Syndecan-1 Depletion Has a Differential Impact on Hyaluronic Acid Metabolism and Tumor Cell Behavior in Luminal and Triple-Negative Breast Cancer Cells

Abstract

Glycosaminoglycans (GAGs) and proteoglycans (PGs) are major components of the glycocalyx. The secreted GAG and CD44 ligand hyaluronic acid (HA), and the cell surface PG syndecan-1 (Sdc-1) modulate the expression and activity of cytokines, chemokines, growth factors, and adhesion molecules, acting as critical regulators of tumor cell behavior. Here, we studied the effect of Sdc-1 siRNA depletion and HA treatment on hallmark processes of cancer in breast cancer cell lines of different levels of aggressiveness. We analyzed HA synthesis, and parameters relevant to tumor progression, including the stem cell phenotype, Wnt signaling constituents, cell cycle progression and apoptosis, and angiogenic markers in luminal MCF-7 and triple-negative MDA-MB-231 cells. Sdc-1 knockdown enhanced HAS-2 synthesis and HA binding in MCF-7, but not in MDA-MB-231 cells. Sdc-1-depleted MDA-MB-231 cells showed a reduced CD24-/CD44+ population. Furthermore, Sdc-1 depletion was associated with survival signals in both cell lines, affecting cell cycle progression and apoptosis evasion. These changes were linked to the altered expression of KLF4, MSI2, and miR-10b and differential changes in Erk, Akt, and PTEN signaling. We conclude that Sdc-1 knockdown differentially affects HA metabolism in luminal and triple-negative breast cancer model cell lines and impacts the stem phenotype, cell survival, and angiogenic factors.

The heparan sulphate proteoglycan Syndecan‐1 (CD138) regulates tumour progression in a 3D model of ductal carcinoma in situ of the breast

“…Commonly, epithelial markers like CDH1 and CLDN are downregulated while mesenchymal markers such as FN‐1 and VIM are upregulated 22 . Previous studies in IBC cells had indicated downregulation of individual EMT markers such as CDH1, CLDN, VIM and snail upon Sdc‐1‐depletion, however, as both epithelial and mesenchymal markers were downregulated, the changes were not suggestive of a complete EMT 18,26,39 . In our DCIS model, Sdc‐1 knockdown was associated with an upregulation of the epithelial markers claudin and (moderately) E‐cadherin, of the mesenchymal marker fibronectin, and a modest downregulation of the mesenchymal marker vimentin (Figure 4).…”

“…22 Previous studies in IBC cells had indicated downregulation of individual EMT markers such as CDH1, CLDN, VIM and snail upon Sdc-1-depletion, however, as both epithelial and mesenchymal markers were downregulated, the changes were not suggestive of a complete EMT. 18,26,39 In our DCIS model, Sdc-1 knockdown was associated with an upregulation of the epithelial markers claudin and (moderately) E-cadherin, of the mesenchymal marker fibronectin, and a modest downregulation of the mesenchymal marker vimentin (Figure 4). Our results do not point towards a total EMT upon Sdc-1 knockdown but rather a partial EMT combined with ECM-interactions and deregulation of proteolysis.…”

“…Both inhibitor treatments rendered the Sdc-1-knockdown dependent moderate increase in heparanase expression statistically significant (Figure 4a, b). Since previous studies in Sdc-1-depleted IBC cells had indicated an impact on the expression of EMT markers as an additional proinvasive mechanism, 18,26 we studied the expression of the cell adhesion molecules and epithelial markers E-cadherin (CDH1), claudin-1 (CLDN1), of the mesenchymal markers Vimentin (Vim), and Fibronectin (FN) along with the proinvasive enzyme heparanase in Sdc-1-depleted and control cells by qPCR. Changes in gene expression of the EMT-related transcriptional regulator ZEB-2 and Heparanase-2 were also analysed, however, the resulting C T -values were >30 (results not shown) with C T = 30 being defined as limit of detection in this project.…”

The Cell Surface Heparan Sulfate Proteoglycan Syndecan-3 Promotes Ovarian Cancer Pathogenesis

“…Since we previously showed that heparan sulfate proteoglycans are capable of modulating breast and colon cancer stem cell properties, associated with therapeutic resistance [ 20 , 21 , 22 , 23 ], we evaluated the potential influence of SDC3 on the growth of three-dimensional spheroids as a readout of stem cell activity in a hanging drop assay [ 24 ]. Both SDC3-depleted and control siRNA-treated SKOV3 and CAOV3 cells formed dense spheroids after 4 days of culture that were surrounded by a margin of more loosely arranged cells ( Figure 2 A, left panel).…”

Characterization of glucose metabolism in breast cancer to guide clinical therapy

“…Moreover, overexpression of SDC1 resulted in increased angiogenesis promoters ( 66 ), including FGF2 and VEGF, and the anti-SDC1 antibody 46F2SIP was confirmed to effectively inhibit angiogenesis and induce vascular normalization ( 67 ). It was found that the reduction of SDC1 arrested cells from S phase to G1 phase, slowed cell cycle progression and inhibited cell proliferation ( 68 ). Therefore, SDC1 may be a suitable targeted therapeutic molecule for BRCA patients with various types.…”