Cancer Research Surprises

Many people would admit to not understanding cancer well, but fewer people would admit to not understanding evolution well.  Here are some challenges to our understanding of both.

Starvation may help cancer treatment. “As little as 48 hours of starvation afforded mice injected with brain cancer cells the ability to endure and benefit from extremely high doses of chemotherapy that non-starved mice could not survive.”

Cancer is evolution in action.  This isn’t a surprise to most researchers these days, but it is to the general public.  Very simply, the cells in your body are individual living organisms, and just like populations of humans and animals, populations of cells undergo Darwinian natural selection.  The difference is that the multicellular organisms (like humans), evolved stringent mechanisms to keep cellular evolution in check because it is bad for the multicellular organism.  When evolutionary pressures find a crack in those mechanisms, the shackles come off, cell populations evolve more freely and this is what we call cancer.  Another difference is that once the host organism dies, the cancerous process stops, and it has to evolve anew within each multicellular organism.  Or maybe that’s not entirely true…

Some cancers are transmittable.  The article talks about the Tasmanian devil population, in which the cancer itself — not a cancer-causing virus — is transmitted via biting.  Genetic diversity in the population is very low and thus the new host’s immune system does not react to the invasion of cancerous cells, thinking that they are part of their own body.  Can cancer be transmitted from human to human?  It is very rare, but under special conditions, yes.  Mothers can transmit tumors to their unborn fetuses, and the article talks about a cancer patient who had a piece of her tumor transplanted to her (healthy) 85-year-old mother.  The transplant was done with everyone’s knowledge and consent as a way to try to better be able to treat the daughter.  Unfortunately the daughter died, and the mother contracted the cancer and died fifteen months later.

Lamarkian inheritance is real.  Remember back to high school biology when you were taught that acquired characteristics are not heritable?  Well, that turns out to be not quite true.  Protection against (or susceptibility to) cancer, for instance, can be acquired through diet and then passed on to offspring.  This study shows that acquired characteristics can be passed down more than one generation.  It’s sobering to think that my choice of eating a Big Mac today instead of broccoli could impact my grandchildren’s chances of getting cancer.

Hat tips: Ann Kulze, John Pepper