MODULATION OF TUMOR IMMUNOGENICITY OF RAT GLIOMA-CELLS BY S-MYC EXPRESSION - ERADICATION OF RAT GLIOMAS IN-VIVO

The Myc family proteins represented by c-Myc are thought to play a cru cial role in cellular proliferation, differentiation, transformation, and apoptosis. In this study, we demonstrated the novel role for a Myc family protein in elicitation of immunogenic phenotypes in tumor cell s. Injection of rat 9L or C6 glioma cells, together with the s-myc gen e linked to the cytomegalovirus promoter, completely prevented formati on of both brain tumors and s.c. tumors derived from the parental glio ma cells. However, introduction of the s-myc gene had no inhibitory ef fect on development of B104-derived neuroblastoma. In addition, unlike the s-myc gene, injection of the c-myc or wild type p53 (wt-p53) gene together with glioma cells did not modulate the tumor immunogenicity and resulted in formation of gliomas in the animals. These findings su ggest that s-Myc expression may stimulate the presentation of a tumor antigen common to 9L and C6 cells to T lymphocytes and augment the act ivity of the host immune system, resulting in prevention of glioma for mation in vivo. This success in tumor eradication indicates the possib ility of application of the s-myc gene for gene therapy of human brain tumors.