A few steps closer to beating cancer?
Cancer is a disease we still don't have a reliable cure for. It is a creepy and mysterious thing we don't yet fully understand. However, scientists are constantly working on discovering the truth about this persistent disease. Now, I want to present to you an interesting discovery that deepens the understanding of cancer - the Peto's paradox.
It all starts in our cells where million of its tiny little parts are guided by chemical reactions, creating and dismantling structures. Their function can be for example to provide some abilities of the cells like creating almost exact copies of themselves. These chemical pathways work within the cell without an error, until they do not. If the number of errors is growing, cells have a special ability to commit a suicide to prevent the problem getting bigger. However, the kill switch is not infallible. When it fails, the cell is turned into the cancer cell.
Don´t worry, more than a half of these cells are killed immediately by our immune system. If not, the cancer is replicating.
The cells are the same size in every living organism so it is clear that smaller animals like mice have less chance to get cancer than we as humans, living 50 times longer and having 3000 times more cells than mice. We simply have more time and mass of cells to increase the probability of getting cancer - but that is not true! And that's Peto's paradox.
It is being explained by 2 ways - evolution and hypertumors
- EVOLUTION
Throughout the evolution, animals got bigger and bigger. The chance of getting cancer was increasing as the number of cells in the animal. The theory says that the animal had to adapt to the increased rate of getting cancer. Cancer doesn't just happen. It's a process that involves many individual mishappenings and mutations in several specific genes within the same cell. When these proto-oncogenes mutate it´s bad news. The cell turns into a cancer cell and with the right mutation of the gene, it loses the ability to kill itself. Then it can for example evolve the ability to hide from the immune system, or quickly multiply. That's why the gene has its own tumor suppressor gene which can effectively repair the broken part of it, or it can send the order for killing the cell because the gene is beyond repair.
It was found out that larger animals like elephants or whales have way more of the repair gene than mice for example. Because of this, elephant cells require more mutations than mice cells to develop a tumor. Nature and evolution always invests in a certain area, so on the contrary somewhere the investment is missing. By elephants, it can be slower healing of their wounds.
- HYPERTUMORS
When the tumor is already existing and it's not killed by the immune system, it naturally thrives in our bodies. The tumor grows bigger and bigger. However it is not easy. Infinite multiplying requires great ammount of energy. So with the right mutation, the tumor can connect the body's blood veins to itself to feed it and help it to slowly kill us.
Cancer cells are not stable, so they mutate endlessly. Now it comes the point when some of the cancer cells are faster in mutating - the cell might suddenly think of itself as individual and stop cooperating! Next it decides to separate from the original tumor and that's the moment where it gets interesting. The tumor basically created another different tumor unconsciously, and it is fighting against the original one! They are now fighting for the same nutrients and resources. It's like a parasite hosting on a different parasite - Hyperparasite. Tumor parasitizing on a different one - Hypertumor. So the cancer is killing cancer!
It is supposed that large animals are filled with tiny tumors but they just don't care because it is not causing them any problem, which all make sense. As you can see in the picture, 2 grams of tumor is equal to 10% of the mouse´s body weight, 0.002% of the human´s and 0.000002% of the whale´s! And when all three tumors require the same number of cells and cell divisions, large animals are just chilling.
Scientists are still unable to prove this theory, but it is highly possible that this would be the reality. This theory can just bring us closer to the cure of this deadly disease called cancer.
link for the video: https://youtu.be/1AElONvi9WQ