Discoveries
Hair graying could shed light on malignant melanoma
Folk wisdom says worry causes hair to turn gray. Dana-Farber researchers' discovery of the true source of this process may shed light on the development of the sometimes-deadly skin cancer malignant melanoma.
Magnified melanoma cells
In a study published late last year, DFCI and Children's Hospital Boston investigators reported that loss of hair color results from a gradual die-off of adult stem cells within hair follicles. In younger people, these cells spawn a regular supply of new pigment-making cells, called melanocytes, which give hair its hue. Melanocytes that have acquired a series of cancer-causing mutations give rise to melanoma.
Researchers led by David E. Fisher, MD, PhD, and Emi Nishimura, MD, PhD, of DFCI and Children's Hospital Boston found that a gene called Bcl-2 seems to be necessary for the normal recycling of hair follicle melanocytes. Without a functioning Bcl-2, newborn mice abruptly lost their melanocyte stem cells eight days after birth and subsequently went gray. More gradual stem cell loss occurs with aging.
"The question now is, What in the hair follicle is responsible for melanocyte stem cells dying off?" Fisher asks. That discovery could lead to treatments that mimic the signaling pathway in melanoma cells, causing the cells to die.
