Why doesn’t the radiation kill the normal cells? I asked Dr. Schupak this question. I told her that I understand that the radiation damages the cancer cells’ DNA, rendering them unable to reproduce. But I didn’t understand why DNA damage doesn’t occur to normal cells during radiation. Her response struck me as sort of comical so here is my general recounting of what she said.
Whether subject to radiation or not, normal cells are always on the look out for DNA damage. They surveil, always inspecting to find and repair damage before DNA replication and cell division.
In contrast, cancer cells do one thing well: they run rampant. Its what they do. They don’t take stock. They don’t surveil. They are ready to, intend to, run rampant. Just run, run, run. Radiation therapy ties their shoelaces together and they are too stupid to know what happened. So they fall on their faces and they die.
So now I am picturing normal cells and cancer cells at the starting line for a race.
Image via Flickr Creative Commons, courtesy of Doug Hansen, and altered by Fletcher.
The normal cells look tortoise-like, wear spectacles, and somehow carry both a clipboard and a box labeled “Repair Genes.”
The cancer cells look hare-like. Nervous and jumpy, they carry water bottles, and wear shorty-shorts and sneakers. A few years ago the starting pistol sounded and those damn rabbits have been running ever since.
But now, after 29 of 30 radiation therapy treatments, my body is littered with dead hares. Their limp, furry bodies are sweaty and spent, and if you look closely at their shoelaces you will see the handiwork of Dr. Schupak and her team.
Feeling too sad, because rabbits are so cute? Get over it: these were arrogant, stupid, buck-toothed, evil, red-eyed motherfuckers that wanted to kill me.
As the neutrophils and macrophages begin to deal with the dead hares, the tortoises slowly plod on by, checking, surveilling, and employing those repair genes as needed.
Slow and steady wins the race.