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

Role of cancer cell-derived exosomal glycoproteins in macrophage polarization

Cancer is a deadly disease marked by abnormal cell growth, proliferation, and metastasis-the spread of cancer from its origin to distant sites. A key factor in tumor progression is the tumor microenvironment (TME), which significantly influences tumor behavior and response to treatment. Within the TME, interactions between cancer cells and surrounding immune cells, particularly tumor-associated macrophages (TAMs), play a critical role in shaping immune responses. This review focuses on recent findings from a systematic PubMed search regarding cancer cell-derived exosomal glycoproteins and their role in modulating macrophage phenotypes. Tumor-derived exosomes, a type of extracellular vesicle (EV), carry glycoproteins-proteins with attached sugar chains-that can influence macrophage polarization. These glycoproteins can reprogram macrophages into either the M1 phenotype (proinflammatory and anti-tumor) or the M2 phenotype (anti-inflammatory and tumor-supportive). The M1 macrophages inhibit tumor progression, while M2 macrophages support tumor growth by promoting immune suppression and tissue remodeling. Understanding how exosomal glycoproteins drive this polarization offers critical insight into cancer immunology and may pave the way for novel therapeutic strategies targeting the TME.

Evaluation of glypican‑3 in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers occurring worldwide, including Mongolia. Although alpha-fetoprotein (AFP) is a widely used marker for HCC, conflicting studies have been published regarding its specificity and sensitivity towards HCC. Glypican-3 (GPC3) is a different promising biomarker for HCC, and there is some evidence to suggest that this protein may be a more specific marker compared with AFP. GPC3 has been shown to fulfill important roles in cell proliferation and division during embryogenesis, and is rarely found in the tissues of healthy adults. The aim of the present study was to investigate the levels of serum GPC3 (sGPC3) and tissue GPC3 in Mongolian patients with HCC. Serum samples from a total of 270 individuals [HCC group, 90 patients; risk group (RG), 90 subjects; and control group, 90 subjects] were evaluated using enzyme-linked immunosorbent assay to identify the sGPC3 levels. In addition, immunohistochemical analysis of the GPC3 was performed on tissue samples from 50 patients with HCC to evaluate the expression of GPC3. sGPC3 level was found to be significantly increased in the HCC group compared with the RG and the control group, with the area under the curve=0.85 (P<0.001). sGPC3 was found to be significantly associated with hepatitis C virus status and cirrhosis (P<0.05). In addition, the tissue expression of GPC3 was associated with the serum AFP (sAFP) level. Finally, positive staining of GPC3 was observed when the sAFP level of the patient was >20 ng/ml. In conclusion, the results from the present study have supported that GPC3 may be a promising marker for HCC, and can be used as a diagnostic marker alongside AFP.

Progresses of T-cell-engaging bispecific antibodies in treatment of solid tumors

T-cell-engaging bispecific antibody (TCB) therapies have emerged as a promising immunotherapeutic approach, effectively redirecting effector T cells to selectively eliminate tumor cells. The therapeutic potential of TCBs has been well recognized, particularly with the approval of multiple TCBs in recent years for the treatment of hematologic malignancies as well as some solid tumors. However, TCBs encounter multiple challenges in treating solid tumors, such as on-target off-tumor toxicity, cytokine release syndrome (CRS), and T cell dysfunction within the immunosuppressive tumor microenvironment, all of which may impact their therapeutic efficacy. In this review, we summarize clinical data on TCBs for solid tumor treatment, highlight the challenges faced, and discuss potential solutions based on emerging strategies from current clinical and preclinical research. These solutions include TCB structural optimization, target selection, and combination strategies. This comprehensive analysis aims to guide the development of TCBs from design to clinical application, addressing the evolving landscape of cancer immunotherapy.

GPC3 Promotes Lung Squamous Cell Carcinoma Progression and HLA-A2-Restricted GPC3 Antigenic Peptide-Modified Dendritic Cell-Induced Cytotoxic T Lymphocytes to Kill Lung Squamous Cell Carcinoma Cells

Lung squamous cell carcinoma (LUSC) is associated with poor clinical prognosis and lacks available targeted agents. GPC3 is upregulated in LUSC. Our study aimed to explore the roles of GPC3 in LUSC and the antitumor effects of HLA-A2-restricted GPC3 antigenic peptide-sensitized dendritic cell (DC)-induced cytotoxic T lymphocytes (CTLs) on LUSC. LUSC cells with GPC3 knockdown and overexpression were built using lentivirus packaging, and cell viability, clone formation, apoptosis, cycle, migration, and invasion were determined. Western blotting was used to detect the expression of cell cycle-related proteins and PI3K-AKT pathway-associated proteins. Subsequently, HLA-A2-restricted GPC3 antigenic peptides were predicted and synthesized by bioinformatic databases, and DCs were induced and cultured in vitro. Finally, HLA-A2-restricted GPC3 antigenic peptide-modified DCs were co-cultured with T cells to generate specific CTLs, and the killing effects of different CTLs on LUSC cells were studied. A series of cell function experiments showed that GPC3 overexpression promoted the proliferation, migration, and invasion of LUSC cells, inhibited their apoptosis, increased the number of cells in S phase, and reduced the cells in G2/M phase. GPC3 knockdown downregulated cyclin A, c-Myc, and PI3K, upregulated E2F1, and decreased the pAKT/AKT level. Three HLA-A2-restricted GPC3 antigenic peptides were synthesized, with GPC3522-530 FLAELAYDL and GPC3102-110 FLIIQNAAV antigenic peptide-modified DCs inducing CTL production, and exhibiting strong targeted killing ability in LUSC cells at 80 : 1 multiplicity of infection. GPC3 may advance the onset and progression of LUSC, and GPC3522-530 FLAELAYDL and GPC3102-110 FLIIQNAAV antigenic peptide-loaded DC-induced CTLs have a superior killing ability against LUSC cells.

Heparan sulfate proteoglycans in cancer: Pathogenesis and therapeutic potential

The heparan sulfate proteoglycans (HSPGs) are glycoproteins that consist of a proteoglycan "core" protein and covalently attached heparan sulfate (HS) chain. HSPGs are ubiquitously expressed in mammalian cells on the cell surface and in the extracellular matrix (ECM) and secretory vesicles. Within HSPGs, the protein cores determine when and where HSPG expression takes place, and the HS chains mediate most of HSPG's biological roles through binding various protein ligands, including cytokines, chemokines, growth factors and receptors, morphogens, proteases, protease inhibitors, and ECM proteins. Through these interactions, HSPGs modulate cell proliferation, adhesion, migration, invasion, and angiogenesis to display essential functions in physiology and pathology. Under physiological conditions, the expression and localization of HSPGs are finely regulated to orchestrate their physiological functions, and this is disrupted in cancer. The HSPG dysregulation elicits multiple oncogenic signaling, including growth factor signaling, ECM and Integrin signaling, chemokine and immune signaling, cancer stem cell, cell differentiation, apoptosis, and senescence, to prompt cell transformation, proliferation, tumor invasion and metastasis, tumor angiogenesis and inflammation, and immunotolerance. These oncogenic roles make HSPGs an attractive pharmacological target for anti-cancer therapy. Several therapeutic strategies have been under development, including anti-HSPG antibodies, peptides and HS mimetics, synthetic xylosides, and heparinase inhibitors, and shown promising anti-cancer efficacy. Therefore, much progress has been made in this line of study. However, it needs to bear in mind that the roles of HSPGs in cancer can be either oncogenic or tumor-suppressive, depending on the HSPG and the cancer cell type with the underlying mechanisms that remain obscure. Further studies need to address these to fill the knowledge gap and rationalize more efficient therapeutic targeting.

Combination of T cell-redirecting bispecific antibody ERY974 and chemotherapy reciprocally enhances efficacy against non-inflamed tumours

Identifying a strategy with strong efficacy against non-inflamed tumours is vital in cancer immune therapy. ERY974 is a humanized IgG4 bispecific T cell-redirecting antibody that recognizes glypican-3 and CD3. Here we examine the combination effect of ERY974 and chemotherapy (paclitaxel, cisplatin, and capecitabine) in the treatment of non-inflamed tumours in a xenograft model. ERY974 monotherapy shows a minor antitumour effect on non-inflamed NCI-H446 xenografted tumours, as infiltration of ERY974-redirected T cells is limited to the tumour-stromal boundary. However, combination therapy improves efficacy by promoting T cell infiltration into the tumour centre, and increasing ERY974 distribution in the tumour. ERY974 increases capecitabine-induced cytotoxicity by promoting capecitabine conversion to its active form by inducing thymidine phosphorylase expression in non-inflamed MKN45 tumour through ERY974-induced IFNγ and TNFα in T cells. We show that ERY974 with chemotherapy synergistically and reciprocally increases antitumour efficacy, eradicating non-inflamed tumours.

Development of an Organ-Directed Exosome-Based siRNA-Carrier Derived from Autologous Serum for Lung Metastases and Testing in the B16/BL6 Spontaneous Lung Metastasis Model

Exosomes are nano-sized extracellular vesicles that are known to carry various messages to distant cells. It was recently reported that cancer-derived exosomes are orientated to metastatic organs. However, there are no reports on drug carrier development using autologous serum-derived exosomes in vivo. The purpose of this study was to deliver therapeutic siRNAs for melanoma lung metastases using autologous serum-derived exosomes. Primary tumors were induced by subcutaneously injecting melanoma cells into the hindlimbs of female C57BL/6 mice. Primary tumors were surgically removed on day 14. On day 21 after tumor removal, lung metastases were evaluated. Exosomes were isolated from serum collected from mice on days 0, 3, 7, 10, and 14 after primary tumor inoculation. After isolating serum exosomes, siRNA-loaded exosomes were prepared. siRNA-loaded exosomes were intravenously injected into the B16/BL6 spontaneous lung metastasis model mice on days 0, 3, 7, and 10 after tumor removal. siRNA-loaded exosomes prepared with autologous serum-derived exosomes significantly decreased the number of metastatic lung colonies. Autologous serum-derived exosomes, which have high organ accumulation, could potentially be used as efficient carriers of therapeutic siRNAs for melanoma patients with lung metastases.

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.

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.

Evaluation of Glypican-3 Expression in Hepatocellular Carcinoma by Using IDEAL IQ Magnetic Resonance Imaging

RATIONALE AND OBJECTIVES

To investigate the value of iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL IQ) and gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for evaluating Glypican-3 (GPC3) expression in hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Seventy-six patients with histopathologic diagnosis of HCC were retrospectively included in this study. In all patients IDEAL IQ and Gd-EOB-DTPA-enhanced MRI were performed preoperatively using a 3 T MRI system. For an identical slice through the liver of each patient a region of interest was drawn on the tumor in the hepatobiliary phase image and copied to the R2* map and fat fraction map produced by IDEAL IQ. A Mann-Whitney U test was used to compare the region of interest values of R2*, fat fraction and uptake of Gd-EOB-DTPA values between patients with positive and negative GPC3 expression HCC. Receiver operating characteristic analysis was used to determine the diagnostic performances of each of the MRI parameters in evaluating GPC3 expression and histological grade in HCC.

RESULTS

R2* value was significantly higher in cases of positive than negative GPC3 expression HCCs (p < 0.001), whereas there were no significant differences in fat fraction and uptake of Gd-EOB-DTPA between the 2 groups (both p > 0.05). R2* value had higher areas under receiver operating characteristic (0.881), sensitivity (85.96%), and specificity (84.21%) compared to the fat fraction and uptake of Gd-EOB-DTPA.

CONCLUSION

R2* value yielded from IDEAL IQ could reliably predict GPC3 expression in HCC prior to surgery.

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.

Molecular principles of metastasis: a hallmark of cancer revisited

Metastasis is the hallmark of cancer that is responsible for the greatest number of cancer-related deaths. Yet, it remains poorly understood. The continuous evolution of cancer biology research and the emergence of new paradigms in the study of metastasis have revealed some of the molecular underpinnings of this dissemination process. The invading tumor cell, on its way to the target site, interacts with other proteins and cells. Recognition of these interactions improved the understanding of some of the biological principles of the metastatic cell that govern its mobility and plasticity. Communication with the tumor microenvironment allows invading cancer cells to overcome stromal challenges, settle, and colonize. These characteristics of cancer cells are driven by genetic and epigenetic modifications within the tumor cell itself and its microenvironment. Establishing the biological mechanisms of the metastatic process is crucial in finding open therapeutic windows for successful interventions. In this review, the authors explore the recent advancements in the field of metastasis and highlight the latest insights that contribute to shaping this hallmark of cancer.

Glypican-3: A New Target for Diagnosis and Treatment of Hepatocellular Carcinoma

Liver cancer is the second leading cause of cancer-related deaths worldwide, and hepatocellular carcinoma is the most common type. The pathogenesis of hepatocellular carcinoma is concealed, its progress is rapid, its prognosis is poor, and the mortality rate is high. Therefore, novel molecular targets for hepatocellular carcinoma early diagnosis and development of targeted therapy are critically needed. Glypican-3, a cell-surface glycoproteins in which heparan sulfate glycosaminoglycan chains are covalently linked to a protein core, is overexpressed in HCC tissues but not in the healthy adult liver. Thus, Glypican-3 is becoming a promising candidate for liver cancer diagnosis and immunotherapy. Up to now, Glypican-3 has been a reliable immunohistochemical marker for hepatocellular carcinoma diagnosis, and soluble Glypican-3 in serum has becoming a promising marker for liquid biopsy. Moreover, various immunotherapies targeting Glypican-3 have been developed, including Glypican-3 vaccines, anti- Glypican-3 immunotoxin and chimeric-antigen-receptor modified cells. In this review, we summarize and analyze the structure and physicochemical properties of Glypican-3 molecules, then review their biological functions and applications in clinical diagnosis, and explore the diagnosis and treatment strategies based on Glypican-3.

Glypican 3-Targeted Therapy in Hepatocellular Carcinoma

Glypican-3 (GPC3) is an oncofetal glycoprotein attached to the cell membrane by a glycophosphatidylinositol anchor. GPC3 is overexpressed in some kinds of tumors, particularly hepatocellular carcinoma (HCC). The prognostic significance of serum GPC3 levels and GPC3 immunoreactivity in tumor cells has been defined in patients with HCC. In addition to its usefulness as a biomarker, GPC3 has attracted attention as a novel therapeutic target molecule, and clinical trials targeting GPC3 are in progress. The major mechanism of anti-GPC3 antibody (GPC3Ab) against cancer cells is antibody-dependent cellular cytotoxicity and/or complement-dependent cytotoxicity. Since GPC3Ab is associated with immune responses, a combination of protocols with immune checkpoint inhibitors has also been investigated. Moreover, some innovative approaches for GPC3-targeting therapy have emerged in recent years. This review introduces the results of recent clinical trials targeting GPC3 in HCC and summarizes the latest knowledge regarding the role of GPC3 in HCC progression and clinical application targeting GPC3.

Role of glypicans in regulation of the tumor microenvironment and cancer progression

Glypicans are evolutionary conserved, cell surface heparan sulfate (HS) proteoglycans that are attached to the cell membrane via a glycosylphosphatidylinositol (GPI) anchor. Glypicans interact with a broad class of soluble and insoluble ligands, such as morphogens, growth factors, chemokines, receptors and components of the extracellular matrix (ECM). Such versatility comes from their ability to interact through both their HS chains and core protein. Glypicans are involved in cellular and tissue development, morphogenesis and cell motility. They exhibit differential expression in several cancers, acting as both tumor promoters and inhibitors in a cancer type-specific manner. They also influence tumor stroma by facilitating angiogenesis, ECM remodeling and alteration of immune cell functions. Glypicans have emerged as a new therapeutic moiety, whose functions can be exploited in the field of targeted therapies and precision medicine in cancer. This is demonstrated by the emergence of several anti-glypican antibody-based immunologics that have been recently developed and are being evaluated in clinical trials. This review will focus on glypican structure and function with an emphasis on their expression in various cancers. Discussion will also center on the potential of glypicans to be therapeutic targets for inhibition of cancer cell growth.

Elevated GPC3 level promotes cell proliferation in liver cancer

The aim of the present study was to investigate the biological role of glypican 3 (GPC3), and to identify its mechanism and clinical significance in the carcinogenesis of liver cancer. A total of 114 patients with liver cancer were involved. Their clinical data, hematoxylin and eosin-stained and Antigen Ki-67 protein (Ki-67) and GPC3 immunohistochemically-stained liver cancer tissue sections were analyzed to evaluate the correlation between the liver cancer proliferation, differentiation and GPC3 expression. Fluorescence microscopy, western blotting, MTT and reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays were performed in HepG2 and HLE cell lines to investigate the potential mechanisms of action. Among the 114 patients with liver cancer enrolled in the present study, 12 exhibited well-differentiated liver cancer, of which 6 (50%) were positive for GPC3. A total of 30 cases exhibited poorly differentiated liver cancer; 26 (87%) of these expressed GPC3 and 11 cases (37%) demonstrated strong positive expression levels. The other 72 liver cancer cases were moderately differentiated; 75% (54/72) of these expressed GPC3 and 12.5% (9/72) exhibited strong positive expression levels. There was a significant association between the levels of GPC3 expression and liver cancer differentiation (χ²=16.306, P=0.008). Ki-67 staining as the criteria of the liver cancer cell proliferation index also indicated a cross correlation between liver cancer proliferation and GPC3 levels. Among the 39 liver cancer samples with a cell proliferation index <5%, only 2.6% (1/39) exhibited strong positive GPC3 staining, but of the 16 cases with a high cell proliferation index >50%, 6 exhibited strong GPC3 staining (37.5%). The difference of cell proliferation indexes between cancer cells were well, moderate and poorly differentiated, and was markedly significant (χ²=26.334, P=0.002), and suggested that liver cancer cell proliferation was positively correlated with GPC3 expression (r=0.316, P=0.001). Consistently, in vitro analysis indicated that GPC3 promoted HepG2 and HLE cell growth, which was more apparent in HepG2 cells. The RT-qPCR results indicated that GPC3 promoted proliferation through the Hedgehog (Hh) pathway in HepG2 cells, but not in HLE cells. In the present study, it was demonstrated that patients with liver cancer with higher GPC3 levels exhibited poorer differentiation and higher proliferation levels. In vitro GPC3 may promote liver cancer cell lines proliferation through the Hh pathway.

Heparan Sulfate and Heparan Sulfate Proteoglycans in Cancer Initiation and Progression

Heparan sulfate (HS) are complex unbranched carbohydrate chains that are heavily modified by sulfate and exist either conjugated to proteins or as free, unconjugated chains. Proteins with covalently bound Heparan sulfate chains are termed Heparan Sulfate Proteoglycans (HSPGs). Both HS and HSPGs bind to various growth factors and act as co-receptors for different cell surface receptors. They also modulate the dynamics and kinetics of various ligand-receptor interactions, which in turn can influence the duration and potency of the signaling. HS and HSPGs have also been shown to exert a structural role as a component of the extracellular matrix, thereby altering processes such as cell adhesion, immune cell infiltration and angiogenesis. Previous studies have shown that HS are deregulated in a variety of solid tumors and hematological malignancies and regulate key aspects of cancer initiation and progression. HS deregulation in cancer can occur as a result of changes in the level of HSPGs or due to changes in the levels of HS biosynthesis and remodeling enzymes. Here, we describe the major cell-autonomous (proliferation, apoptosis/senescence and differentiation) and cell-non-autonomous (angiogenesis, immune evasion, and matrix remodeling) roles of HS and HSPGs in cancer. Finally, we discuss therapeutic opportunities for targeting deregulated HS biosynthesis and HSPGs as a strategy for cancer treatment.

Role of Glypican-3 in the growth, migration and invasion of primary hepatocytes isolated from patients with hepatocellular carcinoma

BACKGROUND

Recently, Glypican-3 (GPC3) has been identified as a potential hepatocellular carcinoma (HCC) diagnostic and/or therapeutic target. GPC3 has been found to be up-regulated in HCC and to be absent in normal and cirrhotic liver. As yet, however, the molecular characteristics of GPC3 and its role in HCC cell physiology and development are still undefined.

METHODS

Human hepatocyte cultures were established from 10 HCC patients. Additional liver samples were obtained from 5 patients without cirrhosis and/or HCC. Soft agar colony formation, (co-)immunofluorescence and Western blot assays were used to characterize the hapatocyte cultures. The expression of GPC3 in the hepatocytes was silenced using siRNA, after which, apoptosis, scratch wound migration and transwell invasion assays were performed.

RESULTS

We found that in HCC precursor hepatocytes GPC3 is increasingly expressed in different forms and at different locations, i.e., a non-cleaved form (70 kDa) was found to be localized in the cytoplasm while a N-terminal cleaved form (N-GPC3: 40 kDa) was fond to be localized in the cytoplasm and at the extracellular side of hepatocyte membranes. In addition, we found that the non-cleaved form of GPC3 co-localizes with Furin-Convertase in the Golgi apparatus. We also found that, similar to GPC3, Furin-Convertase is expressed in HCC precursor cells, suggesting a role in GPC3 processing. Subsequent siRNA-mediated GPC3 silencing resulted in a temporary inhibition of cell proliferation, migration and ivasion, while inducing apoptosis in transformed hepatocytes.

CONCLUSION

Our data reveal new aspects of the role of GPC3 in early hepatocyte transformation. In addition we conclude that GPC3 may serve as a new HCC immune-therapeutic target.

Proteoglycans remodeling in cancer: Underlying molecular mechanisms

Extracellular matrix is a highly dynamic macromolecular network. Proteoglycans are major components of extracellular matrix playing key roles in its structural organization and cell signaling contributing to the control of numerous normal and pathological processes. As multifunctional molecules, proteoglycans participate in various cell functions during morphogenesis, wound healing, inflammation and tumorigenesis. Their interactions with matrix effectors, cell surface receptors and enzymes enable them with unique properties. In malignancy, extensive remodeling of tumor stroma is associated with marked alterations in proteoglycans' expression and structural variability. Proteoglycans exert diverse functions in tumor stroma in a cell-specific and context-specific manner and they mainly contribute to the formation of a permissive provisional matrix for tumor growth affecting tissue organization, cell-cell and cell-matrix interactions and tumor cell signaling. Proteoglycans also modulate cancer cell phenotype and properties, the development of drug resistance and tumor stroma angiogenesis. This review summarizes the proteoglycans remodeling and their novel biological roles in malignancies with particular emphasis to the underlying molecular mechanisms.

An anti–glypican 3/CD3 bispecific T cell–redirecting antibody for treatment of solid tumors

Cancer care is being revolutionized by immunotherapies such as immune checkpoint inhibitors, engineered T cell transfer, and cell vaccines. The bispecific T cell–redirecting antibody (TRAB) is one such promising immunotherapy, which can redirect T cells to tumor cells by engaging CD3 on a T cell and an antigen on a tumor cell. Because T cells can be redirected to tumor cells regardless of the specificity of T cell receptors, TRAB is considered efficacious for less immunogenic tumors lacking enough neoantigens. Its clinical efficacy has been exemplified by blinatumomab, a bispecific T cell engager targeting CD19 and CD3, which has shown marked clinical responses against hematological malignancies. However, the success of TRAB in solid tumors has been hampered by the lack of a target molecule with sufficient tumor selectivity to avoid “on-target off-tumor” toxicity. Glypican 3 (GPC3) is a highly tumor-specific antigen that is expressed during fetal development but is strictly suppressed in normal adult tissues. We developed ERY974, a whole humanized immunoglobulin G–structured TRAB harboring a common light chain, which bispecifically binds to GPC3 and CD3. Using a mouse model with reconstituted human immune cells, we revealed that ERY974 is highly effective in killing various types of tumors that have GPC3 expression comparable to that in clinical tumors. ERY974 also induced a robust antitumor efficacy even against tumors with nonimmunogenic features, which are difficult to treat by inhibiting immune checkpoints such as PD-1 (programmed cell death protein–1) and CTLA-4 (cytotoxic T lymphocyte–associated protein–4). Immune monitoring revealed that ERY974 converted the poorly inflamed tumor microenvironment to a highly inflamed microenvironment. Toxicology studies in cynomolgus monkeys showed transient cytokine elevation, but this was manageable and reversible. No organ toxicity was evident. These data provide a rationale for clinical testing of ERY974 for the treatment of patients with GPC3-positive solid tumors.

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.

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.

Prognostic and clinicopathological significance of glypican-3 overexpression in hepatocellular carcinoma: A meta-analysis

AIM: To investigate the prognostic and clinicopathological significance of glypican-3 (GPC3) overexpression in hepatocellular carcinoma (HCC).

METHODS: Publications were searched using PubMed, EMBASE, the Cochrane Library and the Chinese Biomedical Literature Database up to March 2013. Inclusion and exclusion criteria were established to screen eligible studies for meta-analysis. The hazard ratios (HRs) of the eligible studies were pooled using RevMan 5.2 software to evaluate the impact of GPC3 overexpression on overall survival (OS) and disease-free survival (DFS) in HCC patients. The correlation between GPC3 expression and clinicopathological parameters of HCC was also analyzed.

RESULTS: A total of five studies with 493 patients were included in the meta-analysis. The combined HRs indicated that GPC3 overexpression can predict poor OS (n = 362 in 3 studies, HR = 2.18, 95%CI: 1.47-3.24, Z = 3.86, P = 0.0001) and DFS (n = 325 in 3 studies, HR = 2.05, 95%CI: 1.43-2.93, Z = 3.94, P < 0.0001) in HCC patients without heterogeneity. Egger’s and Begg’s tests were applied to detect publication bias, and the results showed that there was no evidence of publication bias detected in the OS studies (the P value for Egger’s test was 0.216) or DFS studies (the P value for Egger’s test was 0.488). The combined odds ratios (ORs) suggested that GPC3 expression tends to be associated with tumor vascular invasion (OR = 2.74, 95%CI: 1.15-6.52, P = 0.02), hepatic cirrhosis (OR = 2.10, 95%CI: 1.31-3.36, P = 0.002), poor tumor differentiation (OR = 0.22, 95%CI: 0.13-0.40, P < 0.00001) and advanced TNM stage (OR = 0.31, 95%CI: 0.18-0.51, P < 0.00001).

CONCLUSION: From this study, we conclude that GPC3 overexpression tends to be associated with a poor prognosis (poor OS or DFS) in HCC.

Heparan sulfate signaling in cancer

Heparan sulfate (HS) is a biopolymer consisting of variably sulfated repeating disaccharide units. The anticoagulant heparin is a highly sulfated intracellular variant of HS. HS has demonstrated roles in embryonic development, homeostasis, and human disease via non-covalent interactions with numerous cellular proteins, including growth factors and their receptors. HS can function as a co-receptor by enhancing receptor-complex formation. In other contexts, HS disrupts signaling complexes or serves as a ligand sink. The effects of HS on growth factor signaling are tightly regulated by the actions of sulfyltransferases, sulfatases, and heparanases. HS has important emerging roles in oncogenesis, and heparin derivatives represent potential therapeutic strategies for human cancers. Here we review recent insights into HS signaling in tumor proliferation, angiogenesis, metastasis, and differentiation. A cancer-specific understanding of HS signaling could uncover potential therapeutic targets in this highly actionable signaling network.

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.

A novel panel of biomarkers in distinction of small well-differentiated HCC from dysplastic nodules and outcome values

Background

Differential diagnosis of high-grade dysplastic nodules (HGDN) and well-differentiated hepatocellular carcinoma (WDHCC) represents a challenge to experienced hepatic clinicians, radiologists and hepatopathologists.

Methods

The expression profiles of aminoacylase-1 (ACY1), sequestosome-1 (SQSTM1) and glypican-3 (GPC3) in low-grade dysplastic nodules (LGDN), HGDN and WDHCC were assessed by immunohistochemistry. The differential diagnostic performances of these three markers alone and in combination for HGDN and WDHCC were investigated by logistic regression models (HGDN = 21; WDHCC = 32) and validated in an independent test set (HGDN, n = 21; WDHCC n = 24). Postoperative overall survival and time to recurrence were evaluated by univariate and multivariate analyses in an independent set of 500 patients.

Results

ACY1, SQSTM1 and GPC3 were differentially expressed in each group. For the differential diagnosis of WDHCC from HGDN, the sensitivity and specificity of the combination of ACY1 + SQSTM1 + GPC3 for detecting WDHCC were 93.8% and 95.2% respectively in the training set, which were higher than any of the three two-marker combinations. The validities of the four diagnostic models were further confirmed in an independent test set, and corresponding good sensitivity and specificity were observed. Interestingly, GPC3 expression in HCC tissues combined with serum α-fetoprotein (AFP) was found to be an independent predictor for overall survival and time to recurrence.

Conclusions

ACY1 + SQSTM1 + GPC3 combination represents a potentially valuable biomarker for distinguishing between WDHCC and HGDN using immunohistochemistry. Meanwhile, low GPC3 staining combined with positive serum AFP may play a practical role in predicting poor postoperative outcome and high tumor recurrence risk.