Cancer — the super mutant or the archaic survivor?
Several years back while writing my master thesis in nutrition immunology, I stumbled upon a very cool article on cancer. I read it and then the authors background caught my eye. P.C.W Davies and C.H. Lineweaver of the Planetary Science Institute, Research School of Astronomy and Astrophysics & Research School of Earth Sciences, Australia. Why would researchers with backgrounds that most possibly enable them to theorise on possible early life and extraterrestrial life write an article on cancer?
The answer is of course found in the article: Cancer might just be a move back in time to an earlier stage of evolution. Back to a time where individual cells didn’t live in highly specialised communities like they do in our bodies, but lived in much simpler collectives of cells where each cell was much more adaptable. That might be why two researchers with the stated kind of background would choose to study and write about cancer, as cancer could provide clues to earlier stages of the modern cells present in our bodies. The authors do not answer that question but they try to answer a more important one — what if cancer was viewed, not as an infinitely adaptable super cell, but as a more ancient cell architecture with a finite number of survival tools that are actually predictable? I’ll put a bit more words on that below
Cancer to most people is probably pure evil.
To researchers it has long been an enigma although an enigma that is being unravelled more and more each day. What these two authors theorise is that cancer is actually a revival of ancient survival mechanisms. Not for the body obviously, but for the cancer itself.
Imagine a countrys constitution. This is the very foundation for a functional modern society. On top of that are all the amendments, the sub specialisations of the law. Before having a constitution, then, maybe not total chaos, but a less structured society would have existed. Then imagine a human body and put the constitution analogy on top of it.
Our bodies are made up of quadrillions of specialised cells. Cells that are, very simply put, governed by a genetic code that is ancient but has been revised trillions of times with new amendments, specialisations. Before that, before several hundreds millions of years of evolution cells were much more adaptable and had a super survival toolbox. Just like a society before a constitution and amendments.
During evolutionary history, cellular conglomerates evolved more and more specialised communities and recently specialised communities such as a human or animal body. For this type of community to work, it requires a huge set of restrictions upon the extremely adaptable cell and its genes. These would be the constitution and following amendments. A typical human cell is not able to survive outside of is close community of similar cell. Thus a liver cell cannot survive in muscle tissue because it needs constant signals from its surroundings that it is a liver cell and thats how it should stay. Without these signals, it would commit suicide or in biologic terms — apoptosis. Also, most cells cannot reproduce and grow as they please. Special molecules prevents this by controlling cellular growth and division. One of these molecules is called p51. A common trait in cancer is a mutation in the p51 molecule. Since p51 is an essential controller of cell growth and division, a mutation in this could spell trouble as a cell with such a mutation that renders p51 non-functional, would be much less restricted in its growth. Just as a single person would be less restricted if an amendment was removed or rendered useless.
Interestingly, cancers follow a common pattern as many of the cellular control mechanisms and molecules have been taken out. The restrictions have been lifted. Such restrictions are considered evolutionary latecomers since specialised cell communities such as the body have developed later than the ancient super survivor cell. And here’s the catch, because everything is stored in the genetic code. Rarely is something thrown out. Most genes and cellular features are revised or reused in new versions, but not thrown out.
Because of this, removing the more recent cellular restrictions reveals a much more ancient genetic toolbox. A toolbox that the cell used to have at its disposal in order to survive on its own — It could move anywhere, produce new mutated variants of its proteins, gather nutrients and so on. And that is what cancer does. It can move through tissue, a process called extravasation and move to other areas of the body as metastases. It can mutate in order to have proteins with new functionalities and it can induce the production of new blood vessels to provide nutrients.
The very intriguing idea of a cancer cell, not as a new super mutant but as a cell stripped of all modern restriction put upon in by evolution, gives an entirely new perspective on cancer treatment. As with the super mutant perspective, the cancer is viewed as an unpredictable killer.
As an ancient survivor, cancer suddenly becomes much more predictable as we know enough about the evolutionary steps of the cell to know what came before modern cells. Everything is written in the genome of modern specialised cells.
And yes, we humans even retain the gene for spitting poison just like the Platypus. The gene coding for that poisonous enzyme has just been silenced, but not removed.
The following article is my own interpretation of a much more detailed idea published in Physical Biology in 2011 with the title:
Cancer tumors as Metazoa 1.0: tapping genes of ancient ancestors
By P C W Davies and C H Lineweaver