Targeting the heparan sulfate proteoglycan/heparanase axis as a novel therapeutic strategy to drive adipogenesis and block tumor growth of dedifferentiated liposarcoma

Abstract

Dedifferentiated liposarcoma (DDLPS) is an aggressive mesenchymal malignancy coexisting with a low grade well-differentiated component. Pathways implicated in liposarcoma growth and dedifferentiation are promoted by heparan sulfate (HS) proteoglycans (HSPG) and their modifying enzymes including heparanase. HSPGs serve as co-receptors enhancing tyrosine kinase signaling and tumor aggressiveness. Targeting these interactions bears promise in attenuating liposarcoma growth. We employed an investigational HS mimetic, the non-anticoagulant heparin CX-01 (dociparstat), to assess its HS competition impact on deregulated adipogenic differentiation and growth of human DDLPS cell lines and patient-derived xenografts (PDXs). Remarkably, CX-01 reduced colony formation and invasive capacities of DDLPS cell lines, inducing cytoskeleton remodeling, lipid accumulation and reactivation of adipogenic program. Mechanistic studies into the anti-DDLPS activity of CX-01 unveiled Syndecan 1 (SDC1)/heparanase system and receptor tyrosine kinase-AKT signaling as targets of cell growth inhibition and induction of differentiation. CX-01 treatment of mice harboring DDLPS PDXs attenuated tumor growth, enhanced lipid content and consistently altered the transcriptome, modulating pathways associated with tumor dedifferentiation (adipogenesis and fatty acid metabolism) and tumor-microenvironment interaction (TGFβ signaling, inflammatory response). In two independent cohorts of DDLPS patients, genes downregulated in CX-01-treated PDXs (SDC1, TIMP1, FN1, COL5A1, and MMP14), were found preeminently expressed in the dedifferentiated, compared to the well-differentiated tumor component and normal fat. This suggests a role for these genes in disease progression. Collectively, this study demonstrates the remarkable potential of HS competition to simultaneously block multiple anti-adipogenic players representing metabolic vulnerabilities, and to promote a differentiated tumor phenotype markedly less aggressive.