Damage to genetic material can lead to mutations that force cells to uncontrollably divide, leading to cancer.
When cells are prepared for separation, their DNA is heavily wrapped around proteins, forming chromosomes. The latter support genetic material. At the end of these chromosomes there are repeatable parts of DNA, the bodymers. They form a protective cap that prevents damage to genetic material.
However, telomers are shortened every time a cell is divided, which means that as cells multiply more and more as they grow older, they become shorter and more likely to lose their ability to protect DNA.
However, cells avoid turning into cancer when their thermometers become too short, and they become zombie cells, a state that stops the division of cells in the process of aging.
Consequently, if such cells do not die, they accumulate in the body; researchers say that they can be healthy because they contribute to the ageing of nearby cells at risk of cancer; they also attract immune cells to destroy cancers.
On the other hand, zombie cells can contribute to the development of the disease, disrupt tissue recovery and immune function, and release chemicals that contribute to the inflammation and growth of the tumor.
The authors wanted to see if direct damage to the body could cause aging and zombie cells, and they attached protein to human cells grown in the lab, and then added a dye to the protein that made it sensitive to light.
If you irradiate cells with long-range red light, it causes proteins to produce free oxygen radicals -- these are high-reactive molecules that can damage DNA. This process takes place directly in the telomers, the rest of the cell remains intact.
The authors found that the direct damage to the body was sufficient to turn the cells into zombies, even if the protective caps were not shortened, probably due to a violation of DNA replication in the bodymers, making the chromosomes even more susceptible to damage or mutations.