Abstract
Previous work has demonstrated that radiation exposure modulates the expression of a series of genes, including those that encode cytoskeletal elements. The experiments reported here were designed to examine (1) the comparative effects of neutrons administered at high versus low dose-rates, (2) the comparative effects of neutrons on cycling versus resting cells and (3) the comparative effects of neutrons versus γrays on β and γactin mRNA accumulation in Syrian hamster embryo (SHE) cells 1 and 3 h post-irradiation. JANUS fission-spectrum neutrons from Argonne National Laboratory's JANUS reactor administered at high (12 cGy/min) dose-rates had little effect on resting cells, but at very low dose-rates (0.1 cGy/min) had a repressive effect on γactin mRNA accumulation. Increased accumulation of βactin mRNA was detected following the exposure of cells to neutrons administered at high dose-rates, but repression of βactin mRNA was observed when neutrons were administered at low dose-rates. Cycling cells (unexposed and neutron irradiated) in all cases expressed higher levels of all actin-specific mRNAs than resting cells; βactin mRNA (but not γactin mRNA) was induced to a greater extent in cycling cells than in resting cells during the first hour following neutron exposure. In resting cells, however, low dose-rate neutrons were more effective than low dose-rate γrays at repressing both γ and βactin mRNA accumulation. These results demonstrate the differential effects of radiation quality (neutrons versus γrays) and cell-cycle state on the modulation of actin isotype-specific gene expression.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1173-1183 |
| Number of pages | 11 |
| Journal | International Journal of Radiation Biology |
| Volume | 59 |
| Issue number | 5 |
| DOIs | |
| State | Published - 1991 |
Funding
Acknowledgements The authors thank Ms H . Leona Berger, Mrs Valerie Gaines, Ms Kay Bexson and Mrs Diane Cockburn for secretarial assistance and Drs Frank R . Collart and Carol S . Giometti for critical review of the manuscript . This work was supported by the US Department of Energy, Office of Health and Environmental Research, under contract No . W-31-109-ENG-38 . The US Government retains a nonexclusive, royalty-free licence to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes .
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging