Action of Hyperthermia on Gene Expression in Friend Erythroleukemia Cells by Dimethyl Sulfoxide or X-Rays

摘要

The effect of heat on gene control and on cell killing by X-rays or dimethyl sulfoxide (DMSO) was studied in cultured Friend erythroleukemia cells (FELC). FELC are very sensitive to heat and X-rays in terms of survival, as measured by the colony-forming assay. Heat inactivation kinetics are similar for FELC and Chinese hamster cells. Thermal enhancement of cell inactivation by irradiation was observed at 42.0 and 45.0deg C, and increased as a function of heating time. The simultaneous application of heat and X-rays had a greater effect in terms of cell inactivation. Dimethyl sulfoxide could induce FELC to synthesize hemoglobin, and hyperthermia could inhibit this response. Likewise, hyperthermia could affect induction of heme synthesis by irradiation. Heating before irradiation enhanced production of heme synthesis, whereas heating after irradiation inhibited induction of heme synthesis. The effects of hyperthermia on the survival and gene induction endpoints were compared. Thus, heat can affect both cell survival and gene induction by irradiation or DMSO. The two endpoints of gene induction and survival (proliferative capacity) responded differently, both quantitatively and qualitatively, to heat and X-rays, implying that different cellular targets are affected for each of these endpoints. (Atomindex citation 13:705435)