Top stem cell researchers moving west to Stanford

Stefan Heller

Michael Clarke

Last November, when California voters approved a measure to fund stem cell research, experts predicted that some of the country's finest scientists would make their way to the Golden State. Now two such researchers have done just that: Stefan Heller, PhD, associate professor of otolaryngology at Harvard Medical School, and Michael Clarke, MD, professor of internal medicine at the University of Michigan Medical School in Ann Arbor, have announced that they are joining the Stanford Institute for Cancer/Stem Cell Biology and Medicine.

Philip Pizzo, MD, dean of the School of Medicine, hailed the two researchers as important additions to Stanford's stem cell research effort. "We are thrilled to have Drs. Clarke and Heller join Stanford," Pizzo said. "I am confident that they will contribute to the important role that Stanford will play in biomedical research and, specifically, our agenda in stem cell and regenerative medicine research."

Scientists believe that research on stem cells could lead to a host of new treatments for diseases, in which these cells are used to create new tissues to replace damaged ones. Lately, much attention has been paid to stem cells from embryos, which can divide to form all tissues of the body. But stem cells from adult tissues, which can divide to produce only cells from that tissue, have already shown great promise. Indeed, adult stem cells isolated at Stanford have already been used successfully to treat disease.

Although the federal government has refused to fund research using new embryonic stem cell lines, California voters approved spending nearly $3 billion in state funds for that and other types of stem cell research over the next 10 years. Both Clarke and Heller said the state's new institute for regenerative medicine, which was established to award the stem cell money, wasn't the only reason they chose to come west to Stanford, but that it certainly played a part in their decision-making.

"I think with the new California Institute for Regenerative Medicine it's a tremendous opportunity for stem cell research," Clarke said. While his current work doesn't involve embryonic stem cells, he said the state's commitment to stem cell research would create a rich community for all stem cell researchers. Clarke added that his future work may involve embryonic stem cells, making increased funding in California a powerful incentive for moving west.

Like Clarke, Heller primarily works with stem cells taken from adult tissues: the inner ear. Still, he also has used embryonic stem cells on occasion, and in those instances he has received money from private donors to fund such embryonic stem cell work. Heller said it would be easier to seek state support in California. "It will give me more chances to apply for funding and conduct certain experiments," he explained.

Both Clarke and Heller are known for being the first to isolate specific types of stem cells.

While at Michigan, Clarke became the first to isolate stem cells from breast tumors. These are the cells that divide and propagate the cancer. Previously, researchers had found stem cells in blood cancers, but there was some doubt as to whether solid tumors also contained these deadly cells. Clarke's 2003 paper put such doubts to rest. "I think that more and more people are coming around and believe that cancers have a self-renewing stem cell population," Clarke said.

Clarke's arrival in September will bolster efforts already under way at Stanford to isolate cancer stem cells in a variety of tumor types. Last year a Stanford group led by Irving Weissman, MD, director of the Institute for Cancer/Stem Cell Biology and Medicine, isolated and characterized cancer stem cells that lead to the acute phase of chronic myelogenous leukemia. By finding the stem cells that allow a cancer to flourish, Clarke and Weissman hope to learn more about how to stop those cells from dividing—laying the basis for finding a cure for cancer.

Clarke will be a professor in the Department of Medicine and associate director of the Institute for Cancer/Stem Cell Biology and Medicine.

Heller's laboratory was the first to demonstrate the existence of pluripotent stem cells within the inner ear. He now studies how these and other stem cells might be coaxed to grow into mature hair cells—sound-sensing cells located in the cochlea. His work raises the possibility of eventually treating deafness with a transplant of these cells.

"Should these efforts yield a means of replenishing lost hair cells, millions of individuals who suffer hearing loss could potentially be helped," said Robert Jackler, MD, professor and chair of the Department of Otolaryngology, who helped recruit Heller from Harvard. "We could well see a conquest of deafness."

The majority of hearing problems, from childhood deafness to age-related hearing deficiency, derive from the loss of hair cells. Heller's work focuses on regenerating such cells from both adult and embryonic stem cells and using the cells to replace a deaf person's damaged tissue. It's important to explore various ways to treat hearing loss, he said, as deafness comes in many different forms.

Upon his October arrival, Heller will become an associate professor in the otolaryngology and molecular and cellular physiology departments. He will lead the otolaryngology department's integrated research laboratory, and he will collaborate with scientists in the Institute for Cancer/Stem Cell Biology and the Stanford Neuroscience Institute, led by William Mobley, MD, PhD.