Experimental studies on specific immunotherapy in nasopharyngeal carcinoma (NPC).

The IgG fraction was isolated from the serum of patients with nasopharyngeal carcinoma and conjugated with ferritin or horseradish peroxidase. The conjugate was injected i.v. in nude mice on which transplanted nasopharyngeal carcinomas were growing. Electron-microscopic examination of the tissue revealed localization of the antibodies of the IgG class (VCA, EBNA) exclusively within the tumor cell association of NPC transplants, mainly on the outer cell membrane, on mitochondria of the cytoplasm, and on the membranes of the endoplasmic reticulum. The possibility of conjugating such EBV-specific and thus NPC tumor cell-related antibodies with cytostatically active substances so as to convey the cytostatics directly to the tumor cells is discussed.