Radiation Doses: Responsible For Promoting Cancer-Capable Cells

Scientists have discovered that low radiation doses equivalent to three CT scans, which are considered safe, give cancer-capable cells a competitive advantage over normal cells in healthy tissues Researchers at the Wellcome Sanger Institute and the University of Cambridge studied the effects of low doses of radiation on the esophagus of mice.
The team found that low doses of radiation increase the number of cells with mutations in p53, a well-known genetic change associated with cancer. However, giving mice an antioxidant before radiation promoted the growth of healthy cells, which exceeded and replaced p53 mutant cells.
The results published today (July 18) in Cell Stem Cell show that low doses of radiation promote the spread of cancer-capable cells in healthy tissues. The researchers recommend that this risk be considered when assessing the safety of radiation. The study also offers the possibility of developing non-toxic preventive measures to reduce the risk of developing cancer by strengthening our healthy cells to overcome and eradicate cancer-capable cells.
Every day we are exposed to various sources of ionizing radiation, including natural radiation in soil and rocks, and in important medical procedures such as CT scans and X-rays.
Low doses of radiation, such as exposure to medical images, are considered safe, as they cause little damage to the DNA and apparently a minimal long-term health effect. Until now, other effects of exposure to low levels of radiation have remained hidden, which means that understanding the true risk associated with low doses of radiation has been difficult.
Researchers have previously shown that our normal tissues, such as skin, are battlefields where mutant cells compete for space against healthy cells. We all have mutant cells capable of cancer in healthy tissues, including those with p53 mutations, which increase in number as we age, but very few eventually become cancer.
In this new study, researchers show that low doses of radiation weigh the odds in favor of mutant cells capable of cancer in the esophagus. The Sanger Institute researchers and their collaborators gave the mice a dose of 50 milligrams of radiation, equivalent to three or four CT scans. As a result, p53 mutant cells spread and outperformed healthy cells.
Dr. David Fernández-Antoran, first author of the Wellcome Sanger Institute, said: "Our bodies are the set of 'Game of clones', a continuous battle for the space between normal and mutant cells. We show that even low doses of radiation, similar to the value of three CT scans, can weigh the odds in favor of cancer-capable mutant cells. We have discovered an additional potential cancer risk as a result of radiation that must be recognized. "
The researchers then gave the mice an over-the-counter antioxidant (N-acetyl cysteine (NAC)) before exposure to the same level of radiation. The team discovered that the antioxidant gave normal cells the boost needed to overcome and eradicate p53 mutant cells.
However, the antioxidant alone without radiation exposure did not help normal cells fight the mutant clones.
Dr. Kasumi Murai, author of the Wellcome Sanger Institute, said: "Giving mice an antioxidant before exposing them to low doses of radiation gave healthy cells the extra boost needed to fight against mutant cells in the esophagus and make them However, we do not know the effect that this therapy would have on other tissues, as it could help cancer cells in other places become stronger. What we do know is that long-term use of antioxidants by itself it is not effective in preventing cancer in people, according to other studies. "
Professor Phil Jones, lead author of the Wellcome Sanger Institute and the MRC Cancer Unit at the University of Cambridge, said: "Diagnostic imaging procedures that use radiation, such as CT scans and x-rays, have a very high level of risk, low, so low that it is difficult to measure. This research helps us better understand the effects of low doses of radiation and the risks it can carry. More research is needed to understand the effects on people. "
The team suggests that this research also highlights the possibility of developing therapies to prevent cancer. By making healthy cells more fit, they naturally expel cancer-capable cells, without toxic side effects to the patient.

By: Preeti Narula
Content: https://www.sciencedaily.com/releases/2019/07/190718150933.htm