Expression of Genes Involved in a Radiation-Induced Bystander Effect

The radiation induced bystander effect is relevant to carcinogenesis, it may have significant implications for risk estimation for radiation exposure. Currently the mechanisms and cellular events are the subject of intense investigation, because little is known. It is thought that the radiation induced bystander response is due to a bystander factor secreted in the medium post irradiation. However the biological nature of this factor is currently unknown, but it is thought to be a protein of some sort that may be involved in the apoptosis cascade. Materials and Methods: HaCaT epithelial cells were used in this study and exposed to 0, 0.5 and 0.05Gy low doses of ionising radiation (IR). The medium was harvested from the cultures post-IR and placed on recipient HaCaT cells for different time points. RNA was extracted from the cells using the TriReagent protocol and stored for subsequent gene expression studies. Specific genes were selected for this study, in particular those involved in the apoptotic cascade. Primer design and primer optimisation methods were carried out to establish definite primer temperatures for the subsequent gene expression studies, using Real-Time PCR. Results: Preliminary gene expression data will be shown along with primer optimisation of the specific apoptosis genes under investigation in this study. Currently a paper is in progress detailing this novel data. Discussion: This data could contribute to the discovery of the molecular mechanisms involved in the production of a radiation induced bystander effect and will therefore have potential clinical relevance for patients undergoing radiotherapy treatment.