Radiation-induced adaptive response for protection against micronucleus formation and neoplastic transformation in C3H 10T1/2 mouse embryo cells

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Radiation Research

DOI:https://doi.org/10.2307/3578755· OSTI ID:56761

Azzam, E I ^[1]; Raaphorst, G P ^[2]; Mitchel, R E.J. ^[1]

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1. Chalk River Labs., Ontario (Canada)
2. Univ. of Ottawa (Canada)

We have monitored the end points of cellular survival, micronucleus formation and neoplastic transformation frequency to assess adaptation to ionizing radiation in the C3H 10T1/2 mouse embryo cell system. Plateau-phase cells were pre-exposed to an adapting dose of 0.1 to 1.5 Gy low-dose-rate {gamma} radiation 3.5 h prior to an acute challenge dose of 4 Gy. No adapting dose improved clonogenic survival detectably, whether the cells were plated immediately after the acute exposure or held in plateau phase for 3.5 h before plating. However, all chronic adapting doses resulted in both a reduction of micronucleus frequency in binucleate cells and about a twofold reduction in neoplastic transformation frequency per viable cell when cells were subsequently exposed to the 4-Gy challenge dose. Our data suggest that a low-dose-rate pre-exposure to ionizing radiation induces an adaptive response in C3H 10T1/2 cells, and that this response enhances DNA double-strand break repair when cells are subsequently exposed to a second radiation dose. This enhanced repair appears to be error-free since these adapted cells are also less susceptible to radiation-induced neoplastic transformation. 10 refs., 2 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 56761
• Report Number(s): CONF-9305202--
• Journal Information: Radiation Research, Journal Name: Radiation Research Journal Issue: 1 Vol. 138; ISSN 0033-7587; ISSN RAREAE
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ACUTE EXPOSURE
ANIMAL CELLS
BIOLOGICAL ADAPTATION
BIOLOGICAL RADIATION EFFECTS
DNA
DOSE-RESPONSE RELATIONSHIPS
GAMMA RADIATION
IONIZING RADIATIONS
RADIOSENSITIVITY
THRESHOLD DOSE