Reduced expression of syndecan-1 in human hepatocellular carcinoma with high metastatic potential

CREB3 suppresses hepatocellular carcinoma progression by depressing AKT signaling through competitively binding with insulin receptor and transcriptionally activating RNA-binding motif protein 38

cAMP responsive element binding protein 3 (CREB3), belonging to bZIP family, was reported to play multiple roles in various cancers, but its role in hepatocellular carcinoma (HCC) is still unclear. cAMP responsive element binding protein 3 like 3 (CREB3L3), another member of bZIP family, was thought to be transcription factor (TF) to regulate hepatic metabolism. Nevertheless, except for being TFs, other function of bZIP family were poorly understood. In this study, we found CREB3 inhibited growth and metastasis of HCC in vitro and in vivo. RNA sequencing indicated CREB3 regulated AKT signaling to influence HCC progression. Mass spectrometry analysis revealed CREB3 interacted with insulin receptor (INSR). Mechanistically, CREB3 suppressed AKT phosphorylation by inhibiting the interaction of INSR with insulin receptor substrate 1 (IRS1). In our study, CREB3 was firstly proved to affect activation of substrates by interacting with tyrosine kinase receptor. Besides, CREB3 could act as a TF to transactivate RNA-binding motif protein 38 (RBM38) expression, leading to suppressed AKT phosphorylation. Rescue experiments further confirmed the independence between the two functional manners. In conclusion, CREB3 acted as a tumor suppressor in HCC, which inhibited AKT phosphorylation through independently interfering interaction of INSR with IRS1, and transcriptionally activating RBM38.

The Intensity and Pattern of Syndecan-1 (CD138) Expression in Normal and Diseased Livers

Introduction Heparan sulfate proteoglycans (HSPGs) belong to the syndecan family, and syndecan-1 (CD138) is a heparan sulfate proteoglycan. Syndecan-1 has a potential role in cell-matrix and cell-cell communications as they are present in cell epithelium. Its expression is different in an extensive range of benign, inflammatory, and neoplastic diseases. In routine histopathology, it is used as a marker for plasma cells. However, it is expressed in a large variety of normal and neoplastic epithelia including squamous epithelium and gastric glandular epithelium expressed in other tissues, i.e., the liver. In the liver, variable expression is seen in cirrhosis, hepatitis, and carcinoma. The objective of this study was to investigate the expression of this marker in normal, inflammatory, and neoplastic lesions of the liver. This in turn may help clinicians to select patients who may benefit from anti-CD138 therapy. It is currently used in the diagnosis and management of plasma cell proliferations. Material and methods This is a retrospective study in which we retrieved 53 formalin-fixed paraffin-embedded (FFPE) liver specimen blocks and selected one block from each case by reviewing the hematoxylin and eosin (H&E) slides of each case. Syndecan-1 (CD138), pancytokeratin, and CD68 expression were analyzed immunohistochemically (IHC) to evaluate the percentage and intensity of CD138 expression in various hepatic entities and identify those entities where syndecan-1 can be consistently used to make a definitive diagnosis. Results The expression of pancytokeratin and CD68 was analyzed in hepatocytes and Kupffer cells, respectively. For syndecan-1 (CD138), 15.4% of cases showed basolateral membranous positivity, 44.6% of cases showed complete membranous positivity, and 40% of cases showed no positivity in hepatocytes. Cytokeratin (CK) was positive as expected in hepatocytes, and CD68 was expressed in Kupffer cells. Conclusion CD138 does not appear to be a reliable surrogate marker for liver disease. However, it may be included with other ancillary markers as a predictor of the stage of chronic liver disease and metastatic potential. The response to anti-CD138 therapy needs to be further studied.

Syndecan-1: A Novel Diagnostic and Therapeutic Target in Liver Diseases

Syndecan-1 (SDC-1), known as a coreceptor of various growth factors or an integrin binding partner, regulates various cell behaviours. Under certain pathological conditions, SDC-1 is shed from the cell surface and plays a protective or pathogenic role in various diseases. In the liver, SDC-1 is highly expressed in hepatocytes, where it is localized on the basolateral surface. It is critical to the cellular and molecular functions of hepatocytes, including their attachment to hepatitis viruses. Previous studies have reported that SDC-1 may function as a novel and promising diagnostic and therapeutic marker for various liver diseases, such as drug-induced liver injury, liver fibrosis, and liver cancer. In this review, we summarize related research and highlight the mechanisms by which SDC-1 participates in the pathogenesis of liver diseases, as well as its potential diagnostic and therapeutic applications. This review is expected to lay the foundation for further therapeutic strategies to target SDC-1 in liver diseases.

Glycosyltransferases EXTL2 and EXTL3 cellular balance dictates Heparan Sulfate biosynthesis and shapes gastric cancer cell motility and invasion

Heparan Sulfate Proteoglycans (HSPGs) are abundant glycoconjugates in cells' glycocalyx and Extracellular Matrix (ECM). By acting as scaffolds for protein-protein interactions, HSPGs modulate extracellular ligand gradients, cell signaling networks, and cell-ECM crosstalk. Aberrant expression of HSPGs and enzymes involved in HSPG biosynthesis and processing has been reported in tumors, with impact in cancer cell behavior and tumor microenvironment properties. However, the roles of specific glycosyltransferases in the deregulated biosynthesis of HSPGs are not fully understood. In this study, we established glycoengineered gastric cancer cell models lacking either Exostosin Like glycosyltransferase 2 (EXTL2) or EXTL3, and revealed their regulatory roles in both Heparan Sulfate (HS) and Chondroitin Sulfate (CS) biosynthesis and structural features. We showed that EXTL3 is key for initiating the synthesis of HS chains in detriment of CS biosynthesis, intervening in the fine-tuned balance of the HS/CS ratio in cells, while EXTL2 functions as a negative regulator of HS biosynthesis, with impact over the glycoproteome of gastric cancer cells. We demonstrated that knock-out of EXTL2 enhanced HS levels along with concomitant upregulation of Syndecan-4, which is a major cell-surface carrier of HS. This aberrant HS expression profile promoted a more aggressive phenotype, characterized by higher cellular motility and invasion, and impaired activation of Ephrin type-A 4 cell surface receptor tyrosine kinase. Our findings uncover the biosynthetic roles of EXTL2 and EXTL3 in the regulation of cancer cell GAGosylation and proteoglycans expression, and unravel the functional consequences of aberrant HS/CS balance in cellular malignant features.

Prognostic Role of Molecular and Imaging Biomarkers for Predicting Advanced Hepatocellular Carcinoma Treatment Efficacy

Simple Summary

Molecular biomarkers play a marginal role in clinical practice for hepatocellular carcinoma (HCC) diagnosis, surveillance and treatment monitoring. Radiological biomarker: alpha-fetoprotein is still a lone protagonist in this field. The potential role of molecular biomarkers in the assessment of prognosis and treatment results could reduce the health costs faced by standard radiology. The majority of efforts are oriented towards early HCC detection, but the field faces an important challenge to find adequate biomarkers for advanced HCC management.

Abstract

Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide and the fourth cause of tumor-related death. Imaging biomarkers are based on computed tomography, magnetic resonance, and contrast-enhanced ultrasound, and are widely applied in HCC diagnosis and treatment monitoring. Unfortunately, in the field of molecular biomarkers, alpha-fetoprotein (AFP) is still the only recognized tool for HCC surveillance in both diagnostic and follow-up purposes. Other molecular biomarkers have little roles in clinical practice regarding HCC, mainly for the detection of early-stage HCC, monitoring the response to treatments and analyzing tumor prognosis. In the last decades no important improvements have been achieved in this field and imaging biomarkers maintain the primacy in HCC diagnosis and follow-up. Despite the still inconsistent role of molecular biomarkers in surveillance and early HCC detection, they could play an outstanding role in prognosis estimation and treatment monitoring with a potential reduction in health costs faced by standard radiology. An important challenge resides in identifying sufficiently sensitive and specific biomarkers for advanced HCC for prognostic evaluation and detection of tumor progression, overcoming imaging biomarker sensitivity. The aim of this review is to analyze the current molecular and imaging biomarkers in advanced HCC.

Syndecan-1 in liver pathophysiology

Syndecan-1 is a heparan sulfate/chondroitin sulfate proteoglycan (PG) of the cell surface and the extracellular matrix, which regulates a broad spectrum of physiological and pathological processes such as cell proliferation, migration, inflammation, matrix remodeling, wound healing, or tumorigenesis. Syndecan-1 represents the major PG of the liver, expressed by hepatocytes and cholangiocytes, and its elevated expression is a characteristic feature of liver diseases. The highest syndecan-1 expression is found in liver cirrhosis and in hepatocellular carcinoma (HCC) developed in cirrhotic livers. In addition, as being a hepatitis C receptor, hepatitis C virus (HCV) infected livers produce extremely large amounts of syndecan-1. The serum levels of the cleaved (shedded) extracellular domain has clinical significance, as its increased concentration reflects on poor prognosis in cirrhosis as well as in cancer. In vivo experiments confirmed that syndecan-1 protects against early stages of fibrogenesis mainly by enhanced clearance of transforming growth factor beta (TGFβ1) and thrombospondin-1 via circulation, and against hepatocarcinogenesis by interfering with several signaling pathways and enhancing cell cycle blockade. In addition, syndecan-1 is capable to hinder lipid metabolism and ribosomal biogenesis in induced cancer models.. These observations together with its participation in the uptake of viruses (e.g. HCV, SARS-CoV-2) indicate that syndecan-1 is a central player in liver pathologies.

Targeting Syndecan-1: New Opportunities in Cancer Therapy

Syndecan-1 (SDC1, CD138) is one of the heparan sulfate proteoglycans and is essential for maintaining normal cell morphology, interacting with extracellular and intracellular protein repertoire as well as mediating signaling transduction upon environmental stimuli. The critical role of SDC1 in promoting tumorigenesis and metastasis has been increasingly recognized in various cancer types, implying a promising potential of utilizing SDC1 as a novel target for cancer therapy. This review summarizes the current knowledge on SDC1 structure and functions, including its role in tumor biology. We also discuss the highlights and limitations of current SDC1-targeted therapies as well as the obstacles in developing new therapeutic methods, offering our perspective on the future directions to target SDC1 for cancer treatment.

SDC1 knockdown induces epithelial-mesenchymal transition and invasion of gallbladder cancer cells via the ERK/Snail pathway

Background

Expression levels of the cell adhesion molecule syndecan-1 (SDC1) have been shown to be inversely proportional to tumor differentiation and prognosis. However, its role in the development of gallbladder cancer (GBC) remains unclear.

Methods

We knocked down SDC1 in GBC cells by RNA interference and determined its roles in cell proliferation, apoptosis, invasion, and migration by Cell Counting Kit-8, colony-formation, flow cytometry, Hoechst 33342 staining, transwell invasion, and scratch wound assays. Expression levels of epithelial–mesenchymal transition (EMT)-related and extracellular signal-regulated kinase (ERK)/Snail pathway proteins were determined by western blotting and immunofluorescence.

Results

Cell proliferation, invasion, and migration were all increased in GBC cells with SDC1 knockdown, compared with cells in the blank control and negative control groups, but apoptosis was similar in all three groups. E-cadherin and β-catenin expression levels were significantly lower and N-cadherin, vimentin, p-ERK1/2, and Snail expression were significantly higher in the SDC1 knockdown group compared with both controls, while ERK1/2 levels were similar in all groups. Reduced E-cadherin and increased vimentin levels were confirmed by immunofluorescence.

Conclusions

SDC1 knockdown promotes the proliferation, invasion, and migration of GBC cells, possibly by regulating ERK/Snail signaling and inducing EMT and cancer cell invasion.

Therapeutic potential of targeting membrane-spanning proteoglycan SDC4 in hepatocellular carcinoma

Syndecan-4 (SDC4) functions as a major endogenous membrane-associated receptor and widely regulates cytoskeleton, cell adhesion, and cell migration in human tumorigenesis and development, which represents a charming anti-cancer therapeutic target. Here, SDC4 was identified as a direct cellular target of small-molecule bufalin with anti-hepatocellular carcinoma (HCC) activity. Mechanism studies revealed that bufalin directly bond to SDC4 and selectively increased SDC4 interaction with substrate protein DEAD-box helicase 23 (DDX23) to induce HCC genomic instability. Meanwhile, pharmacological promotion of SDC4/DDX23 complex formation also inactivated matrix metalloproteinases (MMPs) and augmented p38/JNK MAPKs phosphorylation, which are highly associated with HCC proliferation and migration. Notably, specific knockdown of SDC4 or DDX23 markedly abolished bufalin-dependent inhibition of HCC proliferation and migration, indicating SDC4/DDX23 signaling axis is highly involved in the HCC process. Our results indicate that membrane-spanning proteoglycan SDC4 is a promising druggable target for HCC, and pharmacological regulation of SDC4/DDX23 signaling axis with small-molecule holds great potential to benefit HCC patients.

Molecular Crosstalk between the Hepatitis C Virus and the Extracellular Matrix in Liver Fibrogenesis and Early Carcinogenesis

Simple Summary

In the era of direct-acting antivirals against the hepatitis C virus (HCV), curing chronic hepatitis C has become a reality. However, while replicating chronically, HCV creates a peculiar state of inflammation and oxidative stress in the infected liver, which fuels DNA damage at the onset of HCV-induced hepatocellular carcinoma (HCC). This cancer, the second leading cause of death by cancer, remains of bad prognosis when diagnosed. This review aims to decipher how HCV durably alters elements of the extracellular matrix that compose the liver microenvironment, directly through its viral proteins or indirectly through the induction of cytokine secretion, thereby leading to liver fibrosis, cirrhosis, and, ultimately, HCC.

Abstract

Chronic infection by the hepatitis C virus (HCV) is a major cause of liver diseases, predisposing to fibrosis and hepatocellular carcinoma. Liver fibrosis is characterized by an overly abundant accumulation of components of the hepatic extracellular matrix, such as collagen and elastin, with consequences on the properties of this microenvironment and cancer initiation and growth. This review will provide an update on mechanistic concepts of HCV-related liver fibrosis/cirrhosis and early stages of carcinogenesis, with a dissection of the molecular details of the crosstalk during disease progression between hepatocytes, the extracellular matrix, and hepatic stellate cells.

Syndecan-1 (CD138), Carcinomas and EMT

Cell surface proteoglycans are known to be important regulators of many aspects of cell behavior. The principal family of transmembrane proteoglycans is the syndecans, of which there are four in mammals. Syndecan-1 is mostly restricted to epithelia, and bears heparan sulfate chains that are capable of interacting with a large array of polypeptides, including extracellular matrix components and potent mediators of proliferation, adhesion and migration. For this reason, it has been studied extensively with respect to carcinomas and tumor progression. Frequently, but not always, syndecan-1 levels decrease as tumor grade, stage and invasiveness and dedifferentiation increase. This parallels experiments that show depletion of syndecan-1 can be accompanied by loss of cadherin-mediated adhesion. However, in some tumors, levels of syndecan-1 increase, but the characterization of its distribution is relevant. There can be loss of membrane staining, but acquisition of cytoplasmic and/or nuclear staining that is abnormal. Moreover, the appearance of syndecan-1 in the tumor stroma, either associated with its cellular component or the collagenous matrix, is nearly always a sign of poor prognosis. Given its relevance to myeloma progression, syndecan-1-directed antibody—toxin conjugates are being tested in clinical and preclinical trials, and may have future relevance to some carcinomas.

Heparan Sulfate Glycosaminoglycans: (Un)Expected Allies in Cancer Clinical Management

In an era when cancer glycobiology research is exponentially growing, we are witnessing a progressive translation of the major scientific findings to the clinical practice with the overarching aim of improving cancer patients' management. Many mechanistic cell biology studies have demonstrated that heparan sulfate (HS) glycosaminoglycans are key molecules responsible for several molecular and biochemical processes, impacting extracellular matrix properties and cellular functions. HS can interact with a myriad of different ligands, and therefore, hold a pleiotropic role in regulating the activity of important cellular receptors and downstream signalling pathways. The aberrant expression of HS glycan chains in tumours determines main malignant features, such as cancer cell proliferation, angiogenesis, invasion and metastasis. In this review, we devote particular attention to HS biological activities, its expression profile and modulation in cancer. Moreover, we highlight HS clinical potential to improve both diagnosis and prognosis of cancer, either as HS-based biomarkers or as therapeutic targets.

Syndecans in cancer: A review of function, expression, prognostic value, and therapeutic significance

While our understanding of tumors and how to treat them has advanced significantly since the days of Aminopterin and the radical mastectomy, cancer remains among the leading causes of death worldwide. Despite innumerable advancements in medical technology the non-static and highly heterogeneous nature of a tumor can make characterization and treatment exceedingly difficult. Because of this complexity, the identification of new cellular constituents that can be used for diagnostic, prognostic, and therapeutic purposes is crucial in improving patient outcomes worldwide. Growing evidence has demonstrated that among the myriad of changes seen in cancer cells, the Syndecan family of proteins has been observed to undergo drastic alterations in expression. Syndecans are transmembrane heparan sulfate proteoglycans that are responsible for cell signaling, proliferation, and adhesion, and many studies have shed light on their unique involvement in both tumor progression and suppression. This review seeks to discuss Syndecan expression levels in various cancers, whether they make reliable biomarkers for detection and prognosis, and whether they may be viable targets for future cancer therapies. The conclusions drawn from the literature reviewed in this article indicate that changes in expression of Syndecan protein can have profound effects on tumor size, metastatic capability, and overall patient survival rate. Further, while data regarding the therapeutic targeting of Syndecan proteins is sparse, the available literature does demonstrate promise for their use in cancer treatment going forward.

Syndecan-1 Promotes Hepatocyte-Like Differentiation of Hepatoma Cells Targeting Ets-1 and AP-1

Syndecan-1 is a transmembrane heparan sulfate proteoglycan which is indispensable in the structural and functional integrity of epithelia. Normal hepatocytes display strong cell surface expression of syndecan-1; however, upon malignant transformation, they may lose it from their cell surfaces. In this study, we demonstrate that re-expression of full-length or ectodomain-deleted syndecan-1 in hepatocellular carcinoma cells downregulates phosphorylation of ERK1/2 and p38, with the truncated form exerting an even stronger effect than the full-length protein. Furthermore, overexpression of syndecan-1 in hepatoma cells is associated with a shift of heparan sulfate structure toward a highly sulfated type specific for normal liver. As a result, cell proliferation and proteolytic shedding of syndecan-1 from the cell surface are restrained, which facilitates redifferentiation of hepatoma cells to a more hepatocyte-like phenotype. Our results highlight the importance of syndecan-1 in the formation and maintenance of differentiated epithelial characteristics in hepatocytes partly via the HGF/ERK/Ets-1 signal transduction pathway. Downregulation of Ets-1 expression alone, however, was not sufficient to replicate the phenotype of syndecan-1 overexpressing cells, indicating the need for additional molecular mechanisms. Accordingly, a reporter gene assay revealed the inhibition of Ets-1 as well as AP-1 transcription factor-induced promoter activation, presumably an effect of the heparan sulfate switch.

Prevalence of Syndecan-1 (CD138) Expression in Different Kinds of Human Tumors and Normal Tissues

Syndecan-1 (CD138) is a transmembrane proteoglycan known to be expressed in various normal and malignant tissues. It is of interest because of a possible prognostic role of differential expression in tumors and its role as a target for indatuximab, a monoclonal antibody coupled with a cytotoxic agent. To comprehensively analyze CD138 in normal and neoplastic tissues, we used tissue microarrays (TMAs) for analyzing immunohistochemically detectable CD138 expression in 2,518 tissue samples from 85 different tumor entities and 76 different normal tissue types. The data showed that CD138 expression is abundant in tumors. At least an occasional weak CD138 immunostaining could be detected in 71 of 82 (87%) different tumor types, and 58 entities (71%) had at least one tumor with a strong positivity. In normal tissues, a particularly strong expression was found in normal squamous epithelium of various organs, goblet and columnar cells of the gastrointestinal tract, and in hepatocytes. The highly standardized analysis of most human cancer types resulted in a ranking order of tumors according to the frequency and levels of CD138 expression. CD138 immunostaining was highest in squamous cell carcinomas such as from the esophagus (100%), cervix uteri (79.5%), lung (85.7%), vagina (89.7%) or vulva (73.3%), and in invasive urothelial cancer (76.2%). In adenocarcinomas, CD138 was also high in lung (82.9%) and colorectal cancer (85.3%) but often lower in pancreas (73.3%), stomach (54.2% in intestinal type), or prostate carcinomas (16.3%). CD138 expression was usually low or absent in germ cell tumors, sarcomas, endocrine tumors including thyroid cancer, and neuroendocrine tumors. In summary, the preferential expression in squamous cell carcinomas of various sites makes these cancers prime targets for anti-CD138 treatments once these might become available. Abundant expression in many different normal tissues might pose obstacles to exploiting CD138 as a therapeutic target, however.

Tissue microarray analysis delineate potential prognostic role of Annexin A7 in prostate cancer progression

Background

Annexin A7 (ANXA7) is a member of the multifunctional calcium or phospholipid-binding annexin gene family. While low levels of ANXA7 are associated with aggressive types of cancer, the clinical impact of ANXA7 in prostate cancer remains unclear. Tissue microarrays (TMA) have revealed several new molecular markers in human tumors. Herein, we have identified the prognostic impact of ANXA7 in a prostate cancer using a tissue microarray containing 637 different specimens.

Methods

The patients were diagnosed with prostate cancer and long-term follow-up information on progression (median 5.3 years), tumor-specific and overall survival data (median 5.9 years) were available. Expression of Ki67, Bcl-2, p53, CD-10 (neutral endopeptidase), syndecan-1 (CD-138) and ANXA7 were analyzed by immunohistochemistry.

Results

A bimodal distribution of ANXA7 was observed. Tumors expressing either high or no ANXA7 were found to be associated with poor prognosis. However, ANXA7 at an optimal level, in between high and no ANXA7 expression, had a better prognosis. This correlated with low Ki67, Bcl-2, p53 and high syndecan-1 which are known predictors of early recurrence. At Gleason grade 3, ANXA7 is an independent predictor of poor overall survival with a p-value of 0.003. Neoadjuvant hormonal therapy, which is known to be associated with overexpression of Bcl-2 and inhibition of Ki67 LI and CD-10, was found to be associated with under-expression of ANXA7.

Conclusions

The results of this TMA study identified ANXA7 as a new prognostic factor and indicates a bimodal correlation to tumor progression.

Proteoglycans Are Attractive Biomarkers and Therapeutic Targets in Hepatocellular Carcinoma

Proteoglycans, which consist of a protein core and glycosaminoglycan chains, are major components of the extracellular matrix and play physiological roles in maintaining tissue homeostasis. In the carcinogenic tissue microenvironment, proteoglycan expression changes dramatically. Altered proteoglycan expression on tumor and stromal cells affects cancer cell signaling pathways, which alters growth, migration, and angiogenesis and could facilitate tumorigenesis. This dysregulation of proteoglycans has been implicated in the pathogenesis of diseases such as hepatocellular carcinoma (HCC) and the underlying mechanism has been studied extensively. This review summarizes the current knowledge of the roles of proteoglycans in the genesis and progression of HCC. It focuses on well-investigated proteoglycans such as serglycin, syndecan-1, glypican 3, agrin, collagen XVIII/endostatin, versican, and decorin, with particular emphasis on the potential of these factors as biomarkers and therapeutic targets in HCC regarding the future perspective of precision medicine toward the "cure of HCC".

Cancer Cell Glycocalyx and Its Significance in Cancer Progression

Cancer is a malignant tumor that threatens the health of human beings, and has become the leading cause of death in urban and rural residents in China. The glycocalyx is a layer of multifunctional glycans that covers the surfaces of a variety of cells, including vascular endothelial cells, smooth muscle cells, stem cells, epithelial, osteocytes, as well as cancer cells. The glycosylation and syndecan of cancer cell glycocalyx are unique. However, heparan sulfate (HS), hyaluronic acid (HA), and syndecan are all closely associated with the processes of cancer progression, including cell migration and metastasis, tumor cell adhesion, tumorigenesis, and tumor growth. The possible underlying mechanisms may be the interruption of its barrier function, its radical role in growth factor storage, signaling, and mechanotransduction. In the later sections, we discuss glycocalyx targeting therapeutic approaches reported in animal and clinical experiments. The study concludes that cancer cells’ glycocalyx and its role in cancer progression are beginning to be known by more groups, and future studies should pay more attention to its mechanotransduction of interstitial flow-induced shear stress, seeking promising therapeutic targets with less toxicity but more specificity.

The transcriptional factor ZEB1 represses Syndecan 1 expression in prostate cancer

Syndecan 1 (SDC-1) is a cell surface proteoglycan with a significant role in cell adhesion, maintaining epithelial integrity. SDC1 expression is inversely related to aggressiveness in prostate cancer (PCa). During epithelial to mesenchymal transition (EMT), loss of epithelial markers is mediated by transcriptional repressors such as SNAIL, SLUG, or ZEB1/2 that bind to E-box promoter sequences of specific genes. The effect of these repressors on SDC-1 expression remains unknown. Here, we demonstrated that SNAIL, SLUG and ZEB1 expressions are increased in advanced PCa, contrarily to SDC-1. SNAIL, SLUG and ZEB1 also showed an inversion to SDC-1 in prostate cell lines. ZEB1, but not SNAIL or SLUG, represses SDC-1 as demonstrated by experiments of ectopic expression in epithelial prostate cell lines. Inversely, expression of ZEB1 shRNA in PCa cell line increased SDC-1 expression. The effect of ZEB1 is transcriptional since ectopic expression of this gene represses SDC-1 promoter activity and ZEB1 binds to the SDC-1 promoter as detected by ChIP assays. An epigenetic mark associated to transcription repression H3K27me3 was bound to the same sites that ZEB1. In conclusion, this study identifies ZEB1 as a key repressor of SDC-1 during PCa progression and point to ZEB1 as a potentially diagnostic marker for PCa.

Sphingosine-1-phosphate induced epithelial-mesenchymal transition of hepatocellular carcinoma via an MMP-7/ syndecan-1/TGF-β autocrine loop

Sphingosine-1-phosphate (S1P) induces epithelial–mesenchymal transition (EMT) in hepatocellular carcinoma (HCC). However, its underlying mechanism remains largely unknown. In the present study, we investigated the correlation between S1P and syndecan-1 in HCC, the molecular mechanism involved, as well as their roles in EMT of HCC. Results revealed a high serum S1P level presents in patients with HCC, which positively correlated with the serum syndecan-1 level. A significant inverse correlation existed between S1P₁ and syndecan-1 in HCC tissues. S1P elicits activation of the PI3K/AKT signaling pathways via S1P₁, which triggers HPSE, leading to increases in expression and activity of MMP-7 and leading to shedding and suppression of syndecan-1. The loss of syndecan-1 causes an increase in TGF-β1 production. The limited chronic increase in TGF-β1 can convert HCC cells into a mesenchymal phenotype via establishing an MMP-7/Syndecan-1/TGF-β autocrine loop. Finally, TGF-β1 and syndecan-1 are essential for S1P-induced epithelial to mesenchymal transition. Taken together, our study demonstrates that S1P induces advanced tumor phenotypes of HCC via establishing an MMP-7/syndecan-1/TGF-β1 autocrine loop, and implicates targetable S1P₁-PI3K/AKT-HPSE-MMP-7 signaling axe in HCC metastasis.

Sulfonation, an underexploited area: from skeletal development to infectious diseases and cancer

Sulfonation is one of the most abundant cellular reactions modifying a wide range of xenobiotics as well as endogenous molecules which regulate important biological processes including blood clotting, formation of connective tissues, and functionality of secreted proteins, hormones, and signaling molecules. Sulfonation is ubiquitous in all tissues and widespread in nature (plants, animals, and microorganisms). Although sulfoconjugates were discovered over a century ago when, in 1875, Baumann isolated phenyl sulfate in the urine of a patient given phenol as an antiseptic, the significance of sulfonation and its roles in human diseases have been underappreciated until recent years. Here, we provide a current overview of the significance of sulfonation reactions in a variety of biological functions and medical conditions (with emphasis on cancer). We also discuss research areas that warrant further attention if we are to fully understand how deficiencies in sulfonation could impact human health which, in turn, could help define treatments to effect improvements in health.

Differences in E-Cadherin and Syndecan-1 Expression in Different Types of Ameloblastomas

Ameloblastomas are a group of benign, locally aggressive, recurrent tumors characterized by their slow and infiltrative growth. E-Cadherin and syndecan-1 are cell adhesion molecules related to the behavior of various tumors, including ameloblastomas. Ninety-nine ameloblastoma samples were studied; the expression of E-cadherin and syndecan-1 were evaluated by immunohistochemistry. E-Cadherin and epithelial syndecan-1 were more highly expressed in intraluminal/luminal unicystic ameloblastoma than in mural unicystic ameloblastoma and solid/multicystic ameloblastoma, whereas the stromal expression of syndecan-1 was higher in mural unicystic ameloblastoma and solid/multicystic ameloblastoma. Synchronicity was observed between E-cadherin and epithelial syndecan-1; the expression was correlated with intensity in all cases. There was a strong association between expression and tumor size and recurrence. The evaluation of the expression of E-cadherin and syndecan-1 are important for determining the potential aggressiveness of ameloblastoma variants. Future studies are required to understand how the expression of these markers is related to tumor aggressiveness.

Clinicopathological and prognostic significance of SDC1 overexpression in breast cancer

Background

Breast cancer is the leading cause of cancer death among global women, and its early diagnosis and treatment are very urgent. Syndecan-1 (SDC1) is a heparin sulfate proteoglycan, which has been linked with the prognosis and treatment response in a various tumor type. To investigate whether SDC1 can serve as a prognostic indictor in breast cancer, bioinformatic analyses were performed in the present study.

Methods

SDC1 expression was assessed using Oncomine analysis. Kaplan-Meier Plotter and bc-GenExMiner were performed to identify the prognostic roles of SDC1 in breast cancer. COSMIC analysis and cBioPortal database were performed to analysis the mutations of SDC1. The heat map and methylation status of SDC1 were identified by performing the UCSC.

Results

We found that SDC1 was more frequently overexpressed in breast cancer than their normal tissues and its expression might be negatively related with some CpG sites. Meanwhile, pooled data suggested that SDC1 mRNA expression is associated worse prognosis of breast cancer. Following data mining in multiple big databases confirmed a positive correlation between SDC1 mRNA expression and PLAU mRNA expression in breast cancer tissues. In addition, high SDC1 expression is associated with increased risked of age, nodal, HER2 and higher SBR grade status.

Conclusion

Our findings suggest that overexpressed SDC1 was identified in breast cancer than in matched normal tissues and is associated with methylation status of SDC1 promoter. Additionally, SDC1 is positively associated with PLAU and might act as a potential prognostic indicator for breast cancer.

Sphingosine 1-phosphate regulates proliferation, cell cycle and apoptosis of hepatocellular carcinoma cells via syndecan-1

Sphingosine 1-phosphate (S1P) plays an important role in hepatocarcinogenesis. We previously demonstrated that S1P induced epithelial-mesenchymal transition of hepatocellular carcinoma (HCC) cells via an MMP-7/Syndecan-1/TGF-β autocrine loop. In the present study, we investigated the regulative role of S1P in cell survival and progression of HCC cells, and tested whether syndecan-1 is required in the S1P action. After transfected with syndecan-1 shRNA, HepG2 and SMMC7721 cells were treated with S1P for 72 h, and then cell proliferation was detected by CCK8 assay, and cell cycle progression and cell apoptosis were detected by flow cytometry. The levels of apoptosis markers including cleaved-Caspase-3 and cleaved-PARP in SMMC7721 cells were examined by western blotting. Results showed that S1P significantly enhanced cell proliferation in HCC cells, which was significantly inhibited by syndecan-1 shRNA. S1P induced the cell proportion in S phase in HCC cells, whereas S1P decreased the proportion of cells in both early and late apoptosis. Syndecan-1 shRNA induced the G2/M arrest in the presence of S1P. In the syndecan-1 shRNA transfected HCC cells, the proportions of late and early apoptotic cells, and levels of cleaved-Caspase-3 and cleaved-PARP were significantly increased in cells with or without S1P treatment. Thus, S1P augments the proportion of cells in S phase of the cell cycle that might translate to enhance HCC cell proliferation and inhibit the cell apoptosis via syndecan-1.

Effects of syndecan-1 on the expression of syntenin and the migration of U251 glioma cells

Glioma is the most frequently occuring primary brain tumor. Syndecan-1 (SDC1) expression is related to poor prognosis of numerous human malignancies including glioma. Syndecan binding protein (SDCBP) is an important partner for SDC1. The present study investigated whether SDC1 and SDCBP are expressed in glioma and their functions on glioma cell migration. An immunohistochemical assay revealed that SDC1 and SDCBP were expressed and were positively related to malignant level of glioma (SDC1, r_s=0.576, P=0.001; SDCBP, r_s=0.661, P<0.001). Moreover, the protein levels of SDC1 were positively correlated with those of SDCBP in glioma tissues (r_s=0.628, P=0.001). In U251 glioma cells, protein levels of SDC1 and SDCBP were both upregulated in U251 cells with SDC1 overexpression, while downregulated with SDC1 knockdown. Transwell assay and scratch-wound healing assay showed that SDC1 overexpression significantly increased U251 cell migration, while SDC1 knockdown had the opposite effects. Rac1 activity, signal transducer and activator of transcription 3 (STAT3) phosphorylation, as well as expression of matrix metalloproteinase 2 (MMP2) and MMP9 was significantly increased by SDC1 overexpression, while was decreased by SDC1 knockdown. In conclusion, SDC1 overexpression upregulated SDCBP expression, and promoted glioma cell migration via Rac1 activation.

3D-spheroids: What can they tell us about pancreatic ductal adenocarcinoma cell phenotype?

We aimed at analyzing the effect of the 3D-arrangement on the expression of some genes and proteins which play a key role in pancreatic adenocarcinoma (PDAC) progression in HPAF-II, HPAC and PL45 PDAC cells cultured in either 2D-monolayers or 3D-spheroids. Cytokeratins 7, 8, 18, 19 were differently expressed in 3D-spheroids compared to 2D-monolayers. Syndecan 1 was upregulated in HPAF-II and PL45 3D-spheroids, and downregulated in HPAC. Heparanase mRNA levels were almost unchanged in HPAF-II, and increased in HPAC and PL45 3D-spheroids. Hyaluronan synthase (HAS) 2 and 3 mRNA increased in all 3D-spheroids compared to 2D-monolayers. CD44 and CD44s were expressed to a lower extent in HPAF-II and HPAC 3D-spheroids. By contrast, the CD44s/v3 and the CD44s/v6 ratio increased in HPAC and PL45 3D-spheroids, compared to 2D-monolayers. The expression of MMP-7 was strongly upregulated in 3D-spheroids. STAT3 was similarly expressed 3D-spheroids or 2D-monolayers, while pSTAT3 was almost undetectable in 2D-monolayers and strongly upregulated in 3D-spheroids. These results suggest that 3D-spheroids represent a cell culture model that allows the characterization of PDAC cell phenotype, adding new information that contributes to a better understanding of the biology and behavior of PDAC cells.

Soluble syndecan-1 (SDC1) serum level as an independent pre-operative predictor of cancer-specific survival in prostate cancer

BACKGROUND

PSA-screening detects many cases of clinically non-aggressive prostate cancer (PC) leading to significant overtreatment. Therefore, pre-operatively available prognostic biomarkers are needed to help therapy decisions. Syndecan-1 (SDC1) is a promising prognostic tissue marker in several cancers including PC but serum levels of shedded SDC1-ectodomain (sSDC1) have not been assessed in PC.

METHODS

A total of 150 patients with PC were included in this study (n = 99 serum samples, n = 103 paraffin-embedded samples (FFPE), n = 52 overlap). SDC1 protein expression and cellular localization was evaluated by immunohistochemistry (IHC), while sSDC1 serum concentrations were measured by ELISA. Serum sSDC1 levels were compared to those of MMP7, which is known to be a protease involved in SDC1 ectodomain-shedding. Clinico-pathological and follow-up data were collected and correlated with SDC1 tissue and serum levels. Disease (PC)-specific (DSS) and overall-survival (OS) were primary endpoints.

RESULTS

Median follow-up was 167 months in the serum- and 146 months in the FFPE-group. SDC1-reactivity was higher in non-neoplastic prostate glands compared to PC. In addition, cytoplasmatic, but not membranous SDC1 expression was enhanced in PC patients with higher Gleason-score >6 PC (P = 0.016). Soluble SDC1-levels were higher in patients with Gleason-score >6 (P = 0.043) and metastatic disease (P = 0.022) as well as in patients with progressed disease treated with palliative transurethral resection (P = 0.002). In addition, sSDC1 levels were associated with higher MMP7 serum concentration (P = 0.005). In univariable analyses, only sSDC1-levels exhibited a trend to unfavorable DSS (P = 0.077). In a multivariable pre-operative model, high pre-operative sSDC1-level (>123 ng/ml) proved to be an independent marker of adverse OS (P = 0.048) and DSS (P = 0.020).

CONCLUSIONS

The present study does not confirm the prognostic relevance of SDC1-IHC. The significant higher sSDC1 serum levels in advanced cases of PC, suggest that SDC1 shedding might be involved in PC progression. Additionally, high sSDC1-level proved to be an independent factor of adverse OS and DSS in a multivariable pre-operative model, making evaluation of sSDC1-levels a promising tool for pre-operative risk-stratification and/or therapy monitoring. Prostate 76:977-985, 2016. © 2016 Wiley Periodicals, Inc.

Syndecans as Cell Surface Receptors in Cancer Biology. A Focus on their Interaction with PDZ Domain Proteins

Syndecans are transmembrane receptors with ectodomains that are modified by glycosaminoglycan chains. The ectodomains can interact with a wide variety of molecules, including growth factors, cytokines, proteinases, adhesion receptors, and extracellular matrix (ECM) components. The four syndecans in mammals are expressed in a development-, cell-type-, and tissue-specific manner and can function either as co-receptors with other cell surface receptors or as independent adhesion receptors that mediate cell signaling. They help regulate cell proliferation and migration, angiogenesis, cell/cell and cell/ECM adhesion, and they may participate in several key tumorigenesis processes. In some cancers, syndecan expression regulates tumor cell proliferation, adhesion, motility, and other functions, and may be a prognostic marker for tumor progression and patient survival. The short cytoplasmic tail is likely to be involved in these events through recruitment of signaling partners. In particular, the conserved carboxyl-terminal EFYA tetrapeptide sequence that is present in all syndecans binds to some PDZ domain-containing proteins that may function as scaffold proteins that recruit signaling and cytoskeletal proteins to the plasma membrane. There is growing interest in understanding these interactions at both the structural and biological levels, and recent findings show their high degree of complexity. Parameters that influence the recruitment of PDZ domain proteins by syndecans, such as binding specificity and affinity, are the focus of active investigations and are important for understanding regulatory mechanisms. Recent studies show that binding may be affected by post-translational events that influence regulatory mechanisms, such as phosphorylation within the syndecan cytoplasmic tail.

Molecular and clinical profiles of syndecan-1 in solid and hematological cancer for prognosis and precision medicine

Syndecan-1 (SDC1, CD138) is a key cell surface adhesion molecule essential for maintaining cell morphology and interaction with the surrounding microenvironment. Deregulation of SDC1 contributes to cancer progression by promoting cell proliferation, metastasis, invasion and angiogenesis, and is associated with relapse through chemoresistance. SDC1 expression level is also associated with responses to chemotherapy and with prognosis in multiple solid and hematological cancers, including multiple myeloma and Hodgkin lymphoma. At the tissue level, the expression levels of SDC1 and the released extracellular domain of SDC1 correlate with tumor malignancy, phenotype, and metastatic potential for both solid and hematological tumors in a tissue-specific manner. The SDC1 expression profile varies among cancer types, but the differential expression signatures between normal and cancer cells in epithelial and stromal compartments are directly associated with aggressiveness of tumors and patient's clinical outcome and survival. Therefore, relevant biomarkers of SDC signaling may be useful for selecting patients that would most likely respond to a particular therapy at the time of diagnosis or perhaps for predicting relapse. In addition, the reciprocal expression signature of SDC between tumor epithelial and stromal compartments may have synergistic value for patient selection and the prediction of clinical outcome.

Syndecan-1 in Cancer: Implications for Cell Signaling, Differentiation, and Prognostication

Syndecan-1, a cell surface heparan sulfate proteoglycan, is critically involved in the differentiation and prognosis of various tumors. In this review, we highlight the synthesis, cellular interactions, and the signalling pathways regulated by syndecan-1. The basal syndecan-1 level is also crucial for understanding the sequential changes involving malignant transformation, tumor progression, and advanced or disseminated cancer stages. Moreover, we focus on the cellular localization of this proteoglycan as cell membrane anchored and/or shed, soluble syndecan-1 with stromal or nuclear accumulation and how this may carry different, highly tissue specific prognostic information for individual tumor types.

Construction and Deciphering of Human Phosphorylation-Mediated Signaling Transduction Networks

Protein phosphorylation is the most abundant reversible covalent modification. Human protein kinases participate in almost all biological pathways, and approximately half of the kinases are associated with disease. PhoSigNet was designed to store and display human phosphorylation-mediated signal transduction networks, with additional information related to cancer. It contains 11 976 experimentally validated directed edges and 216 871 phosphorylation sites. Moreover, 3491 differentially expressed proteins in human cancer from dbDEPC, 18 907 human cancer variation sites from CanProVar, and 388 hyperphosphorylation sites from PhosphoSitePlus were collected as annotation information. Compared with other phosphorylation-related databases, PhoSigNet not only takes the kinase-substrate regulatory relationship pairs into account, but also extends regulatory relationships up- and downstream (e.g., from ligand to receptor, from G protein to kinase, and from transcription factor to targets). Furthermore, PhoSigNet allows the user to investigate the impact of phosphorylation modifications on cancer. By using one set of in-house time series phosphoproteomics data, the reconstruction of a conditional and dynamic phosphorylation-mediated signaling network was exemplified. We expect PhoSigNet to be a useful database and analysis platform benefiting both proteomics and cancer studies.

Effects of fucoidan on proliferation, AMP-activated protein kinase, and downstream metabolism- and cell cycle-associated molecules in poorly differentiated human hepatoma HLF cells

Survival rates are low in patients with poorly differentiated hepatocellular carcinoma (HCC). Fucoidan, a sulfated polysaccharide derived from brown seaweed, has anticancer activity; however, the effects of fucoidan on poorly differentiated HCC remain unclear. In this study, we investigated the effects of fucoidan on AMP-activated protein kinase (AMPK), a proliferation regulator, and its downstream metabolism- and cell cycle-related molecules in a poorly differentiated human hepatoma HLF cell line. HLF cells were treated with fucoidan (10, 50, or 100 µg/ml; n=4) or phosphate buffered saline (control; n=4) for 96 h. Proliferation was evaluated by counting cells every 24 h. AMPK, TSC2, mTOR, GSK3β, acetyl-CoA carboxylase (ACC), ATP-citrate lyase, p53, cyclin D1, cyclin-dependent kinase (CDK) 4, and CDK6 expression and/or phosphorylation were examined by immunoblotting 24 h after treatment with 100 µg/ml fucoidan. Cell cycle progression was analyzed by fluorescence-activated cell sorter 48 h after treatment. Treatment with 50 or 100 µg/ml fucoidan significantly and dose- and time-dependently suppressed HLF cell proliferation (P<0.0001). Fucoidan induced AMPK phosphorylation on Ser172 24 h after treatment. Although no differences were seen in expression and phosphorylation levels of TSC2, mTOR, GSK3β, ATP-citrate lyase, and p53 between the control and fucoidan-treated HLF cells, fucoidan induced ACC phosphorylation on Ser79. Moreover, fucoidan decreased cyclin D1, CDK4 and CDK6 expression 24 h after treatment. Furthermore, HLF cells were arrested in the G1/S phase 48 h after fucoidan treatment. We demonstrated that fucoidan suppressed HLF cell proliferation with AMPK phosphorylation. We showed that fucoidan phosphorylated ACC and downregulated cyclin D1, CDK4 and CDK6 expression. Our findings suggest that fucoidan inhibits proliferation through AMPK-associated suppression of fatty acid synthesis and G1/S transition in HLF cells.

Advances in the molecular functions of syndecan-1 (SDC1/CD138) in the pathogenesis of malignancies

Syndecan-1 (SDC1, synd, CD138) is the most widely studied member of four structurally related cell surface heparan sulfate proteoglycans (HSPG). Although SDC1 has been implicated in a wide range of biological functions, its altered expression often produces malignant phenotypes, which arise from increased cell proliferation and cell growth, cell survival, cell invasion and metastasis, and angiogenesis. Recent studies revealed much about the underlying molecular roles of SDC1 in these processes. The changes in SDC1 expression also have a direct impact on the clinical course of cancers, as evident by its prognostic significance. Accumulating evidence suggest that SDC1 is involved in stimulation of cancer stem cells (CSC) or tumor initiating cells (TIC) and this may affect disease relapse, and resistance to therapy. This review discusses the progress on the pro-tumorigenic role(s) of SDC1 and how these roles may impact the clinical aspect of the disease. Also discussed, are the current strategies for targeting SDC1 or its related signaling.

Syndecans as modulators and potential pharmacological targets in cancer progression

Extracellular matrix (ECM) components form a dynamic network of key importance for cell function and properties. Key macromolecules in this interplay are syndecans (SDCs), a family of transmembrane heparan sulfate proteoglycans (HSPGs). Specifically, heparan sulfate (HS) chains with their different sulfation pattern have the ability to interact with growth factors and their receptors in tumor microenvironment, promoting the activation of different signaling cascades that regulate tumor cell behavior. The affinity of HS chains with ligands is altered during malignant conditions because of the modification of chain sequence/sulfation pattern. Furthermore, matrix degradation enzymes derived from the tumor itself or the tumor microenvironment, like heparanase and matrix metalloproteinases, ADAM as well as ADAMTS are involved in the cleavage of SDCs ectodomain at the HS and protein core level, respectively. Such released soluble SDCs "shed SDCs" in the ECM interact in an autocrine or paracrine manner with the tumor or/and stromal cells. Shed SDCs, upon binding to several matrix effectors, such as growth factors, chemokines, and cytokines, have the ability to act as competitive inhibitors for membrane proteoglycans, and modulate the inflammatory microenvironment of cancer cells. It is notable that SDCs and their soluble counterparts may affect either the behavior of cancer cells and/or their microenvironment during cancer progression. The importance of these molecules has been highlighted since HSPGs have been proposed as prognostic markers of solid tumors and hematopoietic malignancies. Going a step further down the line, the multi-actions of SDCs in many levels make them appealing as potential pharmacological targets, either by targeting directly the tumor or indirectly the adjacent stroma.

Rationale for clinical trials of coagulation: reactive drugs in hepatocellular carcinoma

Evidence for the regulation of cancer growth by components of the blood coagulation mechanism provides abundant opportunity for the development of novel hypotheses for the experimental treatment of malignancy. Information available on the heterogeneity in mechanisms of interaction between various cancer cell types, and procoagulant and fibrinolytic pathways, platelets, glycosaminoglycan-regulated growth factors and cell-adhesion molecules indicates that insightful clinical trial design may allow targeting of individual cancer cell types with agents capable of intercepting mechanisms of growth control that are relevant to specific tumor types. This paper reviews the evidence that the common anticoagulant, heparin, inhibits hepatocellular carcinoma cell proliferation and hepatocellular carcinoma tumor dissemination in experimental animals. Clinical trials of heparin performed to date have shown increased tumor response rates and survival in other tumor types. Expression of urokinase-type plasminogen activator by hepatocellular carcinoma cells enhances tumor cell proliferation, motility, invasiveness and metastatic dissemination. Inhibition of the urokinase-type plasminogen activator/plasmin system by protease inhibitors such as aprotinin (Trasylol, Bayer) have shown improvement in the clinical course of certain tumor types. These data suggest that drugs that are well-known in the field of vascular medicine may find a role in the treatment of hepatocellular carcinoma, a common tumor type that has resisted containment by other means.

Molecular markers of cell adhesion in ameloblastomas. An update

Ameloblastoma is the most common odontogenic tumor of epithelial origin, and though it is of a benign nature, it frequently infiltrates the bone, has a high rate of recurrence and could potentially become malignant. Cellular adhesion potentially plays an important role in the manifestation of these characteristics and in the tumor biology of ameloblastomas. Losses of cell-cell and extracellular matrix adhesion and cohesion are among the first events that occur in the invasion and growth of tumors of epithelial origin. The present review includes a description of the molecules that are involved in cell adhesion as reported for various types of ameloblastomas and discusses the possible roles of these molecules in the biological behaviors of this odontogenic tumor. Knowledge of the complex mechanisms in which these molecules play a role is critical for the research and discovery of future therapeutic targets.

Hypoxia reduces CD138 expression and induces an immature and stem cell-like transcriptional program in myeloma cells

Although CD138 expression is a hallmark of plasma cells and myeloma cells, reduced CD138 expression is occasionally found. However, the mechanisms underlying CD138 downregulation in myeloma cells remain unclear. Previous reports suggest that the bone marrow microenvironment may contribute to CD138 downregulation. Among various factors in the tumor microenvironment, hypoxia is associated with tumor progression, poor clinical outcomes, dedifferentiation and the formation of cancer stem cell niches in solid tumors. Since recent findings showed that progression of multiple myeloma (MM) delivers hypoxia within the bone marrow, we hypothesized that CD138 expression may be regulated by hypoxia. In the present study, we examined whether the expression of CD138 and transcription factors occurred in myeloma cells under hypoxic conditions. MM cell lines (KMS-12BM and RPMI 8226) were cultured under normoxic or hypoxic conditions for up to 30 days. Changes in the phenotype and the expression of surface antigens and transcription factors were analyzed using flow cytometry, RT-PCR and western blotting. All-trans retinoic acid (ATRA) was used to examine the phenotypic changes under hypoxic conditions. The expression levels of CD138, CS1 and plasma cell-specific transcription factors decreased under hypoxic conditions, while those of CD20, CXCR4 and B cell-specific transcription factors increased compared with those under normoxic conditions. Stem cell-specific transcription factors were upregulated under hypoxic conditions, while no difference was observed in ALDH activity. The reduced CD138 expression under hypoxic conditions recovered when cells were treated with ATRA, even under hypoxic conditions, along with decreases in the expression of stem cell-specific transcription factor. Interestingly, ATRA treatment sensitized MM cells to bortezomib under hypoxia. We propose that hypoxia induces immature and stem cell-like transcription phenotypes in myeloma cells. Taken together with our previous observation that decreased CD138 expression is correlated with disease progression, the present data suggest that a hypoxic microenvironment affects the phenotype of MM cells, which may correlate with disease progression.

Expression of syndecan-4 and correlation with metastatic potential in testicular germ cell tumours

Although syndecan-4 is implicated in cancer progression, there is no information for its role in testicular germ cell tumours (TGCTs). Thus, we examined the expression of syndecan-4 in patients with TGCTs and its correlation with the clinicopathological findings. Immunohistochemical staining in 71 tissue specimens and mRNA analysis revealed significant overexpression of syndecan-4 in TGCTs. In seminomas, high percentage of tumour cells exhibited membranous and/or cytoplasmic staining for syndecan-4 in all cases. Stromal staining for syndecan-4 was found in seminomas and it was associated with nodal metastasis (P = 0.04), vascular/lymphatic invasion (P = 0.01), and disease stage (P = 0.04). Reduced tumour cell associated staining for syndecan-4 was observed in nonseminomatous germ cell tumours (NSGCTs) compared to seminomas. This loss of syndecan-4 was associated with nodal metastasis (P = 0.01), vascular/lymphatic invasion (P = 0.01), and disease stage (P = 0.01). Stromal staining for syndecan-4 in NSGCTs did not correlate with any of the clinicopathological variables. The stromal expression of syndecan-4 in TGCTs was correlated with microvessel density (P = 0.03). Our results indicate that syndecan-4 is differentially expressed in seminomas and NSGCTs and might be a useful marker. Stromal staining in seminomas and reduced levels of syndecan-4 in tumour cells in NSGCTs are related to metastatic potential, whereas stromal staining in TGCTs is associated with neovascularization.

Decreased expression of intercellular adhesion molecules in acantholytic squamous cell carcinoma compared with invasive well-differentiated squamous cell carcinoma of the skin

Intercellular adhesion proteins are poorly characterized in acantholytic squamous cell carcinoma (ASCC), a more aggressive tumor than nonacantholytic invasive well-differentiated squamous cell carcinoma (SCC) of the skin. In this study we compared expression of Dsg3, E-cadherin, and syndecan-1 in ASCC and SCC. Immunohistochemical detection of Dsg3, E-cadherin, and syndecan-1 in 22 ASCCs and 22 SCCs was graded on a semiquantitative scale for intensity of staining (SI) and degree of circumferential staining (CS) about the cell membrane. Results were assessed by means of conditional logistic regression and χ(2) analysis. Dsg3 and E-cadherin expression (SI, CS) was significantly decreased (P < .05) in ASCC compared with SCC, whereas staining for syndecan-1 was similar in the 2 tumor types. Differences in expression of adhesion markers between ASCC and SCC may contribute to the development of acantholysis in ASCC and its more aggressive biologic behavior.

Polyunsaturated fatty acid metabolism in prostate cancer

Polyunsaturated fatty acids (PUFA) play important roles in the normal physiology and in pathological states including inflammation and cancer. While much is known about the biosynthesis and biological activities of eicosanoids derived from ω6 PUFA, our understanding of the corresponding ω3 series lipid mediators is still rudimentary. The purpose of this review is not to offer a comprehensive summary of the literature on fatty acids in prostate cancer but rather to highlight some of the areas where key questions remain to be addressed. These include substrate preference and polymorphic variants of enzymes involved in the metabolism of PUFA, the relationship between de novo lipid synthesis and dietary lipid metabolism pathways, the contribution of cyclooxygenases and lipoxygenases as well as terminal synthases and prostanoid receptors in prostate cancer, and the potential role of PUFA in angiogenesis and cell surface receptor signaling.

CD138 (syndecan-1) expression in bone-forming tumors

CD138 (syndecan-1), a cell surface proteoglycan, is sensitive and specific for plasmacytic differentiation in hematologic disorders. Expression of CD138 has been observed in a majority of epithelial neoplasms and, rarely, soft tissue tumors. However, its expression in bone tumors has not been evaluated. We studied CD138 expression in 27 osteosarcomas, 12 benign bone-forming tumors (osteoid osteoma and osteoblastoma), and 17 reactive bone cases. CD138 expression was also evaluated in a tissue microarray (TMA) constructed from 24 osteosarcomas, 24 chondrosarcomas, 12 giant cell tumors of bone, and 9 normal bone samples. Membranous expression of CD138 was found in an average of 31% of osteosarcoma cases (16/51; 14/27 [52%] in in-house cases; 2/24 [8%] in TMA cases) and in 83% of osteoid osteoma/osteoblastoma cases (10/12). Subsequent immunoglobulin κ and λ stains were negative in the CD138+ cases. All cases of chondrosarcoma, giant cell tumor of bone, and normal/reactive bone tested were nonreactive with anti-CD138. Our results show that CD138 reactivity for neoplastic cells in bone is not a definitive marker for plasmacytic origin, and caution is required to interpret CD138+ cells from a bony lesion for which a hematologic etiology has not been established.

Inter-strain heterogeneity in rat hepatic transcriptomic responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

The biochemical and toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) have been the subject of intense study for decades. It is now clear that essentially all TCDD-induced toxicities are mediated by DNA-protein interactions involving the Aryl Hydrocarbon Receptor (AHR). Nevertheless, it remains unknown which AHR target genes cause TCDD toxicities. Several groups, including our own, have developed rodent model systems to probe these questions. mRNA expression profiling of these model systems has revealed significant inter-species heterogeneity in rodent hepatic responses to TCDD. It has remained unclear if this variability also exists within a species, amongst rodent strains. To resolve this question, we profiled the hepatic transcriptomic response to TCDD of diverse rat strains (L-E, H/W, F344 and Wistar rats) and two lines derived from L-E×H/W crosses, at consistent age, sex, and dosing (100 μg/kg TCDD for 19 h). Using this uniquely consistent dataset, we show that the majority of TCDD-induced alterations in mRNA abundance are strain/line-specific: only 11 genes were affected by TCDD across all strains, including well-known dioxin-responsive genes such as Cyp1a1 and Nqo1. Our analysis identified two novel universally dioxin-responsive genes as well as 4 genes induced by TCDD in dioxin-sensitive rats only. These 6 genes are strong candidates to explain TCDD-related toxicities, so we validated them using 152 animals in time-course (0 to 384 h) and dose-response (0 to 3000 μg/kg) experiments. This study reveals that different rat strains exhibit dramatic transcriptional heterogeneity in their hepatic responses to TCDD and that inter-strain comparisons can help identify candidate toxicity-related genes.

Antithetic roles of proteoglycans in cancer

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

Prognostic significance of syndecan-1 expression in cervical cancers

Objective

Syndecans are reported to have variable expression in several solid tumors and blood cancers. The cause provoking altered expression of syndecans is not known to date. We studied copy number status of syndecan-1 (SDC1) and significance of SDC1 gene product (syndecan-1, SDC1) expression in cervical cancers.

Methods

Using 121 cases of cervical cancer tissues, we screened SDC1 expression pattern using immunohistochemistry. We analyzed the relationship between SDC1 expression and clinicopathological parameters. To find possible causes of the expression change, we exploited interphase fluorescent in situ hybridization to screen copy number alteration of SDC1.

Results

Among 121 cases, 101 (83.5%) were positive and 20 (16.4%) were negative for SDC1. Among the parameters, age, histological type, and grade were significantly associated with SDC1 expression (p<0.05). Strong SDC1 expression in the cytoplasm showed better patient survival (p=0.02). In multivariate regression model, grade and SDC1 expression were independent prognostic factors (p<0.05). SDC1 in cervical cancers did not show copy number alteration.

Conclusion

Strong SDC1 expression in the cytoplasm of tumor cells predicts better patient survival. The change of SDC1 expression in cervical cancers is not caused by copy number alteration of the gene.