (OSM). Induction required the shared receptor subunit gp130, and correlated with increased tyrosine phosphorylation of STAT3. Maximal cytokine-mediated induction was not observed in the presence of protein synthesis inhibitor cycloheximide, suggesting additional regulatory factors play an important role. ELISA measurement of GP73 and IL-6 levels in the sera of patients with pre-malignant liver disease revealed a significant correlation between circulating levels of the two proteins. Similarly, a sensitive ELISA assay was developed to measure circulating OSM. OSM levels were elevated 6-7 fold in sera from patients with either cirrhosis or HCC relative to controls without liver disease. Although there was an association between levels of GP73 and OSM in serum from people with liver cirrhosis, there was not a statistically significant correlation in HCC, suggesting that the role of the cytokines in determining circulating levels may be complex. To our knowledge, this is the first report of OSM elevation being associated with liver disease.

Biomarkers for hepatocellular carcinoma: progression in early diagnosis, prognosis, and personalized therapy

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. Currently, surgical resection, liver transplantation, and local ablation are considered curative therapeutic practices for HCC. The diagnosis of HCC without pathologic confirmation is achieved by analyzing serum alpha-fetoprotein (AFP) levels combined with imaging techniques, including ultrasonography, magnetic resonance imaging, and computerized tomography. Although progress has been made in the diagnosis and management of HCC, its prognosis remains dismal. Various new technologies have identified numerous novel biomarkers with potential diagnostic as well as prognostic value, including Dickkopf-1 and Golgi protein 73. These biomarkers not only help in the early diagnosis and prediction of prognosis, but also assist in identifying potential targets for therapeutic interventions. In this article, we provide an up-to-date review of the biomarkers that are used for early diagnosis, prognosis prediction, and personalized treatment of HCC.

An overview of biomarkers for the diagnosis of hepatocellular carcinoma

CONTEXT

Primary liver cancer is one of the most common and deadly malignant neoplasms worldwide. The incidence and mortality rates for hepatocellular carcinoma (HCC) are virtually identical, reflecting the poor overall survival of patients with this kind of tumor. Effective therapies mostly achieved if the HCC diagnosis is made at early stages of the tumor. Surveillance tests include serologic and radiologic examinations.

EVIDENCE ACQUISITION

In this review, an overview of biomarkers for the diagnosis of HCC and future challenges in this popular field has been presented.

RESULTS

Serum tumor markers, such as alpha-fetoprotein (AFP) and des-gammacarboxy prothrombin (DCP) are commonly used for the surveillance, but their roles have been intensely debated despite the existence of sensitive radiologic tests. Most HCC-related cancer biomarkers are involved in chronic inflammation and cancer. These biomarkers, according to their biologic characteristics are primarily divided into three groups including onco-foetal protein, stress protein, and post-translational modification.

CONCLUSIONS

Because of the limitations of traditional HCC biomarkers, exploration for novel biomarkers for the diagnosis of HCC is an evolving process.

Generation and characterization of an anti-GP73 monoclonal antibody for immunoblotting and sandwich ELISA

Recently, serum Golgi protein 73 (GP73) levels have been found to be elevated in patients with hepatocellular carcinoma (HCC), and GP73 has been proposed as a novel marker for HCC. However, GP73 levels in patients remain controversial due to the specificity of the anti-GP73 antibody-based enzyme linked immunosorbent assay (ELISA). Therefore, an anti-GP73 antibody with high specificity was highly demanded. In the present study, by hybridoma screening, we generated an anti-GP73 monoclonal antibody (mAb) designated as 6A2 using recombinant GP73 protein produced by prokaryotic expression. The specificity of 6A2 was evaluated by Western blotting, immunohistochemistry and immunoprecipitation. The results showed that 6A2 recognized GP73 in both native and denatured forms. In addition, we have developed a sandwich ELISA using 6A2 and GP73 polyclonal antibody generated in New Zealand white rabbits according to standard procedures, and measured the serum GP73 level of patients using this assay. Our results showed that serum GP73 levels of HCC patients were significantly higher than those of healthy controls (P = 0.0036). Furthermore, for the first time, GP73 serum level was found to be elevated in patients with breast cancer compared with healthy controls (P = 0.0172).

Xenopus as a model system for the study of GOLPH2/GP73 function: Xenopus GOLPH2 is required for pronephros development

GOLPH2 is a highly conserved protein. It is upregulated in a number of tumors and is being considered as an emerging biomarker for related diseases. However, the function of GOLPH2 remains unknown. The Xenopus model is used to study the function of human proteins. We describe the isolation and characterization of Xenopus golph2, which dimerizes and localizes to the Golgi in a manner similar to human GOLPH2. Xenopus golph2 is expressed in the pronephros during early development. The morpholino-mediated knockdown of golph2 results in edema formation. Additionally, Nephrin expression is enhanced in the glomus, and the expression of pronephric marker genes, such as atp1b1, ClC-K, NKCC2, and NBC1, is diminished in the tubules and duct. Expression patterns of the transcription factors WT1, Pax2, Pax8, Lim1, GATA3, and HNF1β are also examined in the golph2 knockdown embryos, the expression of WT1 is increased in the glomus and expanded laterally in the pronephric region. We conclude that the deletion of golph2 causes an increase in the expression of WT1, which may promote glomus formation and inhibit pronephric tubule differentiation.

Cloning and characterization of human Golgi phosphoprotein 2 gene (GOLPH2/GP73/GOLM1) promoter

Human Golgi phosphoprotein 2 gene (also known as GOLPH2, GP73 or GOLM1) encodes an epithelial-specific Golgi membrane protein which can be induced by virus infection. It is also overexpressed in a number of tumors and is currently considered as an early diagnosis marker for hepatocellular carcinoma. However, little is known about how GOLPH2 is dysregulated in these disease conditions and the functional implications of its overexpression. The aim of this study is to investigate human GOLPH2 regulation mechanisms. We cloned a 2599 bp promoter fragment of GOLPH2 and found it maintained epithelial specificity. By deletion analysis, a repressive region (-864 to -734 bp), a positive regulatory region (-734 to -421 bp) and a core promoter region (-421 to -79 bp) were identified. Sequence analysis revealed that GOLPH2 core promoter was devoid of canonical TATA element and classified as a TATA-less promoter. Adenoviral early region 1A (E1A) was able to activate GOLPH2 and the CtBP interaction domain of E1A was sufficient but not required for activation. A GC-box motif (-89 to -83 bp) in GOLPH2 core promoter region partly mediated E1A transactivation. These results delineated regulatory regions and functional element in GOLPH2 promoter, elucidated adenoviral E1A stimulation mechanisms and provided insight into GOLPH2 functions.

The Golgi localization of GOLPH2 (GP73/GOLM1) is determined by the transmembrane and cytoplamic sequences

Golgi phosphoprotein 2 (GOLPH2) is a resident Golgi type-II membrane protein upregulated in liver disease. Given that GOLPH2 traffics through endosomes and can be secreted into the circulation, it is a promising serum marker for liver diseases. The structure of GOLPH2 and the functions of its different protein domains are not known. In the current study, we investigated the structural determinants for Golgi localization using a panel of GOLPH2 truncation mutants. The Golgi localization of GOLPH2 was not affected by the deletion of the C-terminal part of the protein. A truncated mutant containing the N-terminal portion (the cytoplasmic tail and transmembrane domain (TMD)) localized to the Golgi. Sequential deletion analysis of the N-terminal indicated that the TMD with a positively charged residue in the cytoplasmic N-terminal tail were sufficient to support Golgi localization. We also showed that both endogenous and secreted GOLPH2 exist as a disulfide-bonded dimer, and the coiled-coil domain was sufficient for dimerization. This structural knowledge is important for the understanding the pathogenic role of GOLPH2 in liver diseases, and the development of GOLPH2-based hepatocellular cancer diagnostic methods.

A study of diagnostic value of golgi protein GP73 and its genetic assay in primary hepatic carcinoma

This study aimed to investigate the diagnostic values of GP73 protein in patients' serum with primary hepatic carcinoma (PHC). Also GP73 mRNA expression level in peripheral blood mononuclear cells (PBMCs) and liver tissue between health controls and PHC patients was interrogated. Finally the role of combined detection of serum GP73 and alpha-fetoprotein (AFP) in high-risk population screening was evaluate, in an attempt to justify the new, sensitive, specific and rapid measure for the diagnosis and detection of PHC. Serum proteins of GP73 and AFP were examined in 73 patients with PHC, 13 patients with hepatic cirrhosis, 32 patients with hepatitis and 62 healthy subjects using enzyme-linked immunosorbent assay (ELISA). The relative expression levels of GP73 mRNA in PBMCs and liver tissues were examined by using SYBR Green quantitative reverse transcription polymerase chain reaction (RT-PCR) assay, calculated with the comparison of Cq value. In contrast to patients with cirrhosis and hepatitis, or healthy subjects, PHC patients had their serum GP73 and AFP significantly elevated (P < 0.05) while their PBMCs GP73 mRNA was not significantly different from those with cirrhosis and hepatitis, or healthy subjects (P > 0.05). The expression level of GP73 mRNA was significantly higher in PHC liver tissue than in normal liver tissue. The sensitivity for serum GP73 and AFP in PHC was 68.5% and 28.8%, respectively while that for the combined detection was up to 74%, justifying that the combined detection could prevent the false negative diagnosis by AFP alone and significantly improve the detection rate. As a new diagnostic biomarker of PHC, GP73 protein in serum was highly sensitive and specific. GP73 mRNA in PHC liver tissue specimens instead of whole blood could be used for the diagnosis of PHC as a tumor biomarker, whose detection was highly invasive, risky and afflicting otherwise. The combined detection of GP73 and AFP in serum effectively improved the diagnosis of PHC, in addition to the screening in high-risk population.

Increased Golgi protein 73 expression in hepatocellular carcinoma tissue correlates with tumor aggression but not survival

BACKGROUND AND AIM

Serum Golgi protein 73 (sGP73) is a novel and promising biomarker for hepatocellular carcinoma (HCC). However, there are few reports on the pattern of GP73 expression in HCC and the relationship of this expression to clinicopathologic features of patients. This study aimed to investigate the expression of GP73 and it correlation with clinical parameters.

METHODS

We examined GP73 expression in HCC and adjacent paracarcinomatous liver (PCL) tissue in 36 HCC patients, and took 14 normal liver (NL) samples from hepatic hemangioma patients. Western blot analysis and quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) were used for analyses.

RESULTS

GP73 expression in HCC was significantly higher than in the corresponding PCL and NL samples at both protein and mRNA levels (P < 0.001). The elevated level of GP73 protein was strongly associated with tumor size, vein invasion, and tumor differentiation, suggesting augmented tumor invasion and metastasis. However, there was no association between GP73 expression and patient survival.

CONCLUSION

Significant overexpression of GP73 at both protein and mRNA levels along with overexpression of GP73 protein is associated with aggressive behavior of HCC, but not overall patient survival. Further research is needed to determine the potential of GP73 as a therapeutic target.

Golgi protein 73(GP73), a useful serum marker in liver diseases

BACKGROUND

This study was performed to quantify the expression of Golgi protein-73 (GP73) in healthy controls and in patients with liver disease, and to evaluate the correlations between GP73 and other serum markers in different liver diseases.

METHODS

Serum GP73 was measured in 478 healthy controls and 296 patients with different types of liver disease. Quantitative hepatitis B virus (HBV) DNA was determined in two chronic hepatitis B (CHB) groups. Other serum liver fibrosis markers were measured in the liver fibrosis group and α-fetoprotein (AFP) was measured in hepatocellular carcinoma (HCC) group. The correlations between GP73 and these markers were evaluated.

RESULTS

The GP73 value in hepatitis B e antigen (HBeAg)-positive CHB group, HBeAg-negative CHB group, liver fibrosis group and HCC group was significantly higher (p<0.001) than that in healthy controls. GP73 showed significant correlation with other markers in the liver fibrosis group and with AFP in the HCC group.

CONCLUSIONS

Compared with healthy controls, GP73 in patients with liver disease was significantly increased. With the progression of liver disease, GP73 showed a significantly increasing trend. These results suggest that GP73 might be used as a serum marker for the diagnosis of liver diseases and for monitoring disease progression.

Overexpression of α1,6-fucosyltransferase in hepatoma enhances expression of Golgi phosphoprotein 2 in a fucosylation-independent manner

Golgi phosphoprotein 2 (GP73) is a type II Golgi protein, which was found on examination of the fucosylated proteome as a potential tumor marker for hepatocellular carcinoma (HCC). The serum levels of both total and fucosylated GP73 were increased in the sera of patients with HCC. Fucosylation is one of the most important oligosaccharide modifications involved in cancer and is catalyzed by α1,6-fucosyltransferase (Fut8). In the present study, we investigated the effect of Fut8 overexpression on GP73 production in the human hepatoma cell line Hep3B. The Fut8 expression vector was transfected into Hep3B cells and the expression of GP73 was investigated by Western blotting and real-time PCR. Overexpression of Fut8 dramatically enhanced the expression of GP73 at the transcriptional level. Surprisingly, this effect was not dependent on cellular fucosylation. Overexpression of a mutant Fut8, which was unable to be localized to the Golgi, did not induce GP73 production, suggesting that the localization of Fut8 in the Golgi apparatus was important for the increase in GP73 expression. This is the first demonstration of GP73 regulation through overexpression of a glycosyltransferase, which may lead to Golgi stress.

Cancer biomarkers for hepatocellular carcinomas: from traditional markers to recent topics

Hepatocellular carcinomas (HCC) are the fifth most common tumor type and the third most common cause of cancer-related death worldwide. Some tumor markers for HCC, such as α-fetoprotein and des-γ-carboxyprothrombin, are used clinically. Recent advances in proteomics and glyco-proteomics might provide various types of novel tumor markers for HCC. While the clinical availability of these tumor markers is important, the molecular mechanisms underlying the production of tumor markers requires further clarification. Our group has investigated the glycobiology of tumor markers. In this review, we describe the impact of novel HCC markers and their possible implications for clinical use.

Serological AFP/Golgi protein 73 could be a new diagnostic parameter of hepatic diseases

We have investigated the changing rule of serum form of GP73 (sGP73) in different hepato-pathologic processes and identified the sGP73 role in inflammation, fibrosis and carcinogenesis since sGP73 has been regarded as a candidate tumor marker. Quantitative enzyme-linked immunosorbent assay detected sGP73 in 535 subjects with hepatocellular carcinoma (HCC), liver cirrhosis (LC), hepatitis, focal nodular hyperplasia (FNH), angioma, intra-hepatic cholangio-carcinoma (ICC) and metastatic cancer from adenocarcinomas (MC). Median sGP73 in LC was higher than in HCC and hepatitis (p = 0.001), and sGP73 in all three groups were higher than those in healthy individuals (p < 0.001); sGP73 in LC patients with Child-Pugh class A was lower than in class B and C (p = 0.001), no significant difference was found between early and advanced HCC groups (110.4 μg/L vs. 102.8 μg/L). AFP/GP73 had a sensitivity of 75.8% and specificity of 79.7% with an area under the receiver operating curve (AUROC) of 0.844 vs. 0.812 for AFP (p = 0.055) with a sensitivity of 95.2% and specificity of 47.1%; in detecting early HCC, AUROC of AFP/GP73 was 0. 804 vs. 0.766 for AFP (p = 0.086). sGP73 correlated with AST, AST/ALT, ALB, A/G and ALP in LC. The positive rate of sGP73 in angioma, FNH, ICC, and MC was 0, 50, 63.3, 53.3%, respectively; AFP/GP73 was 0.796 with the sensitivity of 81.4% and specificity of 70.0% when differentiating MC from AFP-negative HCC. Increased sGP73 is related to hepatic impairment and chronic fibrosis, and when combined with AFP could improve the differential diagnosis of hepatic diseases.

A comparative evaluation of Golgi protein-73, fucosylated hemopexin, α-fetoprotein, and PIVKA-II in the serum of patients with chronic hepatitis, cirrhosis, and hepatocellular carcinoma

BACKGROUND

Golgi protein-73 (GP73) and fucosylated proteins have been proposed as potential serum markers for liver disease and/or hepatocellular carcinoma (HCC). The purpose of this study was to compare the sensitivity and specificity of serum GP73 and fucosylated hemopexin (Fuc-HPX) with α-fetoprotein (AFP) and with protein induced by the absence of vitamin K or antagonist-II (PIVKA-II) for diagnosing chronic hepatitis, cirrhosis, and HCC.

METHODS

The concentration of GP73 in human sera was determined using an enzyme-linked immunosorbent assay employing mouse monoclonal and rabbit polyclonal GP73 antibodies. Fuc-HPX was detected using a lectin chemiluminescence-linked immunosorbent assay using a mouse monoclonal anti-hemopexin antibody and Aleuria aurantia lectin. A total of 229 serum samples from patients with chronic hepatitis, cirrhosis, and HCC, as well as from normal individuals were evaluated using these four markers.

RESULTS

GP73 and Fuc-HPX showed significantly higher values in samples from patients with cirrhosis and HCC than in samples from patients with hepatitis and from normal individuals. The areas under the curves (AUCs) for GP73, Fuc-HPX, AFP, and PIVKA-II were 0.90, 0.77, 0.74, and 0.88, respectively, for liver cirrhosis and HCC samples vs. hepatitis and normal samples. The AUCs of GP73, Fuc-HPX, AFP, and PIVKA-II were 0.78, 0.72, 0.81, and 0.90, respectively, for HCC samples vs. all other samples.

CONCLUSIONS

PIVKA-II showed superior sensitivity and specificity for HCC compared with the other three markers. GP73 may be useful for detecting cirrhosis as a risk factor for HCC. Fuc-HPX showed inferior sensitivity and specificity compared to the other markers.

Serum markers of hepatocellular carcinoma

BACKGROUND

The hepatocellular carcinoma is one of the most common malignant tumors and carries a poor survival rate. The management of patients at risk for developing HCC remains intricate.

METHODS

A literature search identified potential markers for hepatocellular carcinoma. These markers were analysed and justification was provided for these factors' inclusion to (or exclusion from) the markers of hepatocellular carcinoma (HCC). A search of the literature was made using cancer literature and the PubMed database for the following keywords: "markers and HCC," "Lens culinaris agglutinin reactive AFP (AFP-L3) and HCC," "Des-γ-carboxy prothrombin (DCP) and HCC," "Glypican-3 and HCC," "Chromogranin A and HCC," "Transforming growth factor β1(TGF) and HCC," "α-l-fucosidase (AFU) and HCC," "Golgi protein-73 (GP73) and HCC," "Hepatocyte growth factor (HGF) and HCC," "Nervous growth factor (NGF) and HCC."

CONCLUSIONS

Despite the large number of studies devoted to the immunohistochemistry of HCC, at the present time, the absolute positive and negative markers for HCC are still lacking, and even those characterized by very high sensitivity and specificity do not have an universal diagnostic usefulness. Given the poor response to current therapies, a better understanding of the molecular pathways active in this disease could potentially provide new targets for therapy. However, AFP shows a low sensitivity, therefore other biomarkers have been developed to make an early diagnosis and improve patients' prognosis.

Golgi phosphoprotein 2 (GOLPH2/GP73/GOLM1) interacts with secretory clusterin

Golgi phosphoprotein 2 (GOLPH2/GP73/GOLM1), a type-II Golgi transmembrane protein of unknown function, is up-regulated in many cancers. Its Golgi luminal domain is potentially the major functional domain. The goal of this study is to identify the proteins interacting with GOLPH2. Using secretory GOLPH2 (sGOLPH2, amino acid residues 55-401) as bait, secretory clusterin (sCLU) was identified as one interacting candidate by yeast two-hybrid screening, and the coiled-coil domain of GOLPH2 was found to be sufficient for interaction with sCLU. The interaction between GOLPH2 and sCLU was confirmed intracellularly and extracellularly. The intracellular co-localization of GOLPH2 and sCLU in Golgi was also shown. These results can help in understanding the biological and pathological significance of GOLPH2.

Advances in understanding the relationship between GP73 and hepatic diseases

Golgi protein-73 (GP73), a recently discovered Golgi glycoprotein localized on the membrane of the Golgi complex, is expressed in many types of human epithelial cells. In normal human liver, GP73 is highly expressed in biliary epithelial cells, but barely detectable in hepatocytes. However, GP73 expression has been found to be strongly up-regulated in hepatocytes and elevated in the serum in patients with liver diseases, especially those with hepatocellular carcinoma (HCC). Thus, GP73 is a candidate serum marker for the early detection of HCC.

Up-regulated Golgi phosphoprotein 2 (GOLPH2) expression in lung adenocarcinoma tissue

OBJECTIVES

The aim of the study was to evaluate Golgi Phosphoprotein 2 (GOLPH2) expression in lung cancer.

DESIGN AND METHODS

GOLPH2 expression was analyzed from 178 lung cancer tumor tissue samples using immunohistochemistry. Levels of 133 lung cancer patients' serum GOLPH2 (sGOLPH2) were also quantitatively compared with 70 healthy individuals by a sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

All adenocarcinoma (ADC) tissue samples (100%) displayed strong staining, 83.6% of which displayed cytoplasmic diffused staining. However, for squamous cell carcinoma samples, only 16.3% displayed strong staining intensity. Statistically, GOLPH2 expression in tissues of ADC was significantly higher than in other types of lung cancer (P<0.001). Levels of sGOLPH2 were also detected. The mean value of sGOLPH2 concentration is 69 ng/ml in lung cancer patients and 53 ng/ml in healthy individuals.

CONCLUSIONS

Significantly elevated GOLPH2 expression was observed in ADC tumor tissues. The levels of sGOLPH2 were about 30% higher in lung cancer patients compared with healthy individuals.

GOLPH2 expression may serve as diagnostic marker in seminomas

BACKGROUND

GOLPH2 (Golgi phosphoprotein 2) is a novel Golgi membrane protein. Despite its unknown physiologic function, however, it has been proposed as a biomarker for hepatocellular and prostate carcinoma due to its upregulation in those cancer entities. Whether the overexpression of GOLPH2 is tumour specific or a generic parameter of malignancy and whether this finding is true for additional carcinomas has not been determined. In this study, we aimed to evaluate the expression pattern of GOLPH2 in testicular seminomas, the most common histologic subtype of testicular neoplasm.

METHODS

GOLPH2 protein expression was assessed by immunohistochemistry in 69 testicular seminomas and compared to the expression rates in matching normal testicular tissue and intratubular germ cell neoplasia of unclassified type (IGCNU). In addition, a subset of Leydig cell tumours was analyzed accordingly.

RESULTS

GOLPH2 was consistently overexpressed (89.9%) in seminomas. Matching non-neoplastic tissue showed weak or negative staining. The observed differences between non-neoplastic and neoplastic tissue were statistically highly significant (p < 0.001). There were no significant associations with tumour status. Interestingly, GOLPH2 was also highly expressed in the intertubular Leydig cells as well as in Leydig cell tumours.

CONCLUSIONS

GOLPH2 protein is highly expressed in seminomas and in Leydig cell tumours. This study fosters the association of GOLPH2 with malignant neoplastic processes. The staining pattern is easily assessable and consistent which is a favourable property especially in clinical settings. GOLPH2 could be a novel immunohistochemical marker for the assessment of testicular neoplasms, especially against the background that in analogy to hepatocellular carcinomas complementary GOLPH2 serum levels might be helpful in detecting metastases or recurrent tumour. Therefore serum studies and analyses of GOLPH2 expression in non-seminomatous germ cell tumours are strongly warranted.

Present and future possibilities for early diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the fifth most common cancer in the world, and the third most frequent oncological cause of death. The incidence of HCC is on the increase. HCC typically develops in patients with chronic liver diseases, and cirrhosis, usually with viral etiology, is the strongest predisposing factor. Nowadays HCC diagnosis is a multistage process including clinical, laboratory, imaging and pathological examinations. The prognosis of HCC is mostly poor, because of detection at an advanced, non-resectable stage. Potentially curative treatment (surgery) is limited and really possible only for cases with small HCC malignancies. For this reason, more effective surveillance strategies should be used to screen for early occurrence of HCC targeted to the population at risk. So far, the generally accepted serological marker is α-fetoprotein (AFP). Its diagnostic accuracy is unsatisfactory and questionable because of low sensitivity, therefore there is a strong demand by clinicians for new HCC-specific biomarkers. In this review, we will focus on other biomarkers that seem to improve HCC diagnosis, such as AFP-L3, des-γ-carboxyprothrombin, α-l-fucosidase, γ-glutamyl transferase, glypican-3, squamous cell carcinoma antigen, a new generation of immunoglobulin M-immunocomplexes, and very promising gene-expression profiling.

Significance of Golgi protein 73, alpha-fetoprotein and vascular endothelial growth factor expression in diagnosis of primary hepatic cancer

AIM: To investigate the expression of Golgi protein 73 (GP73), alpha-fetoprotein (AFP) and vascular endothelial growth factor (VEGF) in primary hepatic cancer (PHC) and analyze their clinical significance.

METHODS: Forty-five PHC and tumor-adjacent specimens and 14 normal liver specimens were included in the study. The expression of GP73, AFP and VEGF in these specimens was detected by immunohistochemistry. The correlation of the expression of these proteins with clinical pathology parameters in PHC was analyzed.

RESULTS: The expression levels of GP73, AFP and VEGF were significantly higher in PHC and tumor-adjacent tissue than in tumor-adjacent tissue (0.143 ± 0.018 vs 0.124 ± 0.027, 0.116 ± 0.026 vs 0.098 ± 0.014, and 0.126 ± 0.027 vs 0.092 ± 0.016, respectively; all P < 0.05) and normal liver tissue (0.124 ± 0.027 vs 0.088 ± 0.029, 0.098 ± 0.014 vs 0.073 ± 0.011, and 0.092 ± 0.016 vs 0.076 ± 0.018, respectively; all P < 0.05), respectively. GP73 expression was positively correlated with pathological grade and cirrhosis, but not with tumor size, number of nodules, clinical stage and serum AFP level. VEGF expression was positively correlated with tumor size, number of nodules, portal vein tumor thrombus and clinical stage, but not with degree of tumor differentiation and serum AFP level. The expression levels of GP73 and VEGF were higher than that of AFP in PHC (both P < 0.05).

CONCLUSION: GP73 is highly expressed in primary liver cancer and can be used as a diagnostic marker for PHC. Combined detection of GP73, AFP and VEGF is helpful for diagnosis of PHC.

Hepatocyte GP73 expression in Wilson disease

BACKGROUND/AIMS

Wilson disease (WD) is a disorder of copper transport caused by mutations within the ATP7B gene. WD is phenotypically variable and can present with predominantly hepatic or neurologic manifestations. The mechanisms responsible for this variability are unknown. GP73, a Golgi membrane protein, is expressed in hepatocytes in response to acute and chronic liver disease.

METHODS

Hepatocyte GP73 expression was examined in the livers of WD patients by semiquantitative immunohistochemistry. GP73 mRNA levels were measured in mice with a deletion of the WD gene (Atp7b(-/-)) by real-time PCR, and these values were compared to the concomitant histological abnormalities and previously reported copper levels.

RESULTS

Hepatocyte GP73 expression was more frequently observed in patients with hepatic versus neurologic presentation (79% vs. 30%, p<0.05). Furthermore, GP73 expression was significantly higher (44.7+/-14.0 vs. 2.0+/-0.81, p<0.05) in patients with hepatic phenotype. In Atp7b(-/-) mice, GP73 mRNA was significantly elevated at 20-46 weeks of age, coincident with extensive hepatic inflammation and fibrosis, but not at 6 weeks, when hepatic histology was normal despite significant copper overload. GP73 mRNA levels normalized concomitantly with the resolution of hepatic injury at 60-weeks. However, in tumor-like nodules GP73 was strikingly elevated.

CONCLUSION

Increased hepatocyte GP73 expression is more commonly a feature of hepatic than neurologic WD, and is triggered in response to inflammation, fibrosis, and dysplasia, rather than copper overload.

Golgi phosphoprotein 2 (GOLPH2) expression in liver tumors and its value as a serum marker in hepatocellular carcinomas

Hepatocellular carcinomas (HCCs) and bile duct carcinomas (BDCs) have a poor prognosis. Therefore, surveillance strategies including sensitive and specific serum markers for early detection are needed. Recently, Golgi Phosphoprotein 2 (GOLPH2) has been proposed as a serum marker for HCC, but GOLPH2 expression data in liver tissues was not available. Using tissue microarrays and immunohistochemistry, we semiquantitatively analyzed GOLPH2 protein expression in patients with HCC (n = 170), benign liver tumors (n = 22), BDC (n = 114) and normal liver tissue (n = 105). A newly designed sandwich enzyme-linked immunoassay (ELISA) was used to analyze GOLPH2 levels in the sera of patients with HCC (n = 62), hepatitis C virus (HCV) (n = 29), BDC (n = 10), and healthy control persons (n = 12). By immunohistochemistry 121/170 (71%) of HCC showed strong GOLPH2 expression, which was significantly associated with a higher tumor grade (P = 0.01). A total of 97/114 (85%) BDCs showed a strong GOLPH2 expression which proved to be an independent prognostic factor for overall survival (P < 0.05). Serum levels of GOLPH2 measured by ELISA were significantly elevated in patients with HCC with underlying HCV infection (median 18 mg/L, P < 0.05) and patients with BDC (median = 14.5 mg/L, P < 0.01) in comparison to healthy controls (median 4 mg/L).

CONCLUSION

GOLPH2 protein is highly expressed in tissues of HCC and BDC. GOLPH2 protein levels are detectable and quantifiable in sera by ELISA. In patients with hepatitis C, serial ELISA measurements in the course of the disease appear to be a promising complementary serum marker in the surveillance of HCC. GOLPH2 should be further evaluated as a serum tumor marker in BDC on a larger scale.

GP73, a resident Golgi glycoprotein, is sensibility and specificity for hepatocellular carcinoma of diagnosis in a hepatitis B-endemic Asian population

Golgi protein-73 (GP73) is a newly identified candidate serum marker for HCC, but GP73 study now is lesser in Asian population. The aims of this study were to determine how GP73 is detected in the serum of healthy, hepatitis B, cirrhosis and HCC by western blotting and RT-PCR, and to establish the sensitivity and specificity of serum GP73 protein and RNA for diagnosing HCC. Serum GP73 was detected by western blotting and RT-PCR, and quantified by densitometric analysis. GP73 was measured in serum from 124 patients with various forms of liver. AFP was tested using commercially available electrochemiluminescence immunoassay. The median sGP73 in patients with HBV-related HCC was significantly higher (P < 0.001) than in healthy individuals and in patients with other diseases. When sGP73 protein was used to detect HBV-related HCC, it had a sensitivity of 77.4% and a specificity of 83.9%, at the optimal cut-off value of 7.4 relative units. The area under the receiver-operating characteristic curve was 0.89. GP73 RNA in patients with HBV-related HCC had a sensitivity of 87.1% and a specificity of 83.9% and AUROC of 0.92. AFP in patients with HCC had a sensitivity of 48.4% and a specificity of 96.8% and AUROC of 0.77. GP73 protein and RNA can be found in the serum of patients with HBV-related HCC obviously higher than of other liver diseases in Asian. GP73 was better than AFP for the diagnosis of HBV-related HCC. RT-PCR is a more sensitive and superior method of quantification than Western blot. Furthermore, our data need to be confirmed in larger cohorts of patients.

Diagnosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the commonest cancers worldwide, particularly in parts of the developing world, and is increasing in incidence. This article reviews the current modalities employed for the diagnosis of HCC, including serum markers, radiological techniques and histological evaluation, and summarises international guidelines for the diagnostic approach to HCC.

GOLPH2 protein expression as a novel tissue biomarker for prostate cancer: implications for tissue-based diagnostics

GOLPH2 is coding the 73-kDa type II Golgi membrane antigen GOLPH2/GP73. Upregulation of GOLPH2 mRNA has been recently reported in expression array analyses of prostate cancer. As GOLPH2 protein expression in prostate tissues is currently unknown, this study aimed at a comprehensive analysis of GOLPH2 protein in benign and malignant prostate lesions. Immunohistochemically detected GOLPH2 protein expression was compared with the basal cell marker p63 and the prostate cancer marker alpha-methylacyl-CoA racemase (AMACR) in 614 radical prostatectomy specimens. GOLPH2 exhibited a perinuclear Golgi-type staining pattern and was preferentially seen in prostatic gland epithelia. Using a semiquantitative staining intensity score, GOLPH2 expression was significantly higher in prostate cancer glands compared with normal glands (P<0.001). GOLPH2 protein was upregulated in 567 of 614 tumours (92.3%) and AMACR in 583 of 614 tumours (95%) (correlation coefficient 0.113, P = 0.005). Importantly, GOLPH2 immunohistochemistry exhibited a lower level of intratumoral heterogeneity (25 vs 45%). Further, GOLPH2 upregulation was detected in 26 of 31 (84%) AMACR-negative prostate cancer cases. These data clearly suggest GOLPH2 as an additional ancillary positive marker for tissue-based diagnosis of prostate cancer.