Characterization and Radiation Response of a Heat-Resistant Variant of V79 Cells

• Published in: Radiation research 1983-01, Vol.93 (1), p.51-61
• Main Authors: Campbell, Shelagh D., Kruuv, Jack, Lepock, James R.
• Format: Article
• Language: English
• Subjects: Animals; Cell Line; Cell lines; Cell Survival - radiation effects; CHO cells; Cricetinae; Cricetulus; DNA Repair; Doubling time; Flasks; Growth; Heat tolerance; HeLa cells; Hot Temperature; Hyperthermia; Kidney cells; Lung; Mutation; Radiation damage; Radiation tolerance; Space life sciences; Time Factors
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3575943

A thermoresistant variant of the established cell line V79-S171-W1 was isolated after treatment with nitrosoguanidine and repeated heat treatments at 42.6 to 43°C, and showed an enhanced ability to survive at 42.6, 43.5, and 44.5°C. The rates of inactivation of the normal and heat-resistant lines differed by approximately a factor of 2 over this temperature range. This level of thermoresistance was stable for the first 80 doublings, but was lost by 120 doublings. This may have been due to a reversion to the normal V79 line since there was no continuous selection pressure and the thermoresistant variant, which was designated at HR7, had a longer average doubling time. Transient thermotolerance was induced in both the V79 and HR7 cells by a 10-min exposure to 44.5°C. After 3 hr incubation at 37°C, both cell lines had an identical sensitivity to further exposure to 44.5°C. Thus the long-term thermoresistance of the HR7 cells may be due to a permanent induction of a low level of thermotolerance. The (ionizing) radiation survival curves and the ability to repair sublethal radiation damage were identical for the thermoresistant variant and the parent cell line.