ANTIBODY PENETRATION OF TUMOR GS-7 XENOGRAFTS IN NUDE-MICE - A MODEL FOR MUCINOUS ADENOCARCINOMA OF THE COLON

A new cell line derived from a human adenocarcinoma of the colon, GS-7 , was propagated as a s.c. tumor in nude mice. This tumor histological ly is a mucinous adenocarcinoma (also designated mucoid or colloid) wi th characteristic large mucin pools that are not lined by an epithelia l layer but may contain scattered, randomly distributed cancer cells, Ten to 20% of human colorectal adenocarcinomas are of this histologica l type, but rapidly growing xenografts with this histology have been r arely used experimentally, This tumor, therefore, constitutes a useful model for similar human tumors. The mucin pools contain large amounts of carcinoembryonic antigen and tumor-associated glycoprotein 72, and the cells express epithelial glycoprotein 2 on their surface. The abi lity of antibodies injected i.v. to penetrate this tumor was investiga ted, using both biotinylated and radioiodinated antibodies (Abs). The results demonstrate that Abs can effectively penetrate the mucin pools , and that large amounts of Ab can localize there. This tumor type may have advantages as a target for certain forms of experimental immunot herapy.