Is there a cancer treatment method that uses a poison and an antidote?

Question

I am wondering if the following method (or similar variations) for treating cancer exists and if so if it works.

The metod is to deliver an ”antidote” to all cells (or all cells of a specific type) in the body, via virus,liposomes or diffusion. Then you wait for the cancer cells to divide which should lower the concentration of the antidote in the newly divided cancer cells. Then you inject the ”poison” into all the cells, the ones which already have the antidote in high enough concentration survive, the ones who doesn’t die.

When looking around to see if this exists all I found were articles about how to target cancer cells specifically, nothing about targeting all cells and using the fact that cancer cells divide quicker to distinguish between them.

Answer 1

When looking around to see if this exists all I found were articles about how to target cancer cells specifically, nothing about targeting all cells and using the fact that cancer cells divide quicker to distinguish between them.

You've misinterpreted how radiation/chemotherapy work. Both are "poisons" in that they cause DNA damage or otherwise irreparably compromise intracellular processes. Because cancer cells are highly active, they are closer to the "apoptotic threshold" required to initiate cell death, so these treatments are exactly what you've described; you just haven't realized that the "antidote" is normal (instead of hyperactive, poorly-regulated) cellular function. Normally-functioning cells that have higher rates of activity are more affected by these poisons, leading to hair loss, GI issues, anemia, mucous membrane damage, etc. That said, supplementing this "antidote" (à la your original question) via redirection towards less- or non-genotoxic cancer therapies is a subject of interest:

Protecting the normal in order to better kill the cancer, Liu et al. Cancer Med. 2015 Sep; 4(9): 1394–1403. doi:10.1002/cam4.488

Most chemo drugs...are mainly genotoxic, not only because they mainly target genomic DNA or some components that affect or are needed for DNA synthesis or repair but also because most mutations are deleterious. The same severity of genotoxicity causes more severe DNA damage in cancer cells than in normal cells, thus eliciting cancer cell-specific killing, because normal cells have intact DNA damage response and intact DNA repair mechanism and thus can arrest proliferation for more efficient DNA repair and to avoid damage by the drug.

Since cells of those highly lethal cancers are always mutating their genes to adapt to a therapy, whereas normal cells always try hard to maintain their genomic integrity, it may be a good idea to shift our focus from the traditional thinking of how to kill cancer cells per se to how to protect normal cells from the toxicity of a particular chemotherapy.