When the cancer prevention mechanisms fail and the cell may become a cancerous cell, "software" found in each of the body's cells comes into action, causing the cell to go out of control. When the "software" goes wrong, cancerous tumors may appear. A team of researchers discovered a new protein that tells cells to eat themselves from the inside
When we get into a difficult situation or a crisis, some of us feel that they are "eating themselves from the inside". When it comes to humans, this feeling is nothing but an image, but this is exactly what can happen to cancer cells. When the cancer prevention mechanisms fail in their role, and the cell may become a cancerous cell that endangers the existence and life of the entire body, a special "software" that lies in each of our body's cells comes into action. This "software" instructs the dangerous cell to lose itself in knowing, thereby commanding life to the entire body. If and when this "software" goes wrong, cancerous tumors may develop. On the other hand, if and when it is activated beyond what is necessary, various degenerative diseases occur in the body (for example, in the nervous system).
This phenomenon, of cell suicide, can occur in two different ways. The more well-known way of suicide is called "apoptosis" (in Greek: "shela", like the leaves falling from the tree in the fall). Apoptosis occurs when the cell produces toxic proteins that cause the cell to break down into components that are "eaten" by nearby cells. The second way is called "autophagy", that is, the cell eats itself from the inside.
Research student Sharon Rif, and Prof. Adi Kimchi, head of the Department of Molecular Genetics at the Weizmann Institute of Science, recently identified a new protein that instructs the cancer cell to choose this suicide path. Their research findings were recently published in the scientific journal Molecular Cell. In fact, it turns out that this new protein is nothing but a shortened version of another protein, which was previously known as one of the factors involved in causing apoptosis. These two proteins are created based on genetic information encoded in the same gene itself, but during the production process of the shortened protein, the ribosome ("the cell's protein factory") begins to read the information, which reaches it in the form of messenger RNA, at a certain point on the surface of the molecule , and not at the beginning. Autophagy is based on intracellular structures, sac-like, seven-deficiency, or stress, through which the cell recycles building blocks. In some cases, this mechanism works too much, so that in trying to recycle the building blocks the cell "eats itself to death". The discovery of this phenomenon raised the question in all its acuteness: Is autophagy a survival mechanism, or on the contrary, a mechanism for self-destruction? This is the question that was at the center of Prof. Kimchi and Sharon Rif's research.
To examine these two possibilities, the scientists disabled two genes that are known to be essential for the construction of the "recycling bags". Thus they discovered that the damage to the production of the bags protected the cells to a significant degree from the process of "self-eating" and death, so that many of them, relatively speaking, survived. From this the scientists concluded, that the excessive formation of the sacs is an ominous stage (for the cell), a kind of necessary stage on the way to self-eating to death. What exactly is the mechanism that activates the process? That is, what is the difference between the two suicide processes? Why does one cell commit suicide by apoptosis, while another cell eats itself to death? The answer to this question is still unknown, but the scientists suggest that the difference stems from the structural difference between the two toxic proteins, which affects their mode of action and the area where they operate in the cell.
Why did two different suicide mechanisms develop in the cell? Prof. Kimchi suggests that the autophagy pathway is a kind of back-up plan, in case the cancer cell is prevented - for various reasons - from sacrificing itself and performing apoptosis. In other words, autophagy is another suicide pathway, or another mechanism that the body has developed to inhibit the development of cancerous tumors. Now the scientists plan to test if this concept is correct, or if, after all, the autophagy process is an independent mechanism that does not depend on whether or not the cancer cell performs apoptosis.
Research students Einat Zaltzkaber and Shani Bialik from the Department of Molecular Genetics, as well as research student Ohad Shipman and Prof. Moshe Oren from the Department of Molecular Cell Biology also participated in the study.
