Mutation and Inactivation of Cultured Mammalian Cells Exposed to Beams of Accelerated Heavy Ions

Abstract

Inactivation and mutation to thioguanine-resistance of V79 hamster cells were studied after irradiation with accelerated helium, boron or nitrogen ions covering a range of linear energy transfer from 28 to 470 keV micrometers-1. For all radiation qualities a dose-dependent increase in mutant frequency was found for doses giving surviving fractions greater than about 0.20. The effectiveness per unit dose for both inactivation and mutation induction increased with the linear energy transfer of the radiation to a maximum in the range 90-200 keV micrometer-1. However, the maximum mutagenic effectiveness relative to gamma-rays was about two or more times that for inactivation. It is suggested that a proportion of the radiation-induced mutants suffer extensive genetic damage, and that some forms of this damage may be induced with high efficiency by radiations of high linear energy transfer.

Applications of amorphous track models in radiation biology

“…Comparisons of calculation [51] to experiments [43][44][45][46] for HPRT mutation in V79 cells are shown in Fig. 3b.…”

“…In Fig. 3a, calculations with the IGK model are compared to data [43][44][45][46] for V79 inactivation. The parameters used for inactivation of V79 cells are shown where m=3, D 0 =1.8 Gy, σ 0 =43 µm 2 , and a 0 =1.1 µm.…”

“…3b. The data are from Belli et al [43] for protons and helium ions, Thacker et al [44] for B ions, and Kiefer and co-workers [45,46] for other heavy ions. A prediction of the model is that a depletion of the mutation cross-section occurs at energies where the inactivation cross-section is a maximum.…”

G2 chromatid damage and repair kinetics in normal human fibroblast cells exposed to low- or high-LET radiation

“…However, some types of damage may confer a proliferative advantage on cells leading to oncogenic cell transformation and carcinogenesis. Indeed, the frequencies of transformation and mutations induced by high-LET radiation have been shown to be greater than those induced by similar doses of low-LET radiation (Thacker et al, 1979;Yang et al, 1985;Suzuki et al, 1989;Tsuboi et al, 1992), suggesting that carcinogenesis is the most important biological effect caused by exposure to high-LET radiation.…”

Development of a low-energy particle irradiation facility for the study of the biological effectiveness of the ion track end

“…track structure) [5]. While the linear energy transfer (LET) is a good indicator of the rate of energy deposition, at extremely high and inhomogeneous LET regions it does not predict biological effects with a simple relationship [6][7][8]. Radiotherapy studies investigating the biological response of different cell lines to different types of charged particles have focused mainly on the cell killing effect on tumour cells in the so-called Spread Out Bragg Peak (SOBP) [9][10][11].…”