INVESTIGATING THE PARAMETERS OF PRE-/POST-CONDITIONING ON HUMAN-DERIVED CANCER CELLS

Abstract

There is a large amount of interest and research currently going into studying the effects of low dose radiation on humans, and bridging the gap with the data from the effects of high dose radiation. Much work is to be done to understand low dose exposures such as from medical treatments and those who work with or around radiation. Two popular and widely known examples of low-dose phenomena are the radiation induced bystander effects and the radioadaptive response (RAR). This research involves the study of the impact of a low dose of radiation that is administered several hours after a high – even fatal – dose is given, which contrasts the traditional RAR where a low priming dose is given before a high dose and can lead to increased cell survival. Many different parameters were checked to see if cell survival can be enhanced or diminished depending on the stage of the cell cycle, cell growth conditions, and cell profiling differences in protein function (namely the TP53 gene). Additionally, the post-conditioning response was contrasted to see if it was possible to see any effects from the newly emerging area of bystander signalling, UV BioPhotons, would be present in cell lines that either did or did not exhibit a post-conditioning effect. It was shown that post-conditioning has a protective effect on survival of the cells in certain dose ranges and certain cell lines. The post-conditioning effect also appears to be stronger in magnitude than the classic RAR. No relationship between gamma-induced biophoton signalling and post-conditioning was observed, nor is it certain whether an acute gamma-field can induce significant UV biophoton damage. This thesis is aimed to explore the various parameters by which post-conditioning effects occur on various Human cancers.