Scientists demonstrated that pigmentation can be restored in albino mice (without pigment) by correcting a genetic mutation in the hair follicle, according to a report in the January 2000 issue of the journal Nature Biotechnology. The authors say hair follicles may someday manufacture proteins for other gene therapy applications.
Researchers created DNA molecules, the chemical basis for inherited traits. The corrective DNA was then applied directly to hairless skin or injected just below the surface. Within a few weeks, pigmented hairs emerged in the treated areas, and tests confirmed the DNA sequence was repaired. In a corresponding commentary, the findings are said to have future commercial potential.
The chief investigator of this study says hair follicles are likely to serve as factories for gene therapy. “The hair follicle can serve as a protein bioreactor [factory] for all different kinds of gene repair,” says Kyonggeun Yoon, PhD, a basic research scientist and associate professor of dermatology at Jefferson Medical College in Philadelphia. “But clinical applications are a long way off. And there’s lots of work to do in delivering corrected DNA more efficiently and selectively.” Yoon says new efforts will focus on more permanent results.
“So far, pigmentation only seems to last about three months after application of corrected DNA. But we think we can enhance DNA delivery to the hair follicle,” says Yoon. “Other possibilities are to correct the mutation at a different stage of hair growth or to correct the DNA in stem cells that give rise to [other cells].” Yoon says she and her colleagues have developed another technique that may someday be used to treat serious dermatological (skin) disorders.
“We’ve also shown that gene repair can also restore pigmentation to skin cells … in albino mice. And there are two genetic disorders that might benefit from this technique,” says Yoon. “One causes skin cancer to develop in sun-exposed areas called xeroderma pigmentosum. The other is called epidermolysis bullosa and is characterized by severe skin blistering.”