On Assignment: for USC Health Magazine of the University of Southern California. I interviewed Martin J. Pera, PhD, founding director of the Center for Stem Cell and Regenerative Medicine at the Keck School of Medicine of USC.
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Promises to Keep
A pioneer in the development of human embryonic stem cells returns home to direct the USC Center for Stem Cell and Regenerative Medicine.
By Nikolas Charles
Fall 2006
"The woods are lovely, dark, and deep, but I have promises to keep, and miles to go before I sleep..."
Robert Frost, the country’s unofficial poet laureate, penned these words in 1923. Decades later, Martin F. Pera took them to heart. As a new Ph.D. graduate with a passion for science, he made a promise to himself that he would impact scientific research no matter how far he had to travel to keep that promise.
His travels began immediately after he received his B.A. in English language and literature from the College of William and Mary in Virginia. From there, he went to Washington, D.C. for a Ph.D. in pharmacology from George Washington University and then England for his postdoctoral work at the Institute of Cancer Research and the Imperial Cancer Research Fund in London, and as a research fellow in the Department of Zoology at Oxford University.
It was in England that his research vision began to take shape. Pera received a National Research Service Award from the National Institutes of Health to do a postdoctorate at the Institute of Cancer Research in London.
Today, he is founding director of the newly created Center for Stem Cell and Regenerative Medicine at the Keck School of Medicine of USC. It is the largest stem cell center in California, and will be housed in the Broad Institute for Integrative Biology and Stem Cell Research.
Pera looks back at his accomplishments and how they influenced him. “I got a two-year fellowship in England intending to come back to the states after that and wound up staying for 16 years,” Pera says. “I went there to work on an anti-cancer drug called cisplatin, which was just coming into widespread use for treating tumors of the testes and other neoplasms. While working there I soon became convinced that the cells we were killing with this drug were more interesting than the drug.”
His new interest led to an opportunity to study the cell biology of testes tumors at the Royal Marsden Hospital near London. “When we removed tumors from patients and looked at them in the microscope, we saw very primitive cells but we also saw various types of mature tissue,” Pera says. “Our whole concept of the embryonic stem cell came from a study of these cancers in mice.”
As Pera’s involvement in stem cell biology and research grew, so did his dedication. “While I was a research fellow at Oxford University from the mid-1980s to mid-1990s, we developed cultured cell lines from these cancers in patients. We knew that the stem cells we had were pluripotent—cells that are able to develop into several different types of cells or tissues in the body,” Pera explains. “At that time, we weren’t studying stem cells with a goal of developing future cell therapies; we were studying them because they were a biological phenomenon.”
There were only a few groups in the world doing this research at that time. Pera and his team knew they had found something of great significance. “The trouble was that what we found was very different from what had been studied in mouse embryonic stem cells,” he says. “We were still unclear whether they resembled the normal stem cell or if they were an aberration due to the process of cancer development and the many genetic abnormalities that are present in the cells.”
In the mid-1990s there was a turning point when James Thomson, Ph.D., professor of anatomy, University of Wisconsin-Madison Medical School, published a paper showing he could derive normal stem cell lines from rhesus monkey embryos. “It turns out that many of the features of these pluripotent stem cell lines were similar to the cells that we’d been studying from human cancers,” Pera says. “When I saw that paper by Thomson, I thought there was a good chance that we could develop normal embryonic stem cells directly from unused in vitro fertilization human embryos.”
Pera has several early influences, including viral oncologist Robin Weiss, Ph.D., who gave him his first opportunity at the Institute of Cancer Research in London and Professor Sir Michael Peckham, with whom he worked at the Royal Marsden Hospital. Pera also named geneticist Roy Stevens, Ph.D., from the Jackson Laboratory in Maine and pathologist Barry Pierce Jr., M.D., from the University of Colorado Health Sciences Center, as scientists who inspired him. “Their work was responsible for a lot of our thinking about embryonic stem cells and about stem cells in cancer.”
But staying true to his promise to follow where progress would lead him, Pera went to Monash University in Melbourne, Australia for the opportunity to work with Alan Trounson, Ph.D. “He was interested in developing stem cell lines from human embryos,” Pera says. “Because of my background in the cell biology of this particular cell type and my track record in developing and characterizing the cell lines, Trounson recruited me to his group.”
Trounson was already well known in the scientific community as a pioneer of in vitro fertilization (IVF). It was the Monash research team of Carl Wood, M.D., and John Leeton, M.D., who reported the first IVF pregnancy in 1973.
Pera made advances in Melbourne, producing work that impacted the scientific community. Before leaving Australia to join USC, Pera was research professor and co-director of the Monash Institute of Medical Research and director of embryonic stem cell research at the Australian Stem Cell Centre, where he also was one of the founding scientists.
“From the early days in Melbourne, one of the most difficult things was explaining what we were doing and what was the potential. I always try to make it clear that while there is enormous potential for this work on human embryonic stem cells, there is much work to do before we get to clinical applications. One of the difficulties has been walking the fine line between communicating the vast potential without promising too much.”
While the potential of stem cell research is clear, most researchers assert that it is nearly impossible to broach the subject out of academic circles without either ethical or legal debates abounding. Pera agrees: “We’ve done a lot in the way of public education over the past eight or nine years. I try to stick to the science. I don’t think it’s my job to comment on the ethics or the philosophy behind it.”
Stem cell research has enormous promise but is filled with challenges. So now, after more than two decades away, Pera’s quest for scientific progress has him back on U.S. soil at the Keck School of Medicine of USC. Here he hopes to keep his promise of advancing the application of stem cell research in regenerative medicine and to address its challenges.
Pera came back to the states specifically to work at USC. “It was too attractive of an opportunity to pass up,” he says. “I think California is going to be one of the world’s centers for this type of work because of the commitment of the state. And USC’s commitment to stem cell research is certainly strong and impressive.” He adds that in addition to running the research group, he wants to help younger scientists achieve their potential. “This was the right time and the right place for me to take on this new challenge.”