Astronauts can develop somatic mutations in the blood circulation system due to their work in extreme environments in space.
Astronauts are at higher risk of developing DNA mutations that can increase the chance of cancer and heart disease later in life, possibly related to spaceflight.
A team from the Icahn School of Medicine at Mount Sinai Hospital (USA) publishes in Nature Communications Biology a study using blood samples from NASA astronauts who flew on space shuttle program missions between 1998 and 2001.
The study
DNA analysis revealed mutations known as somatic (acquired throughout life and not transmitted) in the blood-forming system (hematopoietic stem cells) of the fourteen astronauts studied.
The identified mutations are characterized by the overrepresentation of blood cells derived from a single clone, a process called clonal hematopoiesis (CH).
These types of mutations are often caused by environmental factors, such as exposure to ultraviolet radiation or certain chemicals, and may be the result of cancer chemotherapy or radiation therapy .
Although CH is not necessarily an indicator of disease, it is associated with an increased risk of cardiovascular disease and blood cancer.
” Astronauts work in an extreme environment where many factors can give rise to somatic mutations, especially space radiation, which means there is a risk that these mutations will develop into clonal hematopoiesis,” said David Goukassian of Icahn. Mount Sinai.
The astronauts studied flew relatively short missions (about twelve days), had an average age of about 42 years; approximately 85% were men and six were on their first space trip.
The samples studied, which were stored at -80 degrees for about 20 years, were taken 10 days before the flight and the day of landing, and from white blood cells three days later.
The frequency of somatic mutations in the genes the researchers tested was less than 2%, the technical threshold for somatic mutations in hematopoietic stem cells to be considered clonal hematopoiesis of indeterminate potential (CHIP).
CHIP is more frequent in elderly individuals and is associated with an increased risk of developing cardiovascular diseases and both hematological and solid cancers.
“Although the clonal hematopoiesis we observed was relatively small in size, the fact that we saw these mutations was surprising given the relatively young age and health of these astronauts,” Goukassian said.
It’s not a certainty
However, the presence of mutations “does not necessarily mean” that astronauts will develop these ailments, “but there is a risk that, over time, this could occur from continued and prolonged exposure to the extreme environment of deep space.”
Therefore, the team stressed the importance of continuous blood tests for astronauts throughout their careers and during their retirement to monitor their health.