Using Cellular DNA Reader to Counter Radiation Damage

Question

I have a space based setting and would like to develop a mechanism that counters radiation damage.
Here is my idea:

The setting 100 years from now. A cellular organelle is developed similar to the CRISPR tool and human beings are genetically modified to carry it in all its cells). The organelle reads through the cell's DNA looking for telltale signs of radiation damage (specifically gaps in the DNA strands). If the organelle locates one of these gaps it releases a protein that signals cytokines to destroy the cell. If the organelle fails to find a gap it simply continues to read the DNA?

Would this approach work? If not how would this system have to be modified to work? If it cannot be made to work what system could achieve increase radiation resistance for human beings?

Answer 1

This is a very cool mechanism---looking for strand breaks is definitely the best marker. I think the body might have a process for repairing single-strand breaks, and your mechanism would kill the cells instead, so that might be an issue. Double-strand breaks often lead to cell death anyways. My worry here is that this doesn't prevent a lot of the acute effects---it could definitely cut down on cancer, but a fair number of the acute effects are direct results of "hey you just killed a bunch of cells" and this doesn't fix that. On the other hand, if what you're worrying about is chronic exposure to low doses---and that's what it seems like---then this approach would work! It's not going to let someone go and hug a reactor (or even carry around a gamma cookie in their pocket), but it is definitely plausible for reducing cancer risk.

As another note, there's not a ton of data on low-dose health data---most of what we have is from bomb survivors and cancer treatment---so as long as it's plausible (which this is) you should be good to go!

Answer 2

Genetic custom nanites with hard-wired DNA code:

So part of the problem with DNA repair is that if it happens too fast, the cells start to engage more radical solutions to fix damage - sloppier repairs, because alive and mutated is better than dead. This is fine for a bacteria - either the repair works, and it lives, or it fails and dies. For a multicellular organism, the cell that lives but grows out of control is cancer. Any actual DNA can be altered, so let's overwrite DNA.

Your organelle can hold a copy of the person's DNA code, but made out of some coding material that is essentially indestructible at a cellular level and unaffected by radiation and mutation. Everyone gets a gene scan as a child, and receive injections of manufactured nanites programmed with their own code as needed. Got cancer? Get injected, and the nanites enter the cells and rewrite the DNA to the original code. Cancer stops. You're going into space and there's lots of radiation? Inject in advance, and add nanites as new cells grow. The nanites could also be tied to a tiny machine implanted that can make new nanites, but my thought is you want ZERO chance of mistaken code, so external and unalterable is better.

The nanites avoid the need for apoptosis, although a targeted form could still be used to rebuild damage from tumor growth (digest tumor, lay down new extracellular matrix for stem cells). The body has lots of mechanisms to slow growth and replication that have downsides in adults as growth slows. The people with these could heal faster safely, possibly even regrow lost tissue. Imagine being resilient like a small child all your life. This could even immortalize people regularly treated and reverse aging. Imagine a corporation selling immortality, and you always need another shot to counteract cells that replicate quickly. Cha-ching.

A slightly scary alternative would be nanites without code, that were connected to an external input with the patient's code. Wirelessly, the patient receives coding allowing a doctor to repair damage and even alter the person's DNA to respond to changing conditions. An unscrupulous corporation or government could insert DNA for obedience, alter their employees to live in alien environments and then leave them there (unable to return because they're no longer Earth-compatible), etc. The evil possibilities are endless.