Fibronectin from human germ-cell tumors resembles amniotic fluid fibronectin

Abstract

Three human germ‐cell tumors established as xeno‐grafts in immunosuppressed mice were shown to produce fibronectin. Immunoperoxidase tissue staining with a specific antiserum revealed human fibronectin in some tumor cells. The cyst fluid which accumulated in the tumors contained human fibronectin as shown by a species‐specific radioimmunoassay. Human fibronectin was isolated from two of the tumor fluids and compared to previously characterized fibronectins. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis and gel electrofocusing showed that the germ‐cell fibronectins resembled amniotic fluid fibronectin with regard to subunit molecular weight and isoelectric point. The distinct features of the amniotic fluid and germ‐cell tumor fibronectin suggest that such fibronectins may provide new oncodevelopmental markers.