Radiation Induced Bystander Effects in Human Lymphoblastoid Cells
Abstract
It is well accepted that cells, in response to radiation, may release transmissible factors. These transmissible factors, clastogenic factors, have been reported to induce genomic instability in cells that have not been directly exposed to radiation. We hypothesize that this observed bystander effect might be a consequence of cellular interactions via secretory proteins released by the irradiated cells to affect the non-irradiated cells and initiate a systemic stress response to deal with the exposure. TK6 cells, a human lymphoblastoid cell line with a stable karyotype (47 chromosomes) and a functional p53 protein, were chosen as the surrogate for determining the stress response activation. Non-irradiated TK6 cells were co-cultured with 1 Gy gamma-irradiated and non-irradiated TK6 cells in trans-wells, where the cells were kept separate but the culture media was free to diffuse across the membrane. Microarray analysis 8 hours post co-culturing monitored the gene expression changes and the dicentric assay was used to evaluate cytogenetic aberrations. Our findings show that this research model is an effective method of demonstrating the bystander effect using the dicentric assay and 7-irradiated cells. From the cytogenetic results it is evident that a bystander effect can be seen; although chromosomal aberrations are more frequent in the irradiated samples compared to the bystander samples, the numbers seen in the bystander samples are significantly greater than those in the controls. From the microarray data, a number of possible protein biomarkers have been identified. These results, taken together, provide a foundation for our future work of identifying systemic protein biomarkers of radiation exposure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2003
- Accession Number
- ADA419379
Entities
People
- Diana Wilkinson
- Erika M. Thorleifson
- Louise Prud'honne-lalonde
- Sylvie Lachapelle
- Tamika M. Segura
Organizations
- Defence Research and Development Canada