The heparan sulfate proteoglycan GPC3 is a potential lung tumor suppressor

Biological and clinical significance of the glypican-3 gene in human lung adenocarcinoma: An in silico analysis

Glypican-3 (GPC3), a membrane-bound heparan sulfate proteoglycan, has long been found to be dysregulated in human lung adenocarcinomas (LUADs). Nevertheless, the function, mutational profile, epigenetic regulation, co-expression profile, and clinicopathological significance of the GPC3 gene in LUAD progression are not well understood. In this study, we analyzed cancer microarray datasets from publicly available databases using bioinformatics tools to elucidate the above parameters. We observed significant downregulation of GPC3 in LUAD tissues compared to their normal counterparts, and this downregulation was associated with shorter overall survival (OS) and relapse-free survival (RFS). Nevertheless, no significant differences in the methylation pattern of GPC3 were observed between LUAD and normal tissues, although lower promoter methylation was observed in male patients. GPC3 expression was also found to correlate significantly with infiltration of B cells, CD8+, CD4+, macrophages, neutrophils, and dendritic cells in LUAD. In addition, a total of 11 missense mutations were identified in LUAD patients, and ~1.4% to 2.2% of LUAD patients had copy number amplifications in GPC3. Seventeen genes, mainly involved in dopamine receptor-mediated signaling pathways, were frequently co-expressed with GPC3. We also found 11 TFs and 7 miRNAs interacting with GPC3 and contributing to disease progression. Finally, we identified 3 potential inhibitors of GPC3 in human LUAD, namely heparitin, gemcitabine and arbutin. In conclusion, GPC3 may play an important role in the development of LUAD and could serve as a promising biomarker in LUAD.

Ηeparan sulphate in infectious and non-infectious exacerbations of COPD

BACKGROUND AND OBJECTIVE

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are associated with worsening health outcomes and effective treatment of each episode is essential. In this study, we aimed to investigate if plasma levels of heparan sulphate (HS) are associated with the aetiology of AECOPD.

METHODS

COPD patients (N = 1189), GOLD grade II-IV, from a discovery cohort (N = 638) and from a validation cohort (N = 551), were included in the study. HS and heparanase (HSPE-1) were measured longitudinally in plasma at stable state, at AECOPD and at 4 weeks follow-up.

RESULTS

Plasma HS was higher in patients with COPD as compared with non-COPD controls and was significantly increased at AECOPD as compared to stable state (p < 0.001) in the discovery and in the validation cohorts. Four distinct exacerbation groups were classified based on aetiology (no-infection/bacterial-infection/viral-infection/bacterial and viral coinfection) in the validation cohort. The fold-increase of HS from stable state to AECOPD was associated with the aetiology of exacerbation and was higher in cases with bacterial and viral coinfections. HSPE-1 was also significantly increased at AECOPD, however, there was no association of HSPE-1 levels with the aetiology of these events. The probability of having an infection at AECOPD was raised as HS levels increased from stable state to AECOPD. This probability was higher for bacterial infections than viral infections.

CONCLUSION

The results of our study indicate that circulating levels of HS are increased at AECOPD and this increase may be associated with the aetiology of these events.

A Novel Inflammatory-Related Gene Signature Based Model for Risk Stratification and Prognosis Prediction in Lung Adenocarcinoma

Inflammation is an important hallmark of cancer and plays a role in both neogenesis and tumor development. Despite this, inflammatory-related genes (IRGs) remain to be poorly studied in lung adenocarcinoma (LUAD). We aim to explore the prognostic value of IRGs for LUAD and construct an IRG-based prognosis signature. The transcriptomic profiles and clinicopathological information of patients with LUAD were obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). Least absolute shrinkage and selection operator (LASSO) analysis and multivariate Cox regression were applied in the TCGA set to generate an IRG risk signature. LUAD cases with from the GSE31210 and GSE30219 datasets were used to validate the predictive ability of the signature. Analysis of the TCGA cohort revealed a five-IRG risk signature consisting of EREG, GPC3, IL7R, LAMP3, and NMUR1. This signature was used to divide patients into two risk groups with different survival rates. Multivariate Cox regression analysis verified that the risk score from the five-IRG signature negatively correlated with patient outcome. A nomogram was developed using the IRG risk signature and stage, with C-index values of 0.687 (95% CI: 0.644-0.730) in the TCGA training cohort, 0.678 (95% CI: 0.586-0.771) in GSE30219 cohort, and 0.656 (95% CI: 0.571-0.740) in GSE30219 cohort. Calibration curves were consistent between the actual and the predicted overall survival. The immune infiltration analysis in the TCGA training cohort and two GEO validation cohorts showed a distinctly differentiated immune cell infiltration landscape between the two risk groups. The IRG risk signature for LUAD can be used to predict patient prognosis and guide individual treatment. This risk signature is also a potential biomarker of immunotherapy.

Extracellular Matrix: Surface Proteoglycans

Cell surface proteoglycans, such as syndecans and glypicans, regulate molecular interactions that mediate cell adhesion, migration, proliferation, and differentiation. Through these activities, surface proteoglycans modulate critical biological processes of development, inflammation, infection, tissue repair, and cancer metastasis. Proteoglycans are unique glycoproteins comprised of one or several glycosaminoglycans attached covalently to core proteins. Glycosaminoglycans mediate the majority of ligand-binding functions of proteoglycans. Accumulating evidence indicates that surface proteoglycans regulate the onset, progression, and outcome of lung diseases, including lung injury, infection, fibrosis, and cancer. This article will review key features of surface proteoglycan biology in lung health and disease.

Identification of Inflammatory Response-Related Gene Signature Associated With Immune Status and Prognosis of Lung Adenocarcinoma

Background: Lung adenocarcinoma (LUAD) is an exceedingly diverse disease, making prognostication difficult. Inflammatory responses in the tumor or the tumor microenvironment can alter prognosis in the process of the ongoing cross-talk between the host and the tumor. Nonetheless, Inflammatory response-related genes’ prognostic significance in LUAD, on the other hand, has yet to be determined.

Materials and Methods: The clinical data as well as the mRNA expression patterns of LUAD patients were obtained from a public dataset for this investigation. In the TCGA group, a multigene prognostic signature was built utilizing LASSO Cox analysis. Validation was executed on LUAD patients from the GEO cohort. The overall survival (OS) of low- and high-risk cohorts was compared utilizing the Kaplan-Meier analysis. The assessment of independent predictors of OS was carried out utilizing multivariate and univariate Cox analyses. The immune-associated pathway activity and immune cell infiltration score were computed utilizing single-sample gene set enrichment analysis. GO keywords and KEGG pathways were explored utilizing gene set enrichment analysis.

Results: LASSO Cox regression analysis was employed to create an inflammatory response-related gene signature model. The high-risk cohort patients exhibited a considerably shorter OS as opposed to those in the low-risk cohort. The prognostic gene signature’s predictive ability was demonstrated using receiver operating characteristic curve analysis. The risk score was found to be an independent predictor of OS using multivariate Cox analysis. The functional analysis illustrated that the immune status and cancer-related pathways for the two-risk cohorts were clearly different. The tumor stage and kind of immune infiltrate were found to be substantially linked with the risk score. Furthermore, the cancer cells’ susceptibility to anti-tumor medication was substantially associated with the prognostic genes expression levels.

Conclusion: In LUAD, a new signature made up of 8 inflammatory response-related genes may be utilized to forecast prognosis and influence immunological state. Inhibition of these genes could also be used as a treatment option.

Does Loss of Immunohistochemical Expression of Glypican 3 in Oral Squamous Cell Carcinoma Play a Role in the Wnt/β-catenin Signaling Pathway?

Glypican 3 (GPC3) is a cell membrane protein and plays a dual role, as a tumor suppressor and oncogene, depending on its structure. It is known to regulate the Wnt/β-catenin signaling pathway and affect cell growth and proliferation. β-catenin plays a major oncogenic role in progression of oral squamous cell carcinoma (OSCC); thus, this study aimed to explore the relationship between β-catenin and GPC3 in OSCC. Immunoexpression of GPC3 and β-catenin was evaluated semiquantitatively in tumor tissue (n=80) and normal oral mucosa tissue (n=20). For GPC3, the percentage of stained cells and the staining intensity were assessed. For β-catenin, the percentage of stained cells, localization, and intensity of staining were assessed at the tumor-invasive front. The Pearson correlation was used to determine the correlation between the GPC3 and β-catenin immunoreactivity. Significantly decreased expression of GPC3 (P=0.008) and a highly significant difference in the case of localization of β-catenin (P=0.0001) were observed in OSCC when compared with normal oral mucosa. Cytoplasmic expression with a shift of β-catenin expression to the nucleus was seen in OSCC in comparison with primarily membranous and membranous and cytoplasmic staining in normal mucosa. A significant difference was observed with respect to localization of stain, with β-catenin staining moving to the nuclear compartment with an increase in the tumor grade (P=0.011). No correlation was observed between β-catenin and GPC3 expression in OSCC cases. It is concluded that loss of expression of GPC3 in OSCC compared with normal oral mucosa indicates that it plays the role of a tumor suppressor gene in OSCC and its expression is therefore silenced in OSCC.

Screening of MicroRNA Related to Irradiation Response and the Regulation Mechanism of miRNA-96-5p in Rectal Cancer Cells

Neoadjuvant chemoradiotherapy has been widely used in the treatment of locally advanced rectal cancer due to the excellent advantages of irradiation in cancer therapy. Unfortunately, not every patient can benefit from this treatment, therefore, it is of great significance to explore biomarkers that can predict irradiation sensitivity. In this study, we screened microRNAs (miRNAs) which were positively correlated with irradiation resistance and found that miRNA-552 and miRNA-183 families were positively correlated with the irradiation resistance of rectal cancer, and found that high expression of miRNA-96-5p enhanced the irradiation resistance of rectal cancer cells through direct regulation of the GPC3 gene and abnormal activation of the canonical Wnt signal transduction pathway. Based on the radioreactivity results of patient-derived xenograft models, this is the first screening report for radio-resistant biomarkers in rectal cancer. Our results suggest that miRNA-96-5p expression is an important factor affecting the radiation response of colorectal cancer cells.

GPC3 affects the prognosis of lung adenocarcinoma and lung squamous cell carcinoma

Background

Glypican 3 (GPC3) is a heparin sulphate proteoglycan whose expression is associated with several malignancies. However, its expression in non-small-cell lung carcinoma (NSCLC) is limited and ambiguous. This study aimed to comprehensively evaluate the expression of GPC3 in NSCLC and develop a risk-score model for predicting the prognosis of NSCLC.

Methods

The gene expression profiles of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) were downloaded from the UCSC Xena database. Using the limma package, the differentially expressed genes (DEGs) between different comparison groups were analysed and the differential expression of GPC3 was calculated. A functional enrichment analysis was conducted for GPC3-associated genes using the DAVID tool. For the GPC3-associated genes shared by the four comparison groups, a protein–protein interaction network was built using the Cytoscape software. After conducting a survival analysis and a Cox regression analysis, the genes found to be significantly correlated with prognosis were selected to construct a risk-score model. Besides, the gene and protein levels of GPC3 were examined by quantitative reverse transcriptase-PCR (qRT-PCR) and immunohistochemistry (IHC) in LUSC tissues and paracancer tissues.

Results

The differential expression of GPC3 was significant (adjusted P < 0.05) in the NSCLC vs. normal, LUAD vs. normal, LUSC versus normal, and LUAD versus. LUSC comparison groups. GPC3 directly interacted with SERPINA1, MFI2, and FOXM1. Moreover, GPC3 expression was significantly correlated with pathologic N, pathologic T, gender, and tumour stage in LUAD samples. Finally, the risk-score model (involving MFI2, FOXM1, and GPC3) for LUAD and that (involving SERPINA1 and FOXM1) for LUSC were established separately. The qRT-PCR result showed that GPC3 expression was much higher in the LUSC tissues than that in the normal group. The IHC results further showed that GPC3 is highly expressed in LUSC tissues, but low in paracancer tissues.

Conclusion

The three-gene risk-score model for LUAD and the two-gene risk-score model for LUSC might be valuable in improving the prognosis of these carcinomas.

Recombinant immunotoxin targeting GPC3 is cytotoxic to H446 small cell lung cancer cells

Glypican-3 (GPC3) is a cell membrane glycoprotein that regulates cell growth and proliferation. Aberrant expression or distribution of GPC3 underlies developmental abnormalities and the development of solid tumours. The strongest evidence for the participation of GPC3 in carcinogenesis stems from studies on hepatocellular carcinoma and lung squamous cell carcinoma. To the best of our knowledge, the role of the GPC3 protein and its potential therapeutic application have never been studied in small cell lung carcinoma (SCLC), despite the known involvement of associated pathways and the high mortality caused by this disease. Therefore, the aim of the present study was to examine GPC3 targeting for SCLC immunotherapy. An immunotoxin carrying an anti-GPC3 antibody (hGC33) and Pseudomonas aeruginosa exotoxin A 38 (PE38) was generated. This hGC33-PE38 protein was overexpressed in E. coli and purified. ADP-ribosylation activity was tested in vitro against eukaryotic translation elongation factor 2. Cell internalisation ability was confirmed by confocal microscopy. Cytotoxicity was analysed by treating liver cancer (HepG2, SNU-398 and SNU-449) and lung cancer (NCI-H510A, NCI-H446, A549 and SK-MES1) cell lines with hGC33-PE38 and estimating viable cells number. A BrdU assay was employed to verify anti-proliferative activity of hGC33-PE38 on treated cells. Fluorescence-activated cell sorting was used for the detection of cell membrane-bound GPC3. The hGC33-PE38 immunotoxin displayed enzymatic activity comparable to native PE38. The protein was efficiently internalised by GPC3-positive cells. Moreover, hGC33-PE38 was cytotoxic to HepG2 cells but had no effect on known GPC3-negative cell lines. The H446 cells were sensitive to hGC33-PE38 (IC₅₀, 70.6±4.6 ng/ml), whereas H510A cells were resistant. Cell surface-bound GPC3 was abundant on the membranes of H446 cells, but absent on H510A. Altogether, the present findings suggested that GPC3 could be considered as a potential therapeutic target for SCLC immunotherapy.

GPI-AP: Unraveling a New Class of Malignancy Mediators and Potential Immunotherapy Targets

With millions of cases diagnosed annually and high economic burden to cover expensive costs, cancer is one of the most difficult diseases to treat due to late diagnosis and severe adverse effects from conventional therapy. This creates an urgent need to find new targets for early diagnosis and therapy. Progress in research revealed the key steps of carcinogenesis. They are called cancer hallmarks. Zooming in, cancer hallmarks are characterized by ligands binding to their cognate receptor and so triggering signaling cascade within cell to make response for stimulus. Accordingly, understanding membrane topology is vital. In this review, we shall discuss one type of transmembrane proteins: Glycosylphosphatidylinositol-Anchored Proteins (GPI-APs), with specific emphasis on those involved in tumor cells by evading immune surveillance and future applications for diagnosis and immune targeted therapy.

Glypican-3: A molecular marker for the detection and treatment of hepatocellular carcinoma☆

Hepatocellular carcinoma (HCC) is a malignant tumor with a fairly poor prognosis (5-year survival of less than 50%). Using sorafenib, the only food and drug administration (FDA)-approved drug, HCC cannot be effectively treated; it can only be controlled at most for a couple of months. There is a great need to develop efficacious treatment against this debilitating disease. Glypican-3 (GPC3), a member of the glypican family that attaches to the cell surface by a glycosylphosphatidylinositol anchor, is overexpressed in HCC cases and is elevated in the serum of a large proportion of patients with HCC. GPC3 expression contributes to HCC growth and metastasis. Furthermore, several different types of antibodies targeting GPC3 have been developed. The aim of this review is to summarize the current literatures on the GPC3 expression in human HCC, molecular mechanisms of GPC3 regulation and antibodies targeting GPC3.

The Role of Glypicans in Cancer Progression and Therapy

Glypicans are a family of heparan sulfate proteoglycans that are attached to the cell membrane via a glycosylphosphatidylinositol anchor. Glypicans interact with multiple ligands, including morphogens, growth factors, chemokines, ligands, receptors, and components of the extracellular matrix through their heparan sulfate chains and core protein. Therefore, glypicans can function as coreceptors to regulate cell proliferation, cell motility, and morphogenesis. In addition, some glypicans are abnormally expressed in cancers, possibly involved in tumorigenesis, and have the potential to be cancer-specific biomarkers. Here, we provide a brief review focusing on the expression of glypicans in various cancers and their potential to be targets for cancer therapy.

Split chimeric antigen receptor-modified T cells targeting glypican-3 suppress hepatocellular carcinoma growth with reduced cytokine release

Background:

Human glypican-3 (hGPC3) is a protein highly expressed in hepatocellular carcinoma (HCC) but limited in normal tissues, making it an ideal target for immunotherapy. The adoptive transfer of hGPC3-specific chimeric antigen receptor T (CAR-T) cells for HCC treatment has been conducted in clinical trials. Due to the rigid construction, conventional CAR-T cells have some intrinsic limitations, like uncontrollable overactivation and inducing severe cytokine release syndrome.

Methods:

We redesigned the hGPC3-specific CAR by splitting the traditional CAR into two parts. By using coculturing assays and a xenograft mouse model, the in vitro and in vivo cytotoxicity and cytokine release of the split anti-hGPC3 CAR-T cells were evaluated against various HCC cell lines and compared with conventional CAR-T cells.

Results:

In vitro data demonstrated that split anti-hGPC3 CAR-T cells could recognize and lyse hGPC3⁺ HepG2 and Huh7 cells in a dose-dependent manner. Impressively, split anti-hGPC3 CAR-T cells produced and released a significantly lower amount of proinflammatory cytokines, including IFN-γ, TNF-α, IL-6, and GM-CSF, than conventional CAR-T cells. When injected into immunodeficient mice inoculated subcutaneously with HepG2 cells, our split anti-hGPC3 CAR-T cells could suppress HCC tumor growth, but released significantly lower levels of cytokines than conventional CAR-T cells.

Conclusions:

We describe here for the first time the use of split anti-hGPC3 CAR-T cells to treat HCC; split anti-hGPC3 CAR-T cells could suppress tumor growth and reduce cytokine release, and represent a more versatile and safer alternative to conventional CAR-T cells treatment.

MetaOmGraph: a workbench for interactive exploratory data analysis of large expression datasets

The diverse and growing omics data in public domains provide researchers with tremendous opportunity to extract hidden, yet undiscovered, knowledge. However, the vast majority of archived data remain unused. Here, we present MetaOmGraph (MOG), a free, open-source, standalone software for exploratory analysis of massive datasets. Researchers, without coding, can interactively visualize and evaluate data in the context of its metadata, honing-in on groups of samples or genes based on attributes such as expression values, statistical associations, metadata terms and ontology annotations. Interaction with data is easy via interactive visualizations such as line charts, box plots, scatter plots, histograms and volcano plots. Statistical analyses include co-expression analysis, differential expression analysis and differential correlation analysis, with significance tests. Researchers can send data subsets to R for additional analyses. Multithreading and indexing enable efficient big data analysis. A researcher can create new MOG projects from any numerical data; or explore an existing MOG project. MOG projects, with history of explorations, can be saved and shared. We illustrate MOG by case studies of large curated datasets from human cancer RNA-Seq, where we identify novel putative biomarker genes in different tumors, and microarray and metabolomics data from Arabidopsis thaliana. MOG executable and code: http://metnetweb.gdcb.iastate.edu/ and https://github.com/urmi-21/MetaOmGraph/.

Paradoxical Role of Glypican-1 in Prostate Cancer Cell and Tumor Growth

Recent studies suggest that glypican-1 (GPC-1) is a biomarker for prostate cancer, but there are few studies elucidating the role of GPC-1 in prostate cancer progression. We observed high expression of GPC-1 in more aggressive prostate cancer cell lines such as PC-3 and DU-145. While inhibition of GPC-1 expression in PC-3 cells decreased cell growth and migration in vitro, it surprisingly increased cell proliferation and migration in DU-145 cells, suggesting that the role of GPC-1 is cell type-dependent. Further, GPC-1 inhibition increased PC-3 tumor size in NCr nude mice xenografts. We hypothesized that the discrepancy between the in vitro and in vivo data is mediated by stromal cells in the tumor microenvironment. Thus, we tested the effect of tumor conditioned media (TCM) on gene expression in human mesenchymal stem cells and fibroblasts. Treatment of stromal cells with TCM from PC-3 cells transfected with GPC-1 shRNA increased the expression of migration markers, endocrine/paracrine biomolecules, and extracellular matrix components. Additionally, the decreased cell growth in GPC-1 knockdown PC-3 cells was rescued by coculturing with stromal cells. These data demonstrate the paradoxical role that GPC-1 plays in prostate cancer cell growth by interacting with stromal cells and through ECM remodeling and endocrine/paracrine signaling.

Signaling network involved in the GPC3-induced inhibition of breast cancer progression: role of canonical Wnt pathway

PURPOSE

We have shown that GPC3 overexpression in breast cancer cells inhibits in vivo tumor progression, by acting as a metastatic suppressor. GPC3-overexpressing cells are less clonogenic, viable and motile, while their homotypic adhesion is increased. We have presented evidences indicating that GPC3 inhibits canonical Wnt and Akt pathways, while non-canonical Wnt and p38MAPK cascades are activated. In this study, we aimed to investigate whether GPC3-induced Wnt signaling inhibition modulates breast cancer cell properties as well as to describe the interactions among pathways modulated by GPC3.

METHODS

Fluorescence microscopy, qRT-PCR microarray, gene reporter assay and Western blotting were performed to determine gene expression levels, signaling pathway activities and molecule localization. Lithium was employed to activate canonical Wnt pathway and treated LM3-GPC3 cell viability, migration, cytoskeleton organization and homotypic adhesion were assessed using MTS, wound healing, phalloidin staining and suspension growth assays, respectively.

RESULTS

We provide new data demonstrating that GPC3 blocks-also at a transcriptional level-both autocrine and paracrine canonical Wnt activities, and that this inhibition is required for GPC3 to modulate migration and homotypic adhesion. Our results indicate that GPC3 is secreted into the extracellular media, suggesting that secreted GPC3 competes with Wnt factors or interacts with them and thus prevents Wnt binding to Fz receptors. We also describe the complex network of interactions among GPC3-modulated signaling pathways.

CONCLUSION

GPC3 is operating through an intricate molecular signaling network. From the balance of these interactions, the inhibition of breast metastatic spread induced by GPC3 emerges.

Evaluation of Glypican-3 expression in benign and malignant salivary gland tumors

Introduction

Glypican-3 (GPC3) is involved in regulation of cell proliferation and morphogenesis. It is abundant in embryonic tissue, but limited in most adult tissues. GPC3 deletion or mutation can disturb the balance between cell apoptosis and proliferation, which may result in tumorigenesis. This study aimed to investigate the GPC3 expression in salivary gland tumors (SGTs) and the adjacent non-neoplastic tissues.

Methods

This study reviewed 50 samples of salivary tumors from the archive of Khalili Hospital, Shiraz, Iran, including 17 cases of pleomorphic adenoma (PA), 16 cases of mucoepidermoid carcinoma (MEC), and 17 cases of adenoid cystic carcinoma (ACC); as well as a control group of 23 cases of normal salivary gland tissues. GPC3 expression was investigated through immunohistochemistry.

Results

GPC3 expression was significantly higher in malignant tumors (MEC and ACC) than in PA, and higher in PA than in the normal salivary glands (P < 0.001). The expression intensity was moderate to strong in malignant tumors and weak to moderate in benign tumors. No strong positivity was observed in normal salivary gland tissues (P < 0.001). Nor was any association detected between the GPC3 expression and intensity with the clinicopathologic parameters.

Conclusion

Although GPC3 overexpression was observed at the protein level in SGTs, and its expression was not related with the clinicopathologic factors, the potential use of GPC3 for diagnostic, therapeutic, and prognostic purposes requires further investigations.

Hepatitis C Virus Mimics Effects of Glypican-3 on CD81 and Promotes Development of Hepatocellular Carcinomas via Activation of Hippo Pathway in Hepatocytes

Glypican (GPC)-3 is overexpressed in hepatocellular carcinomas (HCCs). GPC3 binds to CD81. Forced expression of CD81 in a GPC3-expressing HCC cell line caused activation of Hippo, a decrease in ezrin phosphorylation, and a decrease in yes-associated protein (YAP). CD81 is also associated with hepatitis C virus (HCV) entry into hepatocytes. Activation of CD81 by agonistic antibody causes activation of tyrosine-protein kinase SYK (SYK) and phosphorylation of ezrin, a regulator of the Hippo pathway. In cultures of normal hepatocytes, CD81 agonistic antibody led to enhanced phosphorylation of ezrin and an increase in nuclear YAP. HCV E2 protein mimicked GPC3 and led to enhanced Hippo activity and decreased YAP in cultured normal human hepatocytes. HCC tissue microarray revealed a lack of expression of CD81 in most HCCs, rendering them insusceptible to HCV infection. Activation of CD81 by agonistic antibody suppressed the Hippo pathway and increased nuclear YAP. HCV mimicked GPC3, causing Hippo activation and a decrease in YAP. HCV is thus likely to enhance hepatic neoplasia by acting as a promoter of growth of early CD81-negative neoplastic hepatocytes, which are resistant to HCV infection, and thus have a proliferative advantage to clonally expand as they participate in compensatory regeneration for the required maintenance of 100% of liver weight (hepatostat).

Glypican-3 induces a mesenchymal to epithelial transition in human breast cancer cells

Breast cancer is the disease with the highest impact on global health, being metastasis the main cause of death. To metastasize, carcinoma cells must reactivate a latent program called epithelial-mesenchymal transition (EMT), through which epithelial cancer cells acquire mesenchymal-like traits.Glypican-3 (GPC3), a proteoglycan involved in the regulation of proliferation and survival, has been associated with cancer. In this study we observed that the expression of GPC3 is opposite to the invasive/metastatic ability of Hs578T, MDA-MB231, ZR-75-1 and MCF-7 human breast cancer cell lines. GPC3 silencing activated growth, cell death resistance, migration, and invasive/metastatic capacity of MCF-7 cancer cells, while GPC3 overexpression inhibited these properties in MDA-MB231 tumor cell line. Moreover, silencing of GPC3 deepened the MCF-7 breast cancer cells mesenchymal characteristics, decreasing the expression of the epithelial marker E-Cadherin. On the other side, GPC3 overexpression induced the mesenchymal-epithelial transition (MET) of MDA-MB231 breast cancer cells, which re-expressed E-Cadherin and reduced the expression of vimentin and N-Cadherin. While GPC3 inhibited the canonical Wnt/β-Catenin pathway in the breast cancer cells, this inhibition did not have effect on E-Cadherin expression. We demonstrated that the transcriptional repressor of E-Cadherin - ZEB1 - is upregulated in GPC3 silenced MCF-7 cells, while it is downregulated when GPC3 was overexpressed in MDA-MB231 cells. We presented experimental evidences showing that GPC3 induces the E-Cadherin re-expression in MDA-MB231 cells through the downregulation of ZEB1.Our data indicate that GPC3 is an important regulator of EMT in breast cancer, and a potential target for procedures against breast cancer metastasis.

Glycosaminoglycans and glycolipids as potential biomarkers in lung cancer

In this report, we used liquid chromatography-mass spectrometry and Western blotting to analyze the content and structure of glycosaminoglycans, glycolipids and selected proteins to compare differences between patient-matched normal and cancerous lung tissues obtained from lung cancer patients. The cancer tissue samples contained over twice as much chondroitin sulfate (CS)/dermatan sulfate (DS) as did the normal tissue samples, while the amount of heparan sulfate (HS) and hyaluronan (HA) in normal and cancer tissues were not significantly different. In HS, several minor disaccharide components, including NS6S, NS2S and 2S were significantly lower in cancer tissues, while the levels of major disaccharides, TriS, NS and 0S disaccharides were not significantly different in normal and cancer tissues. In regards to CS/DS, the level of 4S disaccharide (the major component of CS-type A and DS) decreased and the level of 6S disaccharide (the major component of CS- type C) increased in cancer tissues. We also compared the content and structure of GAGs in lung tissues from smoking and non-smoking patients. Analysis of the glycolipids showed all lipids present in these lung tissues, with the exception of sphingomyelin were higher in cancer tissues than in normal tissues. Western analysis showed that syndecan 1 and 2 proteoglycans displayed much higher expression in cancer tissue/biopsy samples. This investigation begins to provide an understanding of patho-physiological roles on glycosaminoglycans and glycolipids and might be useful in identifying potential biomarkers in lung cancer.

Can glypican-3 be a disease-specific biomarker?

Background

Glypican-3 (GPC3) is a cell surface-bound proteoglycan which has been identified as a potential biomarker candidate in hepatocellular carcinoma, lung carcinoma, severe pneumonia, and acute respiratory distress syndrome (ARDS). The aim of our review is to evaluate whether GPC3 has utility as a disease-specific biomarker, to discuss the potential involvement of GPC3 in cell biology, and to consider the changes of GPC3 gene and protein expression and regulation in hepatocellular carcinoma, lung cancer, severe pneumonia, and ARDS.

Results

Immunohistochemical studies have suggested that over-expression of GPC3 is associated with a poorer prognosis for hepatocellular carcinoma patients. Expression of GPC3 leads to an increased apoptosis response in human lung carcinoma tumor cells, and is considered to be a candidate lung tumor suppressor gene. Increased serum levels of GPC3 have been demonstrated in ARDS patients with severe pneumonia.

Conclusions

Glypican-3 could be considered as a clinically useful biomarker in hepatocellular carcinoma, lung carcinoma, and ARDS, but further research is needed to confirm and expand on these findings.

Biology and function of glypican-3 as a candidate for early cancerous transformation of hepatocytes in hepatocellular carcinoma (Review)

Glypican-3 (GPC-3), a transmembrane heparan sulfate proteoglycan (HSPG), has recently been investigated as a player in tissue-dependent cellular signaling, specifically as a regulator of growth. Noteworthy, the regulatory protein has been implicated in both stimulatory and inhibitory pathways involving cell growth. Initially, GPC-3 was thought to act as a cell cycle regulator, as a loss-of-function mutation in the gene caused a hyper-proliferative state known as Simpson-Golabi-Behmel (SGB) overgrowth syndrome. Additionally, certain cancer types have displayed a downregulation of GPC-3 expression. More recently, the protein has been evaluated as a useful marker for hepatocellular carcinoma (HCC) due to its increased expression in the liver during times of growth. In contrast, the GPC-3 marker is not detectable in normal adult liver. Immunotherapy that targets GPC-3 and its affiliated proteins is under investigation as these new biomarkers may hold potential for the detection and treatment of HCC and other diseases in which GPC-3 may be overexpressed. Studies have reported that an overexpression of GPC-3 in HCC predicts a poorer prognosis. This prognostic value further pushes the question regarding GPC-3's role in the regulation and progression of HCC. This review will summarize the current knowledge regarding the clinical aspects of GPC-3, while also synthesizing the current literature with the aim to better understand this molecule's biological interactions at a molecular level, not only in the liver, but in the rest of the body as well. Due to the existing gap in the literature surrounding GPC-3, we believe further investigation of function, structure and domains, cellular localization, and other subfields is warranted to evaluate the protein as a whole, as well as its part in the study of HCC.

Adoptive immunotherapy using T lymphocytes redirected to glypican-3 for the treatment of lung squamous cell carcinoma

There are unmet medical needs for patients with lung squamous cell carcinoma (LSCC). Therefore, in this study, we explored the antitumor potential of third-generation glypican 3 (GPC3)-redirected chimeric antigen receptor (CAR)-engineered T lymphocytes (CARgpc3 T cells) in tumor models of LSCC. First, we demonstrated by immunohistochemistry (IHC) that GPC3 was expressed in 66.3% of LSCC samples and in 3.3% of lung adenocarcinoma (LAD) samples but not in normal lung tissues. In the presence of GPC3-positive LSCC cells, CARgpc3 T cells were highly activated and increased in number. CARgpc3 T cells could specifically lyse GPC3-positive LSCC cells in vitro. In two established LSCC xenograft models, CARgpc3 T cells could almost completely eliminate the growth of GPC3-positive cells. Additionally, the CARgpc3 T cells were able to persist in vivo and efficiently infiltrate the cancerous tissues. Taken together, these findings indicate that CARgpc3 T cells might be a novel potential therapeutic agent for the treatment of patients with LSCC.

Expression of PAX8 Target Genes in Papillary Thyroid Carcinoma

PAX8 is a thyroid-specific transcription factor whose expression is dysregulated in thyroid cancer. A recent study using a conditional knock-out mouse model identified 58 putative PAX8 target genes. In the present study, we evaluated the expression of 11 of these genes in normal and tumoral thyroid tissues from patients with papillary thyroid cancer (PTC). ATP1B1, GPC3, KCNIP3, and PRLR transcript levels in tumor tissues were significantly lower in PTCs than in NT, whereas LCN2, LGALS1 and SCD1 expression was upregulated in PTC compared with NT. Principal component analysis of the expression of the most markedly dysregulated PAX8 target genes was able to discriminate between PTC and NT. Immunohistochemistry was used to assess levels of proteins encoded by the two most dyregulated PAX8 target genes, LCN2 and GPC3. Interestingly, GPC3 was detectable in all of the NT samples but none of the PTC samples. Collectively, these findings point to significant PTC-associated dysregulation of several PAX8 target genes, supporting the notion that PAX8-regulated molecular cascades play important roles during thyroid tumorigenesis.

Downregulation of glypican-3 expression increases migration, invasion, and tumorigenicity of human ovarian cancer cells

Glypican-3 (GPC3) is a membrane of heparan sulfate proteoglycan family involved in cell proliferation, adhesion, migration, invasion, and differentiation during the development of the majority of mesodermal tissues and organs. GPC3 is explored as a potential biomarker for hepatocellular carcinoma screening. However, as a tumor-associated antigen, its role in ovarian cancer remains elusive. In this report, the expression levels of GPC3 in the various ovarian cancer cells were determined with quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and GPC3 expression in ovarian cancer UCI 101 and A2780 cells was knocked down by siRNA transfection, and the effects of GPC3 knockdown on in vitro cell proliferation, migration, and invasion were respectively analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay and Transwell migration assay. Additionally, the effect of GPC3 knockdown on in vivo tumorigenesis were investigated in athymic nude mice. The results indicated that GPC3 knockdown significantly promoted cell proliferation and increased cell migration and invasion by upregulation of matrix metalloproteinase (MMP)-2 and MMP-9 expression and downregulation of tissue inhibitor of metalloproteinase-1 expression. Additionally, GPC3 knockdown also increased in vivo tumorigenicity of UCI 101 and A2780 cells and final tumor weights and volumes after subcutaneous cell injection in the nude mice. The results of immunohistochemical staining and Western blotting both demonstrated a lower expression of GPC3 antigen in the tumors of GPC3 knockdown groups than that of negative control groups. Moreover, transforming growth factor-β2 protein expression in the tumors of GPC3 knockdown groups was significantly increased, which at least contributed to tumor growth in the nude mice. Taken together, these findings suggest that GPC3 knockdown promotes the progression of human ovarian cancer cells by increasing their migration, invasion, and tumorigenicity, and suggest that GPC3 is a potential therapeutic target for ovarian cancer patients.

Proteoglycan-based diversification of disease outcome in head and neck cancer patients identifies NG2/CSPG4 and syndecan-2 as unique relapse and overall survival predicting factors

Background

Tumour relapse is recognized to be the prime fatal burden in patients affected by head and neck squamous cell carcinoma (HNSCC), but no discrete molecular trait has yet been identified to make reliable early predictions of tumour recurrence. Expression of cell surface proteoglycans (PGs) is frequently altered in carcinomas and several of them are gradually emerging as key prognostic factors.

Methods

A PG expression analysis at both mRNA and protein level, was pursued on primary lesions derived from 173 HNSCC patients from whom full clinical history and 2 years post-surgical follow-up was accessible. Gene and protein expression data were correlated with clinical traits and previously proposed tumour relapse markers to stratify high-risk patient subgroups.

Results

HNSCC lesions were indeed found to exhibit a widely aberrant PG expression pattern characterized by a variable expression of all PGs and a characteristic de novo transcription/translation of GPC2, GPC5 and NG2/CSPG4 respectively in 36%, 72% and 71% on 119 cases. Importantly, expression of NG2/CSPG4, on neoplastic cells and in the intralesional stroma (Hazard Ratio [HR], 6.76, p = 0.017) was strongly associated with loco-regional relapse, whereas stromal enrichment of SDC2 (HR, 7.652, p = 0.007) was independently tied to lymphnodal infiltration and disease-related death. Conversely, down-regulated SDC1 transcript (HR, 0.232, p = 0.013) uniquely correlated with formation of distant metastases. Altered expression of PGs significantly correlated with the above disease outcomes when either considered alone or in association with well-established predictors of poor prognosis (i.e. T classification, previous occurrence of precancerous lesions and lymphnodal metastasis). Combined alteration of all three PGs was found to be a reliable predictor of shorter survival.

Conclusions

An unprecedented PG-based prognostic portrait is unveiled that incisively diversifies disease course in HNSCC patients beyond the currently known clinical and molecular biomarkers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1336-4) contains supplementary material, which is available to authorized users.

Glycosylation alterations in lung and brain cancer

Alterations in glycosylation are common in cancer and are thought to contribute to disease. Lung cancer and primary malignant brain cancer, most commonly glioblastoma, are genetically heterogeneous diseases with extremely poor prognoses. In this review, we summarize the data demonstrating that glycosylation is altered in lung and brain cancer. We then use specific examples to highlight the diverse roles of glycosylation in these two deadly diseases and illustrate shared mechanisms of oncogenesis. In addition to alterations in glycoconjugate biosynthesis, we also discuss mechanisms of postsynthetic glycan modification in cancer. We suggest that alterations in glycosylation in lung and brain cancer provide novel tumor biomarkers and therapeutic targets.

Discovery and diagnostic value of a novel oncofetal protein: glypican 3

Glypican 3 is a membrane-bound heparan sulfate proteoglycan, which has recently been identified as a marker for liver cancer and germ cell malignancies. Individuals with loss-of-function mutations for the glypican 3 gene exhibit Simpson-Golabi-Behmel syndrome, a rare X-linked overgrowth disorder. Expression of glypican 3 mRNA and protein is normally silenced in most adult organs and may reappear during malignant transformation. In the past few years, immunohistochemical and molecular characteristics of glypican 3 in hepatocellular carcinoma have been elucidated. More recently, glypican 3 has been emerging as a new diagnostic marker for germ cell tumors and especially testicular and ovarian yolk sac tumors. However, in other tumors such as renal cell carcinomas, squamous cell carcinomas, and melanomas, studies disagree on the level of glypican 3 expression. Finally, there is the controversial notion of glypican 3 as a tumor suppressor gene. In this review article, we update current knowledge on glypican 3 expression in normal and neoplastic tissues, evaluate its utility as a tumor marker in clinical practice, and explore its role as a novel oncofetal protein with clinical implications. Our focus is on the diagnostic value of glypican 3 in germ cell tumors and other neoplasms in addition to hepatocellular carcinoma. In conclusion, glypican 3 has been proven to be a useful immunohistochemical marker in distinguishing yolk sac tumors, choriocarcinomas, and Wilms tumors from other malignancies histologically mimicking these primitive tumors. Clinically, we recommend that glypican 3 be used as part of a panel of markers in subtyping testicular germ cell tumors.

Silencing of the glypican-3 gene affects the biological behavior of human hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death in the world. The gene glypican-3 (GPC3) is reported to be a potential therapeutic target for HCC. In this study, we use RNA interference with lentiviral vectors to explore the effect of GPC3 silencing on the biological behavior of HCC cells and the potential role of the GPC3 protein in the activation of epithelial-mesenchymal transition (EMT), which relates to HCC cell invasion and migration. Our data suggest that GPC3 silencing leads to a decrease in HCC cell proliferation and to an increase in apoptosis. We demonstrated that GPC3 silencing regulates cell invasion and migration, most probably through the activation of the EMT cellular program. In conclusion, GPC3 is associated with the HCC cell biological behavior, while the relationship between GPC3 and EMT in tumorigenesis of HCC deserves future investigation.

AP-2α downregulation by cigarette smoke condensate is counteracted by p53 in human lung cancer cells

Cumulative findings have demonstrated that the dysregulation of tumor suppressor genes may be implicated in cigarette smoke-induced carcinogenesis. Activating enhancer-binding protein 2 (AP-2) is a eukaryotic transcriptional factor that plays a significant role in embryonic development and tumorigenesis. The vertebrate AP-2 family consists of AP-2α, AP-2β, AP-2γ, AP-2δ and AP-2ε. Previous studies have suggested that cigarette smoking disrupts AP-2 regulation. In the present study, we investigated the effects of cigarette smoke condensate (CSC) on AP-2α expression in human lung cancer cell lines (NCI-H1299, NCI-H446 and A549), as well as the potential mechanisms involved. Using RT-qPCR, we found that CSC decreased AP-2α expression by suppressing its transcription in human lung cancer cell lines, particularly in p53-deficient NCI-H1299 cells. Western blotting and luciferase assays were implemented and we found that the restoration of p53 expression rescued the NCI-H1299 cells from CSC-induced AP-2α loss, while the silencing of p53 resulted in increased AP-2α loss induced by CSC, suggesting an antagonizing role of p53 in the regulation of AP-2α by CSC. Our results indicate that AP-2α downregulation may be involved in smoke-induced lung carcinogenesis.

GPC3 expression in mouse ovarian cancer induces GPC3‑specific T cell-mediated immune response through M1 macrophages and suppresses tumor growth

Glypican-3 (GPC3) is specifically expressed in ovarian clear cell carcinoma (OCCC), hepatocellular carcinoma (HCC), and melanoma and lung cancer. GPC3 is being explored as a potential candidate for OCCC and HCC immunotherapy. As a tumor-associated antigen, induction of immune response of GPC3 in ovarian cancer remains elusive. We established a GPC3 transgenic mouse ovarian cancer cell line, OV2944-HM-1 (HM-1), and used the intraperitoneal ovarian cancer mouse model to investigate immune response in GPC3-expressing tumor. We found that GPC3 expression in the tumor increased F4/80⁺CD86⁺ macrophage (M1) proportion and caused GPC3-specific CD8⁺ T cell immune responses, and prolonged mouse survival. Our results demonstrated that GPC3 expression induced T cell-mediated immune response in this mouse ovarian cancer model and also provided supportive evidence that GPC3 is an ideal target for ovarian cancer immunotherapy.

Critical analysis of the potential of targeting GPC3 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide. The treatment options for patients with advanced HCC are limited, and novel treatment strategies are required urgently. Glypican-3 (GPC3), a member of the glypican family of heparan sulfate proteoglycans, is overexpressed in 72%−81% of HCC cases, and is correlated with a poor prognosis. GPC3 regulates both stimulatory and inhibitory signals, and plays a key role in regulating cancer cell growth. GPC3 is released into the serum, and so might be a useful diagnostic marker for HCC. GPC3 is also used as an immunotherapeutic target in HCC. A Phase I study of a humanized anti-GPC3 monoclonal antibody, GC33, revealed a good safety profile and potential antitumor activity, and a Phase II trial is currently ongoing. In addition, the authors’ investigator-initiated Phase I study of a GPC3-derived peptide vaccine showed good safety and tolerability, and demonstrated that the GPC3 peptide-specific cytotoxic T-lymphocyte frequency in peripheral blood correlated with overall survival in HCC patients. A sponsor-initiated Phase I clinical trial of a three-peptide cocktail vaccine, which includes a GPC3-derived peptide, is also underway. GPC3 is currently recognized as a promising therapeutic target and diagnostic marker for HCC. This review introduces the recent progress in GPC3 research, from biology to clinical impact.

Extracellular matrix proteins expression profiling in chemoresistant variants of the A2780 ovarian cancer cell line

Ovarian cancer is the leading cause of death among gynaecological malignancies. Extracellular matrix (ECM) can affect drug resistance by preventing the penetration of the drug into cancer cells and increased resistance to apoptosis. This study demonstrates alterations in the expression levels of ECM components and related genes in cisplatin-, doxorubicin-, topotecan-, and paclitaxel-resistant variants of the A2780 ovarian cancer cell line. Affymetrix Gene Chip Human Genome Array Strips were used for hybridisations. The genes that had altered expression levels in drug-resistant sublines were selected and filtered by scatter plots. The genes that were up- or downregulated more than fivefold were selected and listed. Among the investigated genes, 28 genes were upregulated, 10 genes were downregulated, and two genes were down- or upregulated depending on the cell line. Between upregulated genes 12 were upregulated very significantly—over 20-fold. These genes included COL1A2, COL12A1, COL21A1, LOX, TGFBI, LAMB1, EFEMP1, GPC3, SDC2, MGP, MMP3, and TIMP3. Four genes were very significantly downregulated: COL11A1, LAMA2, GPC6, and LUM. The expression profiles of investigated genes provide a preliminary insight into the relationship between drug resistance and the expression of ECM components. Identifying correlations between investigated genes and drug resistance will require further analysis.

Immunohistochemistry for the novel markers glypican 3, PAX8, and p40 (ΔNp63) in squamous cell and urothelial carcinoma

OBJECTIVES

To examine squamous cell carcinomas (SCCs) from diverse anatomic sites and invasive urothelial carcinomas (UCs) for expression of the oncofetal antigen glypican 3 (GPC3), the paired box transcription factor PAX8, and the ΔN isoform of p63 (p40).

METHODS

Immunohistochemistry for GPC3, PAX8, and p40 was performed on whole sections of 107 SCCs from 11 anatomic sites and 49 UCs; evaluation included extent and intensity of staining.

RESULTS

GPC3 was detected in 20% of SCCs and 12% of UCs and PAX8 in 3% of SCCs, limited to the uterine cervix, and 10% of UCs. p40 Was found in 99% of SCCs and 96% of UCs.

CONCLUSIONS

GPC3 expression is frequent in SCC/UC, awareness of which should guard against an incorrect diagnosis of hepatocellular carcinoma, while PAX8, limited in distribution, may have some use in suggesting a cervical or urothelial tract origin in a metastatic squamotransitional carcinoma of unknown primary. There is no drop-off in sensitivity for the diagnoses of SCC or UC with ΔNp63-specific immunohistochemistry, and if this performance can be extended to other applications, p40 may supplant the dominant "pan-p63" antibody clone.

Reevaluation of glypican-3 as a serological marker for hepatocellular carcinoma

BACKGROUND

Glypican-3 (GPC3) is a novel histochemical marker of hepatocellular carcinoma (HCC). However, its utility as a serologic marker for HCC is not conclusive.

METHODS

A total of 1037 subjects, including 155 patients with HCC, 180 with chronic hepatitis, 124 with liver cirrhosis, 442 with non-HCC cancer and 136 healthy controls, were analyzed for serum GPC3 (sGPC3) by an ELISA constructed with 2 monoclonal antibodies.

RESULTS

The average level of sGPC3 in HCC patients was 99.94±267.2ng/ml, which was significantly higher than in patients with chronic hepatitis (10.45±46.02ng/ml, P<0.0001), liver cirrhosis (19.44±50.88ng/ml, P=0.0013), non-HCC cancer (20.50±98.33ng/ml, P<0.0001) and healthy controls (4.14±31.65ng/ml, P<0.0001). The sensitivity of sGPC3 in HCC diagnosis was 40.0%, whereas the specificity was 98.5%, 94.4% and 87.1% in healthy controls, chronic hepatitis patients and liver cirrhosis patients, respectively. In addition, 13.5% (28/207) of lung cancer patients and 13.2% (9/68) of thyroid cancer patients had positive results with sGPC3.

CONCLUSION

Serum GPC3 is a potential marker for HCC. However, the presence of sGPC3 in patients with lung cancer and thyroid cancer might limit its application as a single marker in the diagnosis of HCC.

Overexpression of GPC3 inhibits hepatocellular carcinoma cell proliferation and invasion through induction of apoptosis

Glypican‑3 (GPC3) is a membrane heparan sulfate proteoglycan involved in cell proliferation, differentiation, adhesion, migration and the development of the majority of mesodermal tissues and organs. GPC3 has been found to be important for the occurrence and development of hepatocellular carcinoma (HCC). Therefore, it may be suitable for use as a novel molecular marker for the diagnosis of primary liver cancer. In the present study, the role of GPC3 in the occurrence and development of HCC was determined. GPC3 recombinant vector was transfected into two HCC cell lines, Huh7 and SK‑HEP‑1, to upregulate the expression of GPC3 and examine changes in the biological behavior of the cells. Results indicate that overexpression of GPC3 in Huh7 and SK‑HEP‑1 cells effectively inhibited cell proliferation and cell invasion through induction of apoptosis. However, cotreatment of the cells with insulin‑like growth factor 2 (IGF2) and fibroblast growth factor 2 (FGF2) was found by Annexin V‑PI flow cytometric analysis to significantly inhibit the apoptotic cell death induced by GPC3 overexpression. These observations indicate that GPC3 may act as a negative regulator of IGF2 and FGF2 pathways. Taken together, these results demonstrate that overexpression of GPC3 inhibits the occurrence and development of HCC.

Glypican-3 expression in gastrointestinal and pancreatic epithelial neoplasms

Glypican-3 (GPC3) is a plasma membrane-bound proteoglycan that can be overexpressed in certain malignancies but has been particularly linked to hepatocellular carcinoma (HCC). GPC3 is currently used as an immunohistochemical marker for HCC, but its expression in epithelial neoplasms of the gastrointestinal (GI) tract and pancreas, a common source of liver metastasis, has not been studied in detail. In this study, we examined GPC3 immunoreactivity in 98 neoplasms of the GI tract including 30 adenocarcinomas (ADCA), 29 squamous cell carcinomas (esophageal and anal), and 39 neuroendocrine carcinomas, and 60 neoplasms of the pancreas including 22 ADCA, 26 pancreatic neuroendocrine neoplasms, and 12 pancreatic acinar cell carcinomas. Two control groups of 32 HCCs and 16 intrahepatic cholangiocarcinomas were also stained with GPC3. Although most (7/12, 58.5%) acinar cell carcinomas were GPC3 positive, pancreatic ADCA and neuroendocrine neoplasms were GPC3 negative. In addition, 27.5%, (8/29) of squamous cell carcinomas, 20% (6/30) of ADCA, and 2.5% (1/39) of neuroendocrine carcinomas of the GI tract were immunoreactive for GPC3. HCC was positive for GPC3 in 75% (24/32) of cases but cholangiocarcinoma was negative. While significant correlation between GPC3 positivity and poor differentiation was observed in HCC only, GPC3 expression did not correlate with tumor size. In conclusion, 14% of GI tract and pancreatic carcinomas/neoplasms (particularly pancreatic acinar cell carcinoma) can express GPC3 by immunohistochemistry. As these tumors commonly metastasize to the liver, this offers a potential pitfall in differentiating between HCC and metastatic carcinoma when evaluating tumors involving the liver.

Induction of CD152 (CTLA-4) and LAP (TGF-β1) in human Foxp3- CD4+ CD25- T cells modulates TLR-4 induced TNF-α production

CD152 (CTLA-4) is a co-stimulatory molecule that is expressed by T cells and negatively regulates immune responses. Here, we report the identification of a novel ligand, GPC(81-95), with the ability to induce both CD152 and LAP (TGF-β1) on human Foxp3(-) CD25(-) CD4(+) T cells. The results demonstrate that GPC(81-95) peptide-induced cell surface CD152 is endocytosed back into the cell during stimulation. The protein export and exocytosis of CD152 is also induced by this ligand. The inhibitory effects of GPC(81-95) on LPS-induced TNF-α production was shown to be closely associated with its ability to induce both LAP (TGF-β1) and CD152. Taken together, we have shown that a novel peptide ligand stimulates LAP (TGF-β1) and CD152 expression on resting CD4 T cells and have demonstrated that GPC(81-95) is a useful tool to study the functional properties of LAP (TGF-β1)(+) CD152(+) CD4(+) T cells.

Antithetic roles of proteoglycans in cancer

Proteoglycans (PGs), a family of complex post-translationally sculptured macromolecules, are fundamental regulators of most normal and aberrant cellular functions. The unparalleled structural-functional diversity of PGs endows them with the ability to serve as critical mediators of the tumor cells' interaction with the host microenvironment, while directly contributing to the organization and dynamic remodeling of this milieu. Despite their indisputable importance during embryonic development and in the adult organism, and their frequent dysregulation in tumor lesions, their precise involvement in tumorigenesis awaits a more decisive demonstration. Particularly challenging is to ascertain to what extent selected PGs may catalyze tumor progression and to what extent they may inhibit it, implying antithetic functions of individual PGs. Integrated efforts are needed to consolidate the routine use of PGs in the clinical monitoring of cancer patients and to broaden the exploitation of these macromolecules as therapeutic targets. Several PGs have the required attributes to be contemplated as effective antigens for immunotherapeutic approaches, while the tangible results obtained in recent clinical trials targeting the NG2/CSPG4 transmembrane PG urge further development of PG-based cancer treatment modalities.

Therapeutic potential of targeting glypican-3 in hepatocellular carcinoma

Glypican-3 (GPC3) is a developmentally-regulated oncofetal protein that has been established as a clinically-relevant biomarker for early hepatocellular carcinoma (HCC). It is one of the first transcripts to appear during malignant hepatocyte transformation, and is expressed at the protein level in approximately half of high-grade dysplastic macronodules in cirrhotic liver. Several studies show it is expressed in most (75 to 100%) of HCCs confirmed by histopathology. The protein is anchored to the hepatocyte membrane by a glycosyl-phosphatidylinositol (GPI) anchor and shows consistent membrane immunostaining pattern, making it a viable target for immunotherapeutic approaches. Targeting GPC3 for therapeutic intervention is a promising approach for the clinical management of HCC and selected other tumors that express the marker.

Points of therapeutic intervention along the Wnt signaling pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. However, there is little known about targeted therapeutics for the treatment of this devastating tumor. Among the growth factor signaling cascades deregulated in HCC, evidences suggest that the WNT/Frizzled-mediated signaling pathway plays a key role in the hepatic carcinogenesis. Aberrant activation of the signaling in HCC is mostly due to deregulated expression of the Wnt/β-catenin signaling components. This leads to the activation of the β-catenin/TCF dependent target genes, which controls cell proliferation, cell cycle, apoptosis or motility. It has been shown that disruption of the Wnt/β-catenin signaling cascade displayed anti-cancer properties in HCC. Currently, no therapeutic molecules targeting the WNT pathway are available or under clinical evaluation for the treatment of HCC. This review will discuss the identified potential molecular targets related to the canonical WNT signaling pathway and their potential therapeutic usefulness.

D-glucuronyl C5-epimerase suppresses small-cell lung cancer cell proliferation in vitro and tumour growth in vivo

BACKGROUND

D-Glucuronyl C5-epimerase (GLCE) is a key enzyme involved in the biosynthesis of heparan sulphate proteoglycans, which has an important role in cell-cell and cell-matrix interactions and signalling. Decreased GLCE expression in human breast tumours and its anti-proliferative effects in breast cancer cells suggest that it may be a candidate tumour-suppressor gene. The aim of this study was to investigate the involvement of GLCE in lung carcinogenesis.

METHODS

D-Glucuronyl C5-epimerase expression in different lung cancer cell lines was determined and the gene was ectopically re-expressed in U2020 small-cell lung cancer cells. Cellular proliferation in vitro and tumour growth in vivo were then examined.

RESULTS

Ectopic re-expression of GLCE in U2020 cells did not affect cell viability but did influence morphology. Cellular proliferation in vitro and tumour formation in vivo were both suppressed. These effects were mediated via downregulation of several pro-angiogenic growth factors and their receptors, including VEGF-A, TGFB1, FGFR2, PDGF-A and PDGF-B, and TNFa and its receptors. Expression of matrix metalloproteinase2, MTA1, PLAU, TIMP3, S100A4, SERPINE1 and TWIST1 was also downregulated.

CONCLUSION

The anti-tumour effects associated with ectopic GLCE re-expression suggest that it may be a potential tumour-suppressor gene and a possible target for lung cancer diagnosis and treatment.

Expression of GPC3 protein and its significance in lung squamous cell carcinoma

The purpose of this study was to investigate GPC3 gene expression in lung squamous cell carcinoma tissue and its correlation with clinical and tumor characteristics. Using RT-PCR, the presence of GPC3 gene expression was detected in cancer tissue and adjacent normal tissue in 66 cases of lung squamous cell carcinoma and positive rates were calculated. Using Western blot, changes in GPC3 protein expression were detected in lung squamous cell carcinoma and adjacent normal tissues. The percentage of tissue samples expressing GPC3 mRNA was significantly higher in lung squamous cell carcinoma than in adjacent normal tissue (P < 0.05). This percentage was also significantly higher for cases with lymph node metastasis than for those without lymph node metastasis (P < 0.05). Further, the percentage of samples expressing GPC3 mRNA was higher with lowering degrees of tumor differentiation (P < 0.05). Rates of GPC3 expression were, however, independent of patient gender, age, and tumor size (P > 0.05). The expression of GPC3 protein in lung squamous cell carcinoma was significantly higher than that in adjacent normal tissues (P < 0.05). The expression in cases with lymph node metastasis was significantly higher than in those without lymph node metastasis (P < 0.05), and GPC3 protein expression increased with lowering degrees of tumor differentiation (P < 0.05). Further investigation is warranted for the association of initiation, development, invasion, and metastasis of disease.

Proteoglycans in cancer biology, tumour microenvironment and angiogenesis

Proteoglycans, key molecular effectors of cell surface and pericellular microenvironments, perform multiple functions in cancer and angiogenesis by virtue of their polyhedric nature and their ability to interact with both ligands and receptors that regulate neoplastic growth and neovascularization. Some proteoglycans such as perlecan, have pro- and anti-angiogenic activities, whereas other proteoglycans, such as syndecans and glypicans, can also directly affect cancer growth by modulating key signalling pathways. The bioactivity of these proteoglycans is further modulated by several classes of enzymes within the tumour microenvironment: (i) sheddases that cleave transmembrane or cell-associated syndecans and glypicans, (ii) various proteinases that cleave the protein core of pericellular proteoglycans and (iii) heparanases and endosulfatases which modify the structure and bioactivity of various heparan sulphate proteoglycans and their bound growth factors. In contrast, some of the small leucine-rich proteoglycans, such as decorin and lumican, act as tumour repressors by physically antagonizing receptor tyrosine kinases including the epidermal growth factor and the Met receptors or integrin receptors thereby evoking anti-survival and pro-apoptotic pathways. In this review we will critically assess the expanding repertoire of molecular interactions attributed to various proteoglycans and will discuss novel proteoglycan functions modulating cancer progression, invasion and metastasis and how these factors regulate the tumour microenvironment.

Significance of GPC3 expression in liver biopsy specimens for differential diagnosis of liver diseases

AIM: To analyze the expression of glypican 3 (GPC3) in different liver diseases and to explore its significance in early diagnosis of hepatocellular carcinoma (HCC).

METHODS: The expression of GPC3 and α-fetoprotein (AFP) was detected by immunohistochemistry in 126 liver needle biopsy specimens from 13 patients with very early stage HCC, 44 patients with early stage HCC, 16 patients with dysplastic nodules, 29 patients with liver cirrhosis, and 24 patients with hepatitis, and in 57 resected HCC specimens from patients with intermediate and advanced HCC. Twenty-eight resected normal liver tissue specimens were used as controls.

RESULTS: The expression of GPC3 in HCC differed significantly from those in other liver diseases (all P < 0.01). Detection of GPC3 expression showed a higher diagnostic sensitivity (80.7%) and specificity (99.4%) than that of AFP (37.7% and 93.6%, respectively). GPC3 was expressed in 92.3% of very early stage HCC and in 72.7% of early stage of HCC. In contrast, AFP only appeared in 38.5% of very early stage HCC and in 34.1% of early stage HCC. The positive rates of GPC3 expression in very early and early stage HCC were significantly higher than those in dysplastic nodules (both P < 0.01). GPC3 and AFP expression was not detected in liver cirrhosis, hepatitis or normal liver tissue. In patients with small HCC, the positive rate of GPC3 expression was 78.6%, and combined detection of GPC3 and AFP had a sensitivity of 85.7%. In patients with small HCC who had an AFP of ≤20 μg/L, the positive rate of GPC3 expression was 70%. The recurrence rate after radical surgery in GPC3-positive patients was higher than that of GPC3-negative ones (P < 0.05).

CONCLUSION: GPC3 is highly expressed in HCC. Detection of GPC3 expression has a high sensitivity and specificity for diagnosis of very early and early stage HCC and therefore represents a potential diagnostic parameter for early HCC. Immunohistochemistry detection of GPC3 in liver needle biopsy specimens is an effective ancillary tool for early diagnosis of HCC. GPC3 expression is an independent prognostic factor for HCC recurrence after surgery.