"This is promising because it means the genetic program for regeneration exists somewhere in the vertebrate family," Heller said. "We know there is an unknown signal to regenerate that we could use, but we first have to find it."
The idea of using drug therapy to cure deafness has been at the back of Heller's mind since he began researching the inner ear 12 years ago, and it has become more plausible as a result of his lab's successes in the field of stem cell research during the past seven years.
Heller gained international attention in 2003 for identifying stem cells that reside within the inner ear. Since then, his research has focused on using these stem cells to regenerate the critically needed hair cells in the inner ear. Later in 2003, his group reached another significant milestone: the team demonstrated that it is possible to coax embryonic stem cells in a test tube to differentiate into hair cells - and then also to have the stem cells differentiate after transplantation in the ears of chicken embryos.
The two different approaches - new drugs and stem cell transplants - are important because drug treatments are unlikely to help everyone. For some people with genetically caused hearing disorders, he explained, no drug is likely to help. "For them, stem cell transplantation may be the answer," he said
But for the majority of those with hearing loss, particularly in the aging population, drug therapy could be the solution. As the population has aged and noise pollution has grown more severe, health experts now estimate that one in three adults over the age of 65 has developed a handicapping hearing loss.
Coming up with the answers is a slow process, Heller said. "This research takes time and money, but we remai
Source:Stanford University Medical Center