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Stem Cell Expert Simmons to Lead Research Program
An international authority on adult blood stem cells and other bone-marrow stem cells, Paul J. Simmons, Ph.D., will lead a new research effort at The University of Texas Health Science Center at Houston.
“We are thrilled to recruit Dr. Paul Simmons as the leader of the
Center for Stem Cell Biology at the Brown Foundation Institute
of Molecular Medicine for the Prevention of Human Diseases
(IMM). He is an outstanding stem cell scientist, and his recruitment
will elevate our stem cell program to a new level,” UT
Health Science Center President James T. Willerson, M.D., said.
Paul Simmons, Ph.D., far right, inspects his new
lab
space at the IMM’s Fayez
S. Sarofim Research
Building, with current UT Health Science Center at
Houston
Development Board President David
Grimes
and his wife, Windi, left, accompanied
by
Suzie and
Phil Conway, immediate past president
of the
Development Board. Photo by Bruce Bennett
Simmons was program head in stem cell research at the Peter MacCallum Cancer Institute in Melbourne, Australia. His research team focuses on the fine molecular details of blood stem cells and of mesenchymal stem cells, which differentiate into bone, cartilage and fat tissue and are thought to have potential for repairing other types of tissue as well. He also is president-elect of the International Society for Stem Cell Research.
“I am delighted that Dr. Simmons is joining the IMM to direct our Stem Cell Research Center. He will help us recruit additional outstanding scientists to expand our current research effort in stem cell biology,” said IMM Director Ferid Murad, M.D., Ph.D., 1998 Nobel Laureate in Physiology or Medicine.
“This is an exciting time to apply this technology to many important and devastating diseases. He will bring some fresh and important approaches to the institute with regard to stem cell research.”
Simmons is expected to recruit another dozen scientists to the IMM, an effort bolstered by the recently completed $230 million New Frontiers campaign.
“We have a responsibility to drive stem cell research from bench to bedside on a foundation of excellence in basic research,” Simmons said. “This is a new discipline at the juncture of stem cell biology, bioengineering and nanotechnology. New discoveries come at the interface between different disciplines and institutions. The opportunities here in Houston are absolutely outstanding. Who wouldn’t jump at the chance to run a large new stem cell program in the largest medical center in the world?”
Simmons’ work is pushing the boundaries of stem cell research in important ways, said the IMM’s Chief Operating Officer, Director- and CEO-Elect C. Thomas Caskey, M.D. “Dr. Simmons’ success in the study of blood-derived stem cells created the platform which launched research to determine how stem cells are differentiated into red cells, white cells, platelets, muscle or neural cells. Deciphering this important question will lead to unprecedented safe therapeutic solutions.”
Small Number of Specialized Cells
Adult stem cells are specialized cells designed to renew the body’s tissues.
Although every adult organ probably has its own resident population of stem cells, such cells have been identified and their properties
defined in only a limited range of organs. Stem cells in adult
tissues also comprise only a very minor population of the total cells.
Simmons has a strong record of both identifying stem cells and developing culture conditions to propagate adult stem cells to generate the large numbers of cells needed for therapeutic applications.
His research focuses on improving existing treatments with blood stem cells, understanding the molecular details of blood and mesenchymal stem cells and their environments in the body, and using techniques honed in these two areas to branch out into the study of more poorly understood stem cells in other adult tissues, including the lungs and kidneys.
Blood stem cells originate in the bone marrow and differentiate into red cells, white cells, platelets – all the cells required for blood. It is these cells that are given intravenously to restore the blood supply of patients who have been treated for diseases such as leukemia in the misnamed procedure commonly known as a bone marrow transplant.
Simmons is looking at ways of making blood stem cell transplants safer. Patients face a period of about eight days after transplantation when no new mature blood cells are generated, including the infection-fighting white cells. Patients are extremely vulnerable to infection at this time and can die from infectious complications.
Simmons’ group developed a means to include more leukocyte-making progenitor cells in transplants. “The clinical trial in this regard was a complete success,” Simmons said. Infection-fighting cells were boosted and there were no episodes of infection.
However, the team had also hoped to see a greater return of the production of platelets, which promote blood clotting, but this did not occur.
Importance of Clinical Trials
“This highlights the great importance of getting involved in clinical
trials,” Simmons said. “The first part was successful; the second part
was not. So you go back to the bench (the laboratory) with a clear understanding of where improvements are required, design experiments
to identify the problem and to test solutions, and then come
back to the clinic to test the improved protocol. It’s a reiterative loop
that focuses and streamlines translational research with the intention
to optimize clinical outcomes for the patient.”
In the case of mesenchymal stem cells, also produced in the bone marrow, Simmons developed an antibody that served as a biomarker to identify these cells, a breakthrough finding. In a landmark paper three years ago, Simmons’ team reported isolating and purifying a population of mesenchymal stem cells and described their ability to differentiate into bone, cartilage and fat.
The rare mesenchymal stem cells are found at a ratio of about 1 cell in 10,000 bone marrow cells, but Simmons’ team cultured a population in which one in two cells grows into a mesenchymal stem cell. These accomplishments are being replicated in a mouse model.
Simmons plans to apply his methods of identifying, growing and studying adult stem cells in other tissues, in particular the lungs and kidneys.
“There is a paucity of effective treatment for cystic fibrosis, chronic
obstructive pulmonary disease, and other lung diseases,” Simmons
said. “There’s little understanding of the stem cells in the respiratory
system. We need to characterize them in order to study their properties
and to identify regulators of their growth and differentiation. This
will provide important clues as to how to derive lung precursors from
stem cells and will ultimately enable the development of novel cellular
therapies for the treatment of currently intractable lung diseases.”
Another huge area of unmet medical need is kidney disease. “We face a tsunami of kidney disease on the horizon, driven in part by the marked increase in diabetes,” he said. “Short of kidney transplantation, current treatments for renal failure are ‘a band aid.’ More effective therapies will be required. We will seek renal stem cells. It’s a very challenging area but the sooner we get there the better.”
By Scott Merville, Public Affairs