ABSTRACT
This chapter describes data from several experimental studies. They include the analysis of interferons (IFN)-γ effects on carcinoembryonic antigen (CEA) expression and shedding using a broad range of human colon carcinoma cell lines, identification of a novel gene product in IFN-γ-treated human gastric carcinoma cells. They also include augmentation of the antitumor effects of an anti-tumor-associated glycoprotein (TAG)-72 radioimmunoconjugate when combined with an IFN-γ-based protocol that up-regulated TAG-72 expression in a human tumor xenograft model. As part of the ongoing development of monoclonal antibody-based strategies for tumor diagnosis and therapy, several experimental lines of investigation have been identified to circumvent some of the limitations of this approach to cancer management. Constitutive CEA expression correlated well with cell differentiation—cells expressing high CEA levels formed well-differentiated tumors, while cells that were either CEA-negative or expressed low amounts of CEA formed poorly differentiated tumors in athymic mice.
