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

Discovery of genomic loci for liver health and steatosis reveals overlap with glutathione redox genetics

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver condition in the United States, encompassing a wide spectrum of liver pathologies including steatosis, steatohepatitis, fibrosis, and cirrhosis. Despite its high prevalence, there are no medications currently approved by the Food and Drug Administration for the treatment of NAFLD. Recent work has suggested that NAFLD has a strong genetic component and identifying causative genes will improve our understanding of the molecular mechanisms contributing to NAFLD and yield targets for future therapeutic investigations. Oxidative stress is known to play an important role in NAFLD pathogenesis, yet the underlying mechanisms accounting for disturbances in redox status are not entirely understood. To better understand the relationship between the glutathione redox system and signs of NAFLD in a genetically-diverse population, we measured liver weight, serum biomarkers aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and graded liver pathology in a large cohort of Diversity Outbred mice. We compared hepatic endpoints to those of the glutathione redox system previously measured in the livers and kidneys of the same mice, and we screened for statistical and genetic associations using the R/qtl2 software. We discovered several novel genetic loci associated with markers of liver health, including loci that were associated with both liver steatosis and glutathione redox status. Candidate genes within each locus point to possible new mechanisms underlying the complex relationship between NAFLD and the glutathione redox system, which could have translational implications for future studies targeting NAFLD pathology.

Molecular mechanisms of human overgrowth and use of omics in its diagnostics: chances and challenges

Overgrowth disorders comprise a group of entities with a variable phenotypic spectrum ranging from tall stature to isolated or lateralized overgrowth of body parts and or organs. Depending on the underlying physiological pathway affected by pathogenic genetic alterations, overgrowth syndromes are associated with a broad spectrum of neoplasia predisposition, (cardio) vascular and neurodevelopmental anomalies, and dysmorphisms. Pathologic overgrowth may be of prenatal or postnatal onset. It either results from an increased number of cells (intrinsic cellular hyperplasia), hypertrophy of the normal number of cells, an increase in interstitial spaces, or from a combination of all of these. The underlying molecular causes comprise a growing number of genetic alterations affecting skeletal growth and Growth-relevant signaling cascades as major effectors, and they can affect the whole body or parts of it (mosaicism). Furthermore, epigenetic modifications play a critical role in the manifestation of some overgrowth diseases. The diagnosis of overgrowth syndromes as the prerequisite of a personalized clinical management can be challenging, due to their clinical and molecular heterogeneity. Physicians should consider molecular genetic testing as a first diagnostic step in overgrowth syndromes. In particular, the urgent need for a precise diagnosis in tumor predisposition syndromes has to be taken into account as the basis for an early monitoring and therapy. With the (future) implementation of next-generation sequencing approaches and further omic technologies, clinical diagnoses can not only be verified, but they also confirm the clinical and molecular spectrum of overgrowth disorders, including unexpected findings and identification of atypical cases. However, the limitations of the applied assays have to be considered, for each of the disorders of interest, the spectrum of possible types of genomic variants has to be considered as they might require different methodological strategies. Additionally, the integration of artificial intelligence (AI) in diagnostic workflows significantly contribute to the phenotype-driven selection and interpretation of molecular and physiological data.

Construction of GPC3-modified Lipopolymer SiRNA Delivery System

BACKGROUND

Gene therapy has been widely concerned because of its unique therapeutic mechanism. However, due to the lack of safe and effective carries, it has not been widely used in clinical practice. Glypican 3 (GPC3) is a highly specific proteoglycan for hepatocellular carcinoma and is a potential diagnostic and therapeutic target for hepatocellular carcinoma. Herein, to monitor the effect of gene therapy and enhance the transfection efficiency of gene carriers, GPC3-modified lipid polyethyleneimine-modified superparamagnetic nanoparticle (GLPS), a type of visualized carrier for siRNA (small-interfering RNA) targeting the liver, was prepared.

METHODS

We performed in vitro gene silencing, cytotoxicity, and agarose gel electrophoresis to identify the optimal GLPS formulation. In vitro MRI and Prussian blue staining verified the liver-targeting function of GLPS. We also analyzed the biocompatibility of GLPS by co-culturing with rabbit red blood cells. Morphological changes were evaluated using HE staining.

RESULTS

The GLPS optimal formulation consisted of LPS and siRNA at a mass ratio of 25:1 and LPS and DSPE-PEG-GPC3 at a molar ratio of 2:3. GLPS exhibited evident liver-targeting function. In vitro, we did not observe morphological changes in red blood cells or hemolysis after co-culture. In vivo, routine blood analysis revealed no abnormalities after GLPS injection. Moreover, the tissue morphology of the kidney, spleen, and liver was normal without injury or inflammation.

CONCLUSION

GLPS could potentially serve as an effective carrier for liver-targeted MRI monitoring and siRNA delivery.

Glypican-3 (GPC-3) Structural Analysis and Cargo in Serum Small Extracellular Vesicles of Hepatocellular Carcinoma Patients

Glypican-3 (GPC-3) is a heparin sulfate proteoglycan located extracellularly and anchored to the cell membrane of transformed hepatocytes. GPC-3 is not expressed in normal or cirrhotic liver tissue but is overexpressed in hepatocellular carcinoma (HCC). Because of this, GPC-3 is one of the most important emerging immunotargets for treatment and as an early detection marker of HCC. To determine if GPC-3 domains associated with serum small extracellular vesicles (sEVs) could be used as an HCC diagnostic marker, we predicted in silico GPC-3 structural properties and tested for the presence of its full-length form and/or cleaved domains in serum sEVs isolated from patients with HCC. Structural analysis revealed that the Furin cleavage site of GPC-3 is exposed and readily accessible, suggesting the facilitation of GPC-3 cleavage events. Upon isolation of sEVs from both hepatocytes, culture media and serum of patients with HCC were studied for GPC-3 content. This data suggests that Furin-dependent GPC-3 cleaved domains could be a powerful tool for detection of initial stages of HCC and serve as a predictor for disease prognosis.

A cell transmembrane peptide chimeric M(27-39)-HTPP targeted therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor, with a growing incidence and death rate worldwide. The aims and challenges of treating HCC include targeting the tumor, entering the tumor tissue, inhibiting the spread and growth of tumor cells. M27-39 is a small peptide isolated from the antimicrobial peptide Musca domestica cecropin (MDC), whereas HTPP is a liver-targeting, cell-penetrating peptide obtained from the circumsporozoite protein (CSP) of Plasmodium parasites. In this study, M27-39 was modified by HTPP to form M(27-39)-HTPP, which targeted tumor penetration to treat HCC. Here, we revealed that M(27-39)-HTPP had a good ability to target and penetrate the tumor, effectively limit the proliferation, migration, and invasion, and induce the apoptosis in HCC. Notably, M(27-39)-HTPP demonstrated good biosecurity when administered at therapeutic doses. Accordingly, M(27-39)-HTPP could be used as a new, safe, and efficient therapeutic peptide for HCC.

Priming treatment with T-cell redirecting bispecific antibody ERY974 reduced cytokine induction without losing cytotoxic activity in vitro by changing the chromatin state in T cells

CD3 bispecific constructs are anticipated to become an important form of cancer immunotherapy, but they frequently cause cytokine release syndrome (CRS) that is difficult to manage in clinical contexts. A combination of intra-patient dose escalation and immunosuppressive treatment is widely used to mitigate CRS. Studies suggest that CRS after subsequent doses of CD3 bispecific constructs is less severe than after the priming dose, and that step-up dosing reduces cytokine levels in animals and humans. However, the mechanism underlying the reduced cytokine induction after priming treatment with CD3 bispecific constructs is unclear. To understand human T-cell activation and chromatin states after priming treatment with CD3 bispecific construct targeting CD3ɛ and glypican 3 (ERY974), we examined cytokine levels, cytokine mRNA expression, CD3ɛ expression, CD3-mediated signal transduction, T cell activation markers, cytotoxicity against target cells, and chromatin states in T cells after ERY974 priming treatment or negative control. The second ERY974 treatment decreased cytokines on Day 8, and ERY974 priming treatment changed the chromatin state in T cells. CD3ɛ expression, CD3-mediated signal transduction, T cell activation markers, and cytotoxicity were similar between the priming treatment with ERY974 and negative control. The present study suggests that chromatin state changes in T cells after the priming treatment was a pivotal factor in the mitigation of cytokine release after the second ERY974 treatment.

Novel Molecular Targets for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of death from cancer globally. Indeed, only a few treatments are available, most of which are effective only for the early stages of the disease. Therefore, there is an urgent needing for potential markers for a specifically targeted therapy. Candidate proteins were selected from datasets of The Human Protein Atlas, in order to identify specific tumor-associated proteins overexpressed in HCC samples associated with poor prognosis. Potential epitopes were predicted from such proteins, and homology with peptides derived from viral proteins was assessed. A multiparametric validation was performed, including recognition by PBMCs from HCC-patients and healthy donors, showing a T-cell cross-reactivity with paired epitopes. These results provide novel HCC-specific tumor-associated antigens (TAAs) for immunotherapeutic anti-HCC strategies potentially able to expand pre-existing virus-specific CD8⁺ T cells with superior anticancer efficacy.

Search for Effective Serum Tumor Markers for Early Diagnosis of Hepatocellular Carcinoma Associated with Hepatitis C

The aim of the study was to identify the most effective serum tumor markers for early diagnosis of hepatocellular carcinoma based on the combination of diagnostic characteristics and correlations.

A Humanized Anti-GPC3 Antibody for Immuno-Positron Emission Tomography Imaging of Orthotopic Mouse Model of Patient-Derived Hepatocellular Carcinoma Xenografts

Simple Summary

Liver cancer, the majority of which is hepatocellular carcinoma, is a typically fatal adult liver malignancy. It is hard to detect in the early stages of the cancer, and therefore patients are often diagnosed at the advanced stages, when treatment options become more limited and survival outcomes are poor. To improve early detection, and therefore treatment and prognosis of liver cancer patients, we have developed an imaging probe for positron emission tomography, targeting a protein, glypican-3, which is specifically expressed at high levels in liver cancer cells. Our probe consists of the ⁸⁹Zr radioisotope conjugated to a humanized monoclonal antibody against glypican-3, and it demonstrates specific ability to detect patient-derived liver cancer xenografts in a mouse model. With a high tumor to normal liver contrast, we believe this imaging probe can provide a useful tool in the early diagnosis and timely medical intervention for liver cancer patients.

Abstract

Glypican-3 (GPC3) is an attractive diagnostic marker for hepatocellular carcinoma (HCC). We previously reported the potential of an ⁸⁹Zr-labeled murine anti-GPC3 antibody (clone 1G12) for immunoPET imaging of HCC in orthotopic patient-derived xenograft (PDX) mouse models. We now humanized the murine antibody by complementarity determining region (CDR) grafting, to allow its clinical translation for human use. The engineered humanized anti-GPC3 antibody, clone H3K3, retained comparable binding affinity and specificity to human GPC3. H3K3 was conjugated with desferrioxamine (Df) and radiolabeled with ⁸⁹Zr to produce the PET/CT tracer ⁸⁹Zr-Df-H3K3. When injected into GPC3-expressing orthotopic HCC PDX in NOD SCID Gamma (NSG) mice, ⁸⁹Zr-Df-H3K3 showed specific high uptake into the orthotopic PDX and minimal, non-specific uptake into the non-tumor bearing liver. Specificity was demonstrated by significantly higher uptake of ⁸⁹Zr-Df-H3K3 into the non-blocked PDX mice, compared with the blocked PDX mice (which received prior injection of 100 mg of unlabeled H3K3). Region of interest (ROI) analysis showed that the PDX/non-tumor liver ratio was highest (mean ± SD: 3.4 ± 0.31) at 168 h post injection; this ratio was consistent with biodistribution studies at the same time point. Thus, our humanized anti-GPC3 antibody, H3K3, shows encouraging potential for use as an immunoPET tracer for diagnostic imaging of HCC patients.

Targeting acute myeloid leukemia cells by CD33 receptor-specific MoS2-based nanoconjugates

Acute myeloid leukemia (AML) is a highly aggressive type of cancer caused by the uncontrolled proliferation of undifferentiated myeloblasts, affecting the bone marrow and blood. Systemic chemotherapy is considered the primary treatment strategy; unfortunately, healthy cells are also affected to a large extent, leading to severe side effects of this treatment. Targeted drug therapies are becoming increasingly popular in modern medicine, as they bypass normal tissues and cells. Two-dimensional MoS₂-based nanomaterials have attracted attention in the biomedical field as promising agents for cancer diagnosis and therapy. Cancer cells typically (over)express distinctive cytoplasmic membrane-anchored or -spanning protein-based structures (e.g., receptors, enzymes) that distinguish them from healthy, non-cancerous cells. Targeting cancer cells via tumor-specific markers using MoS₂-based nanocarriers loaded with labels or drugs can significantly improve specificity and reduce side effects of such treatment. SKM-1 is an established AML cell line that has been employed in various bio-research applications. However, to date, it has not been used as the subject of studies on selective cancer targeting by inorganic nanomaterials. Here, we demonstrate an efficient targeting of AML cells using MoS₂nanoflakes prepared by a facile exfoliation route and functionalized with anti-CD33 antibody that binds to CD33 receptors expressed by SKM-1 cells. Microscopic analyses by confocal laser scanning microscopy supplemented by label-free confocal Raman microscopy proved that (anti-CD33)-MoS₂conjugates were present on the cell surface and within SKM-1 cells, presumably having been internalized via CD33-mediated endocytosis. Furthermore, the cellular uptake of SKM-1 specific (anti-CD33)-MoS₂conjugates assessed by flow cytometry analysis was significantly higher compared with the cellular uptake of SKM-1 nonspecific (anti-GPC3)-MoS₂conjugates. Our results indicate the importance of appropriate functionalization of MoS₂nanomaterials by tumor-recognizing elements that significantly increase their specificity and hence suggest the utilization of MoS₂-based nanomaterials in the diagnosis and therapy of AML.

Cellular based treatment modalities for unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and is unfortunately associated with an overall poor prognosis and high mortality. Early and intermediate stages of HCC allow for treatment with surgical resection, ablation and even liver transplantation, however disease progression warrants conventional systemic therapy. For years treatment options were limited to molecular-targeting medications, of which sorafenib remains the standard of care. The recent development and success of immune checkpoint inhibitors has proven to be a breakthrough in the treatment of HCC, but there is an urgent need for the development of further novel therapeutic treatments that prolong overall survival and minimize recurrence. Current investigation is focused on adoptive cell therapy including chimeric antigen receptor-T cells (CAR-T cells), T cell receptor (TCR) engineered T cells, dendritic cells, natural killer cells, and tumor infiltrating lymphocyte cells, which have shown remarkable success in the treatment of hematological and solid tumor malignancies. In this review we briefly introduce readers to the currently approved systemic treatment options and present clinical and experimental evidence of HCC immunotherapeutic treatments that will hopefully one day allow for revolutionary change in the treatment modalities used for unresectable HCC. We also provide an up-to-date compilation of ongoing clinical trials investigating CAR-T cells, TCR engineered T cells, cancer vaccines and oncolytic viruses, while discussing strategies that can help overcome commonly faced challenges when utilizing cellular based treatments.

A novel multifunctional gold nanorod-mediated and tumor-targeted gene silencing of GPC-3 synergizes photothermal therapy for liver cancer

Tumor-specific targeted delivery is a major obstacle to clinical treatment of hepatocellular carcinoma (HCC). Here we have developed a novel multi-functional nanostructure GAL-GNR-siGPC-3, which consists of Galactose (GAL) as the HCC-targeting moiety, golden nanorods (GNR) as a framework to destroy tumor cells under laser irradiation, and siRNA of Glypican-3 (siGPC-3) which induce specifically gene silence of GPC-3 in HCC. Glypican-3 (GPC-3) gene is highly associated with HCC and is a new potential target for HCC therapy. On the other hand, Gal can specifically bind to the asialoglycoprotein receptor which is highly expressed on membrane of hepatoma cells. GAL and siGPC-3 can induce targeted silencing of GPC-3 gene in hepatoma cells. In vivo and in vitro results showed that GAL-GNR-siGPC-3 could significantly induce downregulation of GPC-3 gene and inhibit the progression of HCC. More notably, GAL-GNR-siGPC-3 could induce both GPC-3 gene silencing and photothermal effects, and the synergistic treatment of tumors was more effective than individual treatments. In summary, GAL-GNR-siGPC-3 achieved a synergistic outcome to the treatment of cancer, which opens up a new approach for the development of clinical therapies for HCC.

Label-free electrochemical aptasensor based on reduced graphene oxide–hemin–chitosan nanocomposite for the determination of glypican-3

A GPC3 electrochemical aptasensor was constructed using an RGO–H–CS-modified SPE as a biosensing platform and GPC3 aptamer as the recognition element.

Human Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma (HCC) is the fifth most common cancer and accounts for 8 [...].

Persistent Polyfunctional Chimeric Antigen Receptor T Cells That Target Glypican 3 Eliminate Orthotopic Hepatocellular Carcinomas in Mice

BACKGROUND AND AIMS

Glypican 3 (GPC3) is an oncofetal antigen involved in Wnt-dependent cell proliferation that is highly expressed in hepatocellular carcinoma (HCC). We investigated whether the functions of chimeric antigen receptors (CARs) that target GPC3 are affected by their antibody-binding properties.

METHODS

We collected peripheral blood mononuclear cells from healthy donors and patients with HCC and used them to create CAR T cells, based on the humanized YP7 (hYP7) and HN3 antibodies, which have high affinities for the C-lobe and N-lobe of GPC3, respectively. NOD/SCID/IL-2Rgcnull (NSG) mice were given intraperitoneal injections of luciferase-expressing (Luc) Hep3B or HepG2 cells and after xenograft tumors formed, mice were given injections of saline or untransduced T cells (mock control), or CAR (HN3) T cells or CAR (hYP7) T cells. In other NOD/SCID/IL-2Rgcnull (NSG) mice, HepG2-Luc or Hep3B-Luc cells were injected into liver, and after orthotopic tumors formed, mice were given 1 injection of CAR (hYP7) T cells or CD19 CAR T cells (control). We developed droplet digital polymerase chain reaction and genome sequencing methods to analyze persistent CAR T cells in mice.

RESULTS

Injections of CAR (hYP7) T cells eliminated tumors in 66% of mice by week 3, whereas CAR (HN3) T cells did not reduce tumor burden. Mice given CAR (hYP7) T cells remained tumor free after re-challenge with additional Hep3B cells. The CAR T cells induced perforin- and granzyme-mediated apoptosis and reduced levels of active β-catenin in HCC cells. Mice injected with CAR (hYP7) T cells had persistent expansion of T cells and subsets of polyfunctional CAR T cells via antigen-induced selection. These T cells were observed in the tumor microenvironment and spleen for up to 7 weeks after CAR T-cell administration. Integration sites in pre-infusion CAR (HN3) and CAR (hYP7) T cells were randomly distributed, whereas integration into NUPL1 was detected in 3.9% of CAR (hYP7) T cells 5 weeks after injection into tumor-bearing mice and 18.1% of CAR (hYP7) T cells at week 7. There was no common site of integration in CAR (HN3) or CD19 CAR T cells from tumor-bearing mice.

CONCLUSIONS

In mice with xenograft or orthoptic liver tumors, CAR (hYP7) T cells eliminate GPC3-positive HCC cells, possibly by inducing perforin- and granzyme-mediated apoptosis or reducing Wnt signaling in tumor cells. GPC3-targeted CAR T cells might be developed for treatment of patients with HCC.

Engineered Anti-GPC3 Immunotoxin, HN3-ABD-T20, Produces Regression in Mouse Liver Cancer Xenografts Through Prolonged Serum Retention

BACKGROUND AND AIMS

Treatment of hepatocellular carcinomas using our glypican-3 (GPC3)-targeting human nanobody (HN3) immunotoxins causes potent tumor regression by blocking protein synthesis and down-regulating the Wnt signaling pathway. However, immunogenicity and a short serum half-life may limit the ability of immunotoxins to transition to the clinic.

APPROACH AND RESULTS

To address these concerns, we engineered HN3-based immunotoxins to contain various deimmunized Pseudomonas exotoxin (PE) domains. This included HN3-T20, which was modified to remove T-cell epitopes and contains a PE domain II truncation. We compared them to our previously reported B-cell deimmunized immunotoxin (HN3-mPE24) and our original HN3-immunotoxin with a wild-type PE domain (HN3-PE38). All of our immunotoxins displayed high affinity to human GPC3, with HN3-T20 having a KD value of 7.4 nM. HN3-T20 retained 73% enzymatic activity when compared with the wild-type immunotoxin in an adenosine diphosphate-ribosylation assay. Interestingly, a real-time cell growth inhibition assay demonstrated that a single dose of HN3-T20 at 62.5 ng/mL (1.6 nM) was capable of inhibiting nearly all cell proliferation during the 10-day experiment. To enhance HN3-T20's serum retention, we tested the effect of adding a streptococcal albumin-binding domain (ABD) and a llama single-domain antibody fragment specific for mouse and human serum albumin. For the detection of immunotoxin in mouse serum, we developed a highly sensitive enzyme-linked immunosorbent assay and found that HN3-ABD-T20 had a 45-fold higher serum half-life than HN3-T20 (326 minutes vs. 7.3 minutes); consequently, addition of an ABD resulted in HN3-ABD-T20-mediated tumor regression at 1 mg/kg.

CONCLUSION

These data indicate that ABD-containing deimmunized HN3-T20 immunotoxins are high-potency therapeutics ready to be evaluated in clinical trials for the treatment of liver cancer.

Preparation and Characterization of Anti-GPC3 Nanobody Against Hepatocellular Carcinoma

Background

Glypican-3 (GPC3) is a newly identified target molecule for the early diagnosis of hepatocellular carcinoma (HCC), while targeted inhibition of GPC3 signaling may help to control the proliferation and metastasis of HCC cells. The purpose of this study was to prepare the anti-GPC3 nanobody and to investigate the affinity of the anti-GPC3 nanobodies in vitro and the anticancer effects on hepatocellular carcinoma in vivo.

Methods

To screen for unknown anti-GPC3 antibodies, we constructed an antibody phage display library. After three rounds of panning, positive phage clones were identified by enzyme-linked immunosorbent assay (ELISA). Further, the nanobody fusion protein was expressed in E. coli BL21 cells and purified by affinity chromatography. Competitive ELISA and flow cytometry were conducted to confirm the affinity of the anti-GPC3 nanobodies in vitro. The antitumor effects of VHH_GPC3 were assessed in vivo.

Results

The results showed that the nanobody VHH_GPC3 had specific high-affinity binding to His-GPC3 antigen. Moreover, VHH_GPC3 exhibited specific binding to commercial human GPC3 and recognized the surface GPC3 protein of the hepatoma cell line HepG2. Importantly, in vivo study showed that GPC3 nanobody suppresses the growth of HepG2 and improves the survival rate of tumor mice.

Discussion

In summary, our new anti-GPC3 nanobody suggests a strong application potential for targeted therapy of liver cancer.

Development of a minimal physiologically-based pharmacokinetic/pharmacodynamic model to characterize target cell depletion and cytokine release for T cell-redirecting bispecific agents in humans

T cell-redirecting bispecific antibodies (bsAbs) are highly potent tumor-killing molecules. Following bsAb mediated engagement with target cells, T cells get activated and kill target cells while inducing cytokine release, which at higher levels may lead to life-threatening cytokine release syndrome (CRS). Clinical evidence suggests that CRS can be mitigated by implementing a stepwise dosing strategy. Here, we developed a mechanism-based minimal physiologically-based pharmacokinetic/pharmacodynamic (mPBPK/PD) model using reported preclinical and clinical data from blinatumomab. The mPBPK/PD model reasonably captured blinatumomab PK and B cell depletion profiles in blood and in various tissue sites of action (i.e., red marrow perivascular niche, spleen, and lymph nodes) in patients with non-Hodgkin's lymphoma (NHL) and acute lymphoblastic leukemia (ALL). Using interleukin 6 (IL-6) as an example, our model quantitatively characterized the mitigation of cytokine release by a blinatumomab 5-15-60 µg/m²/day stepwise dosing regimen comparing to a 60 µg/m²/day flat dose in NHL patients. Furthermore, by only modifying the system parameters specific for ALL patients, the mPBPK/PD model successfully predicted the mitigation of IL-6 release by a blinatumomab 5-15 µg/m²/day stepwise dosing regimen comparing to a 15 µg/m²/day flat dose. Our work provided a case example to show how mPBPK/PD model can be used to support the discovery and clinical development of T cell-redirecting bsAbs.

High glypican-3 expression characterizes a distinct subset of ovarian clear cell carcinomas in Canadian patients: an opportunity for targeted therapy

The expression frequency and distribution of glypican-3 (GPC3) was retrospectively assessed by immunohistochemistry in 316 accurately phenotyped ovarian clear cell carcinoma (OCCC) specimens from Canadian patients. The study aimed to evaluate the prevalence of this biomarker in OCCC in a mixed-ethnicity Canadian population and to evaluate associations of GPC3 expression with clinicopathological parameters. Tissue microarrays with napsin A or HNF1β positive and WT1-negative OCCC specimens were evaluated using a GPC3 antibody clone 1G12. Membranous, cytoplasmic, and Golgi pattern GPC3 expression was noted in 184 of 316 (58.2%) cases; 63 of 316 (20%) cases showed high GPC3 expression (>50% of tumor cells were positive). GPC3 expression was not associated with age, stage, and residual disease after primary surgery. High GPC3 expression did not correlate with a specific morphological pattern or the presence of endometriosis. Furthermore, GPC3 expression was not significantly associated with survival in the entire cohort. Statistically significant association of high GPC3 expression was noted with higher body mass index, napsin A positivity, estrogen receptor (ER) negativity, and ARID1A retention. In a stratified analysis by ARID1A status, high GPC3 expression was significantly associated with unfavorable outcomes in cases with loss of ARID1A (n=10; log rank p=0.0048). Women diagnosed with OCCC and high GPC3 expression were also more likely to receive adjuvant chemotherapy. Considering the tumor-specific membranous expression of GPC3 in 58% of cases and high interobserver reproducibility, GPC3 immunohistochemistry is a robust predictive test for inclusion in clinical trials for GPC3-targeted therapies for OCCC.

Gene Therapy for Liver Cancers: Current Status from Basic to Clinics

The liver is a key organ for metabolism, protein synthesis, detoxification, and endocrine function, and among liver diseases, including hepatitis, cirrhosis, malignant tumors, and congenital disease, liver cancer is one of the leading causes of cancer-related deaths worldwide. Conventional therapeutic options such as embolization and chemotherapy are not effective against advanced-stage liver cancer; therefore, continuous efforts focus on the development of novel therapeutic options, including molecular targeted agents and gene therapy. In this review, we will summarize the progress toward the development of gene therapies for liver cancer, with an emphasis on recent clinical trials and preclinical studies.

Bone Marrow-Derived Mesenchymal Stem Cell Potential Regression of Dysplasia Associating Experimental Liver Fibrosis in Albino Rats

Objectives

Assessing the therapeutic efficacy of superparamagnetic iron oxide nanoparticles (SPIO) labeled bone marrow-derived mesenchymal stem cells (BM-MSCs) on experimental liver fibrosis and associated dysplasia.

Materials and Methods

MSCs were obtained from 10 male Sprague-Dawley rats while 50 female rats were divided into control (CG), liver fibrosis (CCL4, intraperitoneal injection of CCl₄ for 8 weeks), and CCL₄ rats treated with SPIO-labeled MSCs (MSCs/CCl₄) with and without continuing CCL₄ injection for another 8 weeks. Assessment included liver histopathology, liver function tests, transmission electron microscopic tracing for homing of SPIO-MSCs, immunofluorescence histochemistry for fibrosis and dysplasia markers (transforming growth factor-beta (TGF-β1), proliferation nuclear antigen (PCNA), glypican 3)), and quantitative gene expression analysis for matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1).

Results

SPIO-labeled MSCs were engrafted in the fibrotic liver and the BM/MSCs demonstrated regression for fibrous tissue deposition and inhibition progression of dysplastic changes in the liver of CCl₄-treated rats on both the histological and molecular levels.

Conclusion

BM-MSCs possess regenerative and antidysplastic potentials.

Glypican-3 Enhances Reprogramming of Glucose Metabolism in Liver Cancer Cells

Glypican-3(GPC3) is a transmembrane protein which has been found to be frequently overexpressed on the surfaces of liver cancer (LC) cells, which contributes to both the growth and metastasis of LC cells. Recently, the expression of GPC3 has been reported to be inversely associated with glucose metabolism activity in LC patients, suggesting that GPC3 may play a role in the regulation of glucose metabolism in LC. However, the role of GPC3 in glucose metabolism reprogramming, as well as in LC cell growth and metastasis, is unknown. Here, we found that GPC3 significantly contributed to the reprogramming of glucose metabolism in LC cells. On the one hand, GPC3 enhanced the glycolysis of LC cells through upregulation of the glycolytic genes of Glut1, HK2, and LDH-A. On the other hand, GPC3 repressed mitochondrial respiration through downregulation of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α), which has been well known as a crucial regulator in mitochondrial biogenesis. Mechanistic investigations revealed that HIF-1α was involved in both GPC3-regulated upregulation of glycolytic genes of HK2, PKM2, and Glut1 and downregulation of mitochondrial biogenesis regulator PGC-1α in LC cells. Additionally, GPC3-regulated reprogramming of glucose metabolism played a critical role in the growth and metastasis of LC cells. Conclusion. Our findings demonstrate that GPC3 is a critical regulator of glucose metabolism reprogramming in LC cells, which provides a strong line of evidence for GPC3 as an important therapeutic target to normalize glucose metabolic aberrations responsible for LC progression.

Study on Diagnostic Values of Astrocyte Elevated Gene 1 (AEG-1) and Glypican 3 (GPC-3) in Hepatocellular Carcinoma

OBJECTIVES

To investigate the diagnostic potential of AEG-1 and GPC-3 in hepatocellular carcinoma (HCC).

METHODS

AEG-1 and GPC-3 immunohistochemistry were performed on HCC, adjacent nontumor tissue (ANT), and dysplastic nodules (DN).

RESULTS

H score of AEG-1 or GPC-3 in HCC was significantly higher than in ANT or DN. In HCC, 92% and 54% showed AEG-1 and GPC-3 positivity, respectively. In ANT, 16.2% were AEG-1 and 7.6% GPC-3 positive. AEG-1 staining was mostly diffuse, whereas GPC-3 frequently showed focal staining. AEG-1 alone showed high sensitivity but low specificity and accuracy. GPC-3, on the other hand, showed high specificity but low sensitivity and accuracy. Combination of both stains boosted the sensitivity, specificity, and accuracy to 94.6%, 89.5%, and 90.5%, respectively, when only diffuse staining was considered as positive.

CONCLUSIONS

AEG-1 or GPC-3 alone seemed not an ideal marker for HCC. The combination of AEG-1 and GPC-3 might improve early diagnosis of HCC.

PiggyBac-engineered T cells expressing a glypican-3-specific chimeric antigen receptor show potent activities against hepatocellular carcinoma

Glypican-3 (GPC3) is an attractive target for chimeric antigen receptor (CAR)-T cell therapy, as it is overexpressed in most hepatocellular carcinoma (HCC) tissues but shows restricted expression in healthy adult tissues. Herein, we generated GPC3-specific CAR-T cells for HCC therapy by electroporation with plasmid DNA encoding the piggyBac (PB) transposon and the hyperactive piggyBac transposase simultaneously instead of by commonly-used viral vectors. Our results demonstrated that GPC3CAR gene was efficiently integrated into the genome of T cells utilizing the PB transposon system. Upon stimulation with GPC3 antigen, GPC3CAR-T cells could be effectively activated, proliferate strongly and secrete high levels of cytokines. It also was demonstrated that GPC3CAR-T cells displayed potent cytotoxicity against GPC3-positive HCC cell lines in vitro by using real-time cell analyser (RTCA) system and the JuLI™ Stage Cell History Recorder. More importantly, in a Huh-7 xenograft mouse model, GPC3CAR-T cells significantly reduced the tumour burden companied with the secretion of high levels of IFN-γ. Moreover, T cells in mice treated with GPC3CAR-T cells could infiltrate into tumour tissues and persist as effector memory T cells (TEM). Overall, our study suggests that the use of PB system-based GPC3CAR-T cell therapy could be a promising clinical strategy for patients with HCC.

An innovative peptide with high affinity to GPC3 for hepatocellular carcinoma diagnosis

Glypican-3 (GPC3) is a key biomarker for early diagnosis of human hepatocellular carcinoma (HCC) due to its overexpression in most HCC tumor tissues. Recently, peptides with high affinity to GPC3 have attracted more attention because of their high biocompatibility, non-immunogenicity, fast clearing and easy modification. Herein, we have designed an innovative GPC3 targeting peptide (sequence: DYEMHLWWGTEL, denoted as IPA) by using structure-based virtual simulation. The higher binding abilities of IPA over the reported peptide (YP) were displayed on different cell lines, showing a positive correlation with GPC3 expressions, which were further verified by the GPC3 protein binding assay. The GPC3 targeting specificity of IPA was proved by peptide blocking and siRNA experiment. The localized anchor of peptide IPA on the cell membranes of HepG2 and Huh-7 with GPC3 overexpression confirmed the GPC3 binding capacity. By connecting a near-infrared dye MPA, the in vivo identification ability of IPA to GPC3 was also demonstrated on GPC3-positive (HepG2) and GPC3-negative (U87) xenograft-bearing mice. These results indicated that the designed IPA presented desirable GPC3 targeting ability, showing promising prospects in detecting the expression of GPC3 for HCC targeting imaging.

[10-gingerol inhibits proliferation of hepatocellular carcinoma HepG2 cells via Src/STAT3 signaling pathway]

OBJECTIVE

To study the inhibitory effect of 10-gingerol on the proliferation of hepatocellular carcinoma HepG2 cells and the role of Src/STAT3 signaling pathway in mediating the effect.

METHODS

SYBYL-X2.1 software was used to simulate the interaction between 10-gingerol and Src. HepG2 cells treated with 10-gingerol at 1, 3, 10 or μol/L for 24 h were assessed for cell viability using MTT assay, and EdU staining was used to detect the cell proliferation and calculate the number of positive cells. The expressions of p-Src and p-STAT3 were detected using Western blotting, and the mRNA expressions of the target genes of STAT3 (cyclin D1 and CMCC) were detected using qPCR.

RESULTS

10-gingerol was capable of forming hydrogen bond with such Src residues as TRY-340, MET-341, MET-314, ASP-404, and ILE-336. MTT assay showed that 10-gingerol at 3 and 10 μmol/L significantly lowered the viability of HepG2 cells (P < 0.001). Treatment with 1, 3, and 10 μmol/L 10-gingerol significantly reduces the number of EdU-positive HepG 2 cells (P < 0.001). Western blotting showed that 10-gingerol at 3 and 10 μmol/L significantly decreased the phosphorylation levels of Src and STAT3 in HepG2 cells (P < 0.01). 10-gingerol at 1, 3, and 10 μmol/L significantly decreased the mRNA expressions of cyclin D1 and CMCC as shown by qPCR (P < 0.01).

CONCLUSIONS

10-gingerol can dose-dependently inhibit the proliferation of HepG2 cells and suppress the activation of Src and STAT3.

Glypican 4 and Mmp14 interact in regulating the migration of anterior endodermal cells by limiting extracellular matrix deposition

During embryogenesis, the germ layers, including the endoderm, undergo convergence and extension movements to narrow and elongate the body plan. In zebrafish, the dorsal migration of endodermal cells during gastrulation is controlled by chemokine signaling, but little is known about how they migrate during segmentation. Here, we show that glypican 4 (Gpc4), a member of the heparin sulfate proteoglycan family, is required for efficient migration of anterior endodermal cells during early segmentation, regulating Rac activation to maintain polarized actin-rich lamellipodia. An endoderm transplantation assay showed that Gpc4 regulates endoderm migration in a non-cell-autonomous fashion. Further analyses revealed that the impaired endoderm migration in gpc4 mutants results from increases in the expression and assembly of fibronectin and laminin, major components of the extracellular matrix (ECM). Notably, we found that matrix metalloproteinase 14 (Mmp14a/b) is required for the control of ECM expression during endoderm migration, with Gpc4 acting through Mmp14a/b to limit ECM expression. Our results suggest that Gpc4 is crucial for generating the environment required for efficient migration of endodermal cells, uncovering a novel function of Gpc4 during development.

Epigenetic Regulation of the Biosynthesis & Enzymatic Modification of Heparan Sulfate Proteoglycans: Implications for Tumorigenesis and Cancer Biomarkers

Emerging evidence suggests that the enzymes in the biosynthetic pathway for the synthesis of heparan sulfate moieties of heparan sulfate proteoglycans (HSPGs) are epigenetically regulated at many levels. As the exact composition of the heparan sulfate portion of the resulting HSPG molecules is critical to the broad spectrum of biological processes involved in oncogenesis, the epigenetic regulation of heparan sulfate biosynthesis has far-reaching effects on many cellular activities related to cancer progression. Given the current focus on developing new anti-cancer therapeutics focused on epigenetic targets, it is important to understand the effects that these emerging therapeutics may have on the synthesis of HSPGs as alterations in HSPG composition may have profound and unanticipated effects. As an introduction, this review will briefly summarize the variety of important roles which HSPGs play in a wide-spectrum of cancer-related cellular and physiological functions and then describe the biosynthesis of the heparan sulfate chains of HSPGs, including how alterations observed in cancer cells serve as potential biomarkers. This review will then focus on detailing the multiple levels of epigenetic regulation of the enzymes in the heparan sulfate synthesis pathway with a particular focus on regulation by miRNA and effects of epigenetic therapies on HSPGs. We will also explore the use of lectins to detect differences in heparan sulfate composition and preview their potential diagnostic and prognostic use in the clinic.