Prognostic significance of osteopontin in hepatitis B virus-related hepatocellular carcinoma

Diagnostic accuracy and prognostic significance of osteopontin in liver cirrhosis and hepatocellular carcinoma: a Meta-analysis

OBJECTIVE

At present, there is no definite suggestion about effective tumour biomarkers for the diagnostic accuracy and prognostic significance of hepatocellular carcinoma (HCC) and liver cirrhosis (LC). The aim of our research was to determine the value of the tumour biomarker osteopontin (OPN), which is encoded by the Spp1 gene, in the diagnosis, prognosis and development of HCC and LC through meta-analysis.

METHODS

A systematic literature search was performed in the PubMed, Embase, Cochrane Library and China National Knowledge Infrastructure electronic databases up to March 2021. Studies evaluating the diagnostic and/or prognostic value of OPN in HCC and/or LC were included.

RESULTS

From the systematic search, 35 studies including 9150 participants were eligible, 25 of which provided data on the diagnostic value of OPN overexpression, while 15 studies provided data on the prognostic value. OPN had high diagnostic accuracy in both HCC and LC patients compared with healthy controls, and the diagnostic efficiency was increased by the biomarker combination OPN + AFP.

CONCLUSIONS

OPN may be adopted as a promising predictive tumour biomarker for the diagnosis and prognosis of HCC and LC and may be a potential therapeutic target.

Risk Factors and Biomarkers for Chronic Hepatitis B Associated Hepatocellular Carcinoma

Globally, hepatitis B virus (HBV) related hepatocellular carcinoma (HCC) is one of the major causes of cancer-related mortality. This is, in part, due to delayed diagnosis and limited therapeutic options with more advanced stages of the disease. Given the prognostic importance of early diagnosis, novel methods for early detection are in need. Unlike most other cancer types, tissue is not required to diagnose HCC and is frequently avoided given the inherent risks of liver biopsy, so less invasive methods of obtaining tumor material are currently under investigation. Material shed from tumors into the periphery are being investigated for their potential to both surveil and diagnose patients for HCC. These materials include circulating tumor cells, DNA, RNA, and exosomes, and are collectively termed a “liquid biopsy”. In this review article, we discuss the evolving literature regarding the different risk factors for HCC and the types of emerging novel biomarkers that show promise in the prevention and early diagnosis of HCC within the context of HBV infection.

Osteopontin: A Key Regulator of Tumor Progression and Immunomodulation

Simple Summary

Anti-PD-1/PD-L1 and anti-CTLA-4-based immune checkpoint blockade (ICB) immunotherapy have recently emerged as a breakthrough in human cancer treatment. Durable efficacy has been achieved in many types of human cancers. However, not all human cancers respond to current ICB immunotherapy and only a fraction of the responsive cancers exhibit efficacy. Osteopontin (OPN) expression is highly elevated in human cancers and functions as a tumor promoter. Emerging data suggest that OPN may also regulate immune cell function in the tumor microenvironment. This review aims at OPN function in human cancer progression and new findings of OPN as a new immune checkpoint. We propose that OPN compensates PD-L1 function to promote tumor immune evasion, which may underlie human cancer non-response to current ICB immunotherapy.

Abstract

OPN is a multifunctional phosphoglycoprotein expressed in a wide range of cells, including osteoclasts, osteoblasts, neurons, epithelial cells, T, B, NK, NK T, myeloid, and innate lymphoid cells. OPN plays an important role in diverse biological processes and is implicated in multiple diseases such as cardiovascular, diabetes, kidney, proinflammatory, fibrosis, nephrolithiasis, wound healing, and cancer. In cancer patients, overexpressed OPN is often detected in the tumor microenvironment and elevated serum OPN level is correlated with poor prognosis. Initially identified in activated T cells and termed as early T cell activation gene, OPN links innate cells to adaptive cells in immune response to infection and cancer. Recent single cell RNA sequencing revealed that OPN is primarily expressed in tumor cells and tumor-infiltrating myeloid cells in human cancer patients. Emerging experimental data reveal a key role of OPN is tumor immune evasion through regulating macrophage polarization, recruitment, and inhibition of T cell activation in the tumor microenvironment. Therefore, in addition to its well-established direct tumor cell promotion function, OPN also acts as an immune checkpoint to negatively regulate T cell activation. The OPN protein level is highly elevated in peripheral blood of human cancer patients. OPN blockade immunotherapy with OPN neutralization monoclonal antibodies (mAbs) thus represents an attractive approach in human cancer immunotherapy.

High Expression of MicroRNA-196a is Associated with Progression of Hepatocellular Carcinoma in Younger Patients

MicroRNAs are small RNAs involved in various biological processes and cancer metastasis. miR-196a was associated with aggressive behaviors in several cancers. The role of miR-196a in hepatocellular carcinoma (HCC) metastasis remains unknown. This study aimed to examine the role of miR-196a in HCC progression. Expression of miR-196a was measured in 83 human HCC samples. The HCC patients with high miR-196a expression had younger ages, lower albumin levels, higher frequency with alpha-fetoprotein (AFP) levels ≥20 ng/mL, more macrovascular invasion, and non-early stages. Kaplan-Meier analysis showed that high miR-196a expression was associated with lower recurrence-free survival. Knockdown of miR-196a decreased transwell invasiveness, sphere formation, transendothelial invasion, and Slug, Twist, Oct4, and Sox2 expression, suppressed angiogenesis, and reduced sizes of xenotransplants and number of pulmonary metastasis. Down-regulation of miR-196a decreased Runx2 and osteopontin (OPN) levels. Knockdown of Runx2 in vitro resulted in comparable phenotypes with miR-196a down-regulation. Restoration of Runx2 in miR-196a-knockdown HCC reverted tumor phenotypes. This study showed that high expression of miR-196a is associated with HCC progression in a subset of younger patients. miR-196a mediates HCC progression via upregulation of Runx2, OPN, epithelial-mesenchymal transition (EMT) regulators, and stemness genes. We proposed that miR-196a can be used as a prognostic marker and a potential therapeutic target.

Selecting patients with hepatocellular carcinoma for liver transplantation: incorporating tumor biology criteria

Liver transplantation (LT) is the optimal therapeutic option for patients with liver cirrhosis and hepatocellular carcinoma (HCC). Due to universal donor shortage, only the patients with limited tumor burden (under the so-called Milan criteria) are considered as potential candidates for LT in most institutions. It is expected that in the near future, more liver grafts will be available for patients with HCC due to the implementation of new direct antivirals against hepatitis C, leaving a prone scenario to consider expanding Milan criteria. A moderate expansion of Milan criteria could be implemented without increasing the risk of tumor recurrence if patients with favorable biological behavior are carefully selected. Incorporating information regarding tumor biology in the decision-making algorithm would result in a more rational use of LT in patients with HCC. In the present review, surrogate markers of tumor biology are critically evaluated as potential tools to be combined with existing radiological criteria. In addition, the current state of liquid biopsy is discussed, as this cutting-edge technology may reshape the management of HCC in the upcoming years.

Overexpression of serum response factor is correlated with poor prognosis in patients with gastric cancer

Serum response factor (SRF) is highly expressed in many tumors, including gastric cancer. However, the exact prognostic utility of SRF in patients with gastric cancer remains unclear. Therefore, in this study, we investigated the expression and prognostic value of SRF in patients with gastric cancer. SRF expression was detected by immunohistochemistry in 149 gastric cancer samples. The relationship between SRF expression and clinicopathological characteristics along with the prognostic significance of SRF in disease-free survival and overall survival of patients was analyzed. We found that the expression of SRF was significantly increased in gastric cancer tissues compared with adjacent noncancerous tissues. Overexpression of SRF was significantly correlated with histologic differentiation, invasion depth, lymph node metastasis, and TNM stage. Furthermore, disease-free survival rate and overall survival rate were both significantly lower for patients with high SRF expression. Multivariate Cox regression analysis identified high SRF expression as an independent prognostic factor for disease-free survival but not for overall survival. Our findings indicate that overexpression of SRF may play an important role in human gastric cancer recurrence and prognosis. SRF may serve as a predictive marker for prognosis of gastric cancer.

Prognostic value of osteopontin in patients with hepatocellular carcinoma: A systematic review and meta-analysis

PURPOSE

The prognostic value of tissue and serum osteopontin (OPN) in hepatocellular carcinoma (HCC) remain controversial. The aim of present meta-analysis was to evaluate the prognostic value of OPN in patients with HCC.

METHODS

Eligible studies were systematically searched by PubMed, EMBASE, and Google scholar. A meta-analysis of 12 studies included 2117 cases was performed to estimate the association between OPN level and overall survival (OS), disease-free survival (DFS) in HCC patients. Subgroup analyses were also performed in the meta-analysis.

RESULTS

The pooled data of studies showed that high OPN level was significantly associated with poor OS (hazard ratios [HR] 1.84; 95% confidence intervals [CI] 1.54-2.20; P = .000) and DFS (HR 1.67; 95% CI 1.40-1.98; P = .000) in HCC. Furthermore, in subgroup analysis, high tissue based OPN by immunohistochemistry detection and serum-based OPN by enzyme-linked immunosorbent assay (ELISA) detection were both significantly associated with OS (tissue: HR 1.88; 95% CI 1.53-2.31; P < .0001; serum: HR 2.38; 95% CI 1.58-3.59; P < .0001). Simultaneously, we also found that OPN expression was positively associated with stage (odds ratios [OR] 5.68; 95% CI 3.443-7.758), tumor size (Size≤5 cm vs >5 cm; OR 2.001; 95% CI1.036-3.867).

CONCLUSION

The current evidence indicates that OPN could serve as a prognostic biomarker and a potential therapeutic target for HCC.

Evaluation of Osteopontin as a Biomarker in Hepatocellular Carcinomas in Egyptian Patients with Chronic HCV Cirrhosis

Background: Hepatocellular carcinoma (HCC) is a high incidence disease in Egypt with a poor prognosis and survival. Biomarkers are important for diagnosis of HCC at an early stage. Osteopontin (OPN), a glycoprotein secreted by macrophages, osteoblasts, and T cells, is also highly expressed in a variety of tumors, such as examples in the breast, colon, and stomach. The present study aimed to correlate the serum level of OPN in HCV-positive hepatocellular carcinoma patients, with OPN expression in tumor and non-tumor liver tissues in order to identify its efficacy as a biomarker for diagnosis. Material and Methods: Out of total of 146 patients, 80 were selected for inclusion in the study. Blood samples as well as specimens of tumor and non-tumor liver tissue were collected. In addition, blood samples from 20 healthy volunteers were obtained as controls. Serum OPN and alpha-fetoprotein (AFP) were evaluated by ELISA for HCC and control groups. OPN and AFP gene expression were examined by real-time PCR, after homogenization and DNA extraction from serum samples and liver tissues. Results: It was found that serum OPN levels were significantly higher in the HCC group compared to normal group (P=0.009), with a strong positive correlation with AFP expression. However, there was no significant difference between OPN expression in tumor and non-tumor liver tissue. Conclusion: Serum OPN is highly suggested to be a professional candidate for HCC early diagnosis, with a diagnostic ability and accuracy equal or higher than for AFP.

Plasma Osteopontin Level as a Diagnostic Marker of Hepatocellular Carcinoma in Patients with Radiological Evidence of Focal Hepatic Lesions

Aims

Hepatocellular carcinoma is one of the most aggressive malignant tumors and has limited treatment options. Needle-guided biopsies have been utilized as a tool to diagnose malignant focal hepatic lesions. These techniques are discouraged because of their complications. Nowadays, alpha fetoprotein is the most widely used tumor marker for screening and diagnosis of hepatocellular carcinoma. Nevertheless, this marker has limitations. The diagnostic role of plasma osteopontin as an adjuvant or alternative marker to alpha fetoprotein to detect hepatocellular carcinoma in Egyptian patients with focal hepatic lesions was evaluated in this study.

Subject and methods

Eighty participants were recruited from the Egyptian National Liver Institute and were self-assigned to three groups, namely, focal hepatic lesions (n = 40), liver cirrhosis (n = 20), and controls (n = 20). Participants' plasma osteopontin and serum alpha fetoprotein levels were determined and were compared across the three groups.

Results

The discriminatory ability of plasma osteopontin for hepatocellular carcinoma was lower than that of alpha fetoprotein. Osteopontin and alpha fetoprotein were not correlated with each other. Neither the gender nor the age of the patients showed a significant association with plasma osteopontin level.

Conclusion

Measuring plasma osteopontin level alone has no advantage over serum alpha fetoprotein in patients with focal hepatic lesions due to chronic liver disease.

The Roles of Matricellular Proteins in Oncogenic Virus-Induced Cancers and Their Potential Utilities as Therapeutic Targets

Matricellular proteins differ from other classical extracellular matrix proteins; for instance, they are transiently expressed as soluble proteins rather than being constitutively expressed in pathological conditions, such as acute viral infections. Accumulating studies have revealed that matricellular proteins, including osteopontin and tenascin-C, both of which interact with integrin heterodimers, are involved in inflammatory diseases, autoimmune disorders, and cancers. The concentrations of these matricellular proteins are elevated in the plasma of patients with certain types of cancers, indicating that they play important roles in oncogenesis. Chronic viral infections are associated with certain cancers, which are distinct from non-viral cancers. Viral oncogenes play critical roles in the development and progression of such cancers. It is vital to investigate the mechanisms of tumorigenesis and, particularly, the mechanism by which viral proteins induce tumor progression. Viral proteins have been shown to influence not only the viral-infected cancer cells, but also the stromal cells and matricellular proteins that constitute the extracellular matrix that surrounds tumor tissues. In this review, we summarize the recent progress on the involvement of matricellular proteins in oncogenic virus-induced cancers to elucidate the mechanism of oncogenesis and consider the possible role of matricellular proteins as therapeutic targets in virus-induced cancers.

Role of Osteopontin in Liver Diseases

Osteopontin (OPN), a multifunctional protein, is involved in numerous pathological conditions including inflammation, immunity, angiogenesis, fibrogenesis and carcinogenesis in various tissues. Extensive studies have elucidated the critical role of OPN in cell signaling such as regulation of cell proliferation, migration, inflammation, fibrosis and tumor progression. In the liver, OPN interacts with integrins, CD44, vimentin and MyD88 signaling, thereby induces infiltration, migration, invasion and metastasis of cells. OPN is highlighted as a chemoattractant for macrophages and neutrophils during injury in inflammatory liver diseases. OPN activates hepatic stellate cells (HSCs) to exert an enhancer in fibrogenesis. The role of OPN in hepatocellular carcinoma (HCC) has also generated significant interests, especially with regards to its role as a diagnostic and prognostic factor. Interestingly, OPN acts an opposing role in liver repair under different pathological conditions. This review summarizes the current understanding of OPN in liver diseases. Further understanding of the pathophysiological role of OPN in cellular interactions and molecular mechanisms associated with hepatic inflammation, fibrosis and cancer may contribute to the development of novel strategies for clinical diagnosis, monitoring and therapy of liver diseases.

Meta-analysis of the prognostic and diagnostic significance of serum/plasma osteopontin in hepatocellular carcinoma

GOALS

The aim of this study was to perform a meta-analysis to evaluate the prognostic and diagnostic significance of serum/plasma osteopontin (OPN) in hepatocellular carcinoma (HCC).

BACKGROUND

The prognostic and diagnostic value of serum/plasma OPN) in HCC remain controversial.

STUDY

Eligible studies were identified through a systematic literature search. A meta-analysis of 8 studies (4 for prognosis and 4 for diagnosis, 1399 patients) was performed to estimate the association between serum/plasma-based OPN elevation and overall survival (OS) and disease-free survival (DFS) in HCC patients, and to evaluate the accuracy of plasma OPN and α-fetoprotein (AFP) in the diagnosis of HCC. Subgroup analyses were also performed in the meta-analysis.

RESULTS

We found that serum/plasma-based OPN elevation was significantly associated with poor OS (HR, 1.96; 95% CI, 1.47-2.61; P<0.00001) and DFS (HR, 1.80; 95% CI, 1.43-2.26; P<0.00001) in HCC. The summary estimates for plasma OPN and AFP in diagnosing HCC in the studies included were as follows: sensitivity, 88% (95% CI, 84%-91%) versus 68% (95% CI, 63%-73%); specificity, 87% (95% CI, 83%-90%) versus 97% (95% CI, 94%-99%); diagnostic odds ratio, 62.87 (95% CI, 10.90-362.60) versus 49.09 (95% CI, 11.36-212.10); and area under SROS, 0.91 (95% CI, 0.85-0.97) versus 0.68 (95% CI, 0.45-1.03).

CONCLUSIONS

The current evidence indicates that serum/plasma-based OPN seems to have significant predictive ability for estimating survival in HCC, and plasma OPN has a comparable accuracy to AFP for the diagnosis of HCC, although the diagnostic value of plasma OPN for early or AFP-negative HCC remains to be assessed by further studies.

Significance of plasma osteopontin in diagnosis of hepatitis C virus-related hepatocellular carcinoma

BACKGROUND AND STUDY AIMS

Alfa fetoprotein (AFP) is widely used as a surveillance test for hepatocellular carcinoma (HCC) among patients with liver cirrhosis (LC). However, the clinical use of AFP has been shown to present some important limitations in sensitivity and specificity. Osteopontin (OPN) is a secreted matrix glycoprotein that is emerging as a significant protein in the biology of HCC. The aim of this study was to assess the diagnostic value of plasma OPN compared with that of AFP in the diagnosis of HCC among hepatitis C virus (HCV)-related LC.

PATIENTS AND METHODS

Plasma levels of OPN and AFP were measured in 69 Egyptian patients with HCV-related LC (35 with HCC and 34 without HCC) and 20 healthy controls.

RESULTS

Both median AFP and OPN levels were significantly higher in the HCC group compared to LC and healthy control groups (p<0.001 in each) and in LC compared to the control group (p<0.001). In the HCC group, both OPN and AFP levels were significantly higher in patients with Child-Pugh class C and B compared to class A (p<0.05 in each). There was no correlation between OPN and AFP levels. The OPN level was significantly higher in patients with multiple focal lesions than in those with single lesions (p<0.05) and in patients with portal vein invasion compared to patients without portal vein invasion (p<0.05). Receiver operator characteristic (ROC) curves showed that the area under the curve (AUC) for OPN and AFP was 0.824 and 0.730, respectively.

CONCLUSION

OPN is a promising tumour marker which could be used as a screening test for the diagnosis of HCC in patients with LC and, hence, improves the prognosis and survival rate of these patients. The association of OPN with the multiplicity of focal lesions and portal vein invasion suggests an additional prognostic value.

The hepatitis B virus-associated tumor microenvironment in hepatocellular carcinoma

In contrast to a majority of cancer types, the initiation of hepatocellular carcinoma (HCC) is intimately associated with a chronically diseased liver tissue, with one of the most prevalent etiological factors being hepatitis B virus (HBV). Transformation of the liver in HBV-associated HCC often follows from or accompanies long-term symptoms of chronic hepatitis, inflammation and cirrhosis, and viral load is a strong predictor for both incidence and progression of HCC. Besides aiding in transformation, HBV plays a crucial role in modulating the accumulation and activation of both cellular components of the microenvironment, such as immune cells and fibroblasts, and non-cellular components of the microenvironment, such as cytokines and growth factors, markedly influencing disease progression and prognosis. This review will explore some of these components and mechanisms to demonstrate both underlying themes and the inherent complexity of these interacting systems in the initiation, progression, and metastasis of HBV-positive HCC.

Predictive potential of IL-18 -607 and osteopontin -442 polymorphism in interferon-based therapy of HCV infection in the Pakistani population

The adaptive immune system plays an important role in response to interferon plus ribavirin treatment of hepatitis C virus (HCV) infection. Cytokines play a significant role in the adaptive immune system. The production of cytokines may be regulated by single nucleotide polymorphisms (SNPs). This study was designed to examine the correlation of some important SNPs of cytokines with interferon plus ribavirin treatment of HCV infection in the Pakistani population. We followed 140 chronic HCV-infected patients in our study. All of these patients had completed their planned course of interferon plus ribavirin treatment. We also considered 120 healthy subjects as controls. The detection of interleukin-18 (IL-18) SNPs was performed by tetra-primers amplification-refectory mutation system polymerase chain reaction, while for genotyping of osteopontin (OPN), transforming growth factor beta (TGFβ), and N-acetylgalactosaminyltransferase 8 (GALNT8) SNPs, allele-specific polymerase chain reaction was performed. The distribution of the IL-18 -607AA genotype varied significantly between healthy control and patient groups. Its distribution was significantly high in healthy subjects than HCV patients (p = 0.031), signifying its potential involvement in the natural clearance of HCV infection. The occurrence of the -607AA genotype of IL-18 was also significantly higher in the sustained virological group (SVR) than in the nonresponder (NR) group (p = 0.046), highlighting its protective involvement in the treatment outcome of chronic HCV infection. The frequency of the OPN -442TT genotype was higher in the SVR group than in the NR group (p = 0.034), indicating a significant possible role of this genotype in therapy for HCV infection. No important association was found between TGFβ and GALNT8 genotypes and the natural clearance and treatment response of HCV infection. IL-18 -607AA and OPN -442TT genotypes can be used as positive predictive markers of interferon plus ribavirin treatment of HCV infection in the Pakistani population.

Extracellular matrix and liver disease

SIGNIFICANCE

The extracellular matrix (ECM) is a dynamic microenvironment that undergoes continuous remodeling, particularly during injury and wound healing. Chronic liver injury of many different etiologies such as viral hepatitis, alcohol abuse, drug-induced liver injury, obesity and insulin resistance, metabolic disorders, and autoimmune disease is characterized by excessive deposition of ECM proteins in response to persistent liver damage.

CRITICAL ISSUES

This review describes the main collagenous and noncollagenous components from the ECM that play a significant role in pathological matrix deposition during liver disease. We define how increased myofibroblasts (MF) from different origins are at the forefront of liver fibrosis and how liver cell-specific regulation of the complex scarring process occurs.

RECENT ADVANCES

Particular attention is paid to the role of cytokines, growth factors, reactive oxygen species, and newly identified matricellular proteins in the regulation of fibrillar type I collagen, a field to which our laboratory has significantly contributed over the years. We compile data from recent literature on the potential mechanisms driving fibrosis resolution such as MF' apoptosis, senescence, and reversal to quiescence.

FUTURE DIRECTIONS

We conclude with a brief description of how epigenetics, an evolving field, can regulate the behavior of MF and of how new "omics" tools may advance our understanding of the mechanisms by which the fibrogenic response to liver injury occurs.

Serum anti-osteopontin autoantibody as a novel diagnostic and prognostic biomarker in patients with hepatocellular carcinoma

Osteopontin (OPN) is a secreted phosphorylated and glycosylated protein, which plays an important role in carcinogenesis and metastasis. In hepatocellular carcinoma (HCC), OPN is being investigated either as a therapeutic target gene or as a biomarker for diagnosis. Yet, the role of the anti-OPN autoantibody in HCC remains unclear. In the present study, the level of serum anti-OPN autoantibody in HCC was analyzed by enzyme-linked immunosorbent assay. Immunohistochemistry (IHC) was also performed to analyze protein expression profiles and the prognostic significance of OPN in HCC. In this study, the prevalence and titer of anti-OPN autoantibodies in HCC were significantly higher than these values in normal human serum (NHS) (P=0.001, P=0.000, respectively). When both α-fetoprotein and the autoantibody against OPN were used simultaneously as diagnostic biomarkers, the sensitivity was up to 65%. In IHC, 59 of the 83 (65.6%) HCC specimens expressed OPN with cytoplasmic positive staining. The overall survival (OS) of HCC patients with OPN-positive tumors was 28.81 months compared to 39.37 months for HCC patients with OPN-negative tumors (P<0.01). Furthermore, multivariate analysis showed that OPN overexpression was the strongest independent adverse prognostic factor for OS (P=0.02). Taken together, our data indicate that the anti-OPN autoantibody may be a supplementary serological biomarker for HCC, and is correlated with poor prognosis in HCC patients.

OPN sesame

Osteopontin (OPN) is a growth regulatory protein for hepatocellular carcinoma (HCC) and a potent chemoattractant for macrophages. Zhu and colleagues recently reported significant clinical associations between poor postoperative prognosis and the concurrent detection of tumoral OPN expression and peritumoral macrophage (PTM) infiltration. An in-depth understanding on the complex interaction between tumoral OPN and macrophage-infiltrated microenvironment opens new doors to novel anticancer treatments.

Epimorphin alters the inhibitory effects of SOX9 on Mmp13 in activated hepatic stellate cells

Background and Aims

Liver fibrosis is a major cause of morbidity and mortality. It is characterised by excessive extracellular matrix (ECM) deposition from activated hepatic stellate cells (HSCs). Although potentially reversible, treatment remains limited. Understanding how ECM influences the pathogenesis of the disease may provide insight into novel therapeutic targets for the disease. The extracellular protein Epimorphin (EPIM) has been implicated in tissue repair mechanisms in several tissues, partially, through its ability to manipulate proteases. In this study, we have identified that EPIM modulates the ECM environment produced by activated hepatic stellate cells (HSCs), in part, through down-regulation of pro-fibrotic Sex-determining region Y-box 9 (SOX9).

Methods

Influence of EPIM on ECM was investigated in cultured primary rat HSCs. Activated HSCs were treated with recombinant EPIM or SOX9 siRNA. Core fibrotic factors were evaluated by immunoblotting, qPCR and chromatin immunoprecipitation (ChIP).

Results

During HSC activation EPIM became significantly decreased in contrast to pro-fibrotic markers SOX9, Collagen type 1 (COL1), and α- Smooth muscle actin (α-SMA). Treatment of activated HSCs with recombinant EPIM caused a reduction in α-SMA, SOX9, COL1 and Osteopontin (OPN), while increasing expression of the collagenase matrix metalloproteinase 13 (MMP13). Sox9 abrogation in activated HSCs increased EPIM and MMP13 expression.

Conclusion

These data provide evidence for EPIM and SOX9 functioning by mutual negative feedback to regulate attributes of the quiescent or activated state of HSCs. Further understanding of EPIM's role may lead to opportunities to modulate SOX9 as a therapeutic avenue for liver fibrosis.

Osteopontin: Versatile modulator of liver diseases

Osteopontin (OPN) is a multifunctional protein, involved in pathological conditions including inflammation, immunity, angiogenesis, fibrosis and cancer progression in various tissues. Hepatic inflammation and fibrosis induced by feeding with a diet deficient in methionine and choline (MCD diet) were markedly attenuated in OPN knockout mice when compared with wild-type mice in the model of non-alcoholic steatohepatitis (NASH). Hepatic cholangiocytes, myofibroblastic stellate cells and natural killer T cells were suggested to secret OPN in mice fed an MCD diet. Plasma and hepatic OPN levels were significantly higher in patients with NASH with advanced fibrosis than in those with early fibrosis. Hepatic OPN mRNA level was correlated with hepatic neutrophil infiltration and fibrosis in patients with alcoholic liver diseases. In those with hepatocellular carcinoma (HCC), OPN levels in plasma and HCC were prognostic factors after liver resection or transplantation. Downregulation of OPN inhibited tumor growth and lung metastasis in nude mice implanted with HCC cells. The single nucleotide polymorphism in the promoter region of the OPN gene was shown to be associated with activity of hepatitis in chronic hepatitis C patients, prognosis in patients with HCC, and growth and lung metastasis of HCC xenografts in nude mice. OPN was reported to be a downstream effecter of Hedgehog pathway, which modulates hepatic fibrosis and carcinogenesis. This review focuses on the roles of OPN in hepatic inflammation, fibrosis and cancer progression. Further elucidation of cellular interactions and molecular mechanisms associated with OPN actions may contribute to development of novel strategies for treatment of the liver diseases.

Correlation and prognostic value of osteopontin and Bcl-2 in hepatocellular carcinoma patients after curative resection

Osteopontin (OPN) may facilitate tumorigenesis and metastasis through prevention of tumor cells from apoptosis. Although previous studies have suggested involvement of enhanced Bcl-2 protein family expression, the role of OPN together with Bcl-2 in hepatocellular carcinoma (HCC) remains unknown. In this study, we used western blotting to detect the OPN and Bcl-2 expression levels in cell lines with different OPN backgrounds and HCC tissues, and tumor tissue microarrays to examine OPN and Bcl-2 expression levels in 454 HCC cases. The Kaplan-Meier method and log-rank test were applied to investigate the predictive values of OPN and Bcl-2 in HCC patients. In vitro assays indicated that OPN expression increased concordantly with increasing metastatic potential in MHCC97-H, MHCC97-L, HepG2 and SMMC-7721 cell lines by western blotting, whereas Bcl-2 expression declined. In addition, Bcl-2 was highly upregulated in OPN knockdown MHCC97-H cell lines. Furthermore, in HCC tissues, it was confirmed that OPN levels were also significantly higher in recurrent tumor tissues compared to non-recurrent tissues by western blotting (p<0.001), whereas the contrary occurred in Bcl-2 (p=0.046). Using immunohistochemistry analysis, patients with higher OPN levels had significantly shorter median survival time and recurrence time compared to the lower ones, although the opposite occurred in Bcl-2 levels. Of note, when OPN and Bcl-2 were combined, we found that the co-index of OPN/Bcl-2 was an independent prognostic factor for both overall survival (p<0.001) and time to recurrence (p<0.001). Our findings demonstrate that OPN/Bcl-2 expression is a promising independent predictor of recurrence and survival in HCC. Additionally, Bcl-2 levels may be regulated by OPN in the HCC microenvironment.

Advances in understanding relationship between osteopontin and metastasis and recurrence of hepatocellular carcinoma

Osteopontin (OPN), first found in normal human tissue, is a secreted phosphorylated glycoprotein and one of the most important adhesion factors. Increased expression of OPN has been found in many types of tumors. OPN plays a very important role in the metastasis and recurrence of hepatocellular carcinoma (HCC). As a tumor marker, OPN may also become a new therapeutic target for cancer. This review aims to elucidate the structure and function of OPN, its role in HCC recurrence and metastasis, and the significance of OPN in HCC diagnosis and treatment.

Hepatocellular tumors: immunohistochemical analyses for classification and prognostication

Following the classification of hepatocellular nodules by the International Working Party in 1995 and further elaboration by the International Consensus Group for Hepatocellular Neoplasia in 2009, entities under the spectrum of hepatocellular nodules have been better characterized. Research work hence has been done to answer questions such as distinguishing high-grade dysplastic nodules from early hepatocellular carcinoma (HCC), delineating the tumor cell origin of HCC, identifying its prognostic markers, and subtyping hepatocellular adenomas. As a result, a copious amount of data at immunohistochemical and molecular levels has emerged. A panel of immunohistochemical markers including glypican-3, heat shock protein 70 and glutamine synthetase has been found to be of use in the diagnosis of small, well differentiated hepatocellular tumors and particularly of HCC. The use of liver fatty acid binding protein (L-FABP), β-catenin, glutamine synthetase, serum amyloid protein and C-reactive protein is found to be helpful in the subtyping of hepatocellular adenomas. The role of tissue biomarkers for prognostication in HCC and the use of biomarkers in subclassifying HCC based on tumor cell origin are also discussed.

Postoperative serum osteopontin level is a novel monitor for treatment response and tumor recurrence after resection of hepatitis B-related hepatocellular carcinoma

BACKGROUND

Presurgery serum osteopontin (OPN) level has been demonstrated to correlate to tumor recurrence and survival of hepatocellular carcinoma (HCC) patients. This study investigated the postoperative dynamic changes of serum OPN level and its clinical significance in HCC patients.

METHODS

Presurgery serum OPN levels were measured by enzyme-linked immunosorbent assay in cohort A of 179 HCC patients and were compared with the multiple controls including different kinds of liver diseases and healthy individuals. In cohort B of 110 patients with resectable HCCs, besides preoperative assays, serum OPN was monitored at 1 week, 1, and ≥2 months after operation.

RESULTS

The baseline presurgery serum OPN of HCC patients was significantly higher than that of the patients with the other kinds of liver diseases (p < 0.0001). The prognostic values of presurgery serum OPN level in HCC patients were further confirmed. The postsurgery OPN levels were significantly elevated within 1 week after HCC resection, then decreased at 1 month and reached the nadir later than 2 months after operations. It increased again at the time of tumor recurrence, then declined after the second removal of recurrent HCCs. Moreover, postoperative OPN in α-fetoprotein-negative and -positive HCC patients had the same changing pattern; it only correlated to liver function and C-reactive protein level.

CONCLUSIONS

After a transient fluctuation, serum OPN levels significantly decrease after curative resection of HCCs. Postoperative serum OPN could serve as a surrogate serologic biomarker for monitoring treatment response and tumor recurrence after HCC resection, including α-fetoprotein-negative ones.

Hepatocellualar carcinoma serum markers

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in some areas of the world. In most cases, HCC is diagnosed at a late stage. Therefore, the prognosis of patients with HCC is generally poor. The recommended screening strategy for patients with cirrhosis includes the determination of serum α-fetoprotein (AFP) levels and an abdominal ultrasound every 6 months to detect HCC at an earlier stage. AFP, however, is a marker characterized by poor sensitivity and specificity, and abdominal ultrasound is highly dependent on the operator's experience. In addition to AFP, Lens culinaris agglutinin-reactive AFP (AFP-L3), des-γ-carboxy prothrombin (DCP), glypican-3 (GPC-3), osteopontin (OPN), and several other biomarkers (such as squamous cell carcinoma antigen-immunoglobulin M complexes [SCCA-IgM], alpha-1-fucosidase [AFU], chromogranin A [CgA], human hepatocyte growth factor, insulin-like growth factor) have been proposed as markers for the early detection of HCC. For these markers, we describe the mechanisms of production, and their diagnostic and prognosis roles. None of them is optimal; however, when used together, their sensitivity in detecting HCC is increased. Recent research has shown that some biomarkers have mitogenic and migratory activities in the angiogenesis of HCC and are a factor of tumor growth.

Role of single nucleotide polymorphisms of KIF1B gene in HBV-associated viral hepatitis

BACKGROUND/AIM

Kinesin family member 1B (KIF1B) gene resides in the chromosomal region 1p36.22 and has been reported to have frequent deletions in a variety of human cancers. A recent genome wide association study (GWAS) study conducted on a Chinese population has reported the involvement of a KIF1B genetic variant in Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). This study aims to investigate the significance of KIF1B genetic variations in HBV-associated hepatitis in patients of Saudi Arabian ethnicity.

METHODS

TaqMan genotyping assay was used to investigate the association of three SNPs (rs17401966, rs12734551, and rs3748578) in 584 normal healthy controls and 660 HBV-infected patients. The patients were categorized into inactive carriers (Case I), active carriers (Case II), Cirrhosis (Case III) and Cirrhosis-HCC (Case IV) sub-groups.

RESULTS

Since SNPs rs12734551 and rs3748578 are in strong linkage disequilibrium (LD) with rs17401966, only results for the latter SNP are reported. Therefore, the allele frequency of rs17401966 among HBV-infected patients and healthy controls were comparable and therefore, no significant association was observed (P=0.2811, Odds Ratio (OR) 0.897). A similar analysis was performed among the different sub-groups in order to determine whether KIF1B SNPs were associated with the advancement of the disease. No significant differences were observed in any of the comparisons performed.

CONCLUSION

Polymorphisms at KIF1B gene locus investigated in this study showed no significant association with HBV infection or with HBV-associated diseases such as liver cirrhosis or HCC.

Osteopontin is a novel downstream target of SOX9 with diagnostic implications for progression of liver fibrosis in humans

Osteopontin (OPN) is an important component of the extracellular matrix (ECM), which promotes liver fibrosis and has been described as a biomarker for its severity. Previously, we have demonstrated that Sex-determining region Y-box 9 (SOX9) is ectopically expressed during activation of hepatic stellate cells (HSC) when it is responsible for the production of type 1 collagen, which causes scar formation in liver fibrosis. Here, we demonstrate that SOX9 regulates OPN. During normal development and in the mature liver, SOX9 and OPN are coexpressed in the biliary duct. In rodent and human models of fibrosis, both proteins were increased and colocalized to fibrotic regions in vivo and in culture-activated HSCs. SOX9 bound a conserved upstream region of the OPN gene, and abrogation of Sox9 in HSCs significantly decreased OPN production. Hedgehog (Hh) signaling has previously been shown to regulate OPN expression directly by glioblastoma (GLI) 1. Our data indicate that in models of liver fibrosis, Hh signaling more likely acts through SOX9 to modulate OPN. In contrast to Gli2 and Gli3, Gli1 is sparse in HSCs and is not increased upon activation. Furthermore, reduction of GLI2, but not GLI3, decreased the expression of both SOX9 and OPN, whereas overexpressing SOX9 or constitutively active GLI2 could rescue the antagonistic effects of cyclopamine on OPN expression.

CONCLUSION

These data reinforce SOX9, downstream of Hh signaling, as a core factor mediating the expression of ECM components involved in liver fibrosis. Understanding the role and regulation of SOX9 during liver fibrosis will provide insight into its potential modulation as an antifibrotic therapy or as a means of identifying potential ECM targets, similar to OPN, as biomarkers of fibrosis.

Osteopontin as potential biomarker and therapeutic target in gastric and liver cancers

Gastric cancer and liver cancer are among the most common malignancies and the leading causes of death worldwide, due to late detection and high recurrence rates. Today, these cancers have a heavy socioeconomic burden, for which a full understanding of their pathophysiological features is warranted to search for promising biomarkers and therapeutic targets. Osteopontin (OPN) is overexpressed in most patients with gastric and liver cancers. Over the past decade, emerging evidence has revealed a correlation of OPN level and clinicopathological features and prognosis in gastric and liver cancers, indicating its potential as an independent prognostic indicator in such patients. Functional studies have verified the potential of OPN knockdown as a therapeutic approach in vitro and in vivo. Furthermore, OPN mediates multifaceted roles in the interaction between cancer cells and the tumor microenvironment, in which many details need further exploration. OPN signaling results in various functions, including prevention of apoptosis, modulation of angiogenesis, malfunction of tumor-associated macrophages, degradation of extracellular matrix, activation of phosphoinositide 3-kinase-Akt and nuclear factor-κB pathways, which lead to tumor formation and progression, particularly in gastric and liver cancers. This editorial aims to review recent findings on alteration in OPN expression and its clinicopathological associations with tumor progression, its potential as a therapeutic target, and putative mechanisms in gastric and liver cancers. Better understanding of the implications of OPN in tumorigenesis might facilitate development of therapeutic regimens to benefit patients with these deadly malignancies.

Osteopontin increases hepatocellular carcinoma cell growth in a CD44 dependant manner

AIM: To investigate the role of osteopontin (OPN) and its splice variants in the proliferation of hepatocellular carcinoma (HCC).

METHODS: The expression of OPN variants in HCC cell lines as well as HCC tissue samples and non-tumour tissue was studied using polymerase chain reaction. OPN variant cDNAs were cloned into a mammalian expression vector allowing both transient expression and the production of stable OPN expressing cell lines. OPN expression was studied in these cells using Western blotting, immunofluoresnce and enzyme linked immunosorbent assay. A CD44 blocking antibody and siRNA targeting of CD44 were used to examine the role of this receptor in the OPN stimulated cell growth observed in culture. Huh-7 cells stably expressing either OPN-A, -B or -C were injected subcutaneously into the flanks of nude mice to observe in vivo tumour growth. Expression of OPN mRNA and protein in these tumours was examined using reverse transcription-polymerase chain reaction and immunohistochemistry.

RESULTS: OPN is expressed in HCC in 3 forms, the full length OPN-A and 2 splice variants OPN-B and -C. OPN variant expression was noted in HCC tissue as well as cognate surrounding cirrhotic liver tissue. Expression of these OPN variants in the HCC derived cell line Huh-7 resulted in secretion of OPN into the culture medium. Transfer of OPN conditioned media to naïve Huh-7 and HepG2 cells resulted in significant cell growth suggesting that all OPN variants can modulate cell proliferation in a paracrine manner. Furthermore the OPN mediated increase in cellular proliferation was dependent on CD44 as only CD44 positive cell lines responded to OPN conditioned media while siRNA knockdown of CD44 blocked the proliferative effect. OPN expression also increased the proliferation of Huh-7 cells in a subcutaneous nude mouse tumour model, with Huh-7 cells expressing OPN-A showing the greatest proliferative effect.

CONCLUSION: This study demonstrates that OPN plays a significant role in the proliferation of HCC through interaction with the cell surface receptor CD44. Modulation of this interaction could represent a novel strategy for the control of HCC.

Osteopontin regulates epithelial mesenchymal transition-associated growth of hepatocellular cancer in a mouse xenograft model

OBJECTIVE

To determine the efficacy of osteopontin (OPN) targeting in hepatocellular cancer (HCC). SUMMARY/BACKGROUND: OPN is associated with HCC growth and metastasis and represents a unique therapeutic target.

METHODS

OPN and epithelial-mesenchymal transition (EMT) markers, α-smooth muscle actin (SMA), vimentin, and tenascin-c, were measured in archived human HCC tissues from metastatic (n = 4) and nonmetastatic (n = 4) settings. Additional studies utilized human Sk-Hep-1 (high OPN expression) and Hep3b (low OPN expression) HCC cells. An RNA aptamer (APT) that avidly binds (Kd = 18 nM; t1/2 = 7 hours) and ablates OPN binding was developed. Adhesion, migration/invasion, and EMT markers were determined with APT or a mutant control aptamer (Mu-APT). RFP-Luc-Sk-Hep-1 were implanted into NOD-scid mice livers and followed by using bioluminescence imaging. After verification of tumor growth, at week 3, APT (0.5 mg/kg; n = 4) or Mu-APT (0.5 mg/kg; n = 4) was injected q48h. When mice were killed at week 8, tumor cells were reisolated and assayed for EMT markers.

RESULTS

OPN and EMT markers were significantly increased in the metastatic cohort. APT inhibited Sk-Hep-1 adhesion and migration/invasion by 5- and 4-fold, respectively. APT significantly decreased EMT protein markers, SMA, vimentin, and tenascin-c. In contrast, APT did not alter Hep3B adhesion, or migration/invasion. EMT markers were slightly decreased. In the in vivo model, at weeks 6 to 8, APT inhibited HCC growth by more than 10-fold. SMA, vimentin, and tenascin-c mRNAs were decreased by 60%, 40%, and 49%, respectively, in RFP-positive Sk-Hep-1 recovered by fluorescence-activated cell sorting (P < 0.04 vs Mu-APT for all).

CONCLUSIONS

APT targeting of OPN significantly decreases EMT and tumor growth of HCC.

Identification of osteopontin as a novel marker for early hepatocellular carcinoma

The aim of this study was to identify a biomarker that could improve alpha-fetoprotein (AFP) performance in hepatocellular carcinoma (HCC) surveillance among patients with cirrhosis. We performed proteomic profiling of plasma from patients with cirrhosis or HCC and validated selected candidate HCC biomarkers in two geographically distinct cohorts to include HCC of different etiologies. Mass spectrometry profiling of highly fractionated plasma from 18 cirrhosis and 17 HCC patients identified osteopontin (OPN) as significantly up-regulated in HCC cases, compared to cirrhosis controls. OPN levels were subsequently measured in 312 plasma samples collected from 131 HCC patients, 76 cirrhosis patients, 52 chronic hepatitis C (CHC) and B (CHB) patients, and 53 healthy controls in two independent cohorts. OPN plasma levels were significantly elevated in HCC patients, compared to cirrhosis, CHC, CHB, or healthy controls, in both cohorts. OPN alone or in combination with AFP had significantly better area under the receiver operating characteristic curve, compared to AFP, in comparing cirrhosis and HCC in both cohorts. OPN overall performance remained higher than AFP in comparing cirrhosis and the following HCC groups: HCV-related HCC, HBV-associated HCC, and early HCC. OPN also had a good sensitivity in AFP-negative HCC. In a pilot prospective study including 22 patients who developed HCC during follow-up, OPN was already elevated 1 year before diagnosis.

CONCLUSION

OPN was more sensitive than AFP for the diagnosis of HCC in all studied HCC groups. In addition, OPN performance remained intact in samples collected 1 year before diagnosis.

Osteopontin expression is associated with hepatopathologic changes in Schistosoma japonicum infected mice

AIM: To investigate osteopontin expression and its association with hepatopathologic changes in BALB/C mice infected with Schistosoma japonicum.

METHODS: The schistosomal hepatopathologic mouse model was established by abdominal infection with schistosomal cercaria. Liver samples were obtained from mice sacrificed at 6, 8, 10, 14, and 18 wk after infection. Liver histopathological changes were observed with hematoxylin-eosin and Masson trichrome staining. The expression of osteopontin was determined with immunohistochemistry, reverse transcription-polymerase chain reaction, and Western blotting. The expression of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) were determined by immunohistochemistry. Correlations of osteopontin expression with other variables (α-SMA, TGF-β1, hepatopathologic features including granuloma formation and degree of liver fibrosis) were analyzed.

RESULTS: Typical schistosomal hepatopathologic changes were induced in the animals. Dynamic changes in the expression of osteopontin were observed at week 6. The expression increased, peaked at week 10 (P < 0.01), and then gradually decreased. Positive correlations between osteopontin expression and α-SMA (r = 0.720, P < 0.01), TGF-β1 (r = 0.905, P < 0.01), granuloma formation (r = 0.875, P < 0.01), and degree of liver fibrosis (r = 0.858, P < 0.01) were also observed.

CONCLUSION: Osteopontin may play an important role in schistosomal hepatopathology and may promote granuloma formation and liver fibrosis through an unexplored mechanism.

Prognostic significance of osteopontin in hepatocellular carcinoma: a meta-analysis

Osteopontin (OPN) has been implicated in tumor development and progression for several years. However, the prognostic value of OPN overexpression in patients with hepatocellular carcinoma (HCC) remains controversial. We performed a meta-analysis to assess the relationship between OPN overexpression and clinical outcome of HCC. A meta-analysis of seven studies (1,158 patients) was carried out to evaluate the association between OPN and overall survival (OS) and disease-free survival (DFS) in HCC patients. The correlation between OPN and tumor vascular invasion or other invasion-related parameters was also assessed. Data were synthesized with random effect model of DerSimonian and Laird, hazard ratio (HR) or odds ratio (OR) with its 95% confidence interval (CI) was used as the effect size estimate. Our analysis results indicated that high OPN expression predicted poor OS (HR: 1.37, 95% CI: 1.21-1.55) and DFS (HR: 1.62, 95% CI: 1.24-2.11) of HCC. OPN overexpression tended to be associated with the presence of tumor vascular invasion (OR: 1.93, 95% CI: 0.97-3.84) and advanced tumor grade (OR: 1.74, 95% CI: 0.95-3.18). By this study, we conclude that OPN overexpression indicates a poor prognosis for patients with HCC, it may also have predictive potential for HCC invasion and metastasis.

Osteopontin: an important molecule in liver diseases

Osteopontin (OPN) is a multi-functional glycoprotein that has been implicated in a number of physiological and pathological events in vivo. Recent studies have shown that abnormal changes in OPN expression occur in many liver diseases and animal models of liver diseases and may play an important role in the pathogenesis of these diseases. Elucidation of mechanisms underlying the role of OPN in the pathogenesis of different liver diseases will help identify new therapeutic targets and develop new drugs for these diseases.

Specific expression of osteopontin and S100A6 in hepatocellular carcinoma

BACKGROUND

Our aim was to identify differential expression of genes in hepatocellular carcinoma (HCC) with the ultimate goal of discovering novel diagnostic and therapeutic targets.

METHODS

We examined differences in gene expression between HCC and noncancerous liver tissue using a cDNA array with probes for 15,843 genes/clones. Two genes, osteopontin (OPN) and S100A6, were found to be >10-fold differentially expressed, and were selected for further immunohistochemical staining in 51 HCC and 10 nonmalignant liver specimens. The relation between OPN and S100A6 alterations and various clinicopathologic parameters was also evaluated.

RESULTS

We found a total of 219 genes that were differentially expressed >3-fold. Of these, 109 were upregulated and 110 downregulated. Within this group, 123 genes, including 59 upregulated and 64 downregulated, had been identified previously. These known genes were mainly involved in cell migration, cytoskeleton dynamics, the signaling pathway and cell cycle, and metabolism. OPN expression and S100A6 expression were seen in 26 of 51 (51.0 %) and 16 of 51 (31.4 %) HCC samples, respectively. More importantly, proteins coded by these genes were not found in any noncancerous liver specimen by immunohistochemical analysis. Expression of these genes correlated with poor differentiation (OPN: P = .013; S100A6: P = .008).

CONCLUSION

OPN, a secreted phosphoprotein that has been increasingly implicated in the progression and metastasis of cancer, and S100A6, a member of the S100 protein family that can perform cell proliferation, differentiation, migration, and cytoskeletal dynamics, may be promising diagnostic markers and therapeutic targets for HCC. In addition, the results encourage future studies involving the roles of these proteins in the development and progression of this cancer.

Osteopontin, a single marker for predicting the prognosis of patients with tumor-node-metastasis stage I hepatocellular carcinoma after surgical resection

BACKGROUND AND AIM

Osteopontin (OPN) has been linked to clinical outcomes in several solid tumors. However, it has not been fully evaluated whether OPN could be used as a single marker for the prognosis of patients with hepatocellular carcinoma (HCC), particularly in patients of the tumor-node-metastasis (TNM) stage I.

METHODS

A total of 151 patients with HCC who underwent surgical resection were enrolled, including 112 patients of the TNM stage I. OPN expression was evaluated using immunohistochemistry in the tissue microarrays derived from these patients. Immunoreactivity was classified according to the percentage and intensity of staining: negative (-), weak (+) and strong (++). The impact of OPN expression on survival of patients was analyzed.

RESULTS

In total, 65.6% (99 of 151) of HCC tissues expressed OPN. Overall survival in patients of OPN (-) group was significantly higher than those of OPN (+) or OPN (++) group (P = 0.049 and P = 0.001). Interestingly, in patients of the TNM stage I, OPN expression was correlated with the early recurrence after surgical resection (P = 0.001). Multivariate analysis showed that OPN expression was an independent prognostic factor for overall survival and disease-free survival in patients with the TNM stage I HCC (hazard ratio, 2.272, P = 0.014 and 1.982, P = 0.037).

CONCLUSIONS

These results suggest that OPN is commonly expressed in HCC and is a useful marker for predicting the prognosis of patients with the TNM stage I HCC, contributing to determining which individual patient needs adjuvant therapy to prevent the early recurrence after surgical resection.

Biomarkers for prediction of metastasis and recurrence of hepatocellular carcinoma

The metastasis of hepatocellular carcinoma (HCC) has long been recognized as a multi-step process that involves multiple factors. Instead of diagnostic models based on single-molecule detection, the combination of multiple molecules will be the trend for early tumor diagnosis or prediction of tumor metastasis and recurrence. Many differentially expressed metastasis-associated genes and proteins have been reported in HCC. This article gives an overview of protein biomarkers for prediction of HCC metastasis and recurrence.

A mutant of hepatitis B virus X protein (HBx Delta 127) enhances hepatoma cell migration via osteopontin involving 5-lipoxygenase

AIM

To explore a novel function of a mutant of the hepatitis B virus X protein (HBx Delta 127) in the promotion of hepatoma cell migration.

METHODS

The effect of HBx Delta 127 and wild type HBx on the migration ability of hepatoblastoma HepG2 cells were examined using wound healing assays in stable transfection systems. The full-length osteopontin(OPN) promoter sequence was cloned into the pGL3-Basic plasmid. The promoter activities of OPN in stably HBx Delta 127-transfected hepatoblastoma HepG2 (HepG2-X Delta 127) and hepatocellular carcinoma H7402 (H7402-X Delta 127) cells were determined using luciferase reporter gene assays. The mRNA expression levels of OPN were detected by RT-PCR. And the effect of MK886, a specific inhibitor of 5-lipoxygenase (5-LOX), on OPN promoter activity and mRNA expression in HepG2-X Delta 127 and H7402-X Delta 127 cells were examined using luciferase reporter gene assays and RT-PCR, respectively. Finally, the migration ability of HepG2-X Delta 127 was observed after treatment with siRNA targeting OPN mRNA and HBx mRNA using wound healing assays.

RESULTS

HepG2-X Delta 127 cells exhibited a greater capacity for wound repair compared to HepG2-X cells. The promoter activity and mRNA expression levels of OPN were also increased in HepG2-X Delta 127 and H7402-X Delta 127 cells. Moreover, MK886 abolished the HBx Delta 127-mediated upregulation of OPN. Wound healing assays demonstrated that the migration ability of HepG2-X Delta 127 cells can be suppressed by treatment with siRNA targeting OPN mRNA and siRNA targeting HBx mRNA.

CONCLUSION

HBx Delta 127 strongly promotes hepatoma cell migration via activation of OPN involving 5-LOX.

Plasma osteopontin concentration correlates with the severity of hepatic fibrosis and inflammation in HCV-infected subjects

BACKGROUND

The association between OPN level and the histological severity of hepatic fibrosis and inflammation in hepatitis C virus (HCV) induced liver fibrosis remains unknown.

METHODS

120 chronic HCV-infected subjects and 75 controls were enrolled in this study. Assessment of liver histology was performed based on liver biopsy. Plasma OPN levels were determined.

RESULTS

Significant differences were noted in the mean plasma OPN levels between subjects with extensive fibrosis and those with mild fibrosis (4.29+/-1.01 ng/ml vs. 2.15+/-0.63 ng/ml, respectively; p<0.001). Similarly, the subjects with higher histological activity index (HAI) score had elevated OPN levels than those with mild HAI score (4.41+/-1.11 ng/ml vs. 2.25+/-0.94 ng/ml, respectively; p<0.001). The correlation between the plasma OPN levels and the severity of liver fibrosis degree and HAI score were noted (r=0.945, and r=0.788, respectively both p<0.001). Logistic regression analysis showed that serum OPN was an independent risk factor contributing to extensive liver fibrosis and inflammation (p=0.0018 and p<0.001, respectively) in patients with HCV subjects.

CONCLUSION

The plasma OPN level is correlated with the severity of liver fibrosis and inflammation, suggesting OPN could be used as a biomarker to evaluate the severity of liver damages in HCV subjects.

Prognostic value of serum osteopontin in hepatocellular carcinoma patients treated with transarterial chemoembolization

BACKGROUND/AIMS

Osteopontin (OPN) is overexpressed in hepatocellular carcinoma (HCC) with postoperative recurrence or extrahepatic metastasis. However, its prognostic value in patients treated with transarterial chemoembolization (TACE) is unclear. We investigated the utility of serum OPN levels and changes therein as prognostic markers in HCC patients who have received TACE.

METHODS

Forty-six patients with HCC were enrolled. Serum OPN levels were measured before and 4 weeks after TACE. Serum biochemistry and computed tomography (CT) scans were analyzed. We evaluated baseline serum OPN levels and subsequent changes therein in relation to tumor responses and cumulative survival rates following TACE. A decreasing pattern was defined as a decrease after TACE of more than 10% relative to baseline levels. A "responder" was defined as a patient who exhibited a tumor necrosis rate of higher than 50% on the follow-up CT scan.

RESULTS

Higher initial serum OPN levels were associated with a large tumor, portal vein invasion, and an advanced tumor stage. Patients who had lower initial serum OPN levels and those who exhibited decreasing patterns after TACE tended to have more favorable tumor responses (P=0.043 and 0.055, respectively) and exhibited better cumulative survival rates (P=0.036 and 0.030, respectively). However, the initial serum OPN level and subsequent changes in serum OPN levels were not independent predictors for survival on multivariate analysis.

CONCLUSIONS

Serum OPN levels were significantly higher in patients with advanced HCC. In addition, HCC patients with low pretreatment serum OPN levels and those for whom serum OPN declined following TACE exhibited better tumor responses and survived for longer.

p53-induced RING-H2 protein, a novel marker for poor survival in hepatocellular carcinoma after hepatic resection

BACKGROUND

Currently, the role of p53-induced RING-H2 protein (PIRH2) in the development of hepatocellular carcinoma (HCC) remains unknown. The objective of this retrospective study was to investigate the expression of PIRH2 and its relation to prognosis in patients with HCC after hepatic resection.

METHODS

Reverse transcriptase-polymerase chain reaction (RT-PCR), quantitative real-time RT-PCR, and Western blot analyses were used to detect expression levels of PIRH2 in 30 samples of HCC tissue and paracarcinomatous liver tissue (PCLT) and in 5 samples of normal liver tissue (NL). In addition, immunohistochemical analysis was performed on 122 HCC specimens and follow-up information data from those patients were reviewed.

RESULTS

Both messenger RNA and protein expression levels of PIRH2 were elevated significantly in HCC tissues compared with PCLT and NL tissues. The increased PIRH2 expression was correlated with vein invasion, Edmondson-Steiner grade, TNM stage, and multiple tumor nodes (P<.05). It is noteworthy that the patients with HCC who had high PIRH2 expression had shorter overall survival and disease-free survival than the patients who had low PIRH2 expression (median survival, 280 days vs 372 days; P = .0002; median disease-free survival, 220 days vs 310 days; P = .0016). Multivariate Cox regression analysis revealed that high PIRH2 expression was an independent prognostic factor for patients with HCC (relative risk, 1.792; P = .009).

CONCLUSIONS

The current data revealed that increased expression of PIRH2 was correlated with poor survival in patients with HCC, indicating that PIRH2 is a novel prognostic marker for HCC.

Proteomic analysis of differentially expressed proteins in hepatitis B virus-related hepatocellular carcinoma tissues

BACKGROUND

Hepatocellular carcinoma (HCC), a major cause of cancer death in China, is preceded by chronic hepatitis and liver cirrhosis (LC). Although hepatitis B virus (HBV) has been regarded as a clear etiology of human hepatocarcinogenesis, the mechanism is still needs to be further clarified. In this study, we used a proteomic approach to identify the differential expression protein profiles between HCC and the adjacent non-tumorous liver tissues.

METHODS

Eighteen cases of HBV-related HCC including 12 cases of LC-developed HCC and 6 cases of chronic hepatitis B (CHB)-developed HCC were analyzed by two-dimensional electrophoresis (2-DE) combined with matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), and the results were compared to those of paired adjacent non-tumorous liver tissues.

RESULTS

A total of 17 differentially expressed proteins with diverse biological functions were identified. Among these, 10 proteins were up-regulated, whereas the other 7 proteins were down-regulated in cancerous tissues. Two proteins, c-Jun N-terminal kinase 2 and ADP/ATP carrier protein were found to be up-regulated only in CHB-developed HCC tissues. Insulin-like growth factor binding protein 2 and Rho-GTPase-activating protein 4 were down-regulated in LC-developed and CHB-developed HCC tissues, respectively. Although 11 out of these 17 proteins have been already described by previous studies, or are already known to be involved in hepatocarcinogenesis, this study revealed 6 new proteins differentially expressed in HBV-related HCC.

CONCLUSION

These findings elucidate that there are common features between CHB-developed HCC and LC-developed HCC. The identified proteins are valuable for studying the hepatocarcinogenesis, and may be potential diagnostic markers or therapeutic targets for HBV-related HCC.

Potent cell growth inhibitory effects in hepatitis B virus X protein positive hepatocellular carcinoma cells by the selective cyclooxygenase-2 inhibitor celecoxib

Hepatitis B virus (HBV) X protein (HBx) and cyclooxygenase-2 (COX-2) are all playing roles in hepatocellular carcinoma (HCC), but the reversing effects of COX-2 inhibitors on the neoplastic features caused by HBx protein is still unclear. To further evaluate the therapeutic potential of celecoxib on HBx mediated transformation, HCC cells transfected with HBx gene were treated with COX-2 selective inhibitor, celecoxib. The amount the main metabolite of COX-2, prostaglandin E2 (PGE2), was determined by using high sensitivity ELISA. Electron microscope and flow cytometry was used to analyze cell apoptosis and cell cycle distribution. RT-PCR and Western blot were used to identify the molecules involved in celecoxib induced cell apoptosis. The results showed that celecoxib inhibited cell growth more significantly and also induced more cell apoptosis in HBx over-expression cells than in control cells. Celecoxib could selectively inhibited COX-2 expression and PGE2 production. Celecoxib also inhibited p(473Ser)Akt, raf and p53 expression, and induced apoptosis by release of cytochrome c and activation of caspase 9, 3, and 6, which were more remarkably in HBx positive cells than in control cells. These results suggest that celecoxib had potent cell growth inhibitory effects on HBx positive HCC cells mainly through inducing more cell apoptosis, and these findings provide a new insight into the anticancer effects of celecoxib against HBx related HCC.

The expression of hypoxia-inducible factor-1alpha in hepatitis B virus-related hepatocellular carcinoma: correlation with patients' prognosis and hepatitis B virus X protein

Hypoxia inducible factor-1alpha (HIF-1alpha) was well correlated with carcinogenesis and tumor progression in many kinds of cancer. In this study, high expression of HIF-1alpha was found in 37 of the 72 (51.39%) tumor specimens, and significantly correlated with venous invasion and lymphonode invasion. Patients with high expression of HIF-1alpha had a significantly shorter overall survival rate and disease-free survival rate than those with low expression. Multivariate analysis showed high HIF-1alpha expression was a borderline independent factor of overall survival. HIF-1alpha expression was also found to be significantly correlated with the expression of hepatitis B virus X protein (HBx), and over-expressed HBx upregulated HIF-1alpha protein expression in vitro. These results suggested that HIF-1alpha, which was partially regulated by HBx, might be a prognostic marker of HBV-related HCC patients.

Lentiviral-mediated miRNA against osteopontin suppresses tumor growth and metastasis of human hepatocellular carcinoma

In our previous study, osteopontin (OPN) was identified as one of the leading genes that promote the metastasis of hepatocellular carcinoma (HCC). However, the mechanism by which OPN promotes metastasis of HCC is not understood. In this study, RNA interference mediated by viral vectors-which could induce a long-lasting down-regulation in gene expression-was applied to analyze the role of OPN in metastasis of HCC. Three lentiviral vectors encoding microRNA against OPN, Lenti.OPNi-1, Lenti.OPNi-2, and Lenti.OPNi-3, were constructed and found to down-regulate the OPN level by 62%, 78%, and 95%, respectively, in HCCLM3 cells which had an overexpression of OPN and a higher metastatic potential. Consequently, both Lenti.OPNi-2 and Lenti.OPNi-3 induced a significant decrease in matrix metalloproteinase (MMP)-2 and urokinase plasminogen activator expression, and led to an obvious inhibition of both in vitro invasion and in vivo lung metastasis of HCCLM3 cells (P < 0.001). Moreover, Lenti.OPNi-3, rather than Lenti.OPNi-2, could also suppress in vitro proliferation and in vivo tumor growth of HCCLM3. Smaller detectable tumors were found in only 50% of mice after implantation of Lenti.OPNi-3-transfected HCCLM3 cells (341 +/- 502.6 mm(3) versus >3500 mm(3) in controls; P < 0.001). Lenti.OPNi-3, not Lenti.OPNi-2, significantly suppressed the MEK/ERK1/2 pathway in HCCLM3 cells. Recombinant OPN was found to induce translocation of p65 into the nucleus of HCC cells and activation of MMP-2 and MEK/ERK/1/2, which were suppressed by the nuclear factor kappaB (NF-kappaB) inhibitor pyrrolidine dithiocarbamate.

CONCLUSION

OPN plays an important role in metastasis as well as tumor growth of HCC, in which different minimum threshold levels of OPN are needed. These effects may occur through activation of the mitogen-activated protein kinase and NF-kappaB pathways, and MMP-2. OPN could be a hopeful target for the control of HCC.