Everolimus exerts anticancer effects through inhibiting the interaction of matrix metalloproteinase-7 with syndecan-2 in colon cancer cells.

Previous work showed that matrix metalloproteinase-7 (MMP-7) regulates colon cancer activities through an interaction with syndecan-2 (SDC-2) and SDC-2-derived peptide that disrupts this interaction and exhibits anticancer activity in colon cancer. Here, to identify potential anticancer agents, a library of 1,379 Food and Drug Administration (FDA)-approved drugs that interact with the MMP-7 prodomain were virtually screened by protein-ligand docking score analysis using the GalaxyDock3 program. Among five candidates selected based on their structures and total energy values for interacting with the MMP-7 prodomain, the known mechanistic target of rapamycin kinase (mTOR) inhibitor, everolimus, showed the highest binding affinity and the strongest ability to disrupt the interaction of the MMP-7 prodomain with the SDC-2 extracellular domain in vitro. Everolimus treatment of the HCT116 human colon cancer cell line did not affect the mRNA expression levels of MMP-7 and SDC-2 but reduced the adhesion of cells to MMP-7 prodomain-coated plates and the cell-surface localization of MMP-7. Thus, everolimus appears to inhibit the interaction between MMP-7 and SDC-2. Everolimus treatment of HCT116 cells also reduced their gelatin-degradation activity and anticancer activities, including colony formation. Interestingly, cells treated with sirolimus, another mTOR inhibitor, triggered less gelatin-degradation activity, suggesting that this inhibitory effect of everolimus was not due to inhibition of the mTOR pathway. Consistently, everolimus inhibited the colony-forming ability of mTOR-resistant HT29 cells. Together, these data suggest that, in addition to inhibiting mTOR signaling, everolimus exerts anticancer activity by interfering with the interaction of MMP-7 and SDC-2, and could be a useful therapeutic anticancer drug for colon cancer.NEW & NOTEWORTHY The utility of cancer therapeutics targeting the proteolytic activities of MMPs is limited because MMPs are widely distributed throughout the body and involved in many different aspects of cell functions. This work specifically targets the activation of MMP-7 through its interaction with syndecan-2. Notably, everolimus, a known mTOR inhibitor, blocked this interaction, demonstrating a novel role for everolimus in inhibiting mTOR signaling and impairing the interaction of MMP-7 with syndecan-2 in colon cancer.

PTN from Leydig cells activates SDC2 and modulates human spermatogonial stem cell proliferation and survival via GFRA1.

BACKGROUND: Spermatogonial stem cells (SSCs) are essential for the maintenance and initiation of male spermatogenesis. Despite the advances in understanding SSC biology in mouse models, the mechanisms underlying human SSC development remain elusive. RESULTS: Here, we analyzed the signaling pathways involved in SSC regulation by testicular somatic cells using single-cell sequencing data (GEO datasets: GSE149512 and GSE112013) and identified that Leydig cells communicate with SSCs through pleiotrophin (PTN) and its receptor syndecan-2 (SDC2). Immunofluorescence, STRING prediction, and protein immunoprecipitation assays confirmed the interaction between PTN and SDC2 in spermatogonia, but their co-localization was observed only in approximately 50% of the cells. The knockdown of SDC2 in human SSC lines impaired cell proliferation, DNA synthesis, and the expression of PLZF, a key marker for SSC self-renewal. Transcriptome analysis revealed that SDC2 knockdown downregulated the expression of GFRA1, a crucial factor for SSC proliferation and self-renewal, and inhibited the HIF-1 signaling pathway. Exogenous PTN rescued the proliferation and GFRA1 expression in SDC2 knockdown SSC lines. In addition, we found downregulation of PTN and SDC2 as well as altered localization in non-obstructive azoospermia (NOA) patients, suggesting that downregulation of PTN and SDC2 may be associated with impaired spermatogenesis. CONCLUSIONS: Our results uncover a novel mechanism of human SSC regulation by the testicular microenvironment and suggest a potential therapeutic target for male infertility.

External quality assessment for detection of methylated Syndecan 2 (SDC2) in China.

OBJECTIVES: Detection of Syndecan 2 (SDC2) methylation in stool DNA is a novel method for the auxiliary diagnosis of early colorectal cancer (CRC). Currently, this method has been widely applied; however, its accuracy and reliability have not been determined. The objective of this pioneering study was to evaluate the performance of clinical laboratories in China for their ability to detect SDC2 methylation from stool DNA. METHODS: We generated a sample panel consisting of clinical and cell samples. The clinical samples were stool specimens from patients with or without CRC, including four positives (prepared by serial dilution from one stool specimen), one negative and one interferential sample. Two cell samples, with positive or negative methylated SDC2, were used as controls. The panel was distributed to 32 clinical laboratories for analysis of SDC2 methylation, and the results were compared and scored. RESULTS: The sample panel was compatible with commercially available assays and it showed appropriate stability to be an external quality assessment material. There were four false results; one hospital laboratory and one commercial diagnostic laboratory had a false-positive and a false-negative result, respectively, and one commercial diagnostic laboratory had both a false-positive and false-negative result. Among the 32 participating laboratories, 29 (90.62%) obtained an acceptable or better performance score, while 3 (9.38%) laboratories required improvement. CONCLUSIONS: Our results demonstrate that the detection of SDC2 methylation from stool DNA was satisfactory in China. Additionally, the importance of external quality assessment was highlighted for monitoring the performance of clinical laboratories.

CD148 Deficiency in Fibroblasts Promotes the Development of Pulmonary Fibrosis.

Rationale: CD148/PTRJ (receptor-like protein tyrosine phosphatase η) exerts antifibrotic effects in experimental pulmonary fibrosis via interactions with its ligand syndecan-2; however, the role of CD148 in human pulmonary fibrosis remains incompletely characterized.Objectives: We investigated the role of CD148 in the profibrotic phenotype of fibroblasts in idiopathic pulmonary fibrosis (IPF).Methods: Conditional CD148 fibroblast-specific knockout mice were generated and exposed to bleomycin and then assessed for pulmonary fibrosis. Lung fibroblasts (mouse lung and human IPF lung), and precision-cut lung slices from human patients with IPF were isolated and subjected to experimental treatments. A CD148-activating 18-aa mimetic peptide (SDC2-pep) derived from syndecan-2 was evaluated for its therapeutic potential.Measurements and Main Results: CD148 expression was downregulated in IPF lungs and fibroblasts. In human IPF lung fibroblasts, silencing of CD148 increased extracellular matrix production and resistance to apoptosis, whereas overexpression of CD148 reversed the profibrotic phenotype. CD148 fibroblast-specific knockout mice displayed increased pulmonary fibrosis after bleomycin challenge compared with control mice. CD148-deficient fibroblasts exhibited hyperactivated PI3K/Akt/mTOR signaling, reduced autophagy, and increased p62 accumulation, which induced NF-κB activation and profibrotic gene expression. SDC2-pep reduced pulmonary fibrosis in vivo and inhibited IPF-derived fibroblast activation. In precision-cut lung slices from patients with IPF and control patients, SDC2-pep attenuated profibrotic gene expression in IPF and normal lungs stimulated with profibrotic stimuli.Conclusions: Lung fibroblast CD148 activation reduces p62 accumulation, which exerts antifibrotic effects by inhibiting NF-κB-mediated profibrotic gene expression. Targeting the CD148 phosphatase with activating ligands such as SDC2-pep may represent a potential therapeutic strategy in IPF.

Substituted Syndecan-2-Derived Mimetic Peptides Show Improved Antitumor Activity over the Parent Syndecan-2-Derived Peptide.

We previously showed that a synthetic peptide (S2-P) corresponding to a portion of the human syndecan-2 (SDC2) sequence can bind to the pro-domain of matrix metalloproteinase-7 (MMP-7) to inhibit colon cancer activities. Since S2-P had a relatively weak binding affinity for the MMP-7 pro-domain, we herein modified the amino acid sequence of S2-P to improve the anticancer potential. On the basis of the interaction structure of S2-P and MMP-7, four peptides were generated by replacing amino acids near Tyr 51, which is critical for the interaction. The SDC2-mimetic peptides harboring an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-D) or with an Ala-to-Phe substitution at the N-terminal side of Tyr 51 and an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-FE) showed improved interaction affinities for the MMP-7 pro-domain. Compared to S2-P, S2-FE was better able to inhibit the SDC2-MMP-7 interaction, the cell surface localization of MMP-7, the gelatin degradation activity of MMP-7, and the cancer activities (cell migration, invasion, and colony-forming activity) of human HCT116 colon cancer cells in vitro. In vivo, S2-FE inhibited the primary tumor growth and lung metastasis of CT26 mouse colon cancer cells in a xenograft mouse model. Together, these data suggest that S2-FE could be useful therapeutic anticancer peptides for colon cancer.

Targeting stromal cell Syndecan-2 reduces breast tumour growth, metastasis and limits immune evasion.

Tumour stromal cells support tumourigenesis. We report that Syndecan-2 (SDC2) is expressed on a nonepithelial, nonhaematopoietic, nonendothelial stromal cell population within breast cancer tissue. In vitro, syndecan-2 modulated TGFß signalling (SMAD7, PAI-1), migration and immunosuppression of patient-derived tumour-associated stromal cells (TASCs). In an orthotopic immunocompromised breast cancer model, overexpression of syndecan-2 in TASCs significantly enhanced TGFß signalling (SMAD7, PAI-1), tumour growth and metastasis, whereas reducing levels of SDC2 in TASCs attenuated TGFß signalling (SMAD7, PAI-1, CXCR4), tumour growth and metastasis. To explore the potential for therapeutic application, a syndecan-2-peptide was generated that inhibited the migratory and immunosuppressive properties of TASCs in association with reduced expression of TGFß-regulated immunosuppressive genes, such as CXCR4 and PD-L1. Moreover, using an orthotopic syngeneic breast cancer model, overexpression of syndecan-2-peptide in TASCs reduced tumour growth and immunosuppression within the TME. These data provide evidence that targeting stromal syndecan-2 within the TME inhibits tumour growth and metastasis due to decreased TGFß signalling and increased immune control.

Colorectal cancer screening using a stool DNA-based SDC2 methylation test: a multicenter, prospective trial.

BACKGROUND: Prevention and early detection of colorectal cancer (CRC) is a global priority, with many countries conducting population-based CRC screening programs. Although colonoscopy is the most accurate diagnostic method for early CRC detection, adherence remains low because of its invasiveness and the need for extensive bowel preparation. Non-invasive fecal occult blood tests or fecal immunochemical tests are available; however, their sensitivity is relatively low. Syndecan-2 (SDC2) is a stool-based DNA methylation marker used for early detection of CRC. Using the EarlyTect™-Colon Cancer test, the sensitivity and specificity of SDC2 methylation in stool DNA for detecting CRC were previously demonstrated to be greater than 90%. Therefore, a larger trial to validate its use for CRC screening in asymptomatic populations is now required. METHODS: All participants will collect their stool (at least 20 g) before undergoing screening colonoscopy. The samples will be sent to a central laboratory for analysis. Stool DNA will be isolated using a GT Stool DNA Extraction kit, according to the manufacturer's protocol. Before performing the methylation test, stool DNA (2 µg per reaction) will be treated with bisulfite, according to manufacturer's instructions. SDC2 and COL2A1 control reactions will be performed in a single tube. The SDC2 methylation test will be performed using an AB 7500 Fast Real-time PCR system. CT values will be calculated using the 7500 software accompanying the instrument. Results from the EarlyTect™-Colon Cancer test will be compared against those obtained from colonoscopy and any corresponding diagnostic histopathology from clinically significant biopsied or subsequently excised lesions. Based on these results, participants will be divided into three groups: CRC, polyp, and negative. The following clinical data will be recorded for the participants: sex, age, colonoscopy results, and clinical stage (for CRC cases). DISCUSSION: This trial investigates the clinical performance of a device that allows quantitative detection of a single DNA marker, SDC2 methylation, in human stool DNA in asymptomatic populations. The results of this trial are expected to be beneficial for CRC screening and may help make colonoscopy a selective procedure used only in populations with a high risk of CRC. TRIAL REGISTRATION: This trial (NCT04304131) was registered at ClinicalTrials.gov on March 11, 2020 and is available at https://clinicaltrials.gov/ct2/show/NCT04304131?cond=NCT04304131&draw=2&rank=1 .

Syndecan-2, negatively regulated by miR-20b-5p, contributes to 5-fluorouracil resistance of colorectal cancer cells via the JNK/ERK signaling pathway.

5-Fluorouracil (5-FU) resistance has been long considered as an obstacle to the efficacy of chemotherapy in colorectal cancer (CRC). In this study, we demonstrated the role of miR-20b-5p-regulated syndecan-2 (SDC2) in 5-FU resistance of CRC cells. 5-FU-resistant SW480 CRC cells were established by treatment of SW480 cells with stepwise increase of 5-FU concentration. The results showed that SDC2 was expressed significantly higher in SW480/5-FU cells than in SW480/WT cells as revealed by quantitative real-time polymerase chain reaction and western blot analysis. MTT assay and BrdU assay showed that SDC2 overexpression led to increased cell survival rate, while SDC2 knockdown reversed the drug resistance of SW480/5-FU cells. Wound healing and transwell invasion assays revealed that knockdown of SDC2 inhibited the migratory and invasive ability of SW480/5-FU cells. Moreover, animal experiments indicated that si-SDC2 plays a suppressive role in tumor growth in vivo. We also confirmed that miR-20b-5p interacted with SDC2, which reversed the effect of SDC2 in SW480/5-FU cells via the c-Jun N-terminal kinase (JNK)/extracellular regulated protein kinases (ERK) signaling pathway. These findings showed that JNK/ERK signaling pathway is involved in miR-20b-5p/SDC2 axis-mediated 5-FU resistance in SW480/5-FU cells, indicating that the miR-20b-5p/SDC2 axis is a potential target for reversing 5-FU resistance in CRC.

Bacteroides fragilis Enterotoxin Upregulates Matrix Metalloproteinase-7 Expression through MAPK and AP-1 Activation in Intestinal Epithelial Cells, Leading to Syndecan-2 Release.

Bacteroides fragilis enterotoxin (BFT) produced by enterotoxigenic B. fragilis (ETBF) causes colonic inflammation. BFT initially contacts intestinal epithelial cells (IECs) and affects the intestinal barrier. Although molecular components of the gut epithelial barrier such as metalloproteinase-7 (MMP-7) and syndecan-2 are known to be associated with inflammation, little has been reported about MMP-7 expression and syndecan-2 shedding in response to ETBF infection. This study explores the role of BFT in MMP-7 induction and syndecan-2 release in IECs. Stimulating IECs with BFT led to the induction of MMP-7 and the activation of transcription factors such as NF-κB and AP-1. MMP-7 upregulation was not affected by NF-κB, but it was related to AP-1 activation. In BFT-exposed IECs, syndecan-2 release was observed in a time- and concentration-dependent manner. MMP-7 suppression was associated with a reduction in syndecan-2 release. In addition, suppression of ERK, one of the mitogen-activated protein kinases (MAPKs), inhibited AP-1 activity and MMP-7 expression. Furthermore, the suppression of AP-1 and ERK activity was related to the attenuation of syndecan-2 release. These results suggest that a signaling cascade comprising ERK and AP-1 activation in IECs is involved in MMP-7 upregulation and syndecan-2 release during exposure to BFT.

Lung Adenocarcinoma Syndecan-2 Potentiates Cell Invasiveness.

Altered expression of syndecan-2 (SDC2), a heparan sulfate proteoglycan, has been associated with diverse types of human cancers. However, the mechanisms by which SDC2 may contribute to the pathobiology of lung adenocarcinoma have not been previously explored. SDC2 levels were measured in human lung adenocarcinoma samples and lung cancer tissue microarrays using immunohistochemistry and real-time PCR. To understand the role of SDC2 in vitro, SDC2 was silenced or overexpressed in A549 lung adenocarcinoma cells. The invasive capacity of cells was assessed using Matrigel invasion assays and measuring matrix metalloproteinase (MMP) 9 expression. Finally, we assessed tumor growth and metastasis of SDC2-deficient A549 cells in a xenograft tumor model. SDC2 expression was upregulated in malignant epithelial cells and macrophages obtained from human lung adenocarcinomas. Silencing of SDC2 decreased MMP9 expression and attenuated the invasive capacity of A549 lung adenocarcinoma cells. The inhibitory effect of SDC2 silencing on MMP9 expression and cell invasion was reversed by overexpression of MMP9 and syntenin-1. SDC2 silencing attenuated NF-κB p65 subunit nuclear translocation and its binding to the MMP9 promoter, which were restored by overexpression of syntenin-1. SDC2 silencing in vivo reduced tumor mass volume and metastasis. These findings suggest that SDC2 plays an important role in the invasive properties of lung adenocarcinoma cells and that its effects are mediated by syntenin-1. Thus, inhibiting SDC2 expression or activity could serve as a potential therapeutic target to treat lung adenocarcinoma.

The melanocortin-1 receptor reversely regulates the melanin synthesis and migration of melanoma cells via dimerization-induced conformational changes.

We previously reported that the melanocortin-1 receptor (MC1R), a key regulator of melanogenesis, regulates cell migration; however, the detailed mechanism remained unknown. Since the homo-dimerization of MC1R by four inter-subunit disulfide bonds is known to be functionally important for melanogenesis, we investigated the importance of MC1R dimerization for cell migration. Unlike the wild-type MC1R, the dimerization-defective mutant MC1R in which four critical Cys residues were replaced with Ala residues (Cys35-267-273-275Ala) significantly inhibited melanin synthesis but enhanced cell migration in human MNT-1 and A375 melanoma cells. This suggests that there may be a reverse correlation between melanin synthesis and cell migration. Interestingly, melanoma cells expressing the dimerization-defective mutant exhibited enhanced expression of the cell surface heparan sulfate proteoglycan, syndecan-2, and knockdown of syndecan-2 expression decreased the mutant-mediated cell migration. Consistently, ASIP, an antagonist of MC1R, enhanced syndecan-2 expression and cell migration and reversed the α-melanocyte-stimulating hormone (α-MSH)-mediated inhibition of syndecan-2 expression. Furthermore, α-MSH reduced the cell migration of MNT1 cells expressing wild-type MC1R but not its dimerization-defective mutant. Together, these data strongly suggest that MC1R reversely regulates melanin synthesis and migration via the conformational changes induced by dimerization.

Syndecan-2 Attenuates Radiation-induced Pulmonary Fibrosis and Inhibits Fibroblast Activation by Regulating PI3K/Akt/ROCK Pathway via CD148.

Radiation-induced pulmonary fibrosis is a severe complication of patients treated with thoracic irradiation. We have previously shown that syndecan-2 reduces fibrosis by exerting alveolar epithelial cytoprotective effects. Here, we investigate whether syndecan-2 attenuates radiation-induced pulmonary fibrosis by inhibiting fibroblast activation. C57BL/6 wild-type mice and transgenic mice that overexpress human syndecan-2 in alveolar macrophages were exposed to 14 Gy whole-thoracic radiation. At 24 weeks after irradiation, lungs were collected for histological, protein, and mRNA evaluation of pulmonary fibrosis, profibrotic gene expression, and α-smooth muscle actin (α-SMA) expression. Mouse lung fibroblasts were activated with transforming growth factor (TGF)-ß1 in the presence or absence of syndecan-2. Cell proliferation, migration, and gel contraction were assessed at different time points. Irradiation resulted in significantly increased mortality and pulmonary fibrosis in wild-type mice that was associated with elevated lung expression of TGF-ß1 downstream target genes and cell death compared with irradiated syndecan-2 transgenic mice. In mouse lung fibroblasts, syndecan-2 inhibited α-SMA expression, cell contraction, proliferation, and migration induced by TGF-ß1. Syndecan-2 attenuated phosphoinositide 3-kinase/serine/threonine kinase/Rho-associated coiled-coil kinase signaling and serum response factor binding to the α-SMA promoter. Syndecan-2 attenuates pulmonary fibrosis in mice exposed to radiation and inhibits TGF-ß1-induced fibroblast-myofibroblast differentiation, migration, and proliferation by down-regulating phosphoinositide 3-kinase/serine/threonine kinase/Rho-associated coiled-coil kinase signaling and blocking serum response factor binding to the α-SMA promoter via CD148. These findings suggest that syndecan-2 has potential as an antifibrotic therapy in radiation-induced lung fibrosis.

IGF-I regulates HT1080 fibrosarcoma cell migration through a syndecan-2/Erk/ezrin signaling axis.

Fibrosarcoma is a tumor of mesenchymal origin, originating from fibroblasts. IGF-I is an anabolic growth factor which exhibits significant involvement in cancer progression. In this study, we investigated the possible participation of syndecan-2 (SDC-2), a cell membrane heparan sulfate (HS) proteoglycan on IGF-I dependent fibrosarcoma cell motility. Our results demonstrate that SDC-2-deficient HT1080 cells exhibit attenuated IGF-I-dependent chemotactic migration (p < 0.001). SDC-2 was found to co-localize to IGF-I receptor (IGF-IR) in a manner dependent on IGF-I activity (P ≤ 0.01). In parallel, the downregulation of SDC-2 significantly inhibited both basal and due to IGF-I action ERK1/2 activation, (p < 0.001). The phosphorylation levels of ezrin (Thr567), which is suggested to act as a signaling bridge between the cellular membrane receptors and actin cytoskeleton, were strongly enhanced by IGF-I at both 1h and 24h (p < 0.05; p < 0.01). The formation of an immunoprecipitative complex revealed an association between SDC2 and ezrin which was enhanced through IGF-I action (p < 0.05). Immunoflourescence demonstrated a co-localization of IGF-IR, SDC2 and ezrin upregulated by IGF-I action. IGF-I enhanced actin polymerization and ezrin/actin specific localization to cell membranes. Finally, treatment with IGF-I strongly increased SDC2 expression at both the mRNA and protein level (p < 0.001). Therefore, we propose a novel SDC2-dependent mechanism, where SDC2 is co-localized with IGF-IR and enhances its' IGFI-dependent downstream signaling. SDC2 mediates directly IGFI-induced ERK1/2 activation, it recruits ezrin, contributes to actin polymerization and ezrin/actin specific localization to cell membranes, ultimately facilitating the progression of IGFI-dependent fibrosarcoma cell migration.

[Clinical significance of syndecan-1 and syndecan-2 expression in gallbladder squamous cell/adenosquamous carcinoma and adenocarcinoma].

Objective: To investigate the expression of syndecan-1 and syndecan-2 and their clinicopathological significance in patients with gallbladder squamous cell (SC)/adenosquamous carcinoma (ASC) and adenocarcinoma (AC). Methods: A total of 126 patients with SC/ASC (n=46) and AC (n=80) were included in this study. The expression levels of syndecan-1 and syndecan-2 were detected by Envison™ immunohistochemistry assay. The clinical and prognostic significance of syndecan-1 and syndecan-2 were analyzed. Results: In the 46 SC/ASC samples, syndecan-1 and syndecan-2 were positively expressed in 29 (63.0%) and 28 (60.9%) tumor tissues, respectively. (Positive expression was defined based on the staining in the component of squamous cell carcinoma. That is to say, the tissue which adenocarcinoma part was positively stained, but squamous cell carcinoma part was negatively stained is also regarded as negative.) In the 80 AC samples, 47 (58.8%) cases showed syndecan-1 positive expression, and 51 (63.8%) showed syndecan-2 positive expression. There was no significant difference in the positive rates of syndecan-1 and syndecan-2 between SC/ASC and AC groups (P>0.05 for all). The levels of syndecan-1 and syndecan-2 were associated with tumor size, TNM staging, lymph node metastasis, invasion of adjacent tissue, and surgical procedures in SC/ASC patients (P<0.05 for all). However, their expression was associated with tumor differentiation, tumor size, TNM staging, lymph node metastasis, invasion of adjacent tissue, and surgical procedures in AC patients (P<0.05 for all). The Kaplan-Meier survival analysis of SC/ASC and AC patients revealed that the average survival time for patients with positive syndecan-1 and syndecan-2 expression was significantly shorter than that of those with negative expression (P<0.01 for all). Cox multivariate analysis indicated that syndecan-1 and syndecan-2 expression were independent unfavorable prognostic factors for SC/ASC and AC patients (P<0.05 for all). Conclusion: The syndecan-1 and syndecan-2 expression are associated with the tumor progression and poor prognosis in patients with gallbladder SC/ASC and AC.

Syndecan-2 enhances E-cadherin shedding and fibroblast-like morphological changes by inducing MMP-7 expression in colon cancer cells.

E-cadherin plays a mechanical role in mediating cell-cell interactions and maintaining epithelial tissue integrity, and the loss of E-cadherin function has been implicated in cancer progression and metastasis. Syndecan-2, a cell-surface heparan sulfate proteoglycan, is upregulated during the development of colon cancer. Here, we assessed the functional relationship between E-cadherin and syndecan-2. We found that stable overexpression of syndecan-2 in a human colorectal adenocarcinoma cell line (HT29) enhanced the proteolytic shedding of E-cadherin to conditioned-media. Either knockdown of matrix metalloproteinase 7 (MMP-7) or inhibition of MMP-7 activity using GM6001 significantly reduced the extracellular shedding of E-cadherin, suggesting that syndecan-2 mediates E-cadherin shedding via MMP-7. Consistent with this notion, enhancement of MMP-7 expression by interleukin-1α treatment increased the shedding of E-cadherin. Conversely, the specific reduction of either syndecan-2 or MMP-7 reduced the shedding of E-cadherin. HT29 cells overexpressing syndecan-2 showed significantly lower cell-surface expression of E-cadherin, decreased cell-cell contact, a more fibroblastic cell morphology, and increased expression levels of ZEB-1. Taken together, these data suggest that syndecan-2 induces extracellular shedding of E-cadherin and supports the acquisition of a fibroblast-like morphology by regulating MMP-7 expression in a colon cancer cell line.

Sdc2 and Tbx16 regulate Fgf2-dependent epithelial cell morphogenesis in the ciliated organ of asymmetry.

Heparan sulfate proteoglycans (HSPGs) control many cellular processes and have been implicated in the regulation of left-right (LR) development by as yet unknown mechanisms. Using lineage-targeted knockdowns, we found that the transmembrane HSPG Syndecan 2 (Sdc2) regulates LR patterning through cell-autonomous functions in the zebrafish ciliated organ of asymmetry, Kupffer's vesicle (KV), including regulation of cell proliferation and adhesion, cilia length and asymmetric fluid flow. Exploring downstream pathways, we found that the cell signaling ligand Fgf2 is exclusively expressed in KV cell lineages, and is dependent on Sdc2 and the transcription factor Tbx16. Strikingly, Fgf2 controls KV morphogenesis but not KV cilia length, and KV morphogenesis in sdc2 morphants can be rescued by expression of fgf2 mRNA. Through an Fgf2-independent pathway, Sdc2 and Tbx16 also control KV ciliogenesis. Our results uncover a novel Sdc2-Tbx16-Fgf2 pathway that regulates epithelial cell morphogenesis.

Effectiveness of fecal DNA syndecan-2 methylation testing for detection of colorectal cancer in a high-risk Chinese population.

BACKGROUND: Colorectal cancer (CRC) is among the most prevalent and life-threatening malignancies worldwide. Syndecan-2 methylation (mSDC2) testing has emerged as a widely used biomarker for early detection of CRC in stool and serum samples. Cancer (CRC) is among the most prevalent and life-threatening malignancies worldwide. mSDC2 testing has emerged as a widely used biomarker for early detection of CRC in stool and serum samples. AIM: To validate the effectiveness of fecal DNA mSDC2 testing in the detection of CRC among a high-risk Chinese population to provide evidence-based data for the development of diagnostic and/or screening guidelines for CRC in China. METHODS: A high-risk Chinese cohort consisting of 1130 individuals aged 40-79 years was selected for evaluation via fecal mSDC2 testing. Sensitivity and specificity for CRC, advanced adenoma (AA) and advanced colorectal neoplasia (ACN) were determined. High-risk factors for the incidence of colorectal lesions were determined and a logistic regression model was constructed to reflect the efficacy of the test. RESULTS: A total of 1035 high-risk individuals were included in this study according to established criteria. Among them, 16 suffered from CRC (1.55%), 65 from AA (6.28%) and 189 from non-AAs (18.26%); 150 patients were diagnosed with polyps (14.49%). Diagnoses were established based upon colonoscopic and pathological examinations. Sensitivities of the mSDC2 test for CRC and AA were 87.50% and 40.00%, respectively; specificities were 95.61% for other groups. Positive predictive values of the mSDC2 test for CRC, AA and ACN were 16.09%, 29.89% and 45.98%, respectively; the negative predictive value for CRC was 99.79%. After adjusting for other high-risk covariates, mSDC2 test positivity was found to be a significant risk factor for the occurrence of ACN (P < 0.001). CONCLUSION: Our findings confirmed that offering fecal mSDC2 testing and colonoscopy in combination for CRC screening is effective for earlier detection of malignant colorectal lesions in a high-risk Chinese population.

Comparative detection of syndecan-2 methylation in preoperative and postoperative stool DNA in patients with colorectal cancer.

BACKGROUND: Early detection of colorectal cancer (CRC) is essential to reduce cancer-related morbidity and mortality. Stool DNA (sDNA) testing is an emerging method for early CRC detection. Syndecan-2 (SDC2) methylation is a potential biomarker for the sDNA testing. Aberrant DNA methylation is an early epigenetic event during tumorigenesis and can occur in the normal colonic mucosa during aging, which can compromise the sDNA test results. AIM: To determine whether methylated SDC2 in sDNA normalizes after surgical resection of CRC. METHODS: In this prospective study, we enrolled 151 patients with CRC who underwent curative surgical resection between September 2016 and May 2020. Preoperative stool samples were collected from 123 patients and postoperative samples were collected from 122 patients. A total of 104 samples were collected from both preoperative and postoperative patients. Aberrant promoter methylation of SDC2 in sDNA was assessed using linear target enrichment quantitative methylation-specific real-time polymerase chain reaction. Clinicopathological parameters were analyzed using the results of SDC2 methylation. RESULTS: Detection rates of SDC2 methylation in the preoperative and postoperative stool samples were 88.6% and 19.7%, respectively. Large tumor size (3 cm, P = 0.019) and advanced T stage (T3-T4, P = 0.033) were positively associated with the detection rate of SDC2 methylation before surgery. Female sex was associated with false positives after surgery (P = 0.030). Cycle threshold (CT) values were significantly decreased postoperatively compared with preoperative values (P < 0.001). The postoperative negative conversion rate for preoperatively methylated SDC2 was 79.3% (73/92). CONCLUSION: Our results suggested that the SDC2 methylation test for sDNA has acceptable sensitivity and specificity. However, small size and early T stage tumors are associated with a low detection rate of SDC2 methylation. As the cycle threshold values significantly decreased after surgery, SDC2 methylation test for sDNA might have a diagnostic value for CRC.

Evolution of immune and stromal cell states and ecotypes during gastric adenocarcinoma progression.

Understanding tumor microenvironment (TME) reprogramming in gastric adenocarcinoma (GAC) progression may uncover novel therapeutic targets. Here, we performed single-cell profiling of precancerous lesions, localized and metastatic GACs, identifying alterations in TME cell states and compositions as GAC progresses. Abundant IgA+ plasma cells exist in the premalignant microenvironment, whereas immunosuppressive myeloid and stromal subsets dominate late-stage GACs. We identified six TME ecotypes (EC1-6). EC1 is exclusive to blood, while EC4, EC5, and EC2 are highly enriched in uninvolved tissues, premalignant lesions, and metastases, respectively. EC3 and EC6, two distinct ecotypes in primary GACs, associate with histopathological and genomic characteristics, and survival outcomes. Extensive stromal remodeling occurs in GAC progression. High SDC2 expression in cancer-associated fibroblasts (CAFs) is linked to aggressive phenotypes and poor survival, and SDC2 overexpression in CAFs contributes to tumor growth. Our study provides a high-resolution GAC TME atlas and underscores potential targets for further investigation.

Role of Syndecans in Ovarian Cancer: New Diagnostic and Prognostic Biomarkers and Potential Therapeutic Targets.

Ovarian cancer (OC) is the eighth cancer both in prevalence and mortality in women and represents the deadliest female reproductive cancer. Due to generally vague symptoms, OC is frequently diagnosed only at a late and advanced stage, resulting in high mortality. The tumor extracellular matrix and cellular matrix receptors play a key role in the pathogenesis of tumor progression. Syndecans are a family of four transmembrane heparan sulfate proteoglycans (PG), including syndecan-1, -2, -3, and -4, which are dysregulated in a myriad of cancers, including OC. Many clinicopathological studies suggest that these proteins are promising diagnostic and prognostic biomarkers for OC. Furthermore, functions of the syndecan family in the regulation of cellular processes make it an interesting pharmacological target for anticancer therapies.