Glypican-3 expression in gastrointestinal and pancreatic epithelial neoplasms

Identification of 68 HLA-A24 and -A2-restricted cytotoxic T lymphocyte-inducing peptides derived from 10 common cancer-specific antigens frequently expressed in various solid cancers

Targeting cancer antigens expressed in cancer cells is necessary to develop cancer-specific immunotherapy. We have performed immunohistochemical analysis of various solid cancer specimens, adding ROBO1, AFP, TGFBI, EphB4, CLDN1, and LAT1 to the previously studied glypican-3 (GPC3), HSP105α, FOXM1, and SPARC, and found that these 10 common cancer antigens are sufficient to cover most solid cancers. These antigens were frequently expressed in various solid cancers but shown to be rarely ex-pressed, with some exceptions, in non-cancerous normal organs adjacent to the cancer. In this study, we predicted 72 and 73 peptides that bind to HLA-A24 and -A2 in silico from the full-length amino acid sequences of these 10 common cancer antigens and immunized each HLA transgenic mouse with a cocktail of synthesized peptides together with the poly I:CLC three times weekly to analyze the antigen-specific immune response. As a result, 68 peptide sequences (30 and 38, respectively) were identified that had higher cytotoxic T lymphocyte (CTL) induction ability than GPC3 298-306 and GPC3 144-152 used in the clinical trials. Furthermore, experiments with cocktail peptide vaccines using mouse models expressing subcutaneous tumors of each antigen showed promising results in terms of safety and efficacy. These peptides identified in this study, derived from 10 common cancer antigens covering all solid cancers, are expected to be clinically applicable as cocktail peptide vaccines.

Glypican-3 and Cytokeratin-19 Expression in Pancreatic Cancer in a Canadian Population

Background/Objectives: One study of pancreatic ductal adenocarcinoma has found expression of glypican-3 (GPC3) and cytokeratin-19 (CK19) determined by immunohistochemistry to be associated with higher stage and grade disease, with a more adverse prognosis. The reported 44% rate of GPC3 expression in pancreatic cancer raises the important possibility that targeted immunotherapies currently in development for hepatocellular carcinoma may also prove useful for GPC3-expressing pancreatic cancers. The present study aims to determine if a similar expression pattern of these markers and stage/grade/prognostic associations is present in our Canadian patient population. Methods: Patients with a pancreatic surgical resection for adenocarcinoma or neuroendocrine tumor (NET) were identified from pathology records over a 5-year period. Immunohistochemistry for GPC3 and CK19 was performed on archived tumor tissue and the proportion of positive cells and intensity of staining were recorded. Grade, stage, and overall survival were compared in patients with NETs that were CK19-positive versus -negative. Results: All 72 pancreatic adenocarcinomas and 20 NETs tested were negative for GPC3, apart from a single case of pancreatic adenocarcinoma. All 72 adenocarcinomas were positive for CK19 expression. Half of the NETs were positive for CK19. There was no correlation between CK19 expression in NETs and tumor grade, lymph node metastasis, distant metastasis, or overall survival. Conclusions: We are skeptical of the reported prognostic value of GPC3 and CK19 in pancreatic adenocarcinomas. CK19 as a prognostic marker in NETs has potential for further study. The results with our protocol for GPC3 immunohistochemistry suggest that pancreatic cancer may be a less promising target for GPC3-targeted immunotherapies than previously thought.

Misunderstood Gastric Perforation of a Pancreatic Acinar Cell Carcinoma: A Wolf in Sheep’s Clothing

A 70-year-old man was admitted to the Emergency Department (ED) for marked asthenia and severe anemia. In addition, a high level of lipase was found. During hospitalization, a locally advanced gastric cancer was diagnosed, with endoscopic evidence of a large polyploid formation originating under the cardias that occupied most of the gastric lumen. A total body CT scan was performed before surgery; the tumor affected the posterior gastric wall, with tenacious infiltration of the pancreatic body. Therefore, we performed a total gastrectomy with esophageal jejunum anastomosis and reconstruction of intestinal continuity according to Roux, distal spleno-pancreatectomy, and cholecystectomy. At histology, a pancreatic acinar cell carcinoma (PACC) with full thickness infiltration of the gastric wall was diagnosed. Acinar cell carcinomas are highly aggressive neoplasms, and surgical resection, when feasible, is the treatment of choice regardless of size, also because the role of neoadjuvant or adjuvant chemo- or radiotherapy remains uncodified.

DT389-YP7, a Recombinant Immunotoxin against Glypican-3 That Inhibits Hepatocellular Cancer Cells: An In Vitro Study

Hepatocellular carcinoma (HCC) is one of the high-metastatic types of cancer, and metastasis occurs in one-third of patients with HCC. To maintain the effectiveness of drug compounds on cancer cells and minimize their side effects on normal cells, it is important to use new approaches for overcoming malignancies. Immunotoxins (ITs), an example of such a new approach, are protein-structured compounds consisting of toxic and binding moieties which can specifically bind to cancer cells and efficiently induce cell death. Here, we design and scrutinize a novel immunotoxin against an oncofetal marker on HCC cells. We applied a truncated diphtheria toxin (DT389) without binding domain as a toxin moiety to be fused with a humanized YP7 scFv against a high-expressed Glypican-3 (GPC3) antigen on the surface of HCC cells. Cytotoxic effects of this IT were investigated on HepG2 (GPC3⁺) and SkBr3 (GPC3⁻) cell lines as positive- and negative-expressed GPC3 antigens. The dissociation constant (Kd) was calculated 11.39 nM and 18.02 nM for IT and YP7 scfv, respectively, whereas only IT showed toxic effects on the HepG2 cell line, and decreased cell viability (IC50 = 848.2 ng/mL). Changing morphology (up to 85%), cell cycle arrest at G2 phase (up to 13%), increasing intracellular reactive oxygen species (ROSs) (up to 50%), inducing apoptosis (up to 38% for apoptosis and 23% for necrosis), and an almost complete inhibition of cell movement were other effects of immunotoxin treatment on HepG2 cells, not on SkBr3 cell line. These promising results reveal that this new recombinant immunotoxin can be considered as an option as an HCC inhibitor. However, more extensive studies are needed to accomplish this concept.

Proteoglycans and their functions in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly malignant disease that has a poor prognosis. Its high lethality is mainly due to the lack of symptoms at early stages, which culminates in diagnosis at a late stage when the tumor has already metastasized. Unfortunately, the common cancer biomarkers have low sensitivity and specificity in esophageal cancer. Therefore, a better understanding of the molecular mechanisms underlying ESCC progression is needed to identify novel diagnostic markers and therapeutic targets for intervention. The invasion of cancer cells into the surrounding tissue is a crucial step for metastasis. During metastasis, tumor cells can interact with extracellular components and secrete proteolytic enzymes to remodel the surrounding tumor microenvironment. Proteoglycans are one of the major components of extracellular matrix. They are involved in multiple processes of cancer cell invasion and metastasis by interacting with soluble bioactive molecules, surrounding matrix, cell surface receptors, and enzymes. Apart from having diverse functions in tumor cells and their surrounding microenvironment, proteoglycans also have diagnostic and prognostic significance in cancer patients. However, the functional significance and underlying mechanisms of proteoglycans in ESCC are not well understood. This review summarizes the proteoglycans that have been studied in ESCC in order to provide a comprehensive view of the role of proteoglycans in the progression of this cancer type. A long term goal would be to exploit these molecules to provide new strategies for therapeutic intervention.

α-Fetoprotein mRNA in situ hybridisation is a highly specific marker of hepatocellular carcinoma: a multi-centre study

BACKGROUND

Pathologic diagnosis of hepatocellular carcinoma (HCC) can be challenging in differentiating from benign and non-hepatocytic malignancy lesions. The aim of this study was to investigate the potential utility of α-fetoprotein (AFP) mRNA RNAscope, a sensitive and specific method, in the diagnosis of HCC.

METHODS

Three independent retrospective cohorts containing 2216 patients with HCC, benign liver lesions, and non-hepatocytic tumours were examined. AFP was detected using ELISA, IHC (Immunohistochemistry), and RNAscope. Glypican3 (GPC3), hepatocyte paraffin-1 (HepPar-1), and arginase-1 (Arg-1) proteins were detected using IHC.

RESULTS

AFP RNAscope improved the HCC detection sensitivity by 24.7-32.7% compared with IHC. In two surgical cohorts, a panel of AFP RNAscope and GPC3 provided the best diagnostic value in differentiating HCC from benign hepatocytic lesions (AUC = 0.905 and 0.811), and a panel including AFP RNAscope, GPC3, HepPar-1, and Arg-1 yielded the best AUC (0.971 and 0.977) when distinguishing HCC from non-hepatocytic malignancies. The results from the liver biopsy cohort were similar, and additional application of AFP RNAscope improved the sensitivity by 18% when distinguishing HCC from benign hepatocytic lesions.

CONCLUSIONS

AFP mRNA detected by RNAscope is highly specific for hepatocytic malignancy and may serve as a novel diagnostic biomarker for HCC.

Development of Glypican-3 Targeting Immunotoxins for the Treatment of Liver Cancer: An Update

Hepatocellular carcinoma (HCC) accounts for most liver cancers and represents one of the deadliest cancers in the world. Despite the global demand for liver cancer treatments, there remain few options available. The U.S. Food and Drug Administration (FDA) recently approved Lumoxiti, a CD22-targeting immunotoxin, as a treatment for patients with hairy cell leukemia. This approval helps to demonstrate the potential role that immunotoxins can play in the cancer therapeutics pipeline. However, concerns have been raised about the use of immunotoxins, including their high immunogenicity and short half-life, in particular for treating solid tumors such as liver cancer. This review provides an overview of recent efforts to develop a glypican-3 (GPC3) targeting immunotoxin for treating HCC, including strategies to deimmunize immunotoxins by removing B- or T-cell epitopes on the bacterial toxin and to improve the serum half-life of immunotoxins by incorporating an albumin binding domain.

Expression of Glypican 3 is an Independent Prognostic Biomarker in Primary Gastro-Esophageal Adenocarcinoma and Corresponding Serum Exosomes

Exosomes are nano-sized membranous vesicles of endosomal origin that carry nucleic acids, lipids and proteins. The cargo of exosomes is cell origin specific and the release of these exosomes and uptake by an acceptor cell is seen as a vital element of cell-cell communication. Here, we sought to investigate the diagnostic and prognostic value of the expression of glypican 3 (GPC3) on primary gastro-esophageal adenocarcinoma (GEA) tissue (tGPC3) and corresponding serum exosomes (eGPC3). Circulating exosomes were extracted from serum samples of 49 patients with GEA and 56 controls. Extracted exosomes were subjected to flow cytometry for the expression of eGPC3 and GPC3 expression on primary GEA tissue samples was determined by immunohistochemistry and correlated to clinicopathological parameters. We found decreased eGPC3 levels in GEA patients compared to healthy controls (p < 0.0001) and high tGPC3 expression. This was significantly associated with poor overall survival (high vs. low eGPC3: 87.40 vs. 60.93 months, p = 0.041, high vs. low tGPC3: 58.03 vs. 84.70 months, p = 0.044). Cox regressional analysis confirmed tGPC3 as an independent prognostic biomarker for GEA (p = 0.02) and tGPC3 expression was validated in two independent cohorts. Our findings demonstrate that eGPC3 and tGPC3 can be used as potential diagnostic and prognostic biomarkers for GEA.

Primary Hepatoid Carcinoma of the Pancreas: A Clinicopathological Study of 3 Cases With Review of Additional 31 Cases in the Literature

Primary pancreatic hepatoid carcinoma (PHC) is very rare. Here, we reported 3 such cases with review of additional 31 cases in the literature. Our 3 patients were male (83, 72, and 54 years old, respectively). Serum α-fetoprotein (AFP) was elevated in 1 patient (case 3, 8338 ng/mL) and not measured in the other two. The PHC in patient 1 (pathological stage pT2N0M0) and patient 2 (pT3N0M0) showed pure hepatocellular carcinoma (HCC)-like morphology, whereas in case 3 it was a PHC with true glandular differentiation (pT4N0M0). The diagnosis of PHC was confirmed with positive immunohistochemical staining in the tumor cells for AFP (2/3), Hep Par 1 (3/3), glypican-3 (2/3), arginase-1 (2/3), and Sal-like protein 4 (1/3). CD10 and polyclonal carcinoembryonic antigen stains show focal canalicular pattern in 2/3 tumors. Patient 1 did not receive further treatment after resection and was alive with no evidence of disease at 107 months. Patient 2 died of postoperative complications, whereas patient 3 received postsurgical chemoradiation and died of disease at 29 months. Our findings and literature review indicate that PHCs can be divided into 4 histological subtypes: with pure HCC-like morphology (n = 22), with neuroendocrine differentiation (n = 8), with true glandular differentiation (n = 3), and with acinar cell differentiation (n = 1). On univariate analysis, pure HCC-like morphology was associated with better disease-specific survival (DSS; P = .04), whereas lymph node and distant metastases were associated with worse DSS ( P = .002 for both). Age, gender, presenting symptoms, serum AFP level, and T stage were not associated with DSS. On multivariate analysis, none of these parameters was significantly associated with DSS.

Update on the pathology of liver neoplasms

Many advances have developed in the pathology of liver tumors in the recent decade. Examples of these advances include the use of glutamine synthetase in the diagnosis of focal nodular hyperplasia, subtyping of hepatocellular adenomas using molecular and immunohistochemical methods, the unraveling of the fusion transcript between the DNAJB1 gene and the PRKACA gene in fibrolamellar carcinoma, and the more unified classification and terminology in intrahepatic bile duct tumors and their precursor lesions. Nevertheless, challenges still remain, e.g., the differential diagnosis between well-differentiated hepatocellular carcinoma and hepatocellular adenoma; distinction among poorly differentiated hepatocellular carcinoma, cholangiocarcinoma and metastatic neoplasm; terminology of the combined hepatocellular carcinoma-cholangiocarcinoma, etc. This review aims to address updates in the pathologic diagnosis and clinical relevance of tumors of the liver and intrahepatic bile ducts in adults and their differential diagnosis and diagnostic pitfalls.

The expansion of targetable biomarkers for CAR T cell therapy

Biomarkers are an integral part of cancer management due to their use in risk assessment, screening, differential diagnosis, prognosis, prediction of response to treatment, and monitoring progress of disease. Recently, with the advent of Chimeric Antigen Receptor (CAR) T cell therapy, a new category of targetable biomarkers has emerged. These biomarkers are associated with the surface of malignant cells and serve as targets for directing cytotoxic T cells. The first biomarker target used for CAR T cell therapy was CD19, a B cell marker expressed highly on malignant B cells. With the success of CD19, the last decade has shown an explosion of new targetable biomarkers on a range of human malignancies. These surface targets have made it possible to provide directed, specific therapy that reduces healthy tissue destruction and preserves the patient's immune system during treatment. As of May 2018, there are over 100 clinical trials underway that target over 25 different surface biomarkers in almost every human tissue. This expansion has led to not only promising results in terms of patient outcome, but has also led to an exponential growth in the investigation of new biomarkers that could potentially be utilized in CAR T cell therapy for treating patients. In this review, we discuss the biomarkers currently under investigation and point out several promising biomarkers in the preclinical stage of development that may be useful as targets.

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.

Update on Ancillary Testing in the Evaluation of High-Grade Liver Tumors

Tissue diagnosis is the gold standard for mass lesions of the liver, but needle core biopsies may sometimes prove challenging. Presented here is a review of a panel of immunohistochemical stains, including hepatocyte in paraffin 1, arginase-1, polyclonal carcinoembryonic antigen, CD10, bile salt export pump, glypican-3, as well as in situ hybridization for albumin RNA, to establish hepatocellular origin in cases in which hepatocellular carcinoma is suspected but the sample is limited or the morphology is challenging, as it may be with cases of scirrhous, fibrolamellar carcinoma, intrahepatic cholangiocarcinoma, and combined hepatocellular-cholangiocarcinoma.

Identification of Glypican-3 as a potential metastasis suppressor gene in gastric cancer

Gastric cancer is a prevalent tumor that is usually detected at an advanced metastatic stage. Currently, standard therapies are mostly ineffective. Here, we report that Glypican-3 (GPC3) is absent in invasive tumors and metastatic lymph nodes, in particular in aggressive and highly disseminated signet ring cell carcinomas. We demonstrate that loss of GPC3 correlates with poor overall survival in patients. Moreover, we show that absence of GPC3 causes up-regulation of MAPK/FoxM1 signaling and that blockade of this pathway alters cellular invasion. An inverse correlation between GPC3 and FoxM1 is also shown in patient samples. These data identify GPC3 as a potential metastasis suppressor gene and suggest its value as a prognostic marker in gastric cancer. Development of therapies targeting signaling downstream of GPC3 are warranted.

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.

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.

Practical Immunohistochemistry in Neoplastic Pathology of the Gastrointestinal Tract, Liver, Biliary Tract, and Pancreas

CONTEXT

- Immunomarkers with diagnostic, therapeutic, or prognostic values have been increasingly used to maximize the benefits of clinical management of patients with neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas.

OBJECTIVES

- To review the characteristics of immunomarkers that are commonly used in surgical pathology practice for neoplasms of the gastrointestinal tract, liver, biliary tract, and pancreas, and to summarize the clinical usefulness of immunomarkers that have been discovered in recent years in these fields.

DATA SOURCES

- Data sources include literature review, authors' research data, and personal practice experience.

CONCLUSIONS

- Immunohistochemistry is an indispensable tool for the accurate diagnosis of neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. Useful immunomarkers are available to help distinguish malignant neoplasms from benign conditions, determine organ origins, and subclassify neoplasms that are morphologically and biologically heterogeneous. Specific immunomarkers are also available to help guide patient treatment and assess disease aggressiveness, which are keys to the success of personalized medicine. Pathologists will continue to play a critical role in the discovery, validation, and application of new biomarkers, which will ultimately improve patient care.

Coupling to a cancer-selective heparan-sulfate-targeted branched peptide can by-pass breast cancer cell resistance to methotrexate

Cancer-selective tetra-branched peptides, named NT4, can be coupled to different functional units for cancer cell imaging or therapy. NT4 peptides specifically bind to lipoprotein receptor-related proteins (LRP) receptors and to heparan sulfate chains on membrane proteoglycans and can be efficiently internalized by cancer cells expressing these membrane targets. Since binding and internalization of NT4 peptides is mediated by specific NT4 receptors on cancer cell membranes and this may allow drug resistance produced by drug membrane transporters to be by-passed, we tested the ability of drug-armed NT4 to by-pass drug resistance in cancer cell lines.

We found that MTX-conjugated NT4 allows drug resistance to be by-passed in MTX-resistant human breast cancer cells lacking expression of folate reduced carrier. NT4 peptides appear to be extremely promising cancer-selective targeting agents that can be exploited as theranostics in personalized oncological applications.

Glypican-3 and KRT19 are markers associating with metastasis and poor prognosis of pancreatic ductal adenocarcinoma

OBJECTIVE

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with metastasis in most patients at diagnosis. The molecular mechanisms associated with its high malignancy have not been fully elucidated. This study investigated the clinicopathological significances of GPC3 and KRT19 expression in PDAC.

METHODS

GPC3, KRT19, and CA19-9 protein expression were measured by immunohistochemistry.

RESULTS

GPC3 and KRT19 protein levels were overexpressed in PDAC tumors compared to normal pancreatic tissues, benign pancreatic tissues, and peritumoral tissues (P< 0.01). The percentage of positive GPC3 and KRT19 expression were significantly higher in PDAC patients with larger tumor size, poorly differentiated tumor, lymph node metastasis, invasion, and TNM stage III/IV disease than in patients with small tumor size, well-differentiated tumor, no lymph node metastasis and invasion, as well as TNM stage I/II stage disease (P< 0.05 or P< 0.01). Benign pancreatic lesions with positive GPC3 and KRT19 protein expression exhibited dysplasia or intraepithelial neoplasia. Kaplan-Meier survival analysis showed that PDAC patients with positive GPC3 and KRT19 expression survived significantly shorter than patients with negative GPC3 and KRT19 expression (P < 0.05 or P< 0.001). Cox multivariate analysis revealed that positive GPC3 and KRT19 expression were independent poor prognosis factors in PDAC patients.

CONCLUSIONS

GPC3 and KRT19 overexpression are associated with carcinogenesis, progression, and poor prognosis in patients with PDAC and a valuable biomarker for diagnosis of PDAC.

Tissue Biomarkers in Hepatocellular Tumors: Which, When, and How

Few tissue markers are currently available to pathologists in the study of hepatocellular tumors. These markers should be used carefully taking into consideration not only morphology but also, and sometimes even more important, the clinical setting where the lesion to be diagnosed had developed. Glypican-3, heat shock protein 70, and glutamine synthetase (GS) are markers currently used, as a single panel, to discriminate the nature of a <2 cm hepatocellular lesion lacking radiological features of hepatocellular carcinoma (HCC) detected in a cirrhotic patient under surveillance. Their use, which can be improved by clathrin heavy chain, is mostly requested on liver biopsy. Hepatocyte paraffin 1, arginase-1, polyclonal carcinoembryonic antigen, CD10, and bile salt export pump are tissue markers used to confirm, at histology, the diagnosis of HCC made by imaging before enrollment for phase III studies on novel anti-HCC drugs. In this setting, pathologists are usually requested a conclusive diagnosis on a liver biopsy of a poorly differentiated, necrotic, enriched in stem-phenotype, carcinoma. Liver fatty acid-binding protein, serum amyloid A, C-reactive protein, prostaglandin D2 synthetase, GS, and β-catenin can be used either on biopsy or surgical specimen to classify hepatocellular adenoma into hepatocyte nuclear factor (HNF-1α) inactivated (steatotic), inflammatory, with dysregulation of sonic hedgehog and prostaglandin pathways, β-catenin mutated, and unclassified.

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.

Liver Metastases of Neuroendocrine Tumors Rarely Show Overlapping Immunoprofile with Hepatocellular Carcinomas

The distinction of hepatocellular carcinoma (HCC), neuroendocrine tumor (NET) metastatic to the liver, and cholangiocarcinoma (CC) can sometimes be challenging on small biopsies. Tissue microarrays were constructed from HCCs, NETs, and CCs. The immunoprofile was evaluated using HepPar1, glypican-3 (GPC3), synaptophysin (SYN), chromogranin A (CHR), CD56, MOC-31, and pCEA. One hundred thirteen HCCs, 48 NETs, and 44 CCs were included. Of HCCs, 107 (95 %) expressed HepPar1 and/or GPC3, 52 (46 %) both, and 97 (88 %) marked with pCEA (canalicular pattern). Seven (6 %) expressed CD56, of which 3 (3 %) expressed SYN. All 7 HCCs that expressed CD56 and/or SYN also expressed HepPar1 and/or GPC3, and none of the HCCs expressed CHR. Fourteen (13 %) expressed MOC-31. All 48 NETs expressed at least one neuroendocrine marker: 47 (98 %) positive for SYN, 40 (83 %) for CHR, 39 (81 %) for CD56, and 34 (71 %) for all three markers. None expressed HepPar1 or GPC3. All 44 CCs showed at least focal reactivity with MOC-31 and pCEA (membranous/cytoplasmic). One (2 %) was positive for HepPar1, 4 (9 %) for GPC3, 1 (2 %) for SYN and CHR, and 7 (16 %) for CD56. HCCs rarely express CD56 and SYN, while all express either HepPar1 or GPC3. NETs do not express HepPar1 or GPC3 and almost always express SYN, while CHR and CD56 are seen in most cases. Rare CCs focally express HepPar1 and GPC3. Utilizing a limited staining panel can efficiently distinguish HCCs, NETs, and CCs and help avoid diagnostic pitfalls on small biopsies.

Expression of Markers of Hepatocellular Differentiation in Pancreatic Acinar Cell Neoplasms: A Potential Diagnostic Pitfall

OBJECTIVES

Pancreatic acinar cell carcinoma (ACC) is a rare tumor that frequently metastasizes to the liver and may present a diagnostic challenge due to its morphologic similarity to hepatocellular carcinoma. We investigated α-fetoprotein (AFP), hepatocyte paraffin antigen 1 (HepPar 1), glypican 3, arginase 1, and albumin messenger RNA (mRNA) in situ hybridization (ISH) in pancreatic neoplasms with ACC differentiation to assess their diagnostic value.

METHODS

AFP, HepPar 1, glypican 3, and arginase 1 immunohistochemical staining was performed on 28 ACCs using a tissue microarray. Albumin mRNA ISH was performed on full-faced sections.

RESULTS

Fifteen tumors were positive for at least one marker. Glypican 3 was positive in seven of 28, AFP in five 28, and albumin mRNA ISH in five of 20. None expressed arginase 1.

CONCLUSIONS

Hepatocellular differentiation markers, including albumin mRNA ISH, may be positive in ACC, but arginase 1 appears to be uniformly negative. Thus, its use may improve the accuracy in distinguishing these neoplasms from hepatocellular carcinoma. If ACC diagnosis is considered, acinar differentiation can be reliably demonstrated by trypsin/chymotrypsin.

Insights into the role of sulfated glycans in cancer cell adhesion and migration through use of branched peptide probe

The tetra-branched peptide NT4 selectively binds to different human cancer cells and tissues. NT4 specifically binds to sulfated glycosaminoglycans on cancer cell membranes. Since sulfated glycosaminoglycans are involved in cancer cell interaction with the extracellular matrix, we evaluated the effect of NT4 on cancer cell adhesion and migration. We demonstrated here that the branched peptide NT4 binds sulfated glycosaminoglycans with high affinity and with preferential binding to heparan sulfate. NT4 inhibits cancer cell adhesion and migration on different proteins, without modifying cancer cell morphology or their ability to produce protrusions, but dramatically affecting the directionality and polarity of cell movement. Results obtained by taking advantage of the selective targeting of glycosaminoglycans chains by NT4, provide insights into the role of heparan sulfate proteoglycans in cancer cell adhesion and migration and suggest a determinant role of sulfated glycosaminoglycans in the control of cancer cell directional migration.

A triple stain of reticulin, glypican-3, and glutamine synthetase: a useful aid in the diagnosis of liver lesions

CONTEXT

The correct histologic diagnosis of mass lesions of the liver can be difficult, especially in biopsy samples. Reticulin, glypican-3, and glutamine synthetae are stains that can help distinguish hepatocellular carcinoma, hepatic adenoma, and focal nodular hyperplasia.

OBJECTIVE

To evaluate the utility of a triple stain of reticulin, glypican-3, and glutamine synthetae in distinguishing hepatocellular carcinoma, hepatic adenoma, and focal nodular hyperplasia.

DESIGN

Whole tissue sections and tissue microarrays were evaluated with a triple stain of reticulin, followed by glutamine synthetae (diaminobenzidine, brown chromogen) and glypican-3 (alkaline phosphatase, red chromogen). The 109 cases evaluated included whole tissue section hepatocellular carcinoma (n = 16), tissue microarray hepatocellular carcinoma (n = 19), whole tissue section hepatic adenoma (n = 15), tissue microarray hepatic adenoma (n = 13), whole tissue section focal nodular hyperplasia (n = 13; 12%), tissue microarray focal nodular hyperplasia (n = 13), as well as nonmalignant liver parenchyma adjacent to hepatocellular carcinoma (n = 20). All cases were scored for reticulin being intact or lost, positive or negative staining for glypican-3, and diffuse, maplike, perivenular, or negative staining for glutamine synthetae.

RESULTS

The combination of intact reticulin with either glypican-3 negativity or negative glutamine synthetae was 92% sensitive and 95% specific in the distinction of tissue microarray hepatic adenoma from hepatocellular carcinoma. For the distinction of tissue microarray focal nodular hyperplasia and hepatic adenoma, maplike glutamine synthetae was most useful and was 85% sensitive and 100% specific.

CONCLUSIONS

The triple stain of reticulin, glypican-3, and glutamine synthetae is useful in the differentiation of hepatocellular carcinoma, hepatic adenoma, and focal nodular hyperplasia on biopsy specimens. Furthermore, this triple stain is advantageous to single stains and can help when aberrant staining patterns are observed.

Current concepts in the immunohistochemical evaluation of liver tumors

Immunohistochemistry often plays an important role in the evaluation of liver tumors. Recent advances have established a classification system for hepatocellular adenomas (HCAs) based on morphology, molecular alterations, and immunohistochemistry. Specifically, loss of liver fatty acid binding protein is seen in HNF1α-inactivated HCA, staining with serum amyloid A is seen in inflammatory HCA, and diffuse staining with glutamine synthetase (GS) is seen in β-catenin activated HCA. A panel of immunohistochemical stains including glypican-3 (GPC-3), heat shock protein 70, and GS are useful in distinguishing HCC from non-malignant dysplastic nodules. Immunohistochemistry is also useful to determine whether a liver tumor is of primary hepatocellular or metastatic origin. Recently described markers useful for this purpose include arginase-1, GPC-3, and bile salt export pump. These newer markers may offer superior utility when compared to traditional markers of hepatocellular differentiation such as alpha-fetoprotein, hepatocyte paraffin-1, polyclonal carcinoembryonic antigen, and CD10. This paper will review recent advances in the immunohistochemical evaluation of liver tumors.

Utility of immunohistochemistry in the pancreatobiliary tract

CONTEXT

Immunohistochemistry has become a useful ancillary study in the identification and classification of pancreatic neoplasms. The diagnostic accuracy has been significantly improved because of the continuous discoveries of tumor-associated biomarkers and the development of effective immunohistochemical panels.

OBJECTIVES

To identify and classify pancreatic neoplasms by immunohistochemistry.

DATA SOURCES

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS

To better guide therapeutic decisions and predict the prognostic outcome, it is crucial to make an accurate diagnosis of a pancreatic neoplasm. Application of appropriate immunohistochemical panels enables pathologists to differentiate pancreaticobiliary adenocarcinomas from reactive conditions and to identify rare types of pancreatic neoplasms. Knowing the utilities and pitfalls of each tumor-associated biomarker is essential to avoiding a potential diagnostic error because an absolutely cancer-specific biomarker does not exist. This article reviews frequently used tumor-associated biomarkers, provides lists of effective immunohistochemical panels, and recommends a diagnostic algorithm as a standard approach to pancreatic neoplasms.

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.

Bioinformatic and immunological analysis reveals lack of support for measles virus related mimicry in Crohn's disease

BACKGROUND

A link between measles virus and Crohn's disease (CD) has been postulated. We assessed through bioinformatic and immunological approaches whether measles is implicated in CD induction, through molecular mimicry.

METHODS

The BLAST2p program was used to identify amino acid sequence similarities between five measles virus and 56 intestinal proteins. Antibody responses to measles/human mimics were tested by an in-house ELISA using serum samples from 50 patients with CD, 50 with ulcerative colitis (UC), and 38 matched healthy controls (HCs).

RESULTS

We identified 15 sets of significant (>70%) local amino acid homologies from two measles antigens, hemagglutinin-neuraminidase and fusion-glycoprotein, and ten human intestinal proteins. Reactivity to at least one measles 15-meric mimicking peptide was present in 27 out of 50 (54%) of patients with CD, 24 out of 50 (48%) with UC (CD versus UC, p = 0.68), and 13 out of 38 (34.2%) HCs (CD versus HC, p = 0.08). Double reactivity to at least one measles/human pair was present in four out of 50 (8%) patients with CD, three out of 50 (6%) with UC (p = 0.99), and in three out of 38 (7.9%) HCs (p >0.05 for all). Titration experiments yielded different extinction curves for anti-measles and anti-human intestinal double-reactive antibodies. Epitope prediction algorithms and three-dimensional modeling provided bioinformatic confirmation for the observed antigenicity of the main measles virus epitopic regions.

CONCLUSIONS

Measles sequences mimicking intestinal proteins are frequent targets of antibody responses in patients with CD, but this reactivity lacks disease specificity and does not initiate cross-reactive responses to intestinal mimics. We conclude that there is no involvement of measles/human molecular mimicry in the etiopathogenesis of CD.

Arginase-1 is a novel immunohistochemical marker of hepatocellular differentiation

Arginase-1 is an enzyme that catalyzes the hydrolysis of arginine to ornithine and urea in the urea cycle. In normal tissues, arginase-1 is primarily expressed in hepatocytes. Recent investigations have reported that the vast majority of hepatocellular carcinomas express this marker, but it is found only rarely in nonhepatocellular tumors. Owing to its restricted expression in hepatocellular carcinomas, arginase-1 has proved to be a useful immunohistochemical marker for assisting in distinguishing between these tumors and other neoplasms with which they may be confused.

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.

GPC1 regulated by miR-96-5p, rather than miR-182-5p, in inhibition of pancreatic carcinoma cell proliferation

To determine the relationships between miR-96-5p/-182-5p and GPC1 in pancreatic cancer (PC), we conducted the population and in vitro studies. We followed 38 pancreatic cancer patients, measured and compared the expression of miR-96-5p/-182-5p, GPC1, characteristics and patients’ survival time of different miR-96-5p/-182-5p expression levels in PC tissues. In an in vitro study, we investigated the proliferation, cycle and apotosis in cells transfected with mimics/inhibitors of the two miRNAs, and determine their effects on GPC1 by dual-luciferase assay. In the follow-up study, we found that the expressions of miR-96-5p/-182-5p were lower/higher in PC tissues; patients with lower/higher levels of miR-96-5p/-182-5p suffered poorer characteristics and decreased survival time. In the in vitro study, the expressions of miR-96-5p/-182-5p were different in cells. Proliferation of cells transfected with miR-96-5p mimics/inhibitors was lower/higher in Panc-1/BxPC-3; when transfected with miR-182-5p mimics/inhibitors, proliferation of cells were higher/lower in AsPC-1/Panc-1. In a cell cycle study, panc-1 cells transfected with miR-96-5p mimics was arrested at G0/G1; BxPC-3 cells transfected with miR-96-5p inhibitors showed a significantly decrease at G0/G1; AsPC-1 cells transfected with miR-182-5p mimics was arrested at S; Panc-1 cells transfected with miR-182-5p inhibitors showed a decrease at S. MiR-96-5p mimics increased the apoptosis rate in Panc-1 cells, and its inhibitors decreased the apoptosis rate in BxPC-3. Dual luciferase assay revealed that GPC1 was regulated by miR-96-5p, not -182-5p. We found that miR-96-5p/-182-5p as good markers for PC; miR-96-5p, rather than -182-5p, inhibits GPC1 to suppress proliferation of PC cells.

Impaired autophagy response in human hepatocellular carcinoma

BACKGROUND

Autophagy is a cellular lysosomal degradation mechanism that has been implicated in chronic liver diseases and hepatocellular carcinoma (HCC). Association of autophagy defect with the development of human HCC has been shown in transgenic mouse model.

AIM

We performed this study to verify whether a defect in autophagy would play a role in human hepatocellular carcinoma (HCC).

METHODS

Archival tissue sections of 20 patients with HCC with or without hepatitis C virus (HCV) infection were studied. All slides were immunostained using monoclonal antibodies to p62 and glypican-3 with appropriate positive and negative controls. The expression of p62 and glycican-3 in the HCC and the surrounding non-tumor was semiquantitated. The cytoplasmic staining was graded as negative, weak or strong.

RESULTS

Positive p62 staining was found in 20 out of 20 (100%) HCCs and negative staining was observed in 20 out of 20 non-tumor areas and cirrhotic nodules. Positive glypican-3 staining was found in 70% of HCCs and negative staining was seen in all non-tumor areas. An autophagy defect leading to increased expression of p62 and glypican-3 was also seen in the HCC cell line (Huh-7.5), but not in the primary human hepatocytes. Activation of cellular autophagy in Huh-7.5 cells efficiently cleared p62 and glypican-3 expression and inhibition of autophagy induced the expression of p62 and glypican-3.

CONCLUSIONS

This study shows that p62 is increased in HCC compared to the surrounding non-tumorous liver tissue suggesting that human HCCs are autophagy defective. We provide further evidence that glypican-3 expression in HCC may also be related to defective autophagy. Our study indicates that p62 immunostain may represent a novel marker for HCC.

Immunohistochemistry in Gastroenterohepatopancreatobiliary Epithelial Neoplasia: Practical Applications, Pitfalls, and Emerging Markers

Immunohistochemistry (IHC) has broad applications in neoplastic gastrointestinal surgical pathology. Although classically used as a diagnostic tool, IHC increasingly provides prognostic and predictive information. This review highlights 11 key uses of IHC (Box 1). Emphasis is placed on specific clinical applications and qualitative aspects of interpretation. Common pitfalls are specifically highlighted. The potential application of emerging markers is discussed in relation to several of the 11 topics. In many instances, an immunostain serves as a surrogate for specific molecular genetic events. Survey of relevant articles forms the evidence basis for this review.

Glycoproteomic discovery of serological biomarker candidates for HCV/HBV infection-associated liver fibrosis and hepatocellular carcinoma

We previously proposed a high-throughput strategy to discover serological biomarker candidates of cancer. This strategy focuses on a series of candidate glycoproteins that are specifically expressed in the original tissues (cells) of the target cancer and that carry glycan structures associated with carcinogenesis [Narimatsu, H., et al. FEBS J.2010, 277(1), 95-105]. Here, we examined the effectiveness of our strategy in identifying biomarkers to assess progression of liver fibrosis and for the early detection of hepatocellular carcinoma (HCC). On the basis of the results of lectin array analyses in culture media of hepatoma cell lines, we captured glycopeptides carrying AAL-ligands (fucosylated glycans) or DSA-ligands (branched glycans) from digests of culture media proteins and sera from HCC patients with a background of liver cirrhosis (LC). Glycoproteins were identified by the IGOT-LC-MS method. In all, 21 candidates were selected from 744 AAL-bound glycoproteins for further verification according to (i) their abundance in serum, (ii) their specific expression in liver, and (iii) the availability of antibodies to the glycoproteins. All selected candidates showed enhancement of AAL-reactivity in sera of HCC patients compared with that of healthy volunteers (HV). These results indicate that our glycoproteomic strategy is effective for identifying multiple glyco-biomarker candidates in a high-throughput manner.