Minisatellite and Hprt mutations in V79 cells irradiated with helium ions and gamma rays

作者：Cherubini R; Canova S; Favaretto S; Bruna V; Battivelli P; Celotti L^*

来源：International Journal of Radiation Biology, 2002, 78(9): 791-797.

DOI：10.1080/09553000210146572

Purpose: To evaluate and compare cytotoxic and mutational effects of graded doses of x-rays and He-4(++) ions at different LET values (nominally 80 and 123 keV/mum) in V79 cells. 4
Materials and methods: He-4(++) ion beams at 80 and 123 keV/mum were supplied by the 7 MV Van de Graaff CN accelerator of the INFN-LNL in the dose range 0.3-24 Gy at a dose rate of I Gy/min. Gamma-irradiation was performed by the Co-60 'gamma beam' of CNR-FRAE (at the INFN-LNL) in the dose range 0.5-6.0 Gy at a dose rate of I Gy/min. After irradiation, the cells were seeded to measure surviving fraction (SF) and mutant frequency (MF) at the Hprt locus on the basis of 6-thioguanine resistance. Alterations at minisatellite sequences (MS) of clones derived from irradiated and unirradiated cells were detected by Southern blot analysis using a multi-locus probe (DNA fingerprinting).
Results: Survival data from He-4(++) irradiation at two LET values (80 and 123 keV/mum) yielded similar results: alpha = (1.08 +/- 0.04)/Gy and (0.90 +/- 0.03)/Gy, respectively. The best fit for mutant induction at the Hprt locus after 80 kcV/mum He-4(++) was a linear function of the dose in the close-interval 0-1.5Gy: alpha = (47.77 +/- 16.01) x 10(-6) /Gy. The best fit for mutant induction after 123 keV/mum He-4(++) in the dose-interval 0-1.2 Gy was a linear-quadratic function: alpha = (86.01 +/- 13.80) x 10(-6)/Gy; beta = (42.87 +/- 11 03) x 10(-6) /Gy(2). For gamma-irradiation, the best fit of Hprt Mutation data gave: alpha = (4.14 +/- 2.67) x 10(-6)/Gy; beta = (0 63 +/- 0.86) x 10(-6) /Gy(2). The best fitting of MS alteration data with linear-quadratic or linear relationships gave: for gamma-rays, alpha = 0.56 mutants/Gy and beta = 0.52 mutants/Gy(2); for 80 keV/mum He-4(++), alpha = 3.70 mutants/Gy and beta = 9.00 mutants/Gy(2); for 123 kcV\mum He-4(++), alpha = 4.36 mutants/Gy.
Conclusions: The results reported here confirmed the higher cytotoxic and mutagenic effects of helium ions in comparison with gamma-irradiation and the ability of DNA fingerprint analysis to investigate DNA damage induced by different ionizing radiations. The results of the mutagenic effects measured by the two tests are in agreement.

• 出版日期2002-9