Altered proliferative and metastatic potential associated with increased expression of syndecan-1

Heparan Sulfate Modulation Affects Breast Cancer Cell Adhesion and Transmigration across In Vitro Blood-Brain Barrier

The disruption of endothelial heparan sulfate (HS) is an early event in tumor cell metastasis across vascular barriers, and the reinforcement of endothelial HS reduces tumor cell adhesion to endothelium. Our recent study showed that while vascular endothelial growth factor (VEGF) greatly reduces HS at an in vitro blood-brain barrier (BBB) formed by human cerebral microvascular endothelial cells (hCMECs), it significantly enhances HS on a breast cancer cell, MDA-MB-231 (MB231). Here, we tested that this differential effect of VEGF on the HS favors MB231 adhesion and transmigration. We also tested if agents that enhance endothelial HS may affect the HS of MB231 and reduce its adhesion and transmigration. To test these hypotheses, we generated an in vitro BBB by culturing hCMECs on either a glass-bottom dish or a Transwell filter. We first quantified the HS of the BBB and MB231 after treatment with VEGF and endothelial HS-enhancing agents and then quantified the adhesion and transmigration of MB231 across the BBB after pretreatment with these agents. Our results demonstrated that the reduced/enhanced BBB HS and enhanced/reduced MB231 HS increase/decrease MB231 adhesion to and transmigration across the BBB. Our findings suggest a therapeutic intervention by targeting the HS-mediated breast cancer brain metastasis.

Effect of the Expression of ELOVL5 and IGFBP6 Genes on the Metastatic Potential of Breast Cancer Cells

Breast cancer (BC) is the leading cause of death from malignant neoplasms among women worldwide, and metastatic BC presents the biggest problems for treatment. Previously, it was shown that lower expression of ELOVL5 and IGFBP6 genes is associated with a higher risk of the formation of distant metastases in BC. In this work, we studied the change in phenotypical traits, as well as in the transcriptomic and proteomic profiles of BC cells as a result of the stable knockdown of ELOVL5 and IGFBP6 genes. The knockdown of ELOVL5 and IGFBP6 genes was found to lead to a strong increase in the expression of the matrix metalloproteinase (MMP) MMP1. These results were in good agreement with the correlation analysis of gene expression in tumor samples from patients and were additionally confirmed by zymography. The knockdown of ELOVL5 and IGFBP6 genes was also discovered to change the expression of a group of genes involved in the formation of intercellular contacts. In particular, the expression of the CDH11 gene was markedly reduced, which also complies with the correlation analysis. The spheroid formation assay showed that intercellular adhesion decreased as a result of the knockdown of the ELOVL5 and IGFBP6 genes. Thus, the obtained data indicate that malignant breast tumors with reduced expression of the ELOVL5 and IGFBP6 genes can metastasize with a higher probability due to a more efficient invasion of tumor cells.

E-Cadherin and Syndecan-1 Expression in Patients With Advanced Non-small Cell Lung Cancer Treated With Chemoradiotherapy

BACKGROUND/AIM

The aim of the study was to investigate whether E-cadherin and syndecan-1 are molecular markers of advanced non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

The expression of E-cadherin and syndecan-1 (SDC1) was examined immunohistochemically on tissue specimens of 64 patients, with stage III disease at presentation. The obtained expression data were correlated with clinical parameters.

RESULTS

Negative expression of SDC1 was correlated with squamous histology (p=0.002). E-cadherin positive expression was significantly associated with increased 2-year overall survival (OS) rate (p=0.032). In the multivariate Cox analysis, performance status 0-1 was an independent predictor of OS (p=0.001) and disease-free survival (DFS) (p=0.001). E-cadherin expression was an independent predictor of OS (p=0.007) and DFS (p=0.029).

CONCLUSION

E-cadherin might be a prognostic factor for OS and DFS in advanced stage NSCLC patients. Further investigations are needed for the establishment of E-cadherin and syndecan-1 as molecular markers, affecting treatment response and survival.

Molecular targets and signaling pathways regulated by nuclear translocation of syndecan-1

Background

The cell-surface heparan sulfate proteoglycan syndecan-1 is important for tumor cell proliferation, migration, and cell cycle regulation in a broad spectrum of malignancies. Syndecan-1, however, also translocates to the cell nucleus, where it might regulate various molecular functions.

Results

We used a fibrosarcoma model to dissect the functions of syndecan-1 related to the nucleus and separate them from functions related to the cell-surface. Nuclear translocation of syndecan-1 hampered the proliferation of fibrosarcoma cells compared to the mutant lacking nuclear localization signal. The growth inhibitory effect of nuclear syndecan-1 was accompanied by significant accumulation of cells in the G0/G1 phase, which indicated a possible G1/S phase arrest.

We implemented multiple, unsupervised global transcriptome and proteome profiling approaches and combined them with functional assays to disclose the molecular mechanisms that governed nuclear translocation and its related functions. We identified genes and pathways related to the nuclear compartment with network enrichment analysis of the transcriptome and proteome. The TGF-β pathway was activated by nuclear syndecan-1, and three genes were significantly altered with the deletion of nuclear localization signal: EGR-1 (early growth response 1), NEK11 (never-in-mitosis gene a-related kinase 11), and DOCK8 (dedicator of cytokinesis 8). These candidate genes were coupled to growth and cell-cycle regulation. Nuclear translocation of syndecan-1 influenced the activity of several other transcription factors, including E2F, NFκβ, and OCT-1. The transcripts and proteins affected by syndecan-1 showed a striking overlap in their corresponding biological processes. These processes were dominated by protein phosphorylation and post-translation modifications, indicative of alterations in intracellular signaling. In addition, we identified molecules involved in the known functions of syndecan-1, including extracellular matrix organization and transmembrane transport.

Conclusion

Collectively, abrogation of nuclear translocation of syndecan-1 resulted in a set of changes clustering in distinct patterns, which highlighted the functional importance of nuclear syndecan-1 in hampering cell proliferation and the cell cycle. This study emphasizes the importance of the localization of syndecan-1 when considering its effects on tumor cell fate.

Electronic supplementary material

The online version of this article (10.1186/s12860-017-0150-z) contains supplementary material, which is available to authorized users.

Midkine and syndecan‑1 levels correlate with the progression of malignant gastric cardiac adenocarcinoma

The present study aimed to determine whether the expression levels of midkine (MK) and syndecan‑1 correlate with the malignant progression and poor prognosis of gastric cardiac adenocarcinoma (GCA). GCA tissue samples (n=72) were obtained from the Department of Pathology of the First Affiliated Hospital of Henan University of Science and Technology (Luoyang, China). The paraffin‑embedded samples had been surgically resected and pathologically diagnosed between 2007 and 2009. Normal gastric cardiac biopsy specimens (n=40) were also collected as the control. The expression levels of MK and syndecan‑1 were assessed by immunohistochemistry using the high‑sensitivity streptavidin‑peroxidase method. Statistical analysis was performed on the data obtained using the SPSS 17.0 statistics package. MK expression was detected in 76.4% of GCA samples and 5% of normal gastric cardiac mucosa specimens. A significant positive correlation was observed between the expression levels of MK and the infiltrative depth of the tumor, the presence of lymph node metastasis and the prognosis of the patients (P<0.05). Syndecan‑1 expression was detected in 38.9% of GCA samples and 100% of normal gastric cardiac mucosa samples. The expression levels of syndecan‑1 were negatively correlated with the grade of differentiation, serosal membrane invasion, lymph node metastasis and the patient's prognosis (P<0.05). Notably, the expression levels of MK and syndecan‑1 were inversely correlated (r=‑0.352, P<0.01) in the GCA tissue samples. These results suggest that high expression levels of MK in GCA tissues may indicate a differentiation stage that is characteristic of malignancy, a late clinical stage and a poor prognosis, whereas increased syndecan‑1 levels may indicate a high degree of differentiation, an early clinical stage and a favorable prognosis. MK and syndecan‑1 may serve as important biomarkers for monitoring the development and progression of GCA.

Syndecan-1 overexpression is associated with nonluminal subtypes and poor prognosis in advanced breast cancer

OBJECTIVES

Syndecan-1 expression is decreased in diverse tumor types but remains controversial in breast carcinomas. The goal of the study was to examine syndecan-1 expression in breast carcinoma and its prognostic significance.

METHODS

The epithelial expression of syndecan-1 was examined in tissue microarrays constructed from 62 consecutive breast carcinoma cases diagnosed between 1997 and 2004 with distant organ metastasis and 10 consecutive control cases (breast carcinoma with no distant metastasis after at least 8 years of follow-up). The prognostic significance of syndecan-1 was estimated by utilizing a Cox proportional hazards regression model.

RESULTS

Among tumors with distant metastasis, syndecan-1 expression was significantly associated with a higher histologic grade and inversely related to hormonal receptor status. The HER2 subtype and triple-negative carcinomas exhibited markedly higher syndecan-1 levels than those of luminal subtypes, while the latter remained significantly higher than nonmetastatic control cases. Furthermore, high syndecan-1 expression had a negative impact on both overall and disease-free survival rates.

CONCLUSIONS

These findings suggest that syndecan-1 may regulate breast cancer cell behavior and thus deserves further investigation to ascertain its potential as a therapeutic target, especially in metastatic, triple-negative carcinomas.

Beneficial effect of glatiramer acetate treatment on syndecan-1 expression in dextran sodium sulfate colitis

Syndecan-1, the most abundant heparan sulfate proteoglycan in the gastrointestinal tract, is reduced in the regenerative epithelium in inflammatory bowel disease (IBD). This study explored the effects of the immunomodulator glatiramer acetate (GA; Copaxone) treatment on syndecan-1 expression in dextran sodium sulfate (DSS)-induced colitis. Acute and chronic colitis was induced in C57BL/6 mice by 2 and 1.5% DSS in tap water, respectively. GA was applied subcutaneously, 2 mg per mouse per day, starting on the day of DSS induction until the mice were sacrificed. Syndecan-1 expression was assessed by immunohistochemistry. The effect of adoptive transfer of GA-specific T cells as an organ-specific therapy also was evaluated. Syndecan-1 expression was significantly lower in both colitis groups compared with that in naive mice (p < 0.0001). GA attenuated clinical scores and pathological manifestations of colitis and led to the reinstatement of normal levels of syndecan-1. After adoptive transfer, GA-specific cells homed to the surface epithelium of the distal colon, accompanied by the augmentation of syndecan-1 staining in their vicinity. We concluded that syndecan-1 expression is reduced in DSS-induced colitis and could be a potential prognostic factor in IBD. Treatment with GA exerts not only an anti-inflammatory effect but also a possible beneficial effect in stabilizing the intestinal epithelium barrier and tissue repair in DSS colitis. GA may be applied as a novel drug for IBD, shifting treatment from immunosuppression toward immunomodulation.

Effect of syndecan-1 overexpression on mesenchymal tumour cell proliferation with focus on different functional domains

OBJECTIVES

Syndecan-1 is a transmembrane proteoglycan involved in various biological processes. Its extracellular, transmembrane and cytoplasmic domains may all participate in signal transduction. The aim of this study was to investigate the biological roles of these domains of syndecan-1.

MATERIALS AND METHODS

We transfected cells of two mesenchymal tumour cell lines with a full-length syndecan-1 construct and three truncated variants, namely 78 construct lacking the EC domain with exception of DRKE sequence; 77 construct lacking extracellular the whole domain and RMKKK corresponding to a short cytoplasmic motif. Subcellular distribution was revealed using confocal laser microscopy. Overexpression of the constructs was verified using real-time RT-PCR and by FACS analysis and effects of syndecan-1 on cell behaviour were explored. Cell cycle analysis allowed for dissection of mechanisms regulating cell proliferation.

RESULTS

Overexpression of syndecan-1 influenced expression profile of the other syndecan members, and decreased tumour cell proliferation significantly by two mechanisms, as follows: increased length of G0/G1 phase was the most evident change in RMKKK and 77 transfectants, whereas prolonged S phase was more obvious in full-length transfectants. Overexpression of syndecan-1 changed the tumour cell morphology in an epithelioid direction.

CONCLUSIONS

Both full-length and truncated syndecan-1 inhibited proliferation of the mesenchymal tumour cells, providing new insights into the importance for cancer growth of different functional domains of this proteoglycan.

Gene Expression Studies Demonstrate that the K-ras/Erk MAP Kinase Signal Transduction Pathway and Other Novel Pathways Contribute to the Pathogenesis of Cumene-induced Lung Tumors

National Toxicology Program (NTP) inhalation studies demonstrated that cumene significantly increased the incidence of alveolar/bronchiolar adenomas and carcinomas in B6C3F1 mice. Cumene or isopropylbenzene is a component of crude oil used primarily in the production of phenol and acetone. The authors performed global gene expression analysis to distinguish patterns of gene regulation between cumene-induced tumors and normal lung tissue and to look for patterns based on the presence or absence of K- ras and p53 mutations in the tumors. Principal component analysis segregated the carcinomas into groups with and without K- ras mutations, but failed to separate the tumors based on p53 mutation status. Expression of genes associated with the Erk MAP kinase signaling pathway was significantly altered in carcinomas with K- ras mutations compared to tumors without K- ras mutations or normal lung. Gene expression analysis also suggested that cumene-induced carcinomas with K- ras mutations have greater malignant potential than those without mutations. In addition, significance analysis of function and expression (SAFE) demonstrated expression changes of genes regulated by histone modification in carcinomas with K- ras mutations. The gene expression analysis suggested the formation of alveolar/bronchiolar carcinomas in cumene-exposed mice typically involves mutation of K- ras, which results in increased Erk MAP kinase signaling and modification of histones.

Syndecan-1, a key regulator of cell viability in endometrial cancer

Syndecan-1 is one of the major proteoglycans on cell surfaces involved in major biological processes. Although loss of syndecan-1 correlates well with the gain of cancerous characteristics in a wide range of cancers, increased expression of syndecan-1 also coincides with adverse outcomes in some cancers, including breast, ovarian and pancreatic cancers. For this Janus-faced attitude of syndecan-1, we sought to examine expression patterns of syndecan-1 in endometrial carcinoma (EC) and gain insight into the roles of syndecan-1. Immunohistochemical examinations of 109 endometrial tissue samples from myoma, hyperplasia and EC uteri revealed that syndecan-1 expression was significantly upregulated in EC compared with hyperplasia (p < 0.001). To evaluate pathophysiological functions of syndecan-1, its expression level was altered, and subsequent outcomes were examined using human endometrial cancer cell lines such as HEC-1A, AN3CA and KLE cells. Overexpression of syndecan-1 increased the growth of HEC-1A cells regardless of anchorage dependence while silencing syndecan-1 by antisense RNAs caused apoptotic cell death. Consistent with decreased viability, the loss of syndecan-1 was also accompanied by a decrease in the activation of Erk and Akt and a concomitant decrease in the phosphorylation of PTEN and PDK1, which are known as negative and positive regulators of Akt activation, respectively. These down-regulatory effects were reversed upon overexpression of syndecan-1. Collectively together, the aforementioned findings lend support to the notion that upregulation of syndecan-1 may be a critical element for endometrial cancers in maintaining their viability and thus can serve as a cancer specific therapeutic and diagnostic marker.

Chondroitin sulfate glycosaminoglycans as major P-selectin ligands on metastatic breast cancer cell lines

The metastatic breast cancer cell line, 4T1, abundantly expresses the oligosaccharide sialylated Lewis x (sLe(x)). SLe(x) oligosaccharide on tumor cells can be recognized by E- and P-selectin, contributing to tumor metastatic process. We observed that both selectins reacted with this cell line. However, contrary to the E-selectin reactivity, which was sLe(x) dependent, P-selectin reactivity with this cell line was sLe(x)-independent. The sLe(x)-Neg variant of the 4T1 cell line with markedly diminished expression of sLe(x) and lack of sLe(a), provided a unique opportunity to characterize P-selectin ligands and their contribution to metastasis in the absence of overlapping selectin ligands and E-selectin binding. We observed that P-selectin binding was Ca(2+)-independent and sulfation-dependent. We found that P-selectin reacted primarily with cell surface chondroitin sulfate (CS) proteoglycans, which were abundantly and stably expressed on the surface of the 4T1 cell line. P-selectin binding to the 4T1 cells was inhibited by heparin and CS glycosaminoglycans (GAGs). Moreover, Heparin administration significantly inhibited experimental lung metastasis. In addition, the data suggest that surface CS GAG chains were involved in P-selectin mediated adhesion of the 4T1 cells to murine platelets and human umbilical vein endothelial cells. The data suggest that CS GAGs are also the major P-selectin-reactive ligands on the surface of human MDA-MET cells. The results warrant conducting clinical studies on the involvement of cell surface CS chains in breast cancer metastasis and evaluation of various CS types and their biosynthetic pathways as target for development of treatment strategies for antimetastatic therapy of this disease.

Syndecan-2 expression increases serum-withdrawal-induced apoptosis, mediated by re-distribution of Fas into lipid rafts, in stably transfected Swiss 3T3 cells

To examine the function of syndecan-2, one of the most abundant heparan sulfate proteoglycans in fibroblasts, we obtained stably transfected Swiss 3T3 clones. We examined the effects of stable syndecan-2 overexpression on programmed cell death, finding that syndecan-2 transfected cells were more sensitive to apoptosis induced by serum-withdrawal than control cells. In addition, overexpression of syndecan-2 correlates with increased membrane levels of the Fas/CD95 receptor, suggesting that the increased serum-withdrawal apoptosis observed in Swiss 3T3 cells might be Fas receptor-dependent. Differences in Fas membrane levels between both control and syndecan-2 transfected cells result from a redistribution of the Fas receptor. Our data clearly demonstrate that increased Fas levels are primarily related to lipid rafts and that this increase is a key factor in Fas/CD95-mediated apoptosis. Moreover, disruption of lipid rafts with methyl-beta-cyclodextrin or filipin significantly reduced apoptosis in response to serum withdrawal. The differences in Fas/CD95 membrane distribution could explain why syndecan-2 transfected cells have a higher susceptibility to serum-withdrawal-induced apoptosis.

Focal Adhesion Kinase Regulates Syndecan-2–Mediated Tumorigenic Activity of HT1080 Fibrosarcoma Cells

Expression of syndecan-2, a transmembrane heparan sulfate proteoglycan, is crucial for the tumorigenic activity in colon carcinoma cells. However, despite the high-level expression of syndecan-2 in mesenchymal cells, few studies have addressed the function of syndecan-2 in sarcoma cells. In HT1080 fibrosarcoma cells, we found that syndecan-2 regulated migration, invasion into Matrigel, and anchorage-independent growth but not cell-extracellular matrix adhesion or proliferation, suggesting that syndecan-2 plays different functional roles in fibrosarcoma and colon carcinoma cells. Consistent with the increased cell migration/invasion of syndecan-2-overexpressing HT1080 cells, syndecan-2 overexpression increased phosphorylation and interaction of focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K), membrane localization of T-lymphoma invasion and metastasis gene-1 (Tiam-1), and activation of Rac. Syndecan-2-mediated cell migration/invasion of HT1080 cells was diminished when (a) cells were cotransfected with nonphosphorylatable mutant FAK Y397F or with other FAK mutants lacking PI3K interactions, (b) cells were treated with a specific PI3K inhibitor, or (c) levels of Tiam-1 were knocked down with small interfering RNAs. Furthermore, expression of several FAK mutants inhibited syndecan-2-mediated enhancement of anchorage-independent growth in HT1080 cells. Taken together, these data suggest that syndecan-2 regulates the tumorigenic activities of HT1080 fibrosarcoma cells and that FAK is a key regulator of syndecan-2-mediated tumorigenic activities.

Gene cataloging and expression profiling in human gastric cancer cells by expressed sequence tags

To understand the molecular mechanism associated with gastric carcinogenesis, we identified genes expressed in gastric cancer cell lines and tissues. Of 97,609 high-quality ESTs sequenced from 36 cDNA libraries, 92,545 were coalesced into 10,418 human Unigene clusters (Build 151). The gene expression profile was produced by counting the cluster frequencies in each library. Although the profiles of highly expressed genes varied greatly from library to library, those genes related to cell structure formation, heat shock proteins, the glycolysis pathway, and the signaling pathway were highly represented in human gastric cancer cell lines and in primary tumors. Conversely, the genes encoding immunoglobulins, ribosomal proteins, and digestive proteins were down-regulated in gastric cancer cell lines and tissues compared to normal tissues. The transcription levels of some of these genes were confirmed by RT-PCR. We found that genes related to cell adhesion, apoptosis, and cytoskeleton formation were particularly up-regulated in the gastric cancer cell lines established from malignant ascites compared to those from primary tumors. This comprehensive molecular profiling of human gastric cancer should be useful for elucidating the genetic events associated with human gastric cancer.

Prognostic Value of Syndecan-1 Expression in Breast Cancer

OBJECTIVE

Syndecan-1 is a cell surface heparan sulphate proteoglycan which participates in cell proliferation, cell migration and cell-matrix interactions. Epithelial syndecan-1 expression is reduced in several malignant tumours, but in breast and pancreatic cancer, increased expression has also been described. Loss of epithelial syndecan-1 has been associated with poor prognosis in some forms of cancer, but previous findings in breast cancer have been contradictory. The objective of this study was to evaluate the prognostic value of the immunohistochemical expression of syndecan-1 in a series of 200 patients with invasive breast cancer with a median follow-up of 17 years.

METHODS

Formalin-fixed paraffin-embedded specimens were stained using a monoclonal antibody against syndecan-1.

RESULTS

Syndecan-1 was expressed in the epithelium in 61% and in the stroma in 67% of the tumours. Epithelial syndecan-1 expression was associated with negative oestrogen receptor (ER) status (p < 0.01), and stromal syndecan-1 expression with positive ER status (p = 0.02). The breast cancer-specific 10-year overall survival for patients with epithelial syndecan-1 expression was 65%, compared with 82% for those with loss of epithelial expression (p = 0.02). Ten-year survival was 66% for those expressing stromal syndecan-1 and 83% for those lacking stromal expression (p = 0.15). Patients with both epithelial and stromal expression had a 10-year survival of only 56%, compared to 78% in patients with other expression pattern combinations (p < 0.002). In Cox multivariate analysis, only axillary involvement and tumour size were significant predictors of breast cancer-specific survival.

CONCLUSION

Concomitant expression of syndecan-1 in both epithelium and stroma may be a predictor of unfavourable prognosis in breast cancer, and in contrast with previous studies, loss of epithelial syndecan-1 was associated with a more favourable prognosis.

Syndecans in tumor cell adhesion and signaling

Anchorage of cells to "heparin"--binding domains that are prevalent in extracellular matrix (ECM) components is thought to occur primarily through the syndecans, a four-member family of transmembrane heparan sulfate proteoglycans that communicate environmental cues from the ECM to the cytoskeleton and the signaling apparatus of the cell. Known activities of the syndecans trace to their highly conserved cytoplasmic domains and to their heparan sulfate chains, which can serve to regulate the signaling of growth factors and morphogens. However, several emerging studies point to critical roles for the syndecans' extracellular protein domains in tumor cell behavior to include cell adhesion and invasion. Although the mechanisms of these activities remain largely unknown, one possibility involves "co-receptor" interactions with integrins that may regulate integrin function and the cell adhesion-signaling phenotype. Thus, alterations in syndecan expression, leading to either overexpression or loss of expression, both of which take place in tumor cells, may have dramatic effects on tumor cell invasion.

Application of differential display to identify genes for lung cancer detection in peripheral blood

A blood assay for detection of lung cancer biomarkers could significantly improve cancer patient prognosis and survival rates. Amplified fragment length polymorphism-differential display (AFLP-DD) was used to identify gene transcripts found in lung cancer tissue and the peripheral blood of lung cancer patients. The clones were evaluated for gene expression in lung cancer tissue, peripheral blood of lung cancer patients and healthy volunteers' blood. The isolated gene transcript clones were found to be from the syndecan 1 gene, collagen 1 gene and 2 novel genes. All 4 transcripts were expressed in normal lung tissue, 4 cultured primary lung cells and 6 lung cancer cell lines. RNA was isolated from peripheral blood samples of 69 lung cancer patients. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to test for the presence of cytokeratin 19 and the 4 gene mRNA transcripts in blood RNA. The positive detection rate of at least 1 of the 5 transcripts was 79% for lung adenocarcinoma and 62% for squamous carcinoma. Using RT-PCR, at least 1 of the markers was found in 53% of stage I patients, 100% of stage II, 71% of stage III and 81% of stage IV lung cancer patients. Blood samples from 20 healthy volunteers were also tested, but only 1 of the 5 transcripts was found in 1 patient. These new molecular markers may aid early detection, staging and follow-up of lung cancer patients by RNA isolated from blood.

High syndecan-1 expression is associated with favourable outcome in squamous cell lung carcinoma treated with radical surgery

Expression of syndecan-1 is down-regulated in many cellular transformation models. We studied the clinical significance of syndecan-1 expression in 116 squamous cell lung carcinomas treated with radical surgery. Paraffin-embedded tissue samples were immunostained with two antibodies against human syndecan-1 (B-B4 and 104-9). Syndecan-1 expression was higher in well differentiated cancers than in moderately or poorly differentiated cancers with either antibody (P=0.001 for B-B4, and P<0.0001 for 104-9), but no significant association was found with the primary tumour size (T-stage) or the clinical stage. When the median expression (10% of cancer cells positive in B-B4 staining) was used as the cut-off value, cancers with high expression were associated with more favourable survival than those with low expression (the 2-year survival rate corrected for intercurrent deaths 84% vs 61%, P=0.026). However, syndecan-1 expression was not an independent prognostic factor in a multivariate survival analysis. We conclude that syndecan-1 expression decreases in parallel with histological dedifferentiation in squamous cell carcinoma of the lung, and that low syndecan-1 expression is associated with unfavourable outcome.

Heparan sulfate proteoglycans in invasion and metastasis

Because heparan sulfate proteoglycans mediate cell adhesion and control the activities of numerous growth and motility factors, they play a critical role in regulating the metastatic behavior of tumor cells. Due to their utilitarian nature, heparan sulfate proteoglycans may at times act as inhibitors of cell invasion and at other times as promoters of cell invasion, with their function being determined by their location (cell surface or extracellular matrix), the heparin-binding molecules they associate with, the presence of modifying enzymes (proteases, heparanases) and the precise structural characteristics of the proteoglycan. Also, the tissue type and pathophysiological state of the tumor influence proteogylcan function. This review summarizes our current knowledge of the role heparan sulfate proteoglycans play in regulating tumor cell metastasis, proposes mechanisms of how these molecules function and examines the potential for discovery of new therapeutic approaches designed to block metastatic cancer.

Syndecan-1 expression is up-regulated in pancreatic but not in other gastrointestinal cancers

Syndecan-1 belongs to the syndecan family of cell surface transmembrane heparan-sulfate proteoglycans, which participate in cell proliferation, cell migration and cell-matrix interactions. Decreased expression of syndecan-1 has been observed in some gastrointestinal malignancies, and it is thought that high levels of syndecan-1 correlate with the maintenance of epithelial morphology and inhibition of invasiveness. In our study, we characterized the expression of syndecan-1 in normal, chronic pancreatitis and primary and metastatic human pancreatic cancer tissues, in cultured pancreatic cancer cell lines and in esophageal, gastric, colon, and liver cancers. Pancreatic cancer cell lines expressed syndecan-1 mRNA and protein at variable levels. In addition, these cells also released syndecan-1 into the culture medium. Pancreatic cancer tissues markedly over-expressed syndecan-1 mRNA in comparison with both chronic pancreatitis (2.4-fold increase, p < 0.01) and normal pancreatic samples (10.6-fold increase, p < 0.01). There was no difference in syndecan-1 mRNA expression between early and advanced tumors. By in situ hybridization and immunohistochemistry, syndecan-1 expression was evident at relatively low levels in the ductal cells and less frequently in acinar cells of the normal pancreas. In chronic pancreatitis, syndecan-1 was present at low to moderate levels in areas with atrophic acinar cells and ductular complexes. In contrast, in pancreatic cancer tissues, syndecan-1 was present at moderate to high levels in the majority of the cancer cells within the tumor mass and also in metastatic lesions of pancreatic tumors. Syndecan-1 mRNA levels in other gastrointestinal malignancies (esophageal, gastric, colon and liver cancers) were not significantly different from the levels observed in the corresponding normal samples. Together, our findings suggest that syndecan-1 expression by pancreatic cancer cells may be of importance in the pathobiology of this disorder and that its role in pancreatic cancer seems to be different from that in other gastrointestinal malignancies.