Time?lapse imaging of cells in spatially fractionated X?ray fields using a mini beam as an alternative to accelerator?based microbeams

Abstract

Due to the small number of accelerator?based X?ray microbeam facilities in the world, their use for biological research purposes is limited. Thus, the development of alternative methods is of high importance for the understanding of X?ray microbeam radiation biology expansion and its future utility. In this study, we performed mini beam irradiation of cells using a lead (Pb) collimator as an alternative method to microbeams. Also, we employed human cervical carcinoma HeLa cells and hTERT?immortalized fibroblast BJ?1 cells that express fluorescence ubiquitination?based cell?cycle indicators (FUCCI). FUCCI labeling was useful in distinguishing irradiated from non?irradiated cells in the case of HeLa cells. Our imaging results clearly showed differences in the behavior of HeLa and BJ-1 cells in spatially heterogeneous radiation fields; in the case of HeLa cells, G2/M phase arrest cells in the cell population were clearly observed. The Pb sub?milli?collimators are a promising alternative to X?ray microbeams for radiobiology studies, and their combination with time?lapse imaging is a possible approach for investigating tissue responses in spatially non?uniform radiation fields.journal articl