Syndecan-2 Affects the Basal and Chemotherapy-Induced Apoptosis in Osteosarcoma

Abstract

Syndecans are transmembrane heparan sulfate proteoglycans controlling cell adhesion, migration, and proliferation. We previously showed that syndecan-2 is involved in the control of apoptosis in cultured osteosarcoma cells. These data led us to the hypothesis that syndecan-2 may play a role in the apoptotic signaling in bone tumors. We immunohistochemically analyzed tissue sections from biopsies from 21 patients with well-characterized osteosarcoma. These tissues expressed low levels of syndecan-2 compared with osteoblasts and osteocytes in normal bone. Cultured human osteosarcoma cells also produced lower mRNA levels of syndecan-2 than normal osteoblastic cells. Moreover, the presence of syndecan-2 correlated with spontaneous apoptosis in osteosarcoma tissues as assessed by detection of DNA fragmentation in situ. Overexpression of syndecan-2 resulted in decreased number of migrating and invading U2OS osteosarcoma cells in Matrigel. In addition, overexpression of syndecan-2 sensitized human osteosarcoma cells to chemotherapy-induced apoptosis, increasing the response to methotrexate, doxorubicin, and cisplatin. Consistently, knockdown of the proteoglycan using stable transfection with a plasmid coding small interfering RNA resulted in inhibition of chemotherapy-induced apoptosis. Analysis of syndecan-2 expression both in biopsies and in corresponding postchemotherapy-resected tumors, as well as in cells treated with methotrexate or doxorubicin, showed that the cytotoxic action of chemotherapy can be associated with an increase in syndecan-2. These results provide support for a tumor-suppressor function for syndecan-2 and suggest that dysregulation of apoptosis may be related to abnormal syndecan-2 expression or induction in osteosarcoma. Moreover, our data identify syndecan-2 as a new factor mediating the antioncogenic effect of chemotherapeutic drugs. [Cancer Res 2007;67(8):3708-15]

The Casitas B Lineage Lymphoma (Cbl) Mutant G306E Enhances Osteogenic Differentiation in Human Mesenchymal Stromal Cells in Part by Decreased Cbl-mediated Platelet-derived Growth Factor Receptor α and Fibroblast Growth Factor Receptor 2 Ubiquitination

“…F/Stro-1ϩ or primary hMSCs were transduced at 50% confluence with lentiviral particles in the presence of Polybrene (10 g/ml or 5 g/ml, respectively) for 48 h. Lentiviral transduction efficacy was evaluated by GFP level under fluorescence microscopy (36). Human shCbl particles were purchased from CliniSciences (Montrouge, France).…”

Targeting the E3 ubiquitin casitas B-lineage lymphoma decreases osteosarcoma cell growth and survival and reduces tumorigenesis

“…The human Cbl complete sequence was amplified by PCR using 5 0 -CCCTCGAGCGGCCACCATGGATTACAAGGATGACGACGATAAG-TGAGCCGG-CAACGTGAAGAAGAGCTCT-3 0 and 5 0 -CGGGGTA-CCCTAGGTAGCTACATG-GGCAGGAGA-3 0 primers, then cloned into the lentiviral HIV-1-derived TRIP vector (34) between the Xho1-Kpn1 sites. Production of virion particles containing the TRIP-Cbl or the empty vector TRIP-(EV) and lentiviral transduction were performed as described.…”

“…Production of virion particles containing the TRIP-Cbl or the empty vector TRIP-(EV) and lentiviral transduction were performed as described. (34) The pBK plasmid containing the human G306ECbl complete sequence that abolishes the binding ability of Cbl phosphotyrosine-binding domain (35) was prepared as described. (32) Human sh-Cbl particles were from Clinisciences (Montrouge, France).…”

Microarray analysis identifies distinct gene expression profiles associated with histological subtype in human osteosarcoma

“…Another component that modulates proliferation, cell adhesion, and migration is Syndecan-2. The Syndecans are cell surface heparan sulphate proteoglycans that can induce apoptosis [23] and sensitise osteosarcoma cells to the cytototoxic effect of chemotherapeutics [24]. Furthermore, in our setting, the expression level of fibroblast growth factor receptor 2 (FGFR2) was significantly different in both osteosarcoma subgroups.…”