Scientists have shown that small doses of radiation are not harmful to stem cells

© Depositphotos / VtanovskiРаковые cellsScientists have shown that small doses of radiation are not harmful to stem cells© Depositphotos / Vtanovski

. Russian scientists have found that small doses of radiation do not cause significant damage in stem cells and lead to the emergence of a large number of mutations in subsequent generations, according to a paper published in the journal Aging.

«The radiation dose in milligray 80 is the dose that often gets people when often used in conjunction with cellular therapy procedures, visualization of internal structures and processes of the body, such as computed tomography and x-rays. Our studies help to predict side effects and health risks in people undergoing increasingly applied cell therapy simultaneously with the diagnostic radiation», — said Sergey Leonov, Director of the Institute of the school of biological and medical physics of MIPT.

People and other living beings negatively react to the radiation for the reason that ionizing radiation directly introduces breaks in the DNA chain or indirectly «breaks» them, giving rise to many chemically aggressive substances when interacting with the contents of the cells. These damages cause many cells to count, that they are irreversibly damaged, causing their mass death and leads to death of the organism as a whole.

Quite a long time, scientists believed that how to tell the authors that cancer occurs as a result of mutations in adult cells of the body, forgetting its role and function, and beginners is uncontrolled when a serious «typos» in the DNA. Research of the last ten years show that this is not true in most cases, and that many types of cancer, in fact, arise as a result of mutations in stem cells, small colonies are present in almost all tissues of the body.

Leonov and his colleagues for several years studying how radiation affects stem cells. Last year they were able to show that stem cells unexpectedly tolerate small doses of ionizing radiation, «stretching» of the phases of division, in which they can quickly repair breaks in DNA.

This discovery led scientists to think about how these episodes may affect the properties are not themselves stem cells, and their distant descendants, resulting from the fission of several generations of descendants of irradiated cells. It is quite possible that their DNA may hide small mutations that will not kill cells directly, but will accelerate their aging or significantly increase the likelihood of developing cancer.

Russian Biophysics checked whether this is so, showering a few samples of stem cells the doses of radiation are used in obtaining x-ray images and other medical procedures and saw how active they breed and what happens inside them in the first days after contact with radiation.

When Leonov and his colleagues irradiated the cells, they increase the activity of the protein gamma-H2AX responsible for repair of double breaks in the DNA helix, and it remained high throughout the day that earlier some scientists believed the sign that it is strong enough to damage the DNA of cells and can generate a huge number of small mutations.

In fact, as the researchers found, similar abnormalities were not associated with radiation, but with a completely different process of cell division, during which DNA may also occur double breaks, the elimination of which also responds to gamma-H2AX.

In the following days and weeks, these stem cells normally grow and thrive, no different from the behavior of non-irradiated cultures of the same cells. In other words, the effects of irradiation of stem cells in the x-ray was not as serious as it was considered previously, and to no serious consequences, it has not, conclude the authors.