Ganglioside GD3 Enhances Adhesion Signals and Augments Malignant Properties of Melanoma Cells by Recruiting Integrins to Glycolipid-enriched Microdomains

Abstract

Ganglioside GD3 is widely expressed in human malignant melanoma cell lines and tumors. Previously, we reported that GD3؉ cells show stronger tyrosine phosphorylation of focal adhesion kinase (FAK), p130Cas , and paxillin when treated with fetal calf serum than GD3؊ cells. In this study, we analyzed the changes in the signals mediated by the interaction between integrins and extracellular matrices (ECM) to clarify how GD3 enhances cell signals in the vicinity of the cell membrane. An adhesion assay with a real time cell electronic sensing system revealed that GD3؉ cells had stronger adhesion to all extracellular matrices examined. In particular, GD3؉ cells attached more strongly to collagen type I and type IV than controls. Correspondingly, they showed stronger tyrosine phosphorylation of FAK and paxillin during adhesion to collagen type I. In the floating pattern of detergent extracts, a high level of integrin ␤1 was found in glycolipid-enriched microdomain (GEM)/rafts in GD3؉ cells before adhesion, whereas a smaller amount of integrin ␤1 was detected in the GEM/rafts of controls. Some phosphorylated forms of FAK as well as total FAK were found in GEM/rafts during cell adhesion only in GD3؉ cells. Another signal consisting of integrin-linked kinase/Akt was also activated during adhesion more strongly in GD3؉ cells than in controls. In double stained GD3؉ cells, GD3 and integrin ␤1 colocalized at the focal adhesion with a punctate pattern. All these results suggested that integrins assembled and formed a cluster in GEM/rafts, leading to the enhanced signaling and malignant properties under GD3 expression.

Membrane sialidase NEU3 is highly expressed in human melanoma cells promoting cell growth with minimal changes in the composition of gangliosides

“…(38,39) Consequently, it has been demonstrated that the melanoma-specific ganglioside GD3 plays crucial roles in increased proliferation, enhanced invasion and cell adhesion in melanoma cells. (25,37) These findings indicate that molecular target therapy can be conducted toward ganglioside GD3 ⁄ GD2 or signaling molecules involved in the enhanced malignant properties of melanoma cells under GD3 expression. (40) NEU3 is a plasma membrane-associated sialidase that was cloned as a ganglioside-specific enzyme.…”

“…(34) Recent progress in the isolation and manipulation of glycosyltransferase cDNA enabled us to investigate the roles of these gangliosides in cancer phenotypes. (35) Since we cloned cDNA of GD3 synthase, (13) we have investigated roles of GD3 synthase in melanomas (25,27,31,36,37) and in small-cell lung carcinomas. (38,39) Consequently, it has been demonstrated that the melanoma-specific ganglioside GD3 plays crucial roles in increased proliferation, enhanced invasion and cell adhesion in melanoma cells.…”

Ganglioside GD3 Enhances Invasiveness of Gliomas by Forming a Complex with Platelet-derived Growth Factor Receptor α and Yes Kinase

“…For example, in human melanoma cells, expression of GD3 up-regulates phosphorylation levels of Akt, p130Cas, FAK, and paxillin after stimulation with fetal calf serum (37). GD3 also enhances adhesion signals by recruiting integrins to GEM/rafts (38). Moreover, GD3 enhances hepatocyte growth factor/Met signals upon cell adhesion to collagen type I (39).…”

Binding of a Sialic Acid-recognizing Lectin Siglec-9 Modulates Adhesion Dynamics of Cancer Cells via Calpain-mediated Protein Degradation

“…FAK is present mainly at the focal adhesion and plays essential roles by interacting with various signaling molecules such as p130Cas, paxillin, and Src family kinases (15). We have investigated the roles of FAK in the enhanced malignant properties such as cell proliferation (16) and cell adhesion to extracellular matrix (17) in malignant melanomas expressing ganglioside GD3. Apoptosis induction of small cell lung cancer cells by anti-ganglioside GD2 monoclonal antibodies via dephosphorylation of FAK was also reported by us (7).…”