By Heather Buschman, Ph.D.
Thomson Reuters has selected Erkki Ruoslahti, M.D., Ph.D., cancer researcher and distinguished professor at Sanford-Burnham Medical Research Institute, as one of its 2012 Citation Laureates. Citation Laureates are scientists that Thomson Reuters predicts will go on to become Nobel Laureates.
Citation Laureates are chosen based on how frequently their research is referenced, or cited, by other scientists. This year, Thomson Reuters selected seven designees in the field of health and medicine, including two San Diego-based cancer researchers, Ruoslahti and Tony Hunter, Ph.D., at the Salk Institute.
Many studies have shown a strong correlation between citations and regard by one’s peers, which is a factor often reflected in major professional awards. Using this quantitative approach, Thomson Reuters has made many correct predictions—50 Citation Laureates have won Nobel Prizes. The 2012 Nobel Prizes will be announced beginning October 8.
Ruoslahti is among the 50 most-cited researchers of the last 20 years and an influential figure in cell biology and cancer research. He was one of the early pioneers in research on cell adhesion—the study of how cells stay in place by sticking to one another and to their surrounding environments. Ruoslahti’s work has clarified many of the fundamental mechanisms responsible for clinically relevant problems, including blood clotting, immune cell homing, and tumor metastasis. His research spawned many drug-discovery programs around the world aimed at finding new treatments for arterial restenosis, thrombosis, cancer, and more—some of which have resulted in FDA-approved drugs.
In addition to his research, Ruoslahti distinguished himself through the leadership and vision he provided during his 13 years as president and chief executive officer of Sanford-Burnham Medical Research Institute (1989-2002). Under his direction, Sanford-Burnham’s National Cancer Institute (NCI)-designated Cancer Center became one of the leading basic cancer research centers in the world.
“Dr. Ruoslahti’s seminal research has made outstanding and vitally important contributions to the study of cancer and other diseases that will serve medicine well into the future,” said Kristiina Vuori, M.D., Ph.D., who completed her postdoctoral training under Ruoslahti’s mentorship and now serves as Sanford-Burnham’s president and director of the Institute’s NCI-designated Cancer Center. “It is testimony to Dr. Ruoslahti’s special talents that he has been able to perform cutting-edge research, while running and building a world-class research Institute—an accomplishment matched by few individuals. He is most deserving of the honor of being named Thomson Reuters Citation Laureate.”
From basic biology to nanotechnology
In the early 1970s, Ruoslahti co-discovered fibronectin, one of the first known extracellular matrix proteins, a family of proteins that make up connective tissues and influence cellular growth, movement, and communication. Ruoslahti then pinpointed the short region of the fibronectin protein and other adhesive proteins that allows them to attach to cells—a string of just three amino acids known as RGD. He and his team also isolated the proteins on cell surfaces that bind fibronectin via RGD. These receptors later became known as integrins.
As a result of Ruoslahti’s work, two FDA-approved drugs based on RGD have come to the market. By inhibiting integrin activity with RGD mimics, these therapies prevent reoccurrence of blocked blood vessels following angioplasty, a procedure to widen arteries obstructed by cholesterol and inflammation (atherosclerosis). A number of additional RGD-based therapeutic drugs are currently in clinical trials for cancer.
Ruoslahti also pioneered the opposite approach—taking advantage of RGD’s affinity for integrins instead of blocking it. He and his team coupled anti-cancer drugs to RGD and other short proteins that specifically home to “vascular zip codes,” markers unique to the blood vessels that feed tumors. They’ve found that adding these homing peptides to current anti-cancer drugs increases potency and reduces toxicity. Extensive efforts are underway to develop RGD-based drugs that suppress new tumor blood vessel growth and block metastasis. In addition, Ruoslahti’s team is now using RGD and similar homing peptides to deliver nanoparticles specifically to tumors, in order to boost current anti-cancer therapies.
“It’s now clear that interactions between cells and the extracellular matrix that surrounds them play major roles in cell and developmental biology,” said Ruoslahti. “I’m proud of our contributions to this field and grateful for the opportunity to see our work make a difference in the treatment of patients.”
Other accomplishments and honors
Ruoslahti received his Ph.D. and M.D. from the University of Helsinki in Finland and conducted his postdoctoral research at the California Institute of Technology. He joined Sanford-Burnham’s faculty in 1979 and served as the Institute’s president from 1989-2002. He is currently a distinguished professor at Sanford-Burnham and an adjunct distinguished professor at the University of California, Santa Barbara.
Ruoslahti is a member of the U.S. National Academy of Sciences, Institute of Medicine, American Academy of Arts and Sciences, and European Molecular Biology Organization. He is the recipient of the G.H.A. Clowes Award, Robert J. and Claire Pasarow Foundation Award, Jacobaeus International Prize, and The Jubilee Award given by the British Biomedical Society. He was a Nobel Fellow at the Karolinska Institute in Stockholm in 1995 and is a Knight of the Order of the White Rose of Finland.
In 2005, Ruoslahti was honored with a Japan Prize, one of the world’s major awards for contributions to progress in science and technology and advancement of world peace and prosperity.