November 15, 2005
Scientists Seek New Treatments for Balding
NEW YORK -- Look around a crowd, and you'll see that lots of middle-aged men are losing their hair. As Baby Boomers, they have every right to demand, What is science doing about this? Quite a bit, it turns out.
A British company, for example, says five guys are walking around with hundreds more hairs than they had before, thanks to an early test of what's been called hair cloning. An American outfit hopes to start testing a similar approach next year.Other scientists are tracking down genes that make some men susceptible to hair loss, and struggling to understand the mysterious biology behind it. For example, how can men lose hair on the top of their heads while their beards and even eyelashes keep going strong?
Black men are far less susceptible, but about a third of 30-year-old white men have signs of what doctors call male-pattern baldness. By the time they're 50, about half of them do. The condition creeps across the head like three tiny armies bent on deforestation: one starting at the back, and two making inroads from the front.
Sure, some men say bald is beautiful. And others can smear on minoxidil (Rogaine) or take Propecia pills, or get hair transplants.
In fact, right now is "the best time in history to be going bald, because there's an awful lot of things that can be done," says Dr. Ken Washenik of the Aderans Research Institute in Philadelphia, which is investigating the "hair cloning" approach.
But the drugs don't help everybody, and not everyone is interested in a transplant. So there's room for new approaches.
To understand the search for new treatments, it helps to know a little about hair and male pattern baldness. (Women can also get hormone-induced baldness like this, but it's not clear if it's really the same condition).
Everybody starts out with a lifetime supply of about 100,000 follicles on the scalp, each primed to produce a single hair shaft. Normally, any given follicle pumps out that shaft for two years to six years, then takes a break for a few weeks. Then it sheds that hair, and starts the cycle over again.
Each day, we lose about 100 hairs this way. No big deal; about an equal number of follicles enter the growth phase on the same day, and at any one time about 90 percent to 95 percent of the follicles are busy growing new hair.
But in some men, in selected places on the scalp, this orderly process goes awry.
The hair-growing phase gets progressively shorter and the resting phase gets longer. So the resulting hairs get shorter and shorter with each trip through the cycle. Eventually, they don't even poke out through the scalp.
What's more, affected follicles take longer to start growing hair again after they've shed the last one. And they shrink, so the hair they produce is finer. On your head, it's like replacing mighty trees with saplings. And the total number of remaining hairs slips by about 5 percent a year.
What causes this? The full picture isn't known, but it clearly involves a combination of genetic susceptibility and hormones, including testosterone.
Researchers are eager to identify the biochemical actors within follicles that could be manipulated to fight baldness. As for genetics, some studies have implicated a particular gene that may be necessary to get the condition but not sufficient to produce baldness on its own, said Stephen Harrap of the University of Melbourne in Australia.
In all, it might take inheriting certain versions of about five genes to get the condition, like getting a bad poker hand, suggested Rodney Sinclair of the university.
In England, meanwhile, a company called Intercytex has just begun human studies of an approach sometimes called hair cloning. It focuses on a particular kind of cell, found at the base of the follicle, that can team up with skin cells to produce new follicles.
Here's the idea: Extract some cells from the areas of a man's head that resist balding, put them in a lab dish and expand their numbers by thousands of times. Then inject these new cells back into the scalp, where they'll work with skin cells to form new follicles. So, unlike transplants, the guy actually ends up with more hairs than he started with.
The company has recently tested this on seven men with thinning hair due to male pattern baldness, and five of them gained hair, says Intercytex chief scientific officer Paul Kemp. This was just an initial study to look for side effects like inflammation, Kemp says, and no such problems appeared.
Not that this restored a full head of hair. The treated areas were just the size of a quarter, and covered places that already had hair, rather than bald spots.
"We didn't want to create these weird and wonderful patterns on their head," Kemp said. "It's such a small area in the hairy area anyway, I would be surprised if they really knew any difference."
Eventually, if further studies go well, the technique could allow hair transplant surgeons to cover more of a bald head, Kemp said. The next round of human research is expected to start next summer.
Someday, men might avoid transplants altogether, just getting periodic shots of their own cells to counterbalance their hair loss. "You would be going thin, and you'd be maintained," Kemp said.
"Sometime in the future, I think baldness will be a choice rather than something you have to suffer," said Kemp. "Any bald people will have chosen to be bald."
Within five years, Kemp says, his company may have a commercial product.
Washenik, of the Philadelphia-based Aderans institute, said his group's efforts in hair cloning have shown promise so far in mice. He hopes studies in people can begin next year.
He said follicles that grow from the transplanted cells should resist balding, because they come from a part of the head that balding doesn't touch. Ordinary hair transplants show that follicles from these resistant regions stay resistant even when planted in bald regions, he said. But even if the transplanted cells do eventually succumb, "you've got years of hair on your scalp that's of benefit to you," said Washenik, who also works for a hair transplantation business called Bosley.
Ultimately, he said, scientists would love to accomplish the same goal with a cream that can be smeared on the scalp and deliver just the right chemical signals to stimulate new follicles to grow.
In any case, he said, it's not just about hair.
Hair follicles, after all, are organs. So what's learned from follicle research may help other scientists who are working to regenerate bigger organs like the liver and kidneys, Washenik said.
The same notion was expressed by Sinclair, who's testing a skin cream in mice that may alter follicle behavior by fiddling with genes. (He says he can't discuss the results because they are a commercial secret.)
Sinclair said follicle research allows scientists to approach not just organ regeneration, but also questions about stem cells, cell growth and gene therapy that may pay off someday in new treatments for diseases like cancer and Alzheimer's.
"The idea of growing hair on a bald scalp is only of moderate interest," Sinclair said in a telephone interview. "If we find the cure for baldness we're not going to stop studying hair."
That's just great, Doc.
But if you do find the cure for baldness, lots of men would like to know.
On the Net:
Stages of male pattern baldness: http://www-ermm.cbcu.cam.ac.uk/02005124h.htm