Soluble syndecan-1 (sCD138) as a prognostic factor independent of mutation status in patients with chronic lymphocytic leukemia

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.

Circulating Heparan Sulfate Proteoglycans as Biomarkers in Health and Disease

Cell-surface heparan sulfate proteoglycans (HSPGs) play key roles in regulating cell behavior, cell signaling, and cell matrix interactions in both physiological and pathological conditions. Their soluble forms from glycocalyx shedding are not merely waste products, but, rather, bioactive molecules, detectable in serum, which may be useful as diagnostic and prognostic markers. In addition, as in the case of glypican-3 in hepatocellular carcinoma, they may be specifically expressed by pathological tissue, representing promising targets for immunotherapy. The primary goal of this comprehensive review is to critically survey the main findings of the clinical data from the last 20 years and provide readers with an overall picture of the diagnostic and prognostic value of circulating HSPGs. Moreover, issues related to the involvement of HSPGs in various pathologies, including cardiovascular disease, thrombosis, diabetes and obesity, kidney disease, cancer, trauma, sepsis, but also multiple sclerosis, preeclampsia, pathologies requiring surgery, pulmonary disease, and others will be discussed.

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.

The extracellular matrix: A key player in the pathogenesis of hematologic malignancies

Hematopoietic stem and progenitor cells located in the bone marrow lay the foundation for multiple lineages of mature hematologic cells. Bone marrow niches are architecturally complex with specific cellular, physiochemical, and biomechanical factors. Increasing evidence suggests that the bone marrow microenvironment contributes to the pathogenesis of hematological neoplasms. Numerous studies have deciphered the role of genetic mutations and chromosomal translocations in the development hematologic malignancies. Significant progress has also been made in understanding how the cellular components and cytokine interactions within the bone marrow microenvironment promote the evolution of hematologic cancers. Although the extracellular matrix is known to be a key player in the pathogenesis of various diseases, it's role in the progression of hematologic malignancies is less understood. In this review, we discuss the interactions between the extracellular matrix and malignant cells, and provide an overview of the role of extracellular matrix remodeling in sustaining hematologic malignancies.

Serum and tissue syndecan-1 levels in renal cell carcinoma

Background

The proteoglycan syndecan-1 is involved in cell proliferation, adhesion and angiogenesis. It was shown to be involved in cancer progression in different tumor entities. So far, the role of syndecan-1 in renal cell carcinoma (RCC), one of the most common diseases in urologic oncology, was little described. Purpose of the present study was to obtain serum concentrations and tissue expression levels of syndecan-1 in a cohort of patients diagnosed with RCC.

Methods

Clinical and follow-up data were obtained from 413 RCC patients. SDC1 levels were determined in serum samples of 100 patients by enzyme-linked immunosorbent assay and tissue SDC1 expression was measured by immunohistochemistry (IHC) in 343 cases. Results were correlated with clinicopathological and follow-up data.

Results

Five and ten years overall and cancer specific survival were 67% and 56% [overall survival (OS)] and 79% and 76% [cancer-specific survival (CSS)]. In female patients and locally advanced disease (≥T3), tissue SDC1 expression was decreased (female 85.6% vs. male 71.1% low tissue SDC1 expression, P=0.0153 and ≤T2 70.0% vs. ≥T3 87.2% low tissue SDC1 expression, P=0.0055) compared to male patients and organ confined disease. Locally advanced tumor stage, presence of lymph node or distant metastases, high Fuhrman grading and clear cell carcinoma as histopathological subtype were independent prognostic factors for reduced CSS and OS. There was no impact of serum SDC1 (sSDC1) serum concentration or SDC1 tissue protein expression on OS, CSS or recurrence free survival (RFS) in uni- or multivariable analysis.

Conclusions

sSDC1 concentration or SDC1 tissue protein expression levels had no influence on patients' prognosis in the present cohort of patients diagnosed with RCC.

CD markers variations in chronic lymphocytic leukemia: New insights into prognosis

Chronic lymphocytic leukemia (CLL) is one of the most commonly occurring adult leukemias that is associated with clonal accumulation of mature apoptosis-resistant B-cells in bone marrow, peripheral blood, and specific tissues. Different pathogenesis factors can contribute to the aggression of the clinical course in this disease. Cytogenetic abnormalities and surface biomarkers of neoplastic CLL cells can be effective in the outcome of CLL, and the examination of changing CD markers expressions in the progression of CLL can be related to the prognosis of this disease. Changing expression levels of CD markers on lymphocytes and other cells in CLL patients can play a role in the aggressive clinical outcomes such as organomegaly, immunodeficiency, and advanced disease stages through their interaction with CLL microenvironment. Given the involvement of CD markers in the pathogenesis of CLL, it can be stated that recognizing the expression changes of CD markers in the cells involved in CLL can be a proper approach to evaluate prognosis among these patients.

Syndecan-1 (sCD138) levels in chronic lymphocytic leukemia: clinical and hematological correlations

BACKGROUND

Syndecan-1 (sCD138) has recently been suggested to predict the clinical course of early-stage chronic lymphocytic leukemia (CLL), but few studies have been reported. This study assessed the role of syndecan-1 in the prognosis of patients with CLL and its correlation with other prognostic markers.

METHODS

This prospective study was performed in the hematology department of an Indian tertiary care center, over nineteen months (Jun. 2009-Jan. 2011). Forty-nine new patients with CLL presented during this period and were included. Twenty age- and gender-matched healthy patients served as controls, and six patients with multiple myeloma were included as positive controls. Baseline serum syndecan-1 concentrations were measured for all patients at presentation using ELISA (Diaclone, Besancon, France). At baseline, patients were divided into low (N=10), intermediate (N=18) and high (N=21) risk cohorts. Serum syndecan-1 levels in these patient subgroups were compared with clinical and laboratory parameters.

RESULTS

The median syndecan-1 level in patients with CLL (73.32 ng/mL, range, 28.71-268.0 ng/mL) was marginally higher than that in healthy patients (63.10 ng/mL, range, 55.0-75.11 ng/mL). At presentation, syndecan-1 levels in patients with CLL correlated strongly with symptomatic disease (cytopenias, P=0.004) and higher clinical stage (Rai stage III and IV, P=0.001) markers and poorly with β2-microglobulin level (P=0.270), diffuse BM infiltration (P=0.882), and surrogate mutation status markers (CD 38, P=0.174 and ZAP-70, P=0.459). Syndecan-1 levels dichotomized by the median value were higher with progressive disease markers, e.g. shorter lymphocyte doubling time (LDT, P=0.015) and increased treatment (P=0.099).

CONCLUSION

In CLL, serum syndecan-1 (sCD138) levels at presentation correlate with disease burden, and higher baseline levels may predict early treatment.

Soluble syndecans: biomarkers for diseases and therapeutic options

Syndecans are important mediators of signalling by transmitting external stimuli into the cells. This role in signal transduction has been attributed mainly to the membrane-bound syndecans. In the last years, however, the soluble ectodomain of syndecans generated by shedding has come into the focus of research as this process has been show to modulate the syndecan-dependent signalling pathways, as well as other pathways. This review summarizes the current knowledge about the induction of syndecan shedding and the different pathways modulated by shed syndecan proteins. This review summarizes the known and putative sheddases for each syndecan and describes the exemplary conditions of sheddase activity for some syndecans. This review summarizes the proposed use of shed syndecans as biomarkers for various diseases, as the shedding process of syndecans depends crucially on tissue- and disease-specific activation of the sheddases. Furthermore, the potential use of soluble syndecans as a therapeutic option is discussed, on the basis of the current literature. LINKED ARTICLES: This article is part of a themed section on Translating the Matrix. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.1/issuetoc.

Endothelial Glycocalyx as Biomarker for Cardiovascular Diseases: Mechanistic and Clinical Implications

INTRODUCTION

The endothelial surface layer is covered with abundant proteoglycans, of which syndecans and glycosaminoglycans are major constituents.

RECENT FINDINGS

Among the endothelial glycocalyx (eGC) constituents, syndecan-1 (sdc1) is a main component, and an elevated serum level of sdc1 may indicate the degradation of eGC. In patients with ischemic heart disease or heart failure, elevation of serum sdc1 has been associated with worsening cardiac and renal function; however, the causal relationship between degradation of eGC and clinical outcomes is unclear. Herein, we review the previous literature on eGC in cardiovascular and noncardiovascular diseases and their clinical implications.

Prognostic value of baseline seric Syndecan-1 in initially unresectable metastatic colorectal cancer patients: a simple biological score

In first-line metastatic colorectal cancer (mCRC), baseline prognostic factors allowing death risk and treatment strategy stratification are lacking. Syndecan-1 (CD138) soluble form was never described as a prognostic biomarker in mCRC. We investigated its additional prognostic value for overall survival (OS). mCRC patients with unresectable disease at diagnosis were treated with bevacizumab-based chemotherapy in two independent prospective clinical trials (development set: n = 126, validation set: n = 51, study NCT00489697 and study NCT00544011, respectively). Serums were collected at baseline for CD138 measurement. OS determinants were assessed and, based on the final multivariate model, a prognostic score was proposed. Two independent OS prognostic factors were identified: Lactate Dehydrogenase (LDH) high level (p = 0.0066) and log-CD138 high level (p = 0.0190). The determination of CD138 binary information (cutoff: 75 ng/mL) allowed the assessment of a biological prognostic score with CD138 and LDH values, identifying three risk groups for death (median OS= 38.9, 30.1 and 19.8 months for the low, intermediate and high risk groups, respectively; p < 0.0001). This score had a good discrimination ability (C-index = 0.63). These results were externally confirmed in the validation set. Our study provides robust evidence in favor of the additional baseline soluble CD138 prognostic value for OS, in mCRC patients. A simple biological scoring system is proposed including LDH and CD138 binary status values.

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.

Soluble CD138/Syndecan-1 Increases in the Sera of Patients with Moderately Differentiated Bladder Cancer

BACKGROUND

CD138/Syndecan-1 (Sdc-1) is expressed on the tumor and stromal cells of invasive bladder carcinoma. CD138/Sdc-1 shedding from the cell surface is associated with the invasive phenotype in lung and breast cancers.

PATIENTS AND METHODS

Soluble CD138/Sdc-1 was measured in the sera of 86 bladder cancer patients and 57 healthy individuals by a commercial ELISA assay.

RESULTS

Soluble Sdc-1 was increased in the sera of patients with bladder cancer (138.42 ± 81.85 vs. 86.48 ± 82.58 ng/ml, p = 0.0003). Patients aged over 70 years had higher levels of CD138/Sdc-1 in their sera (159.7 ± 15.77 vs. 124.5 ± 9.99 ng/ml, p = 0.025), and soluble Sdc-1 levels were higher in the sera of patients with moderately differentiated tumors compared to poorly differentiated ones (170.47 ± 85.06 vs. 101.79 ± 68.24 ng/ml, p = 0.01). The soluble Sdc-1 level was higher in muscle-invasive (154.45 ± 83.60 vs. 89.9 ± 55.02 ng/ml) but not lymphatic-invasive (106.25 ± 52.10 vs. 123.43 ± 63.76 ng/ml) tumors (p = 0.027 and 0.45, respectively). A non-significant trend of soluble Sdc-1 increase in the sera of male patients compared to female patients was observed (145.38 ± 85.47 vs. 110.20 ± 59.04 ng/ml, p = 0.054).

CONCLUSION

The elevated levels of soluble CD138/Sdc-1 in older bladder cancer patients and those with muscular invasion sheds some light on the mechanisms of the disease invasion.

Comparative glycomics of leukocyte glycosaminoglycans

Glycosaminoglycans (GAGs) vary widely in disaccharide and oligosaccharide content in a tissue-specific manner. Nonetheless, there are common structural features, such as the presence of highly sulfated non-reducing end domains on heparan sulfate (HS) chains. Less clear are the patterns of expression of GAGs on specific cell types. Leukocytes are known to express GAGs primarily of the chondroitin sulfate (CS) type. However, little is known regarding the properties and structures of the GAG chains, their variability among normal subjects, and changes in structure associated with disease conditions. We isolated peripheral blood leukocyte populations from four human donors and extracted GAGs. We determined the relative and absolute disaccharide abundances for HS and CS GAGs classes using size exclusion chromatography-mass spectrometry (SEC-MS). We found that all leukocytes express HS chains with a level of sulfation that is more similar to heparin than to organ-derived HS. The levels of HS expression follows the trend T cells/B cells > monocytes/natural killer cells > polymorphonuclear leukocytes (PMNs). In addition, CS abundances were considerably higher than total HS but varied considerably in a leukocyte cell type-specific manner. Levels of CS were higher for myeloid lineage cells (PMNs and monocytes) than for lymphoid cells (B, T and natural killer (NK) cells). This information establishes the range of GAG structures expressed on normal leukocytes and is necessary for subsequent inquiry into disease conditions.

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.