In the course of evolution our bodies have learned to get rid of the affected stem cells. Scientists from the cancer center of the University of Colorado have revealed the mechanism of cancer protection body as a result of radiation exposure. A new study has shown that the reprogramming of cells can protect the body against the development of cancer.
Our body is not able to deal with a radiation leak from a nuclear reactor or x-rays. Him the strength to cope only with a few cells when receiving dangerous doses of radiation or other attacks on DNA, says study author James Degregory, Professor of biochemistry and molecular genetics from the school of medicine of the University of Colorado.
The research team Degregory studied the effect of radiation on the blood stem cells of mice. It is seen that full exposure of the body increases the likelihood of differentiation in stem cells of the hematopoietic system. Some cells (the majority) follow this instruction. Stem cells with a very specific mutation can preserve its originality. The study showed that inhibition of the gene C/EBPA allowed some stem cells to maintain its previous functionality and occupy a dominant position in the system.
Mutations and other genetic changes involving gene C/EBPA is associated with acute myeloid leukemia in humans. The mutation causes not radiation itself, and the restructuring of the hematopoietic system, resulting in the exposed people develop cancer.
This is evolution by natural selection. In a healthy blood system, healthy stem cells predominate over cells with a mutation C/EBPA. But under the effect of radiation mutated stem cells prevail.
It is easier to understand with the following example: reducing the population of chipmunks is changing the ecosystem, thereby increasing the squirrel population. The same thing is happening with the cells – effect of radiation on the body increases the number of stem cells with C/EBPA mutation.
The study showed that the activation of the signaling pathways of hematopoietic stem cells does not allow them to differentiate under the influence of radiation. Even months after irradiation cells can get their features back.
If I acted in a situation when the organism needs to be subjected to radiation, we would freeze part of their hematopoietic stem cells, says the researcher.
The researcher explained this step the fact that injection of healthy hematopoietic stem cells in irradiated organism would allow the healthy blood system to get rid of irradiated cells, even with carcinogenic mutations.
It is hoped that in future there would be preparations for the recovery of stem cells exposed to radiation, is summarized Degregory.
The study was published in the journal Stem Cells.