title: An evaluation of novel real-time technology as a tool for measurement of radiobiological and radiation-induced bystander effects.
abstract: The xCELLigence real-time cell impedance system uses a non-invasive and label-free method to create a cell index that is a composite measure of cell proliferation. The aim of this study was to evaluate xCELLigence against clonogenic assay (gold standard) for measuring radiobiological effects and radiation-induced bystander effects (RIBE). A radiobiological study was conducted by irradiating EMT6.5, 4T1.2 and NMUMG cell lines with different radiation doses, while a RIBE study was done using transfer of conditioned media (CM) harvested from donor to the same type of recipient cell (EMT6.5, 4T1.2, NMUMG, HACAT and SW48). CM was harvested using two protocols which differed in the dose chosen and the exposure to the recipient cells. Results showed that xCELLigence measured a radiobiological effect which correlated with the clonogenic assay. For the RIBE study, no statistically significant differences were observed between xCELLigence or clonogenic survival in control or recipient cells incubated with CM in protocol one. However, there was a significant increase in cell index slope using CM from EMT-6.5 cells irradiated at 7.5 Gy compared with the control group under the second protocol. No other evidence of RIBE was detected by either xCELLigence or clonogenic assay. In conclusion, xCELLigence methods can measure radiobiological effects and the results correlate with clonogenic assay. We observed a lack of RIBE in all tested cell lines with the clonogenic assay; however, we observed a RIBE effect in EMT6.5 cells under one particular protocol that showed RIBE is cell type dependent, is not universally observed and can be detected in different assays.
authors.affiliation: Department of Obstetrics and Gynaecology, Royal Women's Hospital, University of Melbourne, Level 7, 20 Flemington Road, Parkville, VIC, 3052, Australia.|Faculty of Medicine, Universiti Teknologi MARA, Sungai Buloh Campus, Jalan Hospital, 47000, Sungai Buloh, Selangor, Malaysia.
authors.forename: Mohammad Johari
authors.initials: MJ
authors.lastname: Ibahim
authors.affiliation: School of Applied Sciences, RMIT University, Melbourne, VIC, 3001, Australia.|William Buckland Radiotherapy Centre, Alfred Hospital, Melbourne, VIC, 3004, Australia.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Crosbie
authors.affiliation: Department of Obstetrics and Gynaecology, Royal Women's Hospital, University of Melbourne, Level 7, 20 Flemington Road, Parkville, VIC, 3052, Australia.
authors.forename: Premila
authors.initials: P
authors.lastname: Paiva
authors.affiliation: Department of Obstetrics and Gynaecology, Royal Women's Hospital, University of Melbourne, Level 7, 20 Flemington Road, Parkville, VIC, 3052, Australia.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynaecology, Royal Women's Hospital, University of Melbourne, Level 7, 20 Flemington Road, Parkville, VIC, 3052, Australia.
authors.forename: Marina
authors.initials: M
authors.lastname: Zaitseva
authors.affiliation: Department of Obstetrics and Gynaecology, Royal Women's Hospital, University of Melbourne, Level 7, 20 Flemington Road, Parkville, VIC, 3052, Australia. parogers@unimelb.edu.au.
authors.forename: Peter A W
authors.initials: PA
authors.lastname: Rogers
mesh_terms: D000818:Animals; D024201:Bystander Effect / Q000528:radiation effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D017077:Culture Media, Conditioned; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D051379:Mice; D011853:Radiobiology / Q000379:methods*; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D017077:Culture Media, Conditioned
keywords: Bystander effects; Clonogenic assay; Radiotherapy; xCELLigence RT-CIS