Related Experiment Video
Updated: Aug 8, 2026
11:24
Measuring DNA Damage and Repair in Mouse Splenocytes After Chronic In Vivo Exposure to Very Low Doses of Beta- and Gamma-Radiation
Published on: July 3, 2015
Low-dose studies of bystander cell killing with targeted soft X rays
G Schettino1, M Folkard, K M Prise
1Gray Cancer Institute, PO Box 100, Mount Vernon Hospital, Northwood, Middlesex, HA6 2JR, United Kingdom. Schettino@gci.ac.uk
Radiation Research
|October 21, 2003
Summary
The ultrasoft X-ray microprobe revealed that targeted irradiation of single V79 cells induces bystander effects, with damaged cells clustering, unlike previously reported binary responses.
Area of Science:
- Radiation Biology
- Cellular Biophysics
- Cancer Research
Background:
- Cellular responses to radiation exposure are critical in understanding radiation biology and cancer treatment.
- The bystander effect, where non-irradiated cells respond to radiation-induced signals from irradiated cells, is a key area of investigation.
- Precisely quantifying these effects at the cellular level requires advanced microbeam technologies.
Purpose of the Study:
- To quantify the bystander response of individual V79 cells using an ultrasoft X-ray microprobe.
- To compare the survival response of V79 cells when all cells are irradiated versus when only a single cell is targeted.
- To investigate the dose-dependency and spatial distribution of bystander effects.
Main Methods:
- Utilized the Gray Cancer Institute ultrasoft X-ray microprobe with a focused carbon K-shell (278 eV) X-ray beam.
- Irradiated V79 cells in vitro with a microbeam (0.25 micrometer spot radius) in the 0-2 Gy dose range.
- Compared cell survival data between population-wide irradiation and single-cell targeted irradiation.
Main Results:
- Cell survival data showed a linear-quadratic response when all cells were targeted, with hypersensitivity at low doses.
- Targeting a single cell resulted in 10% cell killing, with effects dependent on dose (<200 mGy) before plateauing.
- Damaged, unirradiated cells formed clusters, indicating non-uniform bystander signaling, differing from previously reported binary responses.
Conclusions:
- The ultrasoft X-ray microprobe enables precise assessment of individual cell radiation responses and bystander effects.
- Bystander effects in V79 cells exhibit dose-dependency and non-uniform spatial distribution, with clustering observed.
- These findings challenge the binary bystander model and highlight the complexity of intercellular communication following radiation exposure.
