Lectin-binding heterogeneity of alphafetoprotein (AFP). An observation in nude mouse xenografts of endodermal sinus tumors and in pediatric surgical patients.

Abstract

We determined by affinity chromatography on concanavalin A-Sepharose the carbohydrate variant patterns of alphafetoprotein in the sera of 15 infants and children with endodermal sinus tumors (five cases), a neonatal mature teratoma (one case), hepatoblastomas (two cases), pancreatic carcinoma (one case), biliary atresia (four cases), neonatal hepatitis (one case) and neonatal hyperbilirubinemia (one case), in the sera from four normal neonates, and in the sera from two kinds of nude mice bearing human endodermal sinus tumors. Sera from patients with endodermal sinus tumors and pancreatic carcinoma were found to contain a relatively high proportion (48.4 +/- 4.5 and 52.6%) of alphafetoprotein which did not bind to concanavalin A. Sera from nude mice with human endodermal sinus tumors contained AFP, 96.2% of which did not bind to concanavalin A. Sera from patients with other lesions (nine cases) and from normal neonates, whose AFPs are all presumed to be of hepatic origin, contained much less (5.9 +/- 3.6%) of the concanavalin A non-binding AFP variant. These results indicate that human AFP has three distinct patterns of reactivity with concanavalin A and that studies in xenograft models may give important information relating to the glycosylation and secretion process of AFP.