High-energy radiation is often used to treat cancer. The radiation kills the cancerous cells, and the cell cycle checkpoint for DNA repair is overwhelmed. Radiation

Question

Quizplus · Accepted Answer

High-energy radiation causes DNA damage that leads to activation of the cell cycle checkpoint for DNA repair. However, if the damage is too severe, the checkpoint is overwhelmed and cells enter apoptosis. This is particularly true at the S and G2 checkpoints, where cells are actively replicating DNA or preparing for division, respectively. Radiation does not inhibit the growth factor at the restriction point (B) or block DNA replication entirely (C). Radiation can harm healthy cells as well as tumor cells, and its effects are often limited to the site of treatment (D). While radiation can kill many tumor cells, it is not always effective against all types of cancer and must be carefully targeted to minimize harm to healthy tissues.

High-Energy Radiation Is Often Used to Treat Cancer