PREVENTION OF BREAST-TUMOR DEVELOPMENT IN-VIVO BY DOWN-REGULATION OF THE P185(NEU) RECEPTOR

Certain strains of transgenic mice that express the rat neu oncogene ( neuT) in mammary epithelial cells develop breast tumours at an average of 44 weeks of age. in this study, intraperitoneal injection of a mon oclonal anti-receptor antibody specific for the rat neuT oncogene prod uct dramatically affected tumour development in these transgenic mice in a dose-dependent manner. A significant proportion (50%) of mice, wh en injected with anti-receptor antibodies, did not develop tumours eve n after 90 weeks of age. The phosphotyrosine levels of the membrane fr action of breast tissues in the anti-receptor antibody-treated mice we re almost completely abolished when a higher dose of antibodies was us ed. This study demonstrates, for the first time, that immunologic mani pulation of an oncogene product can effectively prevent the developmen t of tumours in a rodent transgenic model.