Syndecan-1-Dependent Regulation of Heparanase Affects Invasiveness, Stem Cell Properties, and Therapeutic Resistance of Caco2 Colon Cancer Cells

Sampath Kumar Katakam; Paride Pelucchi; Cinzia Cocola; Rolland Reinbold; Israel Vlodavsky; Burkhard Greve; Martin Götte

doi:10.3389/fonc.2020.00774

Syndecan-1-Dependent Regulation of Heparanase Affects Invasiveness, Stem Cell Properties, and Therapeutic Resistance of Caco2 Colon Cancer Cells

Front Oncol. 2020 May 14:10:774. doi: 10.3389/fonc.2020.00774. eCollection 2020.

Authors

Sampath Kumar Katakam¹, Paride Pelucchi², Cinzia Cocola², Rolland Reinbold², Israel Vlodavsky³, Burkhard Greve⁴, Martin Götte¹

Affiliations

¹ Department of Gynecology and Obstetrics, Münster University Hospital, Münster, Germany.
² Institute of Biomedical Technologies, National Research Council, Milan, Italy.
³ The Rappaport Faculty of Medicine, Technion Integrated Cancer Center (TICC), Haifa, Israel.
⁴ Department of Radiotherapy-Radiooncology, Münster University Hospital, Münster, Germany.

Abstract

The heparan sulfate proteoglycan Syndecan-1 binds cytokines, morphogens and extracellular matrix components, regulating cancer stem cell properties and invasiveness. Syndecan-1 is modulated by the heparan sulfate-degrading enzyme heparanase, but the underlying regulatory mechanisms are only poorly understood. In colon cancer pathogenesis, complex changes occur in the expression pattern of Syndecan-1 and heparanase during progression from well-differentiated to undifferentiated tumors. Loss of Syndecan-1 and increased expression of heparanase are associated with a change in phenotypic plasticity and an increase in invasiveness, metastasis and dedifferentiation. Here we investigated the regulatory and functional interplay of Syndecan-1 and heparanase employing siRNA-mediated silencing and plasmid-based overexpression approaches in the human colon cancer cell line Caco2. Heparanase expression and activity were upregulated in Syndecan-1 depleted cells. This increase was linked to an upregulation of the transcription factor Egr1, which regulates heparanase at the promoter level. Inhibitor experiments demonstrated an impact of focal adhesion kinase, Wnt and ROCK-dependent signaling on this process. siRNA-depletion of Syndecan-1, and upregulation of heparanase increased the colon cancer stem cell phenotype based on sphere formation assays and phenotypic marker analysis (Side-population, NANOG, KLF4, NOTCH, Wnt, and TCF4 expression). Syndecan-1 depletion increased invasiveness of Caco2 cells in vitro in a heparanase-dependent manner. Finally, upregulated expression of heparanase resulted in increased resistance to radiotherapy, whereas high expression of enzymatically inactive heparanase promoted chemoresistance to paclitaxel and cisplatin. Our findings provide a new avenue to target a stemness-associated signaling axis as a therapeutic strategy to reduce metastatic spread and cancer recurrence.

Keywords: cancer stem cells; colon cancer; heparan sulfate; heparanase; proteoglycan; syndecan.