Question

Cancer cells often lack normal DNA damage response and cell-cycle control mechanisms. Why does this make them more susceptible to DNA-damaging chemotherapies?

1) Cancer cells will arrest in the cycle and will not grow further.
2) Cancer cells have the ability to repair the DNA properly and thus will not accumulate mutations as quickly.
3) Cancer cells might ignore the normal mechanisms that halt the cell cycle in response to damage, and subsequent division with damage leads to death.
4) Cancer cells with activating mutations in Ras will amplify the damage through the Ras signaling pathway.

Answer 1

Cancer cells' susceptibility to DNA-damaging chemotherapies stems from their lack of response to DNA damage and failure to halt and repair before division, leading to cell death or the accumulation of fatal mutations.

Step-by-step explanation:

Cancer cells are characterized by unchecked cell division due to a breakdown in the mechanisms that regulate the cell cycle. When DNA damage occurs in these cells, they fail to enact normal DNA damage response mechanisms, which makes them more susceptible to DNA-damaging chemotherapies. The correct answer to why this makes them susceptible is option 3: Cancer cells might ignore the normal mechanisms that halt the cell cycle in response to damage, and subsequent division with damage leads to death. Normal cells would typically halt division and attempt to repair DNA damage; cancer cells, however, are more likely to continue dividing without repair, which can result in the accumulation of lethal mutations or the triggering of cell death mechanisms as a result of the chemotherapy.