A paradoxical discovery was made by British scientists: Healthy cells of healthy people carry hundreds or even thousands of mutations, but most people do not get cancer, as one would expect.
Scientists at Cambridge University and Genetics Institute Wellcome Sanger, who published the study in Science, discovered for the first time that up to middle age, at least half of the esophagus of healthy people carries cells with cancerous mutations.
The study, which was carried out on nine healthy organ donors who died between the ages of 20 and 75, brings to light a hitherto hidden world of mutations that grow as people grow older. Each of us accumulates genetic mutations throughout his life. As it is now discovered, the healthy cells of the 20-30 year old man’s esophagus have several hundred mutations each, which have grown to over 2,000 per cell in the middle age.
However, only the mutations in about ten genes seem to be the most important ones and those that impart a competitive advantage to a cell to expand and occupy much of the tissue of an organ.
“In the microscope, the esophagus tissue appears totally normal, which is expected when it comes from healthy people without a trace of cancer. But when we made genetic analysis of the tissue, we were shocked, seeing that in fact the healthy esophagus was full of mutations. We discovered that until a man reaches middle age, he probably has more mutated than healthy cells, “said lead researcher Professor Phil Jones.
“We found that genetic mutations associated with cancer spread to normal tissues, thus revealing how our cells mutate, compete and evolve to colonize our tissues as we grow older. Given the importance of these mutations for cancer, it is noteworthy that until now we have been unaware of the magnitude of this phenomenon, “said genetician Dr. Inigo Martincorena.
The basic question – and the paradox – is because these mutant cells, which proliferate faster than normal and thus gradually acquire an organ like the esophagus, are not “translated” into cancer and what is what prevents them from creating a cancerous tumor .
Cancer results from cell mutations. It is estimated that five to ten key mutations in a healthy cell are needed to become cancerous. Some of these mutations can be caused by the environment (solar or other radiation, chemicals, cigarette smoke, alcohol, etc.), while others from the organism itself without an external cause.
“Because someone has cancer-related mutations, it does not really mean malignancy,” said Dr. New York Times, a cancer biologist, Dr. Scott Kennedy, of the University of Washington.
So why is cancer not more common as there are so many hidden mutations inside us? One possible explanation, according to the researchers, is that in each person’s body, as in every ecosystem, there is an uninterrupted invisible “war” between “good” and “bad” mutations (something similar to the “war” between the bacteria) . In a body that remains healthy, probably the harmless mutations have – at least – the upper hand. This possibility opens new healing possibilities for the future.