Journal article
Time-Temperature Analyses of Cell Killing of Synchronous G1 and S Phase Chinese Hamster Cells in Vitro
Radiation research, Vol.113(2), pp.318-333
02/1988
DOI: 10.2307/3577206
PMID: 3340736
Abstract
Time-temperature analyses of durations of heating required to achieve isosurvival were used to compare hyperthermic cell killing of synchronous Chinese hamster ovary (CHO) cells heated in G1 or S at temperatures of 42 to 45.5°C. G1 populations were obtained by incubation of mitotic cells for 90 min at 37°C. S phase populations were obtained by incubation of mitotic cells for 12 h at 37°C in medium supplemented with 2 μg/ml aphidicolin, a reversible inhibitor of DNA α polymerase; S phase survival was also determined in an aphidicolin-free system by using high specific activity [3 H]thymidine. In both systems, the thermosensitivity was similar and decreased as the cells progressed from early S phase, in agreement with earlier studies (R. A. Read, M. H. Fox, and J. S. Bedford. Radiat. Res. 98, 491-505 (1984)). A comparison of Arrhenius plots of the inverse of durations of heating required to achieve isosurvival for cells heated in G1 or S phase showed similar temperature dependence above 43.5°C, yet the plots for heat-sensitive S phase cells were offset from those for heat-resistant G1 cells by about 1.5°C, i.e., S phase cells respond to 43°C with a rate similar to that observed in G1 cells heated at 44.5°C. Using least-squares regression of the semilog plots, the curves were analyzed either as continually bending curves or as two straight lines with a break at 43.5°C. When the data were analyzed using two straight lines, no significant differences in the slopes of the time-temperature plots of G1 or S phase cells were observed. A quantitative comparison between the two methods of data analysis demonstrated that in both phases the data were better fit with a continuously curving line, rather than two straight lines.
Details
- Title: Subtitle
- Time-Temperature Analyses of Cell Killing of Synchronous G1 and S Phase Chinese Hamster Cells in Vitro
- Creators
- Michael A MackeyWilliam C Dewey
- Resource Type
- Journal article
- Publication Details
- Radiation research, Vol.113(2), pp.318-333
- DOI
- 10.2307/3577206
- PMID
- 3340736
- ISSN
- 0033-7587
- eISSN
- 1938-5404
- Language
- English
- Date published
- 02/1988
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology
- Record Identifier
- 9984064573002771
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