Bystander Effects. Bystander Effects. The signals sent by the bystander cells may help repair the damaged cell, or it may trigger the cell to commit cell suicide. When a cell is damaged by radiation, it can send signals to bystander cells, which are the cells near the “hit” cell.
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The signals sent by the bystander cells may help repair the damaged cell, or it may trigger the cell to commit cell suicide.
When a cell is damaged by radiation, it can send signals to bystander cells, which are the cells near the “hit” cell.
The signals sent by the damaged cell may disrupt the normal function of it’s neighboring cells, or it may stimulate them to respond with additional signals back to the damaged cell or to other nearby cells.
Radiation causes free radicals to damage only the cell that is “hit” by direct ionization
Radiation causes free radicals to trigger cell-cell communication and cell- matrix communication to cells other than those which are “hit” by the direct ionization.How does radiation interact with cells?
Direct cell contact
Death Inducing Factor
Clastogenic FactorsHow do cells communicate to each other?
Sawant et al.2000
The site of deposition of the radioactive material is the site of cancer induction
TracheaInduction of p53 in Rat Tracheal Epithelium by Radon
p53 Up-regulated in All Cells
Few Cells Hit
Ford et al 1997
Shielded Cells culture?
Lower half of lungs irradiated with 10 GyThe influence of communication on radiation-induced micronuclei in lung
Lung cells shielded from direct radiation showed a major increase in the production of micronuclei (one indicator of chromosome damage) when other cells in the lung tissue were irradiated, indicating some type of communication between cells.
Khan et al 1998