The genomes of humans and other multicellular creatures contain several sets of genes with a special «instructions» for the self-destruction of cells in certain conditions. For example, such a «programmed suicide,» or apoptosis in the language of science, occurs when damage to cellular DNA, the viral penetration in the core and in some other situations when it is necessary for the survival of the organism as a whole.
Many of these reactions do not run themselves, and as a result of contact of the shell of the cells with the special signaling molecules, explained Vladimir Gogvadze, fellow of the Faculty of fundamental medicine of Moscow state University. This allows the immune system to kill «rebellious» cells that can become the progenitors of cancerous tumors. In parallel, the body gets rid of decrepit cells.
Scientists have studied the work of one of these «switches of death» protein FasL. A lot of molecules and the shell of human cells, and within them. Despite the fact that the structure of FasL has been well studied, scientists did not know exactly what signaling molecules are forced to kill a cell. More to the point, scientists do not understand how a protein within the cell membrane and interacts with its internal content.
Russian researchers managed to close the gap in biology.
They figured out how FasL can be used for «braking» process of cell death. It became possible thanks to experiments on a special line of cancer cells grown in the University lab and ITEB. The DNA of these cells, as biologists say, modified so that they can be forced to produce massive amounts of FasL or completely stop the synthesis of this protein. These manipulations helped to understand the mechanism of apoptosis.
Experiments have shown that the «suicide button» need another protein — caveolin-1. It is present in the membranes of human cells and plays an important role in the work of the special sections of caveola. There are going and are read by signal molecules coming from the environment.
Caveolin-1 plays an important role in apoptosis: FasL inside there is a kind of «seat» for caveolin, the removal of which disconnects the program of cellular suicide and does not allow the cell to self-destruct. This occurs even when very high concentrations of both protein.
It is noteworthy that it works with many other proteins that are responsible for apoptosis.
The discovery is particularly interesting in the context of cancer, whose cells lose their ability to destroy itself. Scientists hope that further study caveolin, FasL and other «death proteins» will help to understand how to forcibly include them in cancer cells. And as a consequence — to destroy cancer cells without affecting healthy tissue.