The video discusses the paradox of cancer in large animals, known as PETO'S PARADOX, where despite having more cells and a longer lifespan, they have less cancer than smaller animals. This paradox is attributed to two main factors: evolution and hyper tumors.
The evolutionary explanation suggests that as multicellular beings developed 600 million years ago, animals became bigger and bigger, adding more cells and hence more chances for cells to be corrupted. This led to the development of better cancer defenses, with animals that did not invest in these defenses dying out. However, cancer doesn't just happen due to individual mistakes and mutations in several specific genes within the same cell.
Hypertumors, or tumors of tumors, are another proposed solution. Cancer can be thought of as a breakdown in cooperation, where normally cells work together to form structures. Cancer cells, however, are selfish and only work for their own short-term benefit. If they're successful, they form tumors, huge cancer collectives that can be very hard to kill. However, making a tumor is hard work and requires a lot of resources and energy. The amount of nutrients they can steal from the body becomes the limiting factor for growth.
The tumor cells trick the body to build new blood vessels directly to the tumor, to feed the thing killing it. The nature of cancer cells may become their own undoing. Cancer cells are inherently unstable and can continue to mutate. Some of them faster than their buddies. If they do this for a while, at some point one of the copies of the copies of the original cancer cell might suddenly think of itself as an individual again and stop cooperating. This means just like the body, the original tumor suddenly becomes an enemy, fighting for the same scarce nutrients and resources. So the newly mutated cells can create a hypertumor. Instead of helping, they cut off the blood supply to their former buddies, which will starve and kill the original cancer cells.
This process can repeat over and over, and this may prevent cancer from becoming a problem for a large organism. It is possible that large animals have more of these hyper tumors than we realize, they might just not become big enough to notice. All three tumors require the same number of cell divisions and have the same number of cells. So an old blue whale might be filled with tiny cancers and just not care.
There are other proposed solutions to Peto's paradox, such as different metabolic rates or different cellular architecture. But right now we just don't know. Scientists are working on the problem. Figuring out how large animals are so resilient to one of the most deadly diseases we know, could open the path to new therapies and treatments.
1. Cancer is a complex biological phenomenon that remains largely unsolved.
2. Large animals seem to be immune to cancer, which contradicts the expected correlation between size and cancer risk.
3. Our cells are protein robots made out of hundreds of millions of parts, guided by complex chemical reactions.
4. These reactions can go wrong, leading to the corruption of the cellular machinery.
5. Cells have kill switches that commit suicide when they detect errors, but these are not infallible.
6. If these kill switches fail, a cell can turn into a cancer cell.
7. Humans live significantly longer and have many more cells than mice, yet the rate of cancer is roughly the same in both species.
8. Even blue whales, which have about 3,000 times more cells than humans, do not seem to get cancer.
9. This is referred to as PETO'S PARADOX: the baffling realization that large animals have much less cancer than they should.
10. Scientists propose two main ways to explain the paradox: evolution and hyper tumors.
11. The first solution suggests that as multicellular beings evolved 600 million years ago, animals became bigger, adding more cells and hence more chances for cells to be corrupted.
12. The second solution, "Hypertumors", suggests that cancer can be thought of as a breakdown in cooperation, where cancer cells are selfish and only work for their own short-term benefit.
13. If they're successful, they form tumors; huge cancer collectives that can be very hard to kill.
14. The nature of cancer cells may become their own undoing, as they can continue to mutate and create a hypertumor.
15. This process can repeat over and over, potentially preventing cancer from becoming a problem for a large organism.
16. Scientists are working on the problem, aiming to figure out how large animals are so resilient to one of the most deadly diseases we know.
17. Today, we are finally beginning to understand cancer, and by doing so, one day we might finally overcome it.