Shift of syndecan-1 expression from epithelial to stromal cells during progression of solid tumours

Association of loss of epithelial syndecan-1 with stage and local metastasis of colorectal adenocarcinomas: an immunohistochemical study of clinically annotated tumors

Background

Syndecan-1 is a transmembrane proteoglycan with important roles in cell-cell and cell-extracellular matrix adhesion and as a growth factor co-receptor. Syndecan-1 is highly expressed by normal epithelial cells and loss of expression has been associated with epithelial-mesenchymal transition and the transformed phenotype. Loss of epithelial syndecan-1 has been reported in human colorectal adenocarcinomas, but whether this has prognostic significance remains undecided. Here we have examined syndecan-1 expression and its potential prognostic value with reference to a clinically annotated tissue microarray for human colon adenocarcinomas.

Methods

Syndecan-1 expression was examined by immunohistochemistry of a tissue microarray containing cores from 158 colorectal adenocarcinomas and 15 adenomas linked to a Cleveland Clinic, IRB-approved database with a mean clinical follow-up of 38 months. The Kaplan-Meier method was used to analyze the relationship between syndecan-1 expression and patient survival. Potential correlations between syndecan-1 expression and the candidate prognostic biomarker fascin were examined.

Results

Syndecan-1 is expressed at the basolateral borders of normal colonic epithelial cells. On adenocarcinoma cells, syndecan-1 was present around cell membranes and in cytoplasm. In 87% of adenocarcinomas, syndecan-1 was decreased or absent; only 13% of patients had stained for syndecan-1 on more than 75% of tumor cells. Decreased syndecan-1 correlated with a higher TNM stage and lymph node metastasis and was more common in males (p = 0.042), but was not associated with age, tumor location or Ki67 index. Reduced tumor syndecan-1 staining also correlated with upregulation of stromal fascin (p = 0.016). Stromal syndecan-1 was observed in 16.6% of tumors. There was no difference in survival between patients with low or high levels of either tumor or stromal syndecan-1.

Conclusion

Syndecan-1 immunoreactivity was decreased in the majority of human colon adenocarcinomas in correlation with TNM stage and metastasis to local lymph nodes. In a small fraction of adenocarcinomas, syndecan-1 was upregulated in the local stroma. Syndecan-1 expression status did not correlate with patient survival outcomes. Combined analysis of syndecan-1 in relation to a potential prognostic biomarker, fascin, identified that loss of tumor syndecan-1 correlated significantly with strong stromal fascin staining.

Prognostic impact of syndecan-1 expression in invasive ductal breast carcinomas

Carcinoma cells lack syndecan-1 expression when they are transiting from an epithelial to a less-differentiated mesenchymal phenotype (epithelial–mesenchymal transition, EMT). Furthermore, a shift of syndecan-1 expression from malignant epithelial cells to reactive stromal cells has also been observed during progression of many carcinomas. Finally, epithelial and/or stromal syndecan-1 expression is of prognostic value in many carcinomas. Because recent results are contradictory in breast carcinomas, we have re-evaluated the prognostic significance of syndecan-1 expression in a cohort of 80 patients with invasive ductal breast carcinomas. The tumours from 80 patients diagnosed with invasive ductal breast carcinomas were used to construct a tissue microarray, which was stained with syndecan-1 by immunohistochemistry. We correlated syndecan-1 expression with clinicopathologic parameters and relapse-free survival (RFS). Exclusive epithelial expression of syndecan-1 is observed in 61.25% of the patients, whereas exclusive stromal expression is observed in 30% of the patients. Only 8.75% of the patients had both stromal and epithelial expressions of syndecan-1. A significant correlation was found between the loss of syndecan-1 epithelial expression and the syndecan-1 stromal expression with high grade of malignancy (P=0.011). The loss of syndecan-1 epithelial expression is correlated with RFS (P=0.001). Using multivariate Cox analysis, loss of epithelial syndecan-1 expression was the only prognostic indicator (P<0.001). We concluded that the loss of syndecan-1 epithelial expression was of strong prognostic value in breast carcinomas.

In vivo and in vitro regulation of syndecan 1 in prostate cells by n-3 polyunsaturated fatty acids

Syndecan 1 is the major proteoglycan produced by epithelial cells. It is strategically localized at the plasma membrane to participate in growth factor signaling and cell-cell and cell-matrix interactions. Its expression may modulate the properties of epithelial lineage tumor cells in which it is generally down-regulated compared with nontumor progenitors. The present study examined the regulation of syndecan 1 in prostate epithelial cells by n-3 polyunsaturated fatty acids. In prostate tissue of mice, syndecan 1 immunostaining was demonstrated in epithelial cells throughout each gland. In animals fed an n-3 polyunsaturated fatty acid-enriched diet, syndecan 1 mRNA was increased in all prostate glands. In the human prostate cancer cell line, PC-3, delivery of exogenous n-3 (but not n-6) fatty acids resulted in up-regulation of syndecan 1 expression. This effect was mimicked by a peroxisome proliferator-activated receptor (PPAR) gamma agonist, troglitazone, and inhibited in the presence of a PPARgamma antagonist and in cells transfected with dominant negative PPARgamma cDNA. Using a luciferase gene driven either by a PPAR response element or by a DR-1 site present in the syndecan 1 promoter, reporter activation was increased by n-3 low density lipoprotein, docosahexaenoic acid, and troglitazone, whereas activity of a luciferase gene placed downstream of a mutant DR-1 site was unresponsive. These findings indicate that syndecan 1 is up-regulated by n-3 fatty acids by a transcriptional pathway involving PPARgamma. This mechanism may contribute to the chemopreventive properties of n-3 fatty acids in prostate cancer.

Proteoglycans: key partners in bone cell biology

The diversity of bone proteoglycan (PG) structure and localisation (pericellular, extracellular in the organic bone matrix) reflects a broad spectrum of biological functions within a unique tissue. PGs play important roles in organizing the bone extracellular matrix, taking part in the structuring of the tissue itself as active regulators of collagen fibrillogenesis. PGs also display selective patterns of reactivity with several constituents including cytokines and growth factors, such as transforming growth factor-beta or osteoprotegerin thereby modulating their bio-availability and biological activity in the bone tissue. In this review, the complex PG composition in bone will be addressed together with the specific role played by PGs (or their GAGs chains) in bone biology, as regulatory molecules for bone resorption and their involvement in bone tumor development. These roles have been determined after modulation of PG expression or mutations in their corresponding genes, which revealed specific roles for these compounds in bone pathologies (e.g. perlecan or glypican-3 mutations observed respectively in chondrodysplasia or dysmorphic syndrome). Finally, the potential therapeutic interest of PGs is discussed based on recent data, more particularly on bone tumor-associated osteolysis as these molecules are involved both in bone resorption and tumor development.

Syndecan-1 and Wingless-type protein-1 in human ameloblastomas

BACKGROUND

Aberrant Wingless type 1 glycoprotein (Wnt) pathway in ameloblastomas and a role of syndecan-1 (SDC1) in activating Wnt signalling were perspected. SDC1 shifting from epithelium to stroma was reported in invasive non-odontogenic neoplasms. The aim of this study was to reveal the role of SDC1 and Wnt1 in intraosseous ameloblastomas (IA(s)).

METHODS

SDC1 and Wnt1 expressions were investigated in 29 ameloblastoma subtypes and seven tooth buds.

RESULTS

SDC1 immunostaining strongly depicted stromal cells, extracellular matrix (ECM) and basement membranes of ameloblastomas. It also showed epithelial tumour cells in the acanthomatous and plexiform subtypes, and it often occurred in stellate reticulum cells and basal ameloblasts of tooth buds. Parallel Wnt1 expression occurred in ameloblastomatous epithelial cells, but it was common in basal cells of tooth buds too. Statistically, a significant correlation was found between the percentage of IA(s)-bearing SDC1-positive stromal cells and ECM and the percentage of IA(s)-bearing Wnt1-positive epithelial cells.

CONCLUSIONS

A role of SDC1 in stromal cells and ECM can be hypothesized as a critical factor for carcinogenesis and local invasiveness of IA(s).

Expression of Extracellular Matrix Proteins in Ovarian Serous Tumors

The aims of this study were to perform a comprehensive expression analysis of the genes encoding extracellular matrix proteins and to investigate the expression pattern in one of these proteins, syndecan 1, in normal ovarian epithelium as well as benign and malignant ovarian serous tumors. Gene expression of 16 different extracellular matrix proteins was analyzed in ovarian serous tumors based on serial analysis of gene expression database. Semiquantitative reverse transcription-polymerase chain reaction was used to validate the serial analysis of gene expression result from each gene. As compared with normal ovarian surface epithelium, we found overexpression of syndecan 1, collagen type IV alpha 2, elastin microfibril interfase located protein 1, and laminin 5 in ovarian serous carcinomas. Syndecan 1 was selected for further study as it has not been well characterized in ovarian cancer and the syndecan 1 antibody was available for immunohistochemistry. Using a syndecan 1-specific monoclonal antibody, we demonstrated that syndecan 1 was expressed in 30.4% of high-grade serous carcinomas, 29.7% of low-grade carcinomas and serous borderline tumors, but none of benign serous cystadenomas and ovarian surface epithelium. Although both high-grade and low-grade serous carcinomas had a similar percentage of syndecan 1-positive cases, the immunointensity in high-grade carcinoma was significantly higher than that in low-grade carcinomas and serous borderline tumors (P = 0.007). In summary, ovarian carcinomas exhibit up-regulated expression of several extracellular matrix proteins, and syndecan 1 represents a novel tumor-associated marker in ovarian serous carcinomas.

Characterisation of two rat mammary tumour models for breast cancer research by gene expression profiling

Breast cancer is the most frequently occurring cancer in women. Treatment options are still an active area of research. Models used for this purpose include induced models in rodents. By the advent of microarrays it has become possible to evaluate models not only for similar morphology or selected markers by polymerase chain reaction (PCR) or immunohistochemistry but also for the expression of thousands of genes at once. This study presents gene expression profiles of the hormone-sensitive 7,12-dimethylbenzanthracene-induced and the metastasising MTLn3-model. The models are discussed for their relevance to breast cancer in humans.

Expression of syndecan-1 (CD138) in nasopharyngeal carcinoma is correlated with advanced stage and poor prognosis

Nasopharyngeal carcinoma (NPC) is an important Epstein-Barr virus-associated head and neck malignancy in Taiwan. Syndecan-1 (CD138) is involved in growth, differentiation, invasiveness, and metastatic potential of certain tumors, but its expression in NPC has never been studied. In this study, detection of expression of syndecan-1 protein and Epstein-Barr virus-encoded latent membrane protein-1 (LMP-1) in primary, recurrent, and metastatic NPC specimens in paraffin sections was performed by immunohistochemistry. The quantity of syndecan-1 messenger RNA in tumor cells was investigated by real-time reverse transcriptase polymerase chain reaction using laser capture microdissection. The results of immunohistochemical staining of syndecan-1 and LMP-1 correlated with clinicopathologic features of NPC. Eighteen (20.9%) of 86 primary, 9 (24.3%) of 37 recurrent, and 15 (44.1%) of 34 metastatic NPC samples were positive for syndecan-1, and 37 (43.0%) primary, 18 (48.6%) recurrent, and 12 (35.3%) metastatic samples were positive for LMP-1 expression. Primary NPCs with syndecan-1 protein expression were more frequently associated with advanced clinical stages and worse 5-year survival rates than those without (P = .015 and P = .0021, respectively). Conversely, the LMP-1 expression did not correlate with tumor stage or prognosis but occurred more often in nonkeratinizing carcinoma than keratinizing squamous cell carcinoma (unpublished observation). The inverse expression of syndecan-1 and LMP-1 was noted in primary NPC specimens (total 4/18 versus 35/68, P = .05). The reverse transcriptase polymerase chain reaction revealed low syndecan-1 messenger RNA levels in both primary and metastatic NPC. In conclusion, the protein expression of syndecan-1 in 21% of primary NPC was associated with advanced disease and poor prognosis, and the protein expression correlated with transcription levels.

Syndecan-1 expression by stromal fibroblasts promotes breast carcinoma growth in vivo and stimulates tumor angiogenesis

The induction of the cell surface heparan sulfate proteoglycan syndecan-1 (Sdc1) in stromal fibroblasts is observed in more than 70% of human breast carcinomas. Using a coculture model, we have recently shown that stromal cell-derived Sdc1 stimulates carcinoma cell proliferation in vitro, and that this activity requires Sdc1 glycanation. In the present study, we investigated the effect of stromal cell Sdc1 on breast carcinoma growth in vivo. MDA-MB-231 human breast carcinoma cells were inoculated into the flanks of athymic nude mice either alone, or as mixed suspensions with Sdc1-transfected or mock-transfected 3T3 mouse fibroblasts. The mixed tumors showed an intimate association between carcinoma cells and stromal fibroblasts and histologically closely resembled poorly differentiated human breast carcinomas. The presence of fibroblasts led to significantly accelerated tumor growth, which was further augmented (88% increase) by forced expression of stromal Sdc1. The hyperemic macroscopic appearance of tumors containing Sdc1-positive stromal cells contrasted with pale tumors developing in the presence of mock-transfected fibroblasts, which prompted us to examine tumor microvessels. Stromal Sdc1 expression was associated with a significantly elevated microvessel density (36% increase) and a larger vessel area (153% increase). To evaluate the relevance of this finding in human breast cancer, the relationship between stromal Sdc1 and tumor vascularity was also examined in a tissue array containing 207 human breast carcinoma samples. Similar to the xenografts, stromal Sdc1 expression correlated with both vessel density (P=0.013) and total vessel area (P=0.0026). In conclusion, stromal fibroblast-derived Sdc1 stimulates breast carcinoma growth and angiogenesis in vivo.

Stromal syndecan-1 expression is an adverse prognostic factor in oral carcinomas

Syndecan-1, a transmembrane proteoglycan, may exert anti-proliferative effects and promote cell growth by binding various growth factors. Malignant epithelial cells often down-regulate their own syndecan-1 production, and are capable of inducing an aberrant syndecan-1 expression in stromal fibroid cells. Decreased tumor cell syndecan-1 levels in human head and neck squamous cell carcinomas indicate poor prognosis, however, no correlation between stromal syndecan-1 expression and clinical parameters has previously been established. By means of immunohistochemistry, we observed a decrease in tumor cell syndecan-1 reactivity in 33/39 oral carcinoma cases, the degree of which, however, correlated only weakly with the clinical outcome (p = 0.097). Conversely, stromal syndecan-1 positivity proved to be a significant risk factor of recurrence (Cox analysis, p = 0.03) and tumor-specific death (p = 0.023) within a 24-month period after operation. Taken together, stromal expression of syndecan-1 is a reliable factor of adverse prognosis in oral carcinomas.

Heparan sulfate proteoglycans and heparanase--partners in osteolytic tumor growth and metastasis

This review summarizes a series of studies demonstrating that heparan sulfate proteoglycans act to promote the growth and metastasis of myeloma and breast tumors, two tumors that home to, and grow within, bone. Much of the growth-promoting effect of proteoglycans in these tumors may reside in the shed form of syndecan-1 that acts to favorably condition the tumor microenvironment. Moreover, the interplay between heparan sulfate and the extracellular enzyme heparanase-1 also has important regulatory implications. Recent studies indicate that the activity of heparanase, which likely releases heparin sulfate-bound growth factors and generates highly active heparan sulfate fragments, also promotes growth and metastasis of myeloma and breast tumors. Understanding the role of heparan sulfate and heparanase in the regulation of tumor behavior may lead to new therapeutic approaches for treating cancer.

Clinicopathological significance of expression of paxillin, syndecan-1 and EMMPRIN in hepatocellular carcinoma

AIM: To evaluate the relationship of expression of paxillin, syndecan-1 and EMMPRIN proteins with clinicopathological features in hepatocellular carcinoma (HCC).

METHODS: Fifty-one patients who underwent HCC resection were recruited in the study. Paxillin, syndecan-1 and EMMPRIN proteins in HCC tissues were detected with immunohistochemical staining.

RESULTS: Of 51 cases of HCC, 23 (45%) exhibited paxillin protein positive expression. Of 42 cases of adjacent non-tumor liver tissues, 24 (57%) exhibited positive expression. Positive paxillin protein expression was associated with low differentiation (r = 0.406, P = 0.004), with the presence of portal vein thrombosis (r = 0.325, P = 0.021), with extra-hepatic metastasis (r = 0.346, P = 0.014). Of 51 cases of HCC, 28 (55%) exhibited syndecan-1 protein positive expression. Of 42 cases of adjacent non-tumor liver tissues, 23 (55%) exhibited positive expression. Positive snydecan-1 protein expression was associated with well differentiation (r = 0.491, P = 0.001), with no extra-hepatic metastasis (r = 0.346, P = 0.014). Of 51 cases of HCC, 28 (55%) exhibited EMMPRIN protein positive expression. Of 42 cases of adjacent non-tumor liver tissues, 21 (50%) exhibited positive expression. Expression of EMMPRIN protein was not associated with serum AFP level, HBsAg status, presence of microsatellite nodule, tumor size, presence of cirrhosis and necrosis, differentiation, presence of portal vein thrombosis, extra-hepatic metastasis, disease-free survival and overall survival (P>0.05). Expression of paxillin protein was correlated conversely with the expression of syndecan-1 protein in HCC (r = -0.366, P = 0.010).

CONCLUSION: Expression of paxillin and syndecan-1 proteins in HCC may affect its invasive and metastatic ability of the tumor. There may be a converse correlation between the expression of paxillin and syndecan-1 protein in HCC. Expression of EMMPRIN protein may be detected in HCC, but it may play little role in the invasion and metastasis of HCC.

Clonogenic growth of human breast cancer cells co-cultured in direct contact with serum-activated fibroblasts

Introduction

Accumulating evidence suggests that fibroblasts play a pivotal role in promoting the growth of breast cancer cells. The objective of the present study was to characterize and validate an in vitro model of the interaction between small numbers of human breast cancer cells and human fibroblasts.

Methods

We measured the clonogenic growth of small numbers of human breast cancer cells co-cultured in direct contact with serum-activated, normal human fibroblasts. Using DNA microarrays, we also characterized the gene expression profile of the serum-activated fibroblasts. In order to validate the in vivo relevance of our experiments, we then analyzed clinical samples of metastatic breast cancer for the presence of myofibroblasts expressing α-smooth muscle actin.

Results

Clonogenic growth of human breast cancer cells obtained directly from in situ and invasive tumors was dramatically and consistently enhanced when the tumor cells were co-cultured in direct contact with serum-activated fibroblasts. This effect was abolished when the cells were co-cultured in transwells separated by permeable inserts. The fibroblasts in our experimental model exhibited a gene expression signature characteristic of 'serum response' (i.e. myofibroblasts). Immunostaining of human samples of metastatic breast cancer tissue confirmed that myofibroblasts are in direct contact with breast cancer cells.

Conclusion

Serum-activated fibroblasts promote the clonogenic growth of human breast cancer cells in vitro through a mechanism that involves direct physical contact between the cells. This model shares many important molecular and phenotypic similarities with the fibroblasts that are naturally found in breast cancers.