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

Combined treatment with human recombinant TNF-alpha (rhTNF-alpha) and hyper thermia at 43 degrees C arrested the growth of mouse fibrosarcoma L929 cell s in vitro. The cytotoxic effect was enhanced in combined treatment compare d with that following administration of rhTNF-alpha or hyperthermia alone. When the cells were subjected to hyperthermia at 43 degrees C for 3 hours a nd then incubated with 0.4 ng/ml rhTNF-alpha at 37 degrees C for 24 hours, a statistically significant 65% decrease in the rate of cellular glucose up take was observed. This suppressive effect was synergistic in terms of effe ct achieved by rhTNF-alpha or hyperthermia individually. Since the growth o f tumour cells depends mainly on catabolism of glucose, our findings indica te that one manner by which combined rhTNF-alpha and hyperthermia treatment inhibits L929 cell growth may be by reducing the supply of glucose to the cells. (C) 1999 Elsevier Science Inc.