Study of irradiation effects on cytokine secretion from retrovirally-transduced tumor cells: a model for tumor vaccination.

We have examined the effects of irradiation on the cytokine secretion from genetically modified human esophageal and gastric carcinomas. Both cell lines were transduced retrovirally to secrete interleukin-2, interleukin-6 and granulocyte-macrophage colony-stimulating factor, respectively. The metabolism of all the transduced cells was partially inhibited by 6 Gy, and greatly inhibited by 20 Gy irradiation. Cytokine productions, however, was not affected by 6 Gy in many cases, and continued to be detected even after 60 Gy irradiation. The analysis of the dose and time of irradiation in each cytokine producer is useful for the designing of tumor vaccine using cytokine gene transfer.