Elevated glypican-1 expression is associated with an unfavorable prognosis in pancreatic ductal adenocarcinoma

Roles of Proteoglycans and Glycosaminoglycans in Cancer Development and Progression

The extracellular matrix (ECM) spatiotemporally controls cell fate; however, dysregulation of ECM remodeling can lead to tumorigenesis and cancer development by providing favorable conditions for tumor cells. Proteoglycans (PGs) and glycosaminoglycans (GAGs) are the major macromolecules composing ECM. They influence both cell behavior and matrix properties through direct and indirect interactions with various cytokines, growth factors, cell surface receptors, adhesion molecules, enzymes, and glycoproteins within the ECM. The classical features of PGs/GAGs play well-known roles in cancer angiogenesis, proliferation, invasion, and metastasis. Several lines of evidence suggest that PGs/GAGs critically affect broader aspects in cancer initiation and the progression process, including regulation of cell metabolism, serving as a sensor of ECM's mechanical properties, affecting immune supervision, and participating in therapeutic resistance to various forms of treatment. These functions may be implemented through the characteristics of PGs/GAGs as molecular bridges linking ECM and cells in cell-specific and context-specific manners within the tumor microenvironment (TME). In this review, we intend to present a comprehensive illustration of the ways in which PGs/GAGs participate in and regulate several aspects of tumorigenesis; we put forward a perspective regarding their effects as biomarkers or targets for diagnoses and therapeutic interventions.

Extracellular Vesicle-Dependent Cross-Talk in Cancer-Focus on Pancreatic Cancer

Extracellular vesicles (EVs) like exosomes and shed microvesicles are generated by many different cells. However, among all the cells, cancer cells are now recognized to secrete more EVs than healthy cells. Tumor-derived EVs can be isolated from biofluids such as blood, urine, ascitic fluid, and saliva. Their numerous components (nucleic acids, proteins, and lipids) possess many pleiotropic functions involved in cancer progression. The tumor-derived EVs generated under the influence of tumor microenvironment play distant roles and promote cellular communication by directly interacting with different cells. Moreover, they modulate extracellular matrix remodeling and tumor progression. Tumor-derived EVs are involved in pre-metastatic niche formation, dependent on the EV-associated protein receptors, and in cancer chemoresistance as they transfer drug-resistance-related genes to recipient cells. Recent advances in preclinical and clinical fields suggest their potential use as biomarkers for diagnosis and prognosis as well as for drug delivery in cancer. In this Review, we discuss EV characteristics and pro-tumor capacities, and highlight the future crucial impact of tumor-derived EVs in pancreatic cancer diagnosis and prognosis.

Sensitive Signal Amplifying a Diagnostic Biochip Based on a Biomimetic Periodic Nanostructure for Detecting Cancer Exosomes

Tumor-derived exosomes are emerging noninvasive biomarker reservoirs that reflect biological information from their parental cells, especially specific markers, including proteins, DNA fragments and RNAs. Recently, analytical methods of tumor-derived exosomes have been increasing growth. However, developing a convenient signal amplification technique to improve the sensitivity of exosomes detection still remains a challenge. Herein, an ultrasensitive and specific exosomes diagnostic biochip is constructed and further applied to circulating tumor exosomes detection in serum. Using an exosomes diagnostic biochip, signal amplification is achieved by combining the advantages of quantum dots with the biomimetic periodic nanostructure of photonic crystals. Glypican-1 (GPC1), a membrane-anchored protein that is overexpressed in exosomes from pancreatic cancer, is detected using nanosized molecular beacons with high luminescence efficiency; then the signal is amplified through photonic crystals. Moreover, the method allows the quantitative analysis of various disease-specific surface proteins on exosomes. We believe that this exosomes diagnostic biochip is likely to have potential as an effective bioassay, which may be helpful for quantification of disease-specific exosomes in clinical use.

The Role of Glypicans in Cancer Progression and Therapy

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

Targeted beta therapy of prostate cancer with 177Lu-labelled Miltuximab® antibody against glypican-1 (GPC-1)

PURPOSE

Chimeric antibody Miltuximab®, a human IgG1 engineered from the parent antibody MIL-38, is in clinical development for solid tumour therapy. Miltuximab® targets glypican-1 (GPC-1), a cell surface protein involved in tumour growth, which is overexpressed in solid tumours, including prostate cancer (PCa). This study investigated the potential of ⁸⁹Zr-labelled Miltuximab® as an imaging agent, and ¹⁷⁷Lu-labelled Miltuximab® as a targeted beta therapy, in a mouse xenograft model of human prostate cancer.

METHODS

Male BALB/c nude mice were inoculated subcutaneously with GPC-1-positive DU-145 PCa cells. In imaging and biodistribution studies, mice bearing palpable tumours received (a) 2.62 MBq [⁸⁹Zr]Zr-DFO-Miltuximab® followed by PET-CT imaging, or (b) 6 MBq [¹⁷⁷Lu]Lu-DOTA-Miltuximab® by Cerenkov imaging, and ex vivo assessment of biodistribution. In an initial tumour efficacy study, mice bearing DU-145 tumours were administered intravenously with 6 MBq [¹⁷⁷Lu]Lu-DOTA-Miltuximab® or control DOTA-Miltuximab® then euthanised after 27 days. In a subsequent survival efficacy study, tumour-bearing mice were given 3 or 10 MBq of [¹⁷⁷Lu]Lu-DOTA-Miltuximab®, or control, and followed up to 120 days.

RESULTS

Antibody accumulation in DU-145 xenografts was detected by PET-CT imaging using [⁸⁹Zr]Zr-DFO-Miltuximab® and confirmed by Cerenkov luminescence imaging post injection of [¹⁷⁷Lu]Lu-DOTA-Miltuximab®. Antibody accumulation was higher (% IA/g) in tumours than other organs across multiple time points. A single injection with 6 MBq of [¹⁷⁷Lu]Lu-DOTA-Miltuximab® significantly inhibited tumour growth as compared with DOTA-Miltuximab® (control). In the survival study, mice treated with 10 MBq [¹⁷⁷Lu]Lu-DOTA-Miltuximab® had significantly prolonged survival (mean 85 days) versus control (45 days), an effect associated with increased cancer cell apoptosis. Tissue histopathology assessment showed no abnormalities associated with [¹⁷⁷Lu]Lu-DOTA-Miltuximab®, in line with other observations of tolerability, including body weight stability.

CONCLUSION

These findings demonstrate the potential utility of Miltuximab® as a PET imaging agent ([⁸⁹Zr]Zr-DFO-Miltuximab®) and a beta therapy ([¹⁷⁷Lu]Lu-DOTA-Miltuximab®) in patients with PCa or other GPC-1 expressing tumours.

The Role of Glypican-1 in the Tumour Microenvironment

Glypican-1 (GPC-1) is a cell surface heparan sulphate proteoglycan that is critical during normal development, but which is not required for normal homoeostasis in the adult. It is, however, overexpressed in a variety of solid tumours and is known to regulate tumour growth, invasion, metastasis and progression, through modulation of tumour cell biology as well as influence on the tumour microenvironment (TME). The role of GPC-1 in the TME and on the tumour cell is broad, as GPC-1 regulates signalling by several growth factors, including FGF, HGF, TGF-β, Wnt and Hedgehog (Hh). Signalling via these pathways promotes tumour growth and invasive and metastatic ability (drives epithelial-to-mesenchymal transition (EMT)) and influences angiogenesis, affecting both tumour and stromal cells. Broad modulation of the TME via inhibition of GPC-1 may represent a novel therapeutic strategy for inhibition of tumour progression. Here, we discuss the complex role of GPC-1 in tumour cells and the TME, with discussion of potential therapeutic targeting strategies.

Tumor Microenvironment: Extracellular Matrix Alterations Influence Tumor Progression

The tumor microenvironment (TME) is composed of various cell types embedded in an altered extracellular matrix (ECM). ECM not only serves as a support for tumor cell but also regulates cell-cell or cell-matrix cross-talks. Alterations in ECM may be induced by hypoxia and acidosis, by oxygen free radicals generated by infiltrating inflammatory cells or by tumor- or stromal cell-secreted proteases. A poorer diagnosis for patients is often associated with ECM alterations. Tumor ECM proteome, also named cancer matrisome, is strongly altered, and different ECM protein signatures may be defined to serve as prognostic biomarkers. Collagen network reorganization facilitates tumor cell invasion. Proteoglycan expression and location are modified in the TME and affect cell invasion and metastatic dissemination. ECM macromolecule degradation by proteases may induce the release of angiogenic growth factors but also the release of proteoglycan-derived or ECM protein fragments, named matrikines or matricryptins. This review will focus on current knowledge and new insights in ECM alterations, degradation, and reticulation through cross-linking enzymes and on the role of ECM fragments in the control of cancer progression and their potential use as biomarkers in cancer diagnosis and prognosis.

Prognostic and predictive factors in pancreatic cancer

Pancreatic cancer is one of the leading causes of cancer death worldwide. Its high mortality rate has remained unchanged for years. Radiotherapy and surgery are considered standard treatments in early and locally advanced stages. Chemotherapy is the only option for metastatic patients. Two treatment regimens, i. e. the association of 5-fluorouracil- irinotecan-oxaliplatin (FOLFIRINOX) and the association of nab-paclitaxel with gemcitabine, have been shown to improve outcomes for metastatic pancreatic adenocarcinoma patients. However, there are not standardized predictive biomarkers able to identify patients who benefit most from treatments. CA19-9 is the most studied prognostic biomarker, its predictive role remains unclear. Other clinical, histological and molecular biomarkers are emerging in prognostic and predictive settings. The aim of this review is to provide an overview of prognostic and predictive markers used in clinical practice and to explore the most promising fields of research in terms of treatment selection and tailored therapy in pancreatic cancer.

Licocoumarone induces BxPC-3 pancreatic adenocarcinoma cell death by inhibiting DYRK1A

Protein kinases play an indispensable role in signaling pathways that regulate tumor cell functions, which represent potent therapeutic targets in cancers. Dual-specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A) as a serine/threonine kinase has recently been reported to be upregulated in pancreatic ductal adenocarcinoma (PDAC) and show protumorigenic effect. By activity-guided phytochemical investigation of the extracts from Glycyrrhiza uralensis Fisch, we expect to find the effective constituents that can suppress pancreatic cancer cell proliferation and/or induce cells apoptotic by inhibiting DYRK1A. Eight isopentenyl-substituted compounds (1-8), including four coumarins (1-4), one benzofuran (5), and three flavonoids (6-8), were isolated and identified from G. uralensis Fisch. Among them, licocoumarone (LC, 5) showed effective inhibitory activity against DYRK1A with an IC50 value of 12.56 μM. Molecular docking analysis suggested that LC completely occupied the whole pocket of DYRK1A and formed obvious hydrophobic interactions and hydrogen bonds with DYRK1A residues. Further in vitro validation, including Microscale Thermophoresis (MST) and drug affinity responsive target stability (DARTS) techniques, demonstrated the specific combining capacity of LC to DYRK1A. Meanwhile, LC induced significant cytotoxicity against DYRK1A-overexpressing BxPC-3 cells with an IC50 value of 50.77 μM. Mechanism studies revealed that LC reduced c-MET protein level by inhibiting DYRK1A. These findings provide preliminary evidences that LC as a natural DYRK1A inhibitor suppresses human pancreatic adenocarcinoma BxPC-3 cell proliferation and induces cell apoptotic, which might present new options and possibilities for targeted therapies in pancreatic cancer therapy.

The Tumor Microenvironment: Focus on Extracellular Matrix

The extracellular matrix (ECM) regulates the development and maintains tissue homeostasis. The ECM is composed of a complex network of molecules presenting distinct biochemical properties to regulate cell growth, survival, motility, and differentiation. Among their components, proteoglycans (PGs) are considered one of the main components of ECM. Its composition, biomechanics, and anisotropy are exquisitely tuned to reflect the physiological state of the tissue. The loss of ECM's homeostasis is seen as one of the hallmarks of cancer and, typically, defines transitional events in tumor progression and metastasis. In this chapter, we discuss the types of proteoglycans and their roles in cancer. It has been observed that the amount of some ECM components is increased, while others are decreased, depending on the type of tumor. However, both conditions corroborate with tumor progression and malignancy. Therefore, ECM components have an increasingly important role in carcinogenesis and this leads us to believe that their understanding may be a key in the discovery of new anti-tumor therapies. In this book, the main ECM components will be discussed in more detail in each chapter.

CD63-GPC1-Positive Exosomes Coupled with CA19-9 Offer Good Diagnostic Potential for Resectable Pancreatic Ductal Adenocarcinoma

Tumor-released extracellular vesicles (EVs) contain tumor-specific cargo distinguishing them from healthy EVs, and making them eligible as circulating biomarkers. Glypican 1 (GPC1)-positive exosome relevance as liquid biopsy elements is still debated. We carried out a prospective study to quantify GPC1-positive exosomes in sera from pancreatic ductal adenocarcinoma (PDAC) patients undergoing up-front surgery, as compared to controls including patients without cancer history and patients displaying pancreatic preneoplasic lesions. Sera were enriched in EVs, and exosomes were pulled down with anti-CD63 coupled magnetic beads. GPC1-positive bead percentages determined by flow cytometry were significantly higher in PDAC than in the control group. Diagnosis accuracy reached 78% (sensitivity 64% and specificity 90%), when results from peripheral and portal blood were combined. In association with echo-guided-ultrasound-fine-needle-aspiration (EUS-FNA) negative predictive value was 80% as compared to 33% for EUS-FNA only. This approach is clinically relevant as a companion test to the already available diagnostic tools, since patients with GPC1-positive exosomes in peripheral blood showed decreased tumor free survival.

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

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

The Expression, Regulation, and Biomarker Potential of Glypican-1 in Cancer

Glypican-1 (GPC-1) and other glypicans are a family of heparan sulfate proteoglycans. These proteins are highly expressed on the cell membrane and in the extracellular matrix, functioning mainly as modulators of growth factor signaling. Some of them are abnormally expressed in cancer, possibly involved in tumorigenesis, and detectable in blood as potential clinical biomarkers. GPC-1 is another glypican member that has been found to be associated with some cancers, and has increasingly interested the cancer field. Here we provide a brief review about GPC-1 in its expression, signaling and potential as a cancer biomarker.

Liquid Biopsy Approach for Pancreatic Ductal Adenocarcinoma

Pancreatic cancer is a public health problem because of its increasing incidence, the absence of early diagnostic tools, and its aggressiveness. Despite recent progress in chemotherapy, the 5-year survival rate remains below 5%. Liquid biopsies are of particular interest from a clinical point of view because they are non-invasive biomarkers released by primary tumours and metastases, remotely reflecting disease burden. Pilot studies have been conducted in pancreatic cancer patients evaluating the detection of circulating tumour cells, cell-free circulating tumour DNA, exosomes, and tumour-educated platelets. There is heterogeneity between the methods used to isolate circulating tumour elements as well as the targets used for their identification. Performances for the diagnosis of pancreatic cancer vary depending of the technique but also the stage of the disease: 30–50% of resectable tumours are positive and 50–100% are positive in locally advanced and/or metastatic cases. A significant prognostic value is demonstrated in 50–70% of clinical studies, irrespective of the type of liquid biopsy. Large prospective studies of homogeneous cohorts of patients are lacking. One way to improve diagnostic and prognostic performances would be to use a combined technological approach for the detection of circulating tumour cells, exosomes, and DNA.

Glypican-1 Promotes Tumorigenesis by Regulating the PTEN/Akt/β-Catenin Signaling Pathway in Esophageal Squamous Cell Carcinoma

BACKGROUND AND AIMS

Glypican-1 (GPC1), a cell-surface heparan sulfate proteoglycan, promotes the pathogenesis of many human cancers. This study focuses on the role of GPC1 in the promotion of cell proliferation and motility in esophageal squamous cell carcinoma (ESCC).

METHODS

The expression and distribution of GPC1 were measured in tumor tissues from 248 ESCC patients using immunohistochemical (IHC) assays. Cell counting (kit-8), flow cytometry, Transwell, wound healing, IHC, and Western blotting assays were performed to examine the molecular mechanisms that underlie how GPC1 enhances cell proliferation and motility.

RESULTS

The level of GPC1 was higher in ESCC tumor samples than in para-tumor tissues (IHC score: 5.42 ± 2.15 vs. 0.86 ± 0.96). Ectopic overexpression of GPC1 in EC9706 cells promoted cell growth and the G1/S phase transition; conversely, GPC1 knockdown in Eca109 cells attenuated cell proliferation and induced G2/M phase arrest. In addition, GPC1 upregulation enhanced ESCC cell motility and induced epithelial mesenchymal transition (EMT), as demonstrated by the aberrant expression of EMT markers. Mechanistically, we demonstrated that GPC1 increased levels of p-Akt and β-catenin and reduced PTEN expression in ESCC.

CONCLUSIONS

Our study indicated that GPC1 promotes the aggressive proliferation of ESCC cells by regulating the PTEN/Akt/β-catenin pathway. GPC1 may be a promising target for ESCC treatment.

Extracellular vesicles derived from cancer-associated fibroblasts induce the migration and invasion of oral squamous cell carcinoma

As one of the most abundant constituents of the tumour microenvironment (TME), cancer-associated fibroblasts (CAF) display critical roles during tumour progression and metastasis. Multiple classes of molecules including growth factors, cytokines, proteases and extracellular matrix proteins, are produced by CAF to act as mediators of the stroma-tumour interactions. One of the main channels for this communication is associated with extracellular vesicles (EV), which are secreted particles loaded with protein and genetic information. In this study, we evaluated the effects of EV derived from CAF primary human cell lines (n = 5) on proliferation, survival, migration, and invasion of oral squamous cell carcinoma (OSCC) cells. As controls, EV from human primary-established normal oral fibroblasts (NOF, n = 5) were used. Our in vitro assays showed that CAF-EV significantly induces migration and invasion of OSCC cells and promote a disseminated pattern of HSC-3 cell invasion in the 3D organotypic assay. Furthermore, gene expression analysis of EV-treated cancer cells revealed changes in the pathways associated with tumour metabolism and up-regulation of tumour invasion genes. Our findings suggest a significant role of CAF-EV in promoting the migration and invasion of OSCC cells, which are related to the activation of cancer-related pathways.

Functions and clinical implications of exosomes in pancreatic cancer

Pancreatic cancer is one of the most aggressive human malignancies and is associated with a dismal prognosis, which can be contributed to its atypical symptoms, metastatic propensity, and significant chemoresistance. Emerging evidence shows that pancreatic cancer cell-derived exosomes (PEXs) play critical roles in tumorigenesis and tumor development, as they are involved in drug resistance, immune evasion and metabolic reprograming, and distant metastasis of pancreatic cancer. Their numerous differentially expressed and functional contents make PEXs promising screening tools and therapeutic targets, which require further exploration. In this review, we focus on the functions of PEX contents and their clinical implications in pancreatic cancer.

High levels of serum glypican-1 indicate poor prognosis in pancreatic ductal adenocarcinoma

Carbohydrate antigen 19‐9 (CA19‐9) fails to demonstrate the predictive value for early detection pancreatic ductal adenocarcinoma (PDAC). Glypican‐1 (GPC1+) exosomes may serve as a noninvasive diagnostic tool to detect early stages of PDAC. Therefore, it is necessary to explore the serum GPC1 levels and determine whether serum GPC1 serves as a novel biomarker for PDAC patients. Blood samples were collected from 156 patients with PDAC, 199 non‐cancer controls, and 240 patients with other cancers. Serological levels of GPC1 were examined by enzyme‐linked immunosorbent assay (ELISA). Finally, a 5‐year follow‐up was monitored to evaluate the correlation between serum GPC1 levels and overall survival in 156 patients with PDAC. The results suggested that levels of serum GPC1 and CA19‐9 were higher in PDAC patients than that of controls (P < 0.05). Serum GPC1 levels in PDAC were different from those in gallbladder carcinoma (P < 0.001), colorectal carcinoma (P < 0.001), gastric carcinoma (P < 0.001), and prostate cancer (P < 0.001), but not hepatocellular carcinoma (P = 0.395) and cholangiocarcinoma (P = 0.724). Receiver operating characteristic curve (ROC) analysis showed that serum CA19‐9 was significantly better than serum GPC1 in distinguishing PDAC patients from the controls (AUC, 95% CI: 0.908, 0.868‐0.947 vs 0.795, 0.749‐0.841, respectively). The serum GPC1 cannot be used as a serum diagnostic biomarker for PDAC patients. The level of serum GPC1 decreased 2 days after surgery (P = 0.001), which were not different from serum GPC1 levels in healthy control (P = 0.381). The overall survival rate was shorter in patients with high levels of serum GPC1 compared to those with low levels of serum GPC1 (log‐rank = 5.16, P = 0.023). Taken together, the results indicate that high levels of serum GPC1 predict poor prognosis in PDAC patients. Serum GPC1 may be a prognosis factor for PDAC patients.

Extracellular vesicles: translational challenges and opportunities

Extracellular vesicles (EVs) are a heterogeneous group of small lipid-enclosed structures with myriad roles in physiology and disease. The recent surge of interest in EVs has led to greater understanding of their biology and appreciation of how they might be utilised as diagnostic and therapeutic tools. There remain, however, a number of challenges that must be overcome before EVs may be used routinely in the clinic. In this review we will discuss the translational potential of EVs and the current technologies available to isolate, purify and analyse EVs and their contents.

Glypican-1 immunohistochemistry does not separate mesothelioma from pulmonary adenocarcinoma

Immunohistochemistry (IHC) is used to help differentiate pleural mesothelioma from pulmonary adenocarcinoma in pleural biopsies and cytology specimens of pleural effusions due to overlapping morphologic features between these two malignancies. The aim of this study is to evaluate IHC glypican-1, a recently proposed marker for epithelioid mesothelioma, in our cohort of mesotheliomas and pulmonary adenocarcinoma. Tissue microarrays with duplicate cores from 33 cases of mesotheliomas (28 epithelioid type and five sarcomatoid type) and 21 cases of pulmonary adenocarcinoma were stained with glypican-1 antibody. The proportion of cases by tumor type showing staining with glypican-1 and the H-score for each tumor type were evaluated. All 33 cases of mesothelioma and all 20 cases of pulmonary adenocarcinoma with interpretable cores showed positive cytoplasmic staining. All but one case of mesothelioma and all pulmonary adenocarcinomas showed staining in at least 80% of the tumor cells. The mean H-score for glypican-1 of mesothelioma (134 ± 59, mean ± SD) was not significantly different from that for pulmonary adenocarcinoma (156 ± 60; P = 0.21). Neither epithelioid type (mean H-score 135 ± 57) nor sarcomatoid type (mean H-score 130 ± 78) of mesothelioma showed different H-scores when compared to pulmonary adenocarcinoma (P = 0.23 and 0.42, respectively). In conclusion, glypican-1 IHC does not differentiate mesothelioma from pulmonary adenocarcinoma.

Extracellular matrix proteins and carcinoembryonic antigen-related cell adhesion molecules characterize pancreatic duct fluid exosomes in patients with pancreatic cancer

BACKGROUND

Exosomes are nanovesicles that have been shown to mediate carcinogenesis in pancreatic ductal adenocarcinoma (PDAC). Given the direct communication of pancreatic duct fluid with the tumor and its relative accessibility, we aimed to determine the feasibility of isolating and characterizing exosomes from pancreatic duct fluid.

METHODS

Pancreatic duct fluid was collected from 26 patients with PDAC (n = 13), intraductal papillary mucinous neoplasm (IPMN) (n = 8) and other benign pancreatic diseases (n = 5) at resection. Exosomes were isolated by serial ultracentrifugation, proteins were identified by mass spectrometry, and their expression was evaluated by immunohistochemistry.

RESULTS

Exosomes were isolated from all specimens with a mean concentration of 5.9 ± 1 × 10⁸ particles/mL and most frequent size of 138 ± 9 nm. Among the top 35 proteins that were significantly associated with PDAC, multiple carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) and extracellular matrix (ECM) proteins were identified. Interestingly, CEACAM 1/5 expression by immunohistochemistry was seen only on tumor epithelia whereas tenascin C positivity was restricted to stroma, suggesting that both tumor and stromal cells contributed to exosomes.

CONCLUSION

This is the first study showing that exosome isolation is feasible from pancreatic duct fluid, and that exosomal proteins may be utilized to diagnose patients with PDAC.

Development of a reliable assay to measure glypican-1 in plasma and serum reveals circulating glypican-1 as a novel prostate cancer biomarker

Prostate cancer is responsible for hundreds of thousands of annual deaths worldwide. The current gold standard in early detection of prostate cancer, the prostate specific antigen test, boasts a high sensitivity but low specificity, resulting in many unnecessary prostate biopsies. Thus, emphasis has been placed on identifying new biomarkers to improve prostate cancer detection. Glypican-1 has recently been proposed as one such biomarker, however further exploration into its predictive power has been hindered by a lack of available, dependable glypican-1 immunoassays. Previously, we identified human glypican-1 as the antigenic target of the MIL-38 monoclonal antibody. Additionally, we have now generated another monoclonal antibody, 3G5, that also recognizes human glypican-1. Here we report the development of a reliable, custom Luminex^® assay that enables precise quantitation of circulating human glypican-1 in plasma and serum. Using this assay, we show for the first time that circulating glypican-1 levels can differentiate non-cancer (normal and benign prostatic hyperplasia) patients from prostate cancer patients, as well as benign prostatic hyperplasia patients alone from prostate cancer patients. Our findings strongly promote future investigation into the use of glypican-1 for early detection of prostate cancer.

Detection of glypican-1 (GPC-1) expression in urine cell sediments in prostate cancer

While measurement of serum prostate specific antigen (PSA) is an important screening tool for prostate cancer, new biomarkers are necessary for better discrimination between presence and absence of disease. The MIL-38 monoclonal antibody is specific for the membrane glycoprotein glypican 1 (GPC-1) and binds to prostate cancer tissue. Urine is known to be a source of cellular material. Thus, we hypothesized that detection of GPC-1 in urine cellular material may identify individuals with prostate cancer. Urine samples from patients with prostate cancer, benign prostatic hyperplasia (BPH), or normal controls were collected and cell sediments prepared. GPC-1-positive cells were detected using a MIL-38 immunofluorescence assay (IFA) and samples were classed positive or negative for GPC-1 expressing cells. Assay sensitivity and specificity, stratified by PSA, was reported. A total of 125 patient samples were analyzed (N = 41 prostate cancer; N = 37 BPH; N = 47 normal controls). The use of MIL-38 to detect GPC-1 by IFA discriminated between prostate cancer and BPH urine specimens with a sensitivity and specificity of 71% and 76%, respectively. Assay specificity increased with increasing PSA, with the highest specificity (89%) for patients with PSA ≥4 ng/ml. At lower PSA (<2 ng/ml) specificity decreased, as evidenced by a greater number of false positives in this concentration range. The odds ratio (OR) and 95% confidence intervals (CIs) for GPC-1-positive cells in patients with prostate cancer, adjusted for PSA, was greatest at the lowest serum PSA (<2 ng/ml; OR = 13.4; 95% CI: 4.0-44.7) compared with no adjustment for PSA (OR = 6.4; 95% CI: 2.8-14.9). The use of MIL-38 for detection of GPC-1 may be a useful tool for detection of prostate cancer.

Glypican-1 is enriched in circulating-exosomes in pancreatic cancer and correlates with tumor burden

Background

Glypican-1 (GPC1) is expressed in pancreatic ductal adenocarcinoma (PDAC) cells and adjacent stromal fibroblasts. Recently, GPC1 circulating exosomes (crExos) have been shown to be able to detect early stages of PDAC. In this study, we investigated the usefulness of crExos GPC1 as a biomarker for PDAC.

Methods

Plasma was obtained from patients with benign pancreatic disease (n = 16) and PDAC (n = 27) prior to pancreatectomy, and crExos were isolated by ultra-centrifugation. Protein was extracted from surgical specimens (adjacent normal pancreas, n = 13; and PDAC, n = 17). GPC1 levels were measured using enzyme-linked immunosorbent assay (ELISA).

Results

There was no significant difference in GPC1 levels between normal pancreas and PDAC tissues. This was also true when comparing matched pairs. However, GPC1 levels were enriched in PDAC crExos (n = 11), compared to the source tumors (n = 11; 97 ± 54 vs. 20.9 ± 12.3 pg/mL; P < 0.001). In addition, PDACs with high GPC1 expression tended to have crExos with higher GPC1 levels. Despite these findings, we were unable to distinguish PDAC from benign pancreatic disease using crExos GPC1 levels. Interestingly, we found that in matched pre and post-operative plasma samples there was a significant drop in crExos GPC1 levels after surgical resection for PDAC (n = 11 vs. 11; 97 ± 54 vs. 77.8 ± 32.4 pg/mL; P = 0.0428). Furthermore, we found that patients with high crExos GPC1 levels have significantly larger PDACs (>4 cm; P = 0.012).

Conclusions

High GPC1 crExos may be able to determine PDAC tumor size and disease burden. However, further efforts are needed to elucidate its role as a diagnostic and/or prognostic biomarker using larger cohorts of PDAC patients.

Exosomes from asbestos-exposed cells modulate gene expression in mesothelial cells

Asbestos exposure is a determinate cause of many diseases, such as mesothelioma, fibrosis, and lung cancer, and poses a major human health hazard. At this time, there are no identified biomarkers to demarcate asbestos exposure before the presentation of disease and symptoms, and there is only limited understanding of the underlying biology that governs asbestos-induced disease. In our study, we used exosomes, 30-140 nm extracellular vesicles, to gain insight into these knowledge gaps. As inhaled asbestos is first encountered by lung epithelial cells and macrophages, we hypothesize that asbestos-exposed cells secrete exosomes with signature proteomic cargo that can alter the gene expression of mesothelial cells, contributing to disease outcomes like mesothelioma. In the present study using lung epithelial cells (BEAS2B) and macrophages (THP-1), we first show that asbestos exposure causes changes in abundance of some proteins in the exosomes secreted from these cells. Furthermore, exposure of human mesothelial cells (HPM3) to these exosomes resulted in gene expression changes related to epithelial-to-mesenchymal transition and other cancer-related genes. This is the first report to indicate that asbestos-exposed cells secrete exosomes with differentially abundant proteins and that those exosomes have a gene-altering effect on mesothelial cells.-Munson, P., Lam, Y.-W., Dragon, J. MacPherson, M., Shukla, A. Exosomes from asbestos-exposed cells modulate gene expression in mesothelial cells.

Five key lncRNAs considered as prognostic targets for predicting pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, and the 5‐year survival rate was only 7.7%. To improve prognosis, a screening biomarker for early diagnosis of pancreatic cancer is in urgent need. Long non‐coding RNA (lncRNA) expression profiles as potential cancer prognostic biomarkers play critical roles in development of tumorigenesis and metastasis of cancer. However, lncRNA signatures in predicting the survival of a patient with PDAC remain unknown. In the current study, we try to identify potential lncRNA biomarkers and their prognostic values in PDAC. LncRNAs expression profiles and corresponding clinical information for 182 cases with PDAC were acquired from The Cancer Genome Atlas (TCGA). A total of 14 470 lncRNA were identified in the cohort, and 175 PDAC patients had clinical variables. We obtained 108 differential expressed lncRNA via R packages. Univariate and multivariate Cox proportional hazards regression, lasso regression was performed to screen the potential prognostic lncRNA. Five lncRNAs have been recognized to significantly correlate with OS. We established a linear prognostic model of five lncRNA (C9orf139, MIR600HG, RP5‐965G21.4, RP11‐436K8.1, and CTC‐327F10.4) and divided patients into high‐ and low‐risk group according to the prognostic index. The five lncRNAs played independent prognostic biomarkers of OS of PDAC patients and the AUC of the ROC curve for the five lncRNAs signatures prediction 5‐year survival was 0.742. In addition, targeted genes of MIR600HG, C9orf139, and CTC‐327F10.4 were explored and functional enrichment was also conducted. These results suggested that this five‐lncRNAs signature could act as potential prognostic biomarkers in the prediction of PDAC patient's survival.

Pancreatic Cancer Diagnosis and Management: Has the Time Come to Prick the Bubble?

Pancreatic cancer (PC) is associated with poor prognosis and very dismal survival rates. The most effective possibility of cure is tumor resection, which is only possible in about 15% of patients diagnosed at early stages of disease progression. Recent whole-genome sequencing studies pointed genetic alterations in 12 core signaling pathways in PC. These observations hint at the possibility that the initial mutation in PC might appear nearly 20 years before any symptoms occur, suggesting that a large window of opportunity may exist for early detection. Biomarkers with the potential to identify pre-neoplastic disease or very early stages of cancer are of great promise to improve patient survival. The concept of liquid biopsy refers to a minimally invasive sampling and analysis of liquid biomarkers that can be isolated from body fluids, primarily blood, urine and saliva. A myriad of circulating molecules may be useful as tumor markers, including cell-free DNA (cfDNA), cell-free RNA (cfRNA), circulating tumor cells (CTC), circulating tumor proteins, and extracellular vesicles, more specifically exosomes. In this review, we discuss with more detail the potential role of exosomes in several aspects related to PC, from initiation to tumor progression and its applicability in early detection and treatment. Exosomes are small circulating extracellular vesicles of 50-150 nm in diameter released from the plasma membrane by almost all cells and exhibit some advantages over other biomarkers. Exosomes are central players of intercellular communication and they have been implicated in a series of biological process, including tumorigenesis, migration and metastasis. Several exosomal microRNAs and proteins have been observed to distinguish PC from benign pancreatic diseases and healthy controls. Besides their possible role in diagnosis, understanding exosomes functions in cancer has clarified the importance of microenvironment in PC progression as well as its influence in proliferation, metastasis and resistance to chemotherapy. Increasing knowledge on cancer exosomes provides valuable insights on new therapeutic targets and can potentially open new strategies to treat this disease. Continuous research is needed to ascertain the reliability of using exosomes and their content as potential biomarkers, so that, hopefully, in the near future, they will provide the opportunity for early diagnosis, treatment intervention and increase survival of PC patients.

Proteoglycans remodeling in cancer: Underlying molecular mechanisms

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

Anti-glypican-1 antibody-drug conjugate exhibits potent preclinical antitumor activity against glypican-1 positive uterine cervical cancer

Glypican-1 (GPC1) is highly expressed in solid tumors, especially squamous cell carcinomas (SCCs), and is thought to be associated with disease progression. We explored the use of a GPC1-targeted antibody-drug conjugate (ADC) as a novel treatment for uterine cervical cancer. On immunohistochemical staining, high expression levels of GPC1 were detected in about 50% of uterine cervical cancer tissues and also in a tumor that had relapsed after chemoradiotherapy. Novel anti-GPC1 monoclonal antibodies were developed, and clone 01a033 was selected as the best antibody for targeted delivery of the cytotoxic agent monomethyl auristatin F (MMAF) into GPC1-positive cells. The anti-GPC1 antibody was conjugated with MMAF. On flow cytometry, HeLa and ME180 cervical cancer cells highly expressed GPC1, however, RMG-I ovarian clear cell cancer cell line showed weak expression. The GPC1-ADC was rapidly internalized into GPC1-expressing cells in vitro and was potently cytotoxic to cancer cells highly expressing GPC1. There were no inhibitory effects on cancer cells with low expression of GPC1. In a murine xenograft model, GPC1-ADC also had significant and potent tumor growth inhibition. GPC1-ADC-mediated G2/M phase cell cycle arrest was detected, indicating that the dominant antitumor effect in vivo was MMAF-mediated. The toxicity of GPC-ADC was tolerable within the therapeutic dose range in mice. Our data showed that GPC1-ADC has potential as a promising therapy for uterine cervical cancer.

Elevated glypican-1 expression is associated with an unfavorable prognosis in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal cancer in humans, with a 5-year survival rate of <5%. Recently, glypican-1 (GPC1)-expressing circulating exosomes were found to be a promising diagnostic tool for PDAC. However, the aberrant expression of GPC1 has not been systematically evaluated in large-scale clinical samples of PDAC. Here, we performed a comprehensive analysis of GPC1 mRNA and protein expression features. Included in this study were 178 PDAC patients from the cancer genome atlas (TCGA) and 186 subjects whose tissues were used in immunohistochemical staining assays. We demonstrated that GPC1 mRNA was silenced in normal pancreata; however, it was re-expressed in PDAC tissues probably because of the promoter hypomethylation. The GPC1 protein was barely expressed in the normal and adjacent noncancerous pancreata. In tumor tissues, 59.7% (111/186) of the detected samples showed positive expression. Notably, GPC1 was elevated in 63.6% (34/55) of early stage cases. High levels of GPC1 were associated with poorer differentiation and larger tumor diameters. Kaplan-Meier analysis showed a significant difference in overall survival between the groups categorized by GPC1 expression (P = 0.0028). Multivariate analyses indicated that GPC1 was a significant risk factor for poor overall survival with a 1.82-fold increase in the hazard ratio (P = 0.0022). In conclusion, during pancreatic tumorigenesis, GPC1 was ectopically expressed and served as an independent poor prognostic factor. Our findings highlighted the alluring prospect of GPC1 as an early diagnostic and prognostic marker as well as a therapeutic target for PDAC.