Hyaluronan Cell Surface Binding Is Induced by Type I Collagen and Regulated by Caveolae in Glioma Cells

Abstract

Hyaluronan (HA) is a component of the brain extracellular matrix environment that is synthesized and secreted by glioma cells. The primary cell surface receptor for HA is CD44, a membrane glycoprotein that is functionally regulated by a membrane type 1 matrix metalloproteinase (MT1-MMP). Both CD44 and MT1-MMP are partially located in Triton X-100-insoluble domains, but no functional link has yet been established between them. In the present study, we studied the regulation of HA cell surface binding in U-87 glioma cells. We show that an MMP-dependent mechanism regulates the intrinsic cell surface binding of HA as ilomastat, a broad MMP inhibitor, increased HA binding to glioma cells. HA binding was also rapidly and specifically up-regulated by 3-fold by type I collagen in U-87 cells, which also induced a significant morphological reorganization associated with the activation of a latent form of MMP-2 through a MT1-MMP-mediated mechanism. Interestingly, caveolae depletion with a cell surface cholesteroldepleting agent ␤-cyclodextrin triggered an additional increase (9-fold) in the binding of HA, in synergy with type I collagen. On the other hand, HA cell surface binding was diminished by the MEK inhibitor PD98059 and by the overexpression of a recombinant, wild type MT1-MMP, whereas its cytoplasmic-deleted form had no effect. Taken together, our results suggest that MT1-MMP regulates, through its cytoplasmic domain, the cell surface functions of CD44 in a collagen-rich pericellular environment. Additionally, we describe a new molecular mechanism regulating the invasive potential of glioma cells involving a MT1-MMP/CD44/caveolin interaction, which could represent a potential target for anti-cancer therapies.The principal molecules that have been identified in the normal brain extracellular matrix (ECM) 1 are hyaluronan (HA; also known as hyaluronic acid, hyaluronate) and chondroitin sulfate (1, 2). HA is an important glycosaminoglycan constituent believed to be implicated in angiogenesis, the formation of new blood vessels from preexisting vasculature. Although the serum level of HA is already used as an indicator of progressive malignant disease (3), its effects on in vivo angiogenesis and endothelial cell (EC) function are complex and have been reported to depend on HA concentration and molecular size (4, 5). Accordingly, whereas high molecular weight HA was shown to inhibit EC functions (6), low molecular weight HA stimulated EC proliferation, tubulogenesis (6, 7), and neovascularization (8). Moreover, small HA polymers efficiently regulated CD44 cell surface functional expression and promoted tumor cell migration (9). Astrocytic tumors of the central nervous system express CD44 among other cell adhesion receptors of the integrin or immunoglobulin superfamily. Although HA is the principal ligand of CD44, other CD44 ligands include the ECM components collagen, fibronectin, laminin, and chondroitin sulfate, whereas mucosal addressin, serglycin, osteopontin, and the class II invariant chain represent ECM-unrelat...

MT1-MMP Down-regulates the Glucose 6-Phosphate Transporter Expression in Marrow Stromal Cells

“…This exciting new role for G6PT in regulating cell mobilization may also affect cell proliferation, cell cycle division, ECM degradation, and response to growth factors. The latter events have, interestingly, also been shown to involve MT1-MMP functions such as in cell migration (46) and in ERK and in RhoA/ROK signaling (14,15,47). More recently, we have revealed several of these MT1-MMP roles in regulating the angiogenic and chemotactic properties of BMSC in response to hypoxia (36) and to brain tumor-derived U-87 glioma cells in vitro and in vivo (48).…”

“…Recently, we highlighted functional cross-talk between the membrane type-1 MMP (MT1-MMP) and the S1P receptor EDG-1-mediated signaling in BMSC chemotaxis (13). Interestingly, aside from its classical role in ECM proteolysis, MT1-MMP is also involved in transducing crucial intracellular signaling that may control several processes related to BMSC mobilization and cell survival (13)(14)(15)(16).Given that impaired chemotaxis was recently observed in bone marrow cells isolated from a microsomal glucose 6-phos-* This work was supported by a grant of the Natural Sciences and EngineeringResearch Council of Canada (NSERC) (to B. A.).…”

Tenascin-C Stimulates Glioma Cell Invasion through Matrix Metalloproteinase-12

“…To this end, we have used a collagen I gel because collagen I is a component of the ECM that glioma cells encounter in vivo (10,11,13,14). In addition, glioma cells and additional ECM molecules can be embedded within the collagen I matrix for further studies.…”

“…In malignant gliomas, many ECM components are overexpressed both in the tumor stroma and at the advancing edge of the tumor within brain parenchyma. These ECM molecules include vitronectin, collagen I, collagen IV, osteopontin, tenascin-C, secreted protein acidic and rich in cysteine, and brain enriched hyaluronan binding (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21). Glioma invasion is thought to occur along ECM protein-containing structures, such as along tracts of myelinated fibers (22)(23)(24).…”

Intracellular processing and activation of membrane type 1 matrix metalloprotease depends on its partitioning into lipid domains

“…MT1-MMP has also been found to be partially located in detergent-resistant membrane fractions (DRM) (Annabi et al, 2001). Recently, new results have been published defining the role of DRM in MT1-MMP/CD44/caveolin interaction and hyaluronan cell surface binding (Annabi et al, 2004). Hence, MT1-MMP membrane partitioning could represent a mechanism for the regulation of its activities.…”