PROMOTION OF METASTASES BY TUMOR-NECROSIS-FACTOR IN RATS BEARING DUNNING R3327 MAT-LYLU PROSTATIC-CANCER

We examined the effects of recombinant human tumor necrosis factor (rT NF) on highly metastatic rat prostatic cancer, Dunning R3327 MAT-LyLu, in vivo. It seemed that the inhibition of tumor growth needed more th an 5 X 10(5) units of rTNF and this dose was near the lethal dose. Con cerning the effect of rTNF on metastasis, we found that the metastasis to lung was promoted by 1 X 10(5) units of rTNF and the promotion of metastasis was restricted by indomethacin. Although MAT-LyLu cells wer e producing a significant amount of prostaglandin E2, rTNF did not enh ance the production. We therefore consider that the promotion of metas tasis was not mediated by prostaglandin E2 from MAT-LyLu cells but was mediated by other very complicated conditions. Further studies are ne cessary to resolve the mechanisms.