The Yin and Yan of bystander versus adaptive response: lessons from the microbeam studies

摘要

Two conflicting phenomena, bystander effect and adaptive response, are important in determining the biological responses at low doses of radiation and have the potential to impact on the shape of the dose-response relationship, Using the Columbia University charged-particle microbeam and the highly sensitive AL cell mutagenic assay, we show here that non-irradiated cells acquire mutagenesis through direct contact with cells whose nuclei had been traversed with two alpha particles each. Pre-treatment of cells with a 0.1-Gy dose X-rays 4 h before alpha particle irradiation significantly decreased this bystander mutagenic response. Results from the present study address some of the fundamental issues regarding both the actual target and radiation dose effect and can impart on our current understanding in radiation risk assessment.