Human neuroectoderm-derived cell line secretes fibronectin that shares the HNK-1/10C5 carbohydrate epitope with neural cell adhesion molecules.
A human malignant melanoma cell line, Melur, secretes several glycoproteins that contain a unique carbohydrate epitope shared by neural cell adhesion molecules and recognized by the monoclonal antibodies HNK-1, L2, and 10C5. In this report, we present evidence that one of the major melanoma glycoproteins containing the HNK-1/10C5 epitope is the cell adhesion molecule, fibronectin, or a fibronectin-like molecule. Melanoma-derived fibronectin was isolated from serum-free conditioned medium by gelatin-Sepharose affinity adsorption and shown to react with monoclonal antibodies HNK-1 and 10C5 in Western blot analysis. HNK-1-containing fibronectin was purified on a gelatin-Sepharose column followed by an affinity column using a monoclonal antibody against the HNK-1 carbohydrate. The purified HNK-1-fibronectin then could be incorporated into the extracellular matrix of hamster fibroblasts in vitro, and such a matrix was detectable using the HNK-1 monoclonal antibody in an immunofluorescence assay. Of the seven neuroectoderm-derived tumor cell lines tested, only the Melur melanoma cell secreted fibronectin containing the HNK-1 carbohydrate. Identification of human neuroectoderm-derived fibronectin as a potential carrier of the HNK-1 carbohydrate suggests a new role for fibronectin in neural development and regeneration, and represents a new model for studying the function of this carbohydrate domain in neural cell adhesion.
Department of Immunology, Research Institute of Scripps Clinic, La Jolla, California.
J R
JR
Harper
S K
SK
Perry
R M
RM
Davis
D M
DM
Laufer
D000943:Antigens, Differentiation / Q000032:analysis*; D018959:CD57 Antigens; D002241:Carbohydrates / Q000276:immunology*; D015816:Cell Adhesion Molecules, Neuronal / Q000276:immunology* / Q000378:metabolism; D000939:Epitopes; D005109:Extracellular Matrix / Q000378:metabolism; D005353:Fibronectins / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008545:Melanoma / Q000378:metabolism*; D013329:Structure-Activity Relationship; D019063:Tenascin; D014407:Tumor Cells, Cultured
D000943:Antigens, Differentiation; D018959:CD57 Antigens; D002241:Carbohydrates; D015816:Cell Adhesion Molecules, Neuronal; D000939:Epitopes; D005353:Fibronectins; D019063:Tenascin