ANTITUMOR EFFECT INDUCED BY THE EXPRESSION OF GRANULOCYTE MACROPHAGE-COLONY-STIMULATING FACTOR GENE IN MURINE COLON-CARCINOMA CELLS

Murine colon carcinoma cells which secrete several kinds of cytokine a fter retroviral transduction with corresponding genes, were examined f or their antitumor effects in syngeneic mice. The mice inoculated with granulocyte macrophage-colony stimulating factor (GM-CSF) producer ce lls showed not only prolonged survival but also reduced tumorigenicity . The antitumor effect caused by the expression of interleukin-4 was l ess than that of GM-CSF, and interleukin-6 producer cells did not show any effects on the survival of the host animals. Histological examina tion of the GM-CSF-producing tumor revealed predominant infiltration o f neutrophils and necrotic change of the tumor. The present study indi cates the feasibility of cancer gene therapy with the expression of GM -CSF gene in tumor cells.