Scientists find link between cancer and gray hair
Researchers have discovered a mechanism where hair pigment stem cells can "sacrifice themselves" by turning into mature cells and causing gray hair to reduce the risk of developing cancer. However, under severe damage such as exposure to carcinogens and ultraviolet radiation, this protective mechanism may fail, and cells begin to divide uncontrollably, creating an environment for melanoma.
Researchers have discovered a mechanism where hair pigment stem cells can "sacrifice themselves" to reduce the risk of developing cancer. According to an article by Professor of Biomedical Sciences at Anglia Ruskin University Justin Stebbing in The Conversation, cited by The Independent, upon certain DNA damage (double-strand breaks), pigment stem cells trigger a process called seno-differentiation. The cell irreversibly turns into a mature pigment cell and disappears from the stem cell pool, leading over time to graying hair. This process prevents the accumulation of mutations that could lead to cancer. However, when exposed to strong carcinogens and ultraviolet radiation in mice, cells bypassed this protective mechanism and began to self-renew and divide despite mutations, creating an environment for melanoma development. Scientists call this "antagonistic fates": the same group of cells can take two different paths. Stebbing notes that gray hair itself does not protect against cancer but is a side effect of the process that removes risky cells. The data were obtained in mice, and it remains to be verified whether this mechanism works in humans. The discovery may help explain the development of melanoma in people without obvious risk factors and the link between cancer and tissue wear in old age.