Induced thermal resistance in HeLa cells

IN mammalian cells, hyperthermia causes temperature-dependent changes in cell growth parameters1, reduces DNA and protein synthesis rates2 and cell metabolism3, and leads to a loss of proliferative capacity4,5. Harris6 has shown that temperature-resistant pig kidney cells can be obtained after multiple exposures to very high thermal doses (colony-forming ability reduced to 10−5–10−6 of controls). The purpose of our experiments was to determine whether a single hyperthermic treatment (44 °C for 1 h) could induce a state of thermotolerance in cells, and if so, what was the mode of origin of the thermal resistant cells.