Enhanced cytotoxicity and suppression of glucose transport rate by combined treatment of recombinant human tumour necrosis factor-α and hyperthermia on L929 cells

Combined treatment with human recombinant TNF-α (rhTNF-α) and hypothermia at 43 °C arrested the growth of mouse fibrosarcoma L929 cells in vitro. The cytotoxic effect was enhanced in combined treatment compared with that following administration of rhTNF-α or hyperthermia alone. When the cells were subjected to hyperthermia at 43 °C for 3 hours and then incubated with 0.4 ng ml rhTNF-α at 37 °C for 24 hours, a statistically significant 65% decrease in the rate of cellular glucose uptake was observed. This suppressive effect was synergistic in terms of effect achieved by rhTNF-α or hyperthermia individually. Since the growth of tumour cells depends mainly on catabolism of glucose, our findings indicate that one manner by which combined rhTNF-α and hyperthermia treatment inhibits L929 cell growth may be by reducing the supply of glucose to the cells.