Leonard Zon to Deliver E. Donnall Thomas Lecture This Morning
Leonard I. Zon, MD, of Children’s Hospital and Dana-Farber Cancer Institute, Howard Hughes Medical Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, always wanted to be a hematologist. “When I was born, my mother told me I would be a doctor,” Dr. Zon said. “Both of her brothers were doctors, and I think she had a great appreciation for their careers. My father was a rocket scientist, and, at one point I thought about being a chemical engineer, but really medicine was in my blood.”
This morning, Dr. Zon will give the 2010 E. Donnall Thomas Lecture titled “Blood Stem Cell Self-Renewal and Differentiation – Lessons From Embryonic Development.” Named after a Nobel Prize laureate and past Society president, this award recognizes pioneering research achievements in hematology. Dr. Zon is receiving this prize for his groundbreaking research into the development and regulation of hematopoietic stem cells.
“It is a great honor to receive this prize and to be counted in the company of some of my mentors and colleagues who have won it previously, including Stuart Orkin, Sam Lux, and David Ginsburg.” Dr. Zon “grew up” as a hematology fellow by participating in ASH annual meetings and has a special appreciation for the E. Donnall Thomas Lecture. “I have great admiration for Dr. Thomas, who worked on animal models, such as the dog, to define the conditions of bone marrow transplantation and then extended these observations to human trials,” Dr. Zon said. “I hope that my work on the zebrafish model has also had an impact on our understanding of human health and disease and may lead to new therapies.”
As the founding president of the International Society for Stem Cell Research, Dr. Zon is not afraid to take on challenges. Long before starting a biomedical society from scratch, which now has more than 3,500 members, he made an early-career decision to embrace the zebrafish as a model for blood diseases. Determined to create a zebrafish genome map, Dr. Zon organized the zebra-fish community, approached the National Institutes of Health to start a zebrafish genome project, and eventually constructed a radiation hybrid map of the genome.
“It was very important to create new technology for the field,” Dr. Zon said. “When I started my career, there were a lot of questions about using zebrafish as a model. Now, it is much more accepted.” Dr. Zon and his colleagues were able to isolate the genes for most of the orthologs of blood-specific genes, develop a technology for positional cloning in the zebrafish, establish techniques for marrow transplants in fish, and, more recently, solidify techniques for chemical screening in zebrafish.
One of Dr. Zon’s greatest accomplishments was a paper, published in 2007, that found a prostaglandin derivative that could increase blood stem cells in zebrafish embryos. The paper showed that this chemical could increase blood stem cell engraftment in mice and could stimulate human cord blood cell engraftment in immunodeficient mice. The chemical is now in clinical trial for cord blood transplantation for leukemia and lymphoma. “As a physician-scientist, it has been very satisfying to see the basic science translate to the bedside,” said Dr. Zon. “In the future, we would like to understand self-renewal at a molecular level and to find factors that enhance homing and engraftment of hematopoietic stem cells.”
Aside from his many accomplishments, Dr. Zon’s work-related memories are near and dear. “I love the ‘a-ha’ moments,” Dr. Zon said. “When I was a postdoctoral fellow in Stu Orkin’s laboratory, I cloned GATA1. I used a novel expression cloning strategy by transfecting pools of cDNAs into COS cells to find binding activity. Pool 13 had the activity. Once we had the pure cDNA, I typed the sequence into the computer, but the programs had to run overnight. We all got coffee in the morning and appeared early to find out that GATA1 had a zinc finger.”
Outside of this work in hematology, Dr. Zon enjoys spending time with his family. He loves attending his children’s soccer matches with his wife, the head of the allergy program at Children’s Hospital of Boston. Additionally, Dr. Zon has played first trumpet in the Longwood Symphony for the past 26 years. “I have two trumpets that were custom made for me by David Monette, the trumpet-maker who created Wynton Marsalis’ trumpets.”
Another influence in Dr. Zon’s life: his mother. She died from breast cancer when he was in medical school. “I have dedicated my career to her memory,” Dr. Zon said.
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