December 19, 2001 - New York, NY.

New research shows that a gene transfer technique may speed regrowth of hair that has been lost during chemotherapy.

Hair loss occurs in an estimated 85% of chemotherapy patients. Regrowth of the lost hair can take from 3 to 6 months, and a small percentage of patients never completely recover their hair. Chemotherapy-induced hair loss is particularly devastating because it is an outward sign of disease, leading some patients to refuse systemic chemotherapy.

Noboru Sato, M.D., Philip Leopold, Ph.D., and Ronald Crystal, M.D., at the Weill Medical College of Cornell University, New York, NY, investigated hair growth in mouse models and its association with the Sonic hedgehog (Shh) gene. The Shh gene is involved in pattern formation of vertebrate organs, including brain, heart, lung, and skeleton. It also appears to play an important role as an initiator of hair follicle growth. The investigators conclude that delivery of this gene into the skin through an adenovirus vector shows potential as a future treatment for accelerating hair regrowth after chemotherapy. Their results appear in the Dec. 19 issue of the Journal of the National Cancer Institute.

The Shh gene controls production of a protein that is part of the normal hair growth regulation cycle. The Shh gene, which had been inserted into an adenovirus vector, was introduced into the skin of mice that had lost hair after injection of the cancer drug cyclophosphamide. Two weeks after the gene was introduced, the mice that received it showed large hair follicles in an active growth phase. In mice receiving unmodified vector after chemotherapy-induced hair loss, or no treatment at all, the skin showed damaged hair follicles.

The authors conclude that their data support the idea that the Shh signaling pathway acts as a biologic switch that accelerates the initiation of the hair growth phase. Therefore, the use of a transient, localized gene transfer technique may prove to be a useful technology for learning about the mechanisms controlling hair regeneration in a variety of disease states. The authors suggest that such knowledge may lead to treatment for chemotherapy-induced hair loss. Ultimately, a combination of treatments that prevent hair loss and accelerate hair follicle recovery may prove to be the most effective for chemotherapy patients.