Thermotolerance in human cells of normal and neoplastic origin

Single cell survival, production of heat shock proteins (HSP) and endogenous levels of glutathione (GSH) were used to monitor the induction of thermotolerance in human cells of normal and neoplastic origin. Carcinoma cells derived from lung and colon were heated in vitro at 430C and 450C for periods of time paralleling treatments used clinically. Primary explants of HUVEC (Human Umbilical Vein Endothelial Cells) and an established human fibroblast line (AG1522) were used as a normal tissue model. Heating at 430 caused the development of heat resistance during a heating exposure, whereas 20 minutes at 450 induced maximal heat resistance state 4 to 6 hours after a priming heat dose. Cells that were given a heat shock were simultaneously exposed to various antineoplastic agents to see if combined modality treatment altered the induction of HSP. The purpose of this study was to determine if a differential effect in the development of thermotolerance could be seen in cells of normal and neoplastic origin