Mode of Action?

Question

Chemo and radiation result in hair loss and nausea. what can be said about the mode of action of there therapies given the cells of the hair follucles and the cells of the gastrointestinal lining reproduce rapidly.

Answer 1

Chemo and radiation cause DNA damage and kill cells that grow fast. Like tumor cells, some cells have short lives and need to be replaced by new cells. Hair follicles and the cells of gastrointestinal lining are in this category, and therefore are affected by chemo and radiation.

Answer 2

Both of these therapies are effective in rapidly dividing cells (which are those around hair follicles and the lining of the gut, but also cancer cells). The mode of action is the accumulation of DNA damage - and works because the rapidly dividing cells will not have enough time to repair the damage being induced. Indeed, many of the cells will commit suicide (apoptosis) rather than continue to divide, depending on the level of the damage.