Suppression of CD44 expression decreases migration and invasion of human glioma cells

Abstract

A unique characteristic of malignant gliomas is their invasive behaviour into surrounding normal brain tissue, making glioma-development a life-threatening disease despite today's advanced multimodality treatment. We have been exploring a molecular targeting strategy against malignant gliomas. By immunising mice with a human glioma cell line SK-MG-4 we obtained a monoclonal antibody (MAb), G-22, that reacts specifically with most human glioma cell lines (Wakabayashi et af., 1988). The antibody has been utilised for various clinical applications, including target imaging (Yoshida et af., 1990) and cerebrospinal-fluid diagnosis of human gliomas (Wakabayashi et al., 1988). We have purified a 85-kDa protein as the antigen of G-22 by imrnuno-affinity chromatography. The sequence of total 54 amino-acid-residues was identical to the portion 55-108 of human CD44. We concluded that the smallest spliced form (85 kDa) of CD44 is strongly expressed in glioma cells (Okada et al., 1994).The CD44 (Okada et al., 1994). In addition, the isoform of CD44 expressed on glioma cells was confirmed to be the smallest spliced form (Li etal., 1993) with a higher affinity for hyaluronic acid than other isoforms. Indeed, the human glioblastoma cell line U-373 MG was found to exhibit binding to hyaluronic acid via CD44 (Asher and Bignami, 1992). This 85-kDa cell-surface glycoprotein has been suggested to be closely associated with actin filaments through its cytoplasmic domain, consistent with the role of CD44H in cell motility and migration (Lacy and Underhill, 1987). Generally the biological attributes leading to cell invasion include adhesion to tissue structures such as ECMs, motility to generate migration, and the ability to influence the local environment so as to create space into which to move (Liotta and Stetler-Stevenson, 1991) by the secretion of proteases (Rao et al., 1993). Considering that hyaluronic acid is a major ECM component in human brain and that astrocytes have been found to produce hyaluronic acid (Asher and Bignami, 1991), high expression of CD44H on glioma cells may be expected to play a critical role in their migration and invasive behaviour.In the present study, we established a CD44-anti-senseexpression cell line named U-251A1 and investigated the migratory response of human glioma cell lines to hyaluronicacid-coated substrates in relation to CD44 expression in vitro. In addition, U-251A1 and its sense-transfected control cell U-251S1 were injected into brains of nude mice to observe differences in growth and invasion patterns in vivo. Our findings suggest that both migratory and invasive properties of human glioma cells depend upon the level of expression of CD44H. MATERIAL AND METHODS Cell finesHuman glioma cell lines GL 9 and GL 11 were derived from glioma patients and established at the Tissue Culture Laboratories of Kamo Hospital (Toyota, Japan) (Wakabayashi et aL, 1988). All cell lines used here were maintained in Dulbecco's modified Eagle's medium (DMEM, GIBCO, Paisley, UK) supplemented with 10% FCS, st...

Autocrine semaphorin 3A signaling promotes glioblastoma dispersal

“…Using FITC-5C2, the transwell migration of A172 cells decreased by 36% with FALI ( Figure 2d). This was comparable to our positive-control CD44 (42%), a cell surface protein that promotes GBM cell migration (Okada et al, 1996). FALI with FITC-IgG, a nonspecific antibody control, did not significantly affect migration.…”

Epidermal growth factor receptor-transfected bone marrow stromal cells exhibit enhanced migratory response and therapeutic potential against murine brain tumors

“…28 Importantly, Fas expression was also undetectable on bulk EGFR-MSCs, excluding the possibility of the undetectable Fas expression on the 2G3 clone being a unique event associated with the cloning (data now shown). CD44, which has been known to mediate cell migration in various cell types including gliomas, 29,30 expressed on both primary and EGFRtransfected MSCs (Table 1). These data indicate that EGFR-MSC were a homogenous cell population devoid of hematopoietic cells.…”

CD44 cleavage induced by a membrane-associated metalloprotease plays a critical role in tumor cell migration

“…CD44, as the principal cell surface receptor for hyaluronic acid (Aruo et al, 1990), has been shown to play a critical role in regulation of tumor cell migration (Thomas et al, 1992;Okada et al, 1996;Goebeler et al, 1996). The cytoplasmic domain of CD44 interacts with the ezrin/radixin/moesin (ERM) family which are thought to function as cross-linking protein between plasma membranes and actin ®laments (Tsukita et al, 1994).…”

“…CD44 has been reported to be a matrix adhesion receptor for HA (Aruo et al, 1990) and to be associated with cell migration (Thomas et al, 1992;Okada et al, 1996;Goebeler et al, 1996). To explore the biological signi®cance of CD44 cleavage, we next sought to examine the role of CD44 cleavage in cancer cell migration on HA.…”

“…These regulation systems involved in CD44-HA interactions have been considered to give CD44 the wide diversity of its biological functions, including tumor growth, invasion and metastasis (GuÈ nthert et al, 1991;Sy et al, 1991;Bartolazzi et al, 1994Bartolazzi et al, , 1995Takahashi et al, 1995;Sheng et al, 1997). Although CD44 is known to take part in cancer cell migration through recognition of HA (Thomas et al, 1992;Okada et al, 1996;Goebeler et al, 1996), the ®ndings raise the question as to how the CD44 function is regulated during the migration process. Cancer cell migration requires a dynamic interaction between the cell and ECM, including not only rapid rates of adhesive formation but also dissolution to allow a cell to progress over substratums (Albelda, 1993;Lauffen-burger and Horwitz, 1996).…”