Circulating syndecan-1 is associated with chemotherapy-resistance in castration-resistant prostate cancer

Soluble Proteoglycans and Proteoglycan Fragments as Biomarkers of Pathological Extracellular Matrix Remodeling

Proteoglycans and their proteolytic fragments diffuse into biological fluids such as plasma, serum, urine, or synovial fluid, where they can be detected by antibodies or mass-spectrometry. Neopeptides generated by the proteolysis of proteoglycans are recognized by specific neoepitope antibodies and can act as a proxy for the activity of certain proteases. Proteoglycan and proteoglycan fragments can be potentially used as prognostic, diagnostic, or theragnostic biomarkers for several diseases characterized by dysregulated extracellular matrix remodeling such as osteoarthritis, rheumatoid arthritis, atherosclerosis, thoracic aortic aneurysms, central nervous system disorders, viral infections, and cancer. Here, we review the main mechanisms accounting for the presence of soluble proteoglycans and their fragments in biological fluids, their potential application as diagnostic, prognostic, or theragnostic biomarkers, and highlight challenges and opportunities ahead of their clinical translation.

Intracellular Osteopontin Promotes the Release of TNFα by Mast Cells to Restrain Neuroendocrine Prostate Cancer

Neuroendocrine prostate cancer (NEPC) is an aggressive form of prostate cancer that emerges as tumors become resistant to hormone therapies or, rarely, arises de novo in treatment-naïve patients. The urgent need for effective therapies against NEPC is hampered by the limited knowledge of the biology governing this lethal disease. Based on our prior observations in the transgenic adenocarcinoma of the mouse prostate (TRAMP) spontaneous prostate cancer model, in which the genetic depletion of either mast cells (MC) or the matricellular protein osteopontin (OPN) increases NEPC frequency, we tested the hypothesis that MCs can restrain NEPC through OPN production, using in vitro co-cultures between murine or human tumor cell lines and MCs, and in vivo experiments. We unveiled a role for the intracellular isoform of OPN, so far neglected compared with the secreted isoform. Mechanistically, we unraveled that the intracellular isoform of OPN promotes TNFα production in MCs via the TLR2/TLR4-MyD88 axis, specifically triggered by the encounter with NEPC cells. We found that MC-derived TNFα, in turn, hampered the growth of NEPC. We then identified the protein syndecan-1 (SDC1) as the NEPC-specific TLR2/TLR4 ligand that triggered this pathway. Interrogating published single-cell RNA-sequencing data, we validated this mechanism in a different mouse model. Translational relevance of the results was provided by in silico analyses of available human NEPC datasets and by immunofluorescence on patient-derived adenocarcinoma and NEPC lesions. Overall, our results show that MCs actively inhibit NEPC, paving the way for innovative MC-based therapies for this fatal tumor. We also highlight SDC1 as a potential biomarker for incipient NEPC.

Switching mechanism from AR to EGFR signaling via 3-O-sulfated heparan sulfate in castration-resistant prostate cancer

Androgen deprivation therapy is given to suppress prostate cancer growth; however, some cells continue to grow hormone-independently as castration-resistant prostate cancer (CRPC). Sulfated glycosaminoglycans promote ligand binding to receptors as co-receptors, but their role in CRPC remains unknown. Using the human prostate cancer cell line C4-2, which can proliferate in hormone-dependent and hormone-independent conditions, we found that epidermal growth factor (EGF)-activated EGFR-ERK1/2 signaling via 3-O-sulfated heparan sulfate (HS) produced by HS 3-O-sulfotransferase 1 (HS3ST1) is activated in C4-2 cells under hormone depletion. Knockdown of HS3ST1 in C4-2 cells suppressed hormone-independent growth, and inhibited both EGF binding to the cell surface and activation of EGFR-ERK1/2 signaling. Gefitinib, an EGFR inhibitor, significantly suppressed C4-2 cell proliferation and growth of a xenografted C4-2 tumor in castrated mouse. Collectively, our study has revealed a mechanism by which cancer cells switch to hormone-independent growth and identified the key regulator as 3-O-sulfated HS.

Novel Histopathological Biomarkers in Prostate Cancer: Implications and Perspectives

Prostate cancer (PCa) is the second most frequently diagnosed cancer in men. Despite the significant progress in cancer diagnosis and treatment over the last few years, the approach to disease detection and therapy still does not include histopathological biomarkers. The dissemination of PCa is strictly related to the creation of a premetastatic niche, which can be detected by altered levels of specific biomarkers. To date, the risk factors for biochemical recurrence include lymph node status, prostate-specific antigen (PSA), PSA density (PSAD), body mass index (BMI), pathological Gleason score, seminal vesicle invasion, extraprostatic extension, and intraductal carcinoma. In the future, biomarkers might represent another prognostic factor, as discussed in many studies. In this review, we focus on histopathological biomarkers (particularly CD169 macrophages, neuropilin-1, cofilin-1, interleukin-17, signal transducer and activator of transcription protein 3 (STAT3), LIM domain kinase 1 (LIMK1), CD15, AMACR, prostate-specific membrane antigen (PSMA), Appl1, Sortilin, Syndecan-1, and p63) and their potential application in decision making regarding the prognosis and treatment of PCa patients. We refer to studies that found a correlation between the levels of biomarkers and tumor characteristics as well as clinical outcomes. We also hypothesize about the potential use of histopathological markers as a target for novel immunotherapeutic drugs or targeted radionuclide therapy, which may be used as adjuvant therapy in the future.

Circulating syndecan-1 and glypican-4 predict 12-month survival in metastatic colorectal cancer patients

Cell surface syndecans and glypicans play important roles in the development and prognosis of colorectal cancer (CRC). Their soluble forms from proteoglycan shedding can be detected in blood and have been proposed as new prognostic biomarkers in several cancer entities. However, studies on circulating syndecan-1 (SDC1) and glypican-4 (GPC4) in CRC are limited. We, therefore, evaluated the impact of plasma SDC1 and GPC4 on the prognosis of metastatic (m)CRC patients. The present study included 93 patients with mCRC. The endpoints were progression-free survival (PFS) and overall survival (OS) at 12 months. SDC1 and GPC4 levels were measured in plasma using enzyme-linked immunosorbent assays. Plasma levels of SDC1 and GPC4 were significantly correlated. Significant correlations of these two markers were also found with carcinoembryonic antigen (CEA). Kaplan-Meier curve analyses indicated that PFS and OS probabilities significantly decreased with increasing levels of SDC1 and GPC4, respectively. Multivariable Cox regression analyses showed that both markers were significantly associated with PFS and OS independently from clinicopathological characteristics including CEA. Respective adjusted hazard ratios (HR) together with corresponding 95% confidence intervals for one standard deviation change of SDC1 were 1.32 [1.02-1.84] for PFS and 1.48 [1.01-2.15] for OS. Adjusted HRs [95% confidence intervals] of GPC4 were 1.42 [1.07-1.89] for PFS and 2.40 [1.51-3.81] for OS. Results from area under the receiver operating characteristic curve analyses suggest that GPC4 and SDC1 add additional prognostic values to CEA for OS. In conclusion, we showed significant associations of circulating SDC1 and GPC4 with poor survival of mCRC patients.

Recombinant expression, purification, and structural analysis of two ectodomains of Syndecan-1

Syndecan-1 (SDC-1) is an integral membrane heparin sulfate proteoglycan that is involved in inflammatory response, cell-signaling, cell proliferation, and numerous other cell-matrix interactions. Like the other members of the syndecan family, very little is known about structural conformations and dynamics of SDC-1. A majority of interactions occur through the extracellular ectodomain, therefore we have dedicated our research efforts to the study this specific portion of SDC-1. The ectodomain is often shed from the cell surface due to various stimuli. The released fragment has already been used as a useful biomarker for prognosis of some diseases and cancers. SDC-1 can be cleaved in different locations depending on the sheddase, generating soluble shed ectodomains that can be carried away in blood sera. In this study, we focus specifically on two main cleavage fragments that can be generated. We show the first successful expression and purification of recombinant SDC-1 ectodomains. Production of SDC-1 in E. coli allows the production of the core protein without risking heterogeneous post-translational modifications such as glycosylation, allowing a certain level of control over protein homogeneity that is not possible in mammalian expression. An expression vector was used to generate two different fusion proteins consisting of a His-tag and a TEV cleavage site for the removal of the fusion partner. SDS-PAGE was used to track the expression as well as the purification. Masses of the isolated proteins were determined using mass spectrometry and the purity and homogeneity were evaluated by solution NMR.

Energy Metabolism-Related Gene Prognostic Index Predicts Biochemical Recurrence for Patients With Prostate Cancer Undergoing Radical Prostatectomy

Background

We aimed to construct and validate an energy metabolism-related gene prognostic index (EMRGPI) to predict biochemical recurrence (BCR) in patients undergoing radical prostatectomy.

Methods

We used Lasso and COX regression analysis to orchestrate the EMRGPI in the TCGA database, and the prognostic value of EMRGPI was further validated externally using the GSE46602. All analyses were conducted with R version 3.6.3 and its suitable packages.

Results

SDC1 and ADH1B were finally used to construct the risk formula. We classified the 430 tumor patients in the TCGA database into two groups, and patients in the high-risk group had a higher risk of BCR than those in the low-risk group (HR: 1.98, 95%CI: 1.18-3.32, p=0.01). Moreover, in the GSE46602, we confirmed that the BCR risk in the high-risk group was 3.86 times higher than that in the low-risk group (95%CI: 1.61-9.24, p=0.001). We found that patients in the high-risk group had significantly higher proportions of residual tumor, older age, and T stage. SDC1 and ADH1B were significantly expressed low in the normal tissues when compared to the tumor tissues, which were opposite at the protein level. The spearman analysis showed that EMRGPI was significantly associated with B cells, CD4+ T cells, CD8+ T cells, neutrophils, macrophages, dendritic cells, stromal score, immune score, and estimate score. In addition, the EMRGPI was positively associated with the 54 immune checkpoints, among which CD80, ADORA2A, CD160, and TNFRSF25 were significantly related to the BCR-free survival of PCa patients undergoing RP.

Conclusions

The EMRGPI established in this study might serve as an independent risk factor for PCa patients undergoing radical prostatectomy.

Breast-conserving surgery and sentinel lymph node biopsy for breast cancer and their correlation with the expression of polyligand proteoglycan-1

BACKGROUND

Breast cancer is a malignant tumor with an unclear etiology and is the most common malignant tumor in women. Surgery is the main clinical treatment for breast cancer. Although traditional total mastectomy combined with axillary lymph node dissection is effective, it can result in shoulder dysfunction, especially in middle-aged and elderly patients with breast cancer with weak constitution and other underlying diseases. Furthermore, the postoperative quality of life is poor.

AIM

To assess breast-conserving surgery and sentinel lymph node biopsy for breast cancer treatment and their correlation with polyligand proteoglycan-1.

METHODS

Overall, 80 patients with breast cancer treated in our hospital from January 2021 to July 2021 were retrospectively selected and divided into an observation group (n = 44) and control group (n = 36) according to the treatment plan. The observation group was treated with breast-conserving surgery and sentinel lymph node biopsy, and the control group was treated with total breast resection. Simultaneously, immunohistochemical staining was used to detect the expression of syndecan-1 (SDC-1) in the lesions, and its relationship with clinicopathological findings was analyzed.

RESULTS

Intraoperative blood loss, operation time, and hospital stay in the observation group were 65.51 ± 9.94 mL, 65.59 ± 9.40 min, and 14.80 ± 3.03 d, respectively, which were significantly lower than those in the control group (P < 0.05). The incidence of postoperative complications in the observation group was 11.36%, which was significantly lower than that in the control group (P < 0.05). The positive expression rate of SDC-1 in the observation group was 25.00%, and there was no significant difference between the groups (P > 0.05). The positive expression rate of SDC-1 in patients with American Joint Committee on Cancer (AJCC) stage II was 14.29%, which was significantly lower than that in patients with AJCC stage I (P < 0.05). The positive expression of SDC-1 had no significant relationship with age, course of disease, site, tissue type, and treatment plan (P > 0.05).

CONCLUSION

Breast preservation surgery and sentinel lymph node biopsy for breast cancer treatment have fewer complications and quicker recovery than those treated with total breast resection. Low SDC-1 expression in breast cancer lesions is related to AJCC staging.

Glycosylation Changes in Prostate Cancer Progression

Prostate Cancer (PCa) is the most commonly diagnosed malignancy and second leading cause of cancer-related mortality in men. With the use of next generation sequencing and proteomic platforms, new biomarkers are constantly being developed to both improve diagnostic sensitivity and specificity and help stratify patients into different risk groups for optimal management. In recent years, it has become well accepted that altered glycosylation is a hallmark of cancer progression and that the glycan structures resulting from these mechanisms show tremendous promise as both diagnostic and prognostic biomarkers. In PCa, a wide range of structural alterations to glycans have been reported such as variations in sialylation and fucosylation, changes in branching, altered levels of Lewis and sialyl Lewis antigens, as well as the emergence of high mannose "cryptic" structures, which may be immunogenic and therapeutically relevant. Furthermore, aberrant expression of galectins, glycolipids, and proteoglycans have also been reported and associated with PCa cell survival and metastasis. In this review, we discuss the findings from various studies that have explored altered N- and O-linked glycosylation in PCa tissue and body fluids. We further discuss changes in O-GlcNAcylation as well as altered expression of galectins and glycoconjugates and their effects on PCa progression. Finally, we emphasize the clinical utility and potential impact of exploiting glycans as both biomarkers and therapeutic targets to improve our ability to diagnose clinically relevant tumors as well as expand treatment options for patients with advanced disease.

Syndecan Family Gene and Protein Expression and Their Prognostic Values for Prostate Cancer

Prostate cancer (PCa) is the leading cause of cancer-associated mortality in men, and new biomarkers are still needed. The expression pattern and protein tissue localization of proteoglycans of the syndecan family (SDC 1-4) and syntenin-1 (SDCBP) were determined in normal and prostatic tumor tissue from two genetically engineered mouse models and human prostate tumors. Studies were validated using SDC 1-4 and SDCBP mRNA levels and patient survival data from The Cancer Genome Atlas and CamCAP databases. RNAseq showed increased expression of Sdc1 in Pb-Cre4/Pten^f/f mouse Pca and upregulation of Sdc3 expression and downregulation of Sdc2 and Sdc4 when compared to the normal prostatic tissue in Pb-Cre4/Trp53^f/f-;Rb1^f/f mouse tumors. These changes were confirmed by immunohistochemistry. In human PCa, SDC 1-4 and SDCBP immunostaining showed variable localization. Furthermore, Kaplan-Meier analysis showed that patients expressing SDC3 had shorter prostate-specific survival than those without SDC3 expression (log-rank test, p = 0.0047). Analysis of the MSKCC-derived expression showed that SDC1 and SDC3 overexpression is predictive of decreased biochemical recurrence-free survival (p = 0.0099 and p = 0.045, respectively), and SDC4 overexpression is predictive of increased biochemical recurrence-free survival (p = 0.035). SDC4 overexpression was associated with a better prognosis, while SDC1 and SDC3 were associated with more aggressive tumors and a worse prognosis.

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.

Loss of expression of Syndecan-1 is associated with Tumor Recurrence, Metastatic Potential, and Poor Survival in patients with Colorectal carcinoma

OBJECTIVE

The loss of expression of syndecansyndecan-1 is associated with poor prognosis in many types of human cancer. The objective of this study was to evaluate the relation between syndecan-1 immunoexpression and several clinicopathological parameters in a subset of colorectal carcinoma (CRC) patients.

METHODS

Pathology tissue blocks of 202 primary tumors, 41 adenomas, and 37 normal colonic mucosae were used in this study. The cases diagnosed in the period 1995-2015 was included in the study. Immunohistochemistry analysis was performed using anti-CD138/syndecan-1 (B-A38) mouse monoclonal antibody. A semiquantitative method was used to score the syndecan-1 expression based on an evaluation of the percentage and intensity of the membranous and cytoplasmic expression. The data collected from Pathology Department at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. This is a retrospective cohort study that was conducted from July 2018 until August 2019.

RESULTS

Loss of syndecan-1 immunoexpression was observed in 72 (42.6%), 5 (12.2%), and 3 (8.1%) cases of CRC, adenomas, and normal mucosae, respectively. Low expression of syndecan-1 showed an association with nodal (p=0.003) and distant (p=0.001) metastasis, lymphovascular invasion (p=0.001), and tumor recurrence (p=0.006). Low syndecan-1 expression were associated with short overall survival (OS) (log rank 4.019, p=0.045) and disease-free survival (DFS) probabilities (log rank 4.748, p=0.029).

CONCLUSION

Loss of syndecan-1 immunoexpression is associated with metastatic potential, tumor recurrence and shorter survival in CRC and is considered a potential biomarker of poor prognosis in CRC patients.

Soluble Syndecan-1 Levels Are Associated with Survival in Platinum-Treated Bladder Cancer Patients

Cisplatin-containing chemotherapy represents the first-line treatment for patients with locally advanced or metastatic muscle-invasive bladder cancer. Recently, novel therapies have become available for cisplatin-ineligible or -resistant patients. Therefore, prediction of cisplatin response is required to optimize therapy decisions. Syndecan-1 (SDC1) tissue expression and serum concentration may be associated with cisplatin resistance. Thus, pre-treatment serum levels of SDC1 and its expression in chemo-naïve tissues were assessed in 121 muscle-invasive bladder cancer patients who underwent postoperative platinum-based chemotherapy. SDC1 concentrations were evaluated by ELISA in 52 baseline and 90 follow-up serum samples and tissue expressions were analyzed by immunohistochemistry in an independent cohort of 69 formalin-fixed paraffin-embedded tumor samples. Pre-treatment SDC1 serum levels were significantly higher in lymph node metastatic (p = 0.009) and female patients (p = 0.026). SDC1 tissue expression did not correlate with clinicopathological parameters. High pre-treatment SDC1 serum level and the presence of distant metastasis were independent risk factors for overall survival (Hazard ratio (HR): 1.439, 95% Confidence interval (CI): 1.003–2.065, p = 0.048; HR: 2.269, 95%CI: 1.053–4.887, p = 0.036). Our results demonstrate an independent association between high baseline serum SDC1 concentration and poor survival in platinum-treated patients. Analyzing baseline serum SDC1 levels may help to predict platinum-containing chemotherapy and could help to optimize therapeutic decision-making.

Roles of Proteoglycans and Glycosaminoglycans in Cancer Development and Progression

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

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.

SDC1 promotes cisplatin resistance in hepatic carcinoma cells via PI3K-AKT pathway

This study is to analyze the potential contribution of Syndecan 1 (SDC1) to cisplatin resistance in hepatic carcinoma. Cell proliferation and viability were determined by direct counting and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, respectively. The protein levels of SDC1, p-AKT, AKT and β-actin were quantified by western blotting. The SDC1 transcript abundance was measured by real-time polymerase chain reaction. The relative expression of SDC1 in clinical liver tumor samples was analyzed with immunohistochemistry. SDC1 was up-regulated in cisplatin-resistant HepG2 cells (denoted as HepG2 CR hereafter). SDC1-knockdown re-sensitized HepG2 CR cells to cisplatin treatment. Ectopic over-expression of SDC1 conferred drug resistance to naïve HepG2 cells. PI3K/AKT pathway was over-activated in HepG2 CR cells, and simultaneous administration with PI3K inhibitor greatly surmounted the resistance. We also demonstrated that SDC1 was aberrantly up-regulated in clinical hepatocellular carcinoma samples. Our study highlighted the importance of SDC1-PI3K/AKT signaling in the cisplatin resistance in hepatocellular carcinoma.

Extracellular matrix-cell interactions: Focus on therapeutic applications

Extracellular matrix (ECM) macromolecules together with a multitude of different molecules residing in the extracellular space play a vital role in the regulation of cellular phenotype and behavior. This is achieved via constant reciprocal interactions between the molecules of the ECM and the cells. The ECM-cell interactions are mediated via cell surface receptors either directly or indirectly with co-operative molecules. The ECM is also under perpetual remodeling process influencing cell-signaling pathways on its part. The fragmentation of ECM macromolecules provides even further complexity for the intricate environment of the cells. However, as long as the interactions between the ECM and the cells are in balance, the health of the body is retained. Alternatively, any dysregulation in these interactions can lead to pathological processes and finally to various diseases. Thus, therapeutic applications that are based on retaining normal ECM-cell interactions are highly rationale. Moreover, in the light of the current knowledge, also concurrent multi-targeting of the complex ECM-cell interactions is required for potent pharmacotherapies to be developed in the future.

Prognostic and clinical significance of syndecan-1 expression in breast cancer: A systematic review and meta-analysis

BACKGROUND

The prognostic value of syndecan-1 (SDC1, also called CD138) in breast cancer remains controversial. Therefore, we performed a meta-analysis to assess the clinical significance of SDC1 expression in breast cancer.

MATERIALS AND METHODS

Various databases were searched to evaluate possible correlations between SDC1 protein or mRNA expression and prognostic significance in breast cancer. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were applied to perform a quantitative meta-analysis.

RESULTS

A total of 1305 breast cancer patients from 9 eligible studies were included in this meta-analysis. Significant associations between elevated SDC1 protein expression and poor disease-free survival (DFS) (HR = 1.55, 95% CI: 1.12-2.14; P = 0.007) and overall survival (OS) (HR = 2.08, 95% CI: 1.61-2.69; P < 0.001) were observed. In addition, enhanced SDC1 protein expression correlated with negative estrogen receptor (ER) expression (OR, 2.38; 95% CI, 1.64-3.44; P < 0.001) and positive human epidermal growth factor receptor 2 (HER2) expression (OR, 1.77; 95% CI, 1.14-2.76; P = 0.01). However, increased SDC1 protein expression did not correlate with relapse-free survival (RFS) (HR = 0.33, 95% CI: 0.03-3.13; P = 0.33). There were no additional significant correlations observed between SDC1 protein expression and other clinical factors, including tumor size, lymph node involvement, nuclear grade, and progesterone receptor (PR) expression.

CONCLUSION

The results of this meta-analysis demonstrate that increased SDC1 protein expression in breast cancer is significantly associated with worse prognosis in terms of DFS and OS, and an aggressive phenotype is associated with negative ER expression and positive HER2 expression.

Heparan Sulfate Proteoglycans in Human Colorectal Cancer

Colorectal cancer is the third most common cancer worldwide, accounting for more than 610,000 mortalities every year. Prognosis of patients is highly dependent on the disease stage at diagnosis. Therefore, it is crucial to investigate molecules involved in colorectal cancer tumorigenesis, with possible use as tumor markers. Heparan sulfate proteoglycans are complex molecules present in the cell membrane and extracellular matrix, which play vital roles in cell adhesion, migration, proliferation, and signaling pathways. In colorectal cancer, the cell surface proteoglycan syndecan-2 is upregulated and increases cell migration. Moreover, expression of syndecan-1 and syndecan-4, generally antitumor molecules, is reduced. Levels of glypicans and perlecan are also altered in colorectal cancer; however, their role in tumor progression is not fully understood. In addition, studies have reported increased heparan sulfate remodeling enzymes, as the endosulfatases. Therefore, heparan sulfate proteoglycans are candidate molecules to clarify colorectal cancer tumorigenesis, as well as important targets to therapy and diagnosis.