[Synergistic effects of human recombinant TNF and hyperthermia on in vitro cytotoxicity and artificial metastases].

Synergistic effects of hyperthermia on the cytotoxicity of TNF were examined, using L-M cells (mouse tumorigenic fibroblasts) and HEL cells (human embryonic lung cells) as targets. The sensitivity of L-M cells to TNF apparently increased when the culture temperature was raised from 37 degrees C to 38.5 degrees C or 40 degrees C, probably reflecting the increased turnover rate of the TNF-receptor complex. The anti-metastatic effects of a combined regimen of TNF (300U) and whole-body hyperthermia (40 degrees C, 30 min) was also examined in Balb/c mice injected with 1 X 10(6) Meth A F15 cells into a tail vein. No effects of TNF or hyperthermia alone were observed on artificial metastasis, while the combination of TNF and hyperthermia remarkably enhanced the inhibition of metastasis. These studies clearly suggest that combination of TNF with hyperthermia provides a significant synergistic effect against tumor.