Estimation of the initial slope of the cell survival curve after irradiation from micronucleus frequency in cytokinesis-blocked cells
- Kyoto Univ. Research Reactor Institute, Osaka (Japan)
We have already reported that the {alpha}/{beta} ratio of the cell survival curve could be estimated from the micronucleus frequency in cytokinesis-blocked cells treated with cytochalasin-B after irradiation. In this paper, we investigate the direct relationship between the {alpha} value and the appearance of micronuclei. Cells of the SCCVII, RIF-1, EMT6, V-79, CHO, HeLa and human esophageal cancer cell lines were used for the study. Low-dose-rate irradiation was used to determine the {alpha} component of the relationship between dose and micronucleus frequency according to the linear-quadratic (LQ) model. A reduction of the dose rate from 3.09 to 0.0142 Gy/min correspondingly decreased the micronucleus frequency; however, the fraction of binucleate cells without micronuclei was not affected in SCCVII and RIF-1 cells. When this fraction was defined as the normal nuclear division fraction, it decreased exponentially as a function of radiation dose. Then dose vs normal nuclear division fraction (NNDF) was fitted as follows: -In NNDF = aD + C, where D is radiation dose in grays and C is constant. The slope of the dose vs normal nuclear division fraction was not affected by dose rate. The correlation was also explored between the slope (a) and the {alpha} value of the cell survival curve determined by the colony formation assay in cells of eight cell lines. These two values showed extremely high agreement: {alpha} = 1.01a + 0.00795 (r = 0.99, P < 0.01). This assay was applied to estimate the {alpha} value of the cell survival curve of human esophageal cancer cell lines established from surgical specimens. 13 refs., 5 figs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 56778
- Report Number(s):
- CONF-9305202-; ISSN 0033-7587; TRN: 95:012957
- Journal Information:
- Radiation Research, Vol. 138, Issue 1; Conference: Molecular, cellular, and genetic basis of radiosensitivity at low doses: a case of induced repair, Whistler (Canada), 9-13 May 1993; Other Information: PBD: Apr 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of in vivo exposure to iodine-131 on the frequency and persistence of micronuclei in human lymphocytes
Studies of Bystander Effects in 3-D Tissue Systems Using a Low-LET Microbeam