These prizes, offered by the Kirk A. and Dorothy P. Landon Foundation and the American Association for Cancer Research, are the largest offered to cancer researchers from a professional society of their peers. Each recipient will receive an unrestricted cash award of $200,000 and present a scientific lecture at the AACR Annual Meeting, held this year from April 16-20 in Anaheim, Calif.
This year's winners are:
"These two outstanding women have produced major breakthroughs in our understanding into the etiology of cancer, with significant implications for the targeted treatment of various cancers," said Margaret Foti, Ph.D., M.D. (h.c.), AACR's chief executive officer. "I am particularly pleased that we are presenting these prestigious awards to two such deserving and trail-blazing scientists."
For more than a quarter century, Elizabeth Blackburn has been investigating the structure and role of telomeres, the tips of genetic material at the end of chromosomes. Prior to her work, all that was known about telomeres (from the Greek word for 'end' and 'part') was that they became shorter with each cell division and, by implication, served as a kind of biological clock that was partly responsible for natural aging.
As a postdoctoral fellow, Blackburn worked to identify the genetic nature of telomeres, showing that they consisted of a series of tandem repeats of a simple DNA sequence. Although the exact sequence of the repeat differs from one species to another, this feature of telomeres holds true for virtually all organisms.
This work set the stage for a second discovery, published in 1985 with then graduate student Carol Greider, Ph.D., of an enzyme called telomerase which is needed if telomeres are to replicate. Though telomerase was found to be critical for normal cell growth, it also was found to play a role in the uncontrolled growth of cancer cells. Scientists now recognize that some 80-90 percent of all cancer cells contain lengthened telomeres, with relatively large quantities of telomerase.
More recently, Blackburn has been applying her insights into telomere biology to the development of a new anti-cancer therapy that forces cells with active telomerase to make errors during telomere synthesis, effectively triggering cellular suicide.
As the enzyme normally is damped down at a certain time in the life of many types of cells, scientists also are exploring whether it could be carefully reactivated to prolong cell life, in order to treat age-related and neurodegenerative disorders, ranging from skin wrinkles to blindness to cardiovascular disease.
"I am deeply honored to be receiving this award," said Blackburn. "The study of telomeres and the telomerase enzyme that creates them has been, and continues to be, a fascinating and rewarding exploration.
"Insights into the role of the telomerase enzyme in some cancers, and the possibility that these findings could lay the groundwork for targeted therapies, are extremely gratifying. Many of us in the field are working hard to advance this prospect."
Janet Rowley is being honored for her groundbreaking contributions to the understanding of how chromosomes can exchange genetic material, resulting in the uncontrolled growth of cells that characterizes cancer. She discovered the first such "translocation" in early 1972, while sorting through photographs of chromosomes from a patient with acute myelogenous leukemia. In this case, she observed that chromosome 8 appeared to trade genetic material with chromosome 21; part of 21 had broken off and moved to chromosome 8, and part of 8 had moved to 21.
Later that same year, she discovered that another defect linked to chronic myelogenous leukemia (CML), known as the Philadelphia chromosome, also resulted from a translocation between chromosomes 9 and 22.
Dr. Rowley and colleagues have since identified several additional chromosomal translocations characteristic of other malignancies, such as the 14;18 translocation seen in follicular lymphoma; and the 15;17 translocation that causes acute promyelocytic leukemia (APL).
This work set in motion the current era of cancer genetics, which has served as a foundation for the identification and validation of myriad new drug targets in human cancers across a variety of tumor types.
"It's an honor to receive such prestigious recognition and to join other distinguished winners who have received this award in the past," said Dr. Rowley.
"I am especially pleased because this award recognizes the critical contributions to cancer research of cytogeneticists worldwide. Our collective discoveries have changed how patients are treated and, in collaboration with other scientists, have led to the discovery of amazingly effective drugs to treat leukemia."
The Landon-AACR Prizes for Basic and Translational Cancer Research were launched in the summer of 2002 to promote, recognize and reward seminal contributions to our understanding of cancer through basic and translational cancer research. These distinguished scientific prizes bring heightened public attention to landmark achievements in the continuing effort to prevent and cure cancer through quality research.
Founded in 1907, the American Association for Cancer Research is a professional society of more than 24,000 laboratory, translational, and clinical scientists engaged in all areas of cancer research in the United States and in more than 60 other countries. AACR's mission is to accelerate the prevention and cure of cancer through research, education, communication, and advocacy. Its principal activities include the publication of five major peer-reviewed scientific journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. AACR's Annual Meeting attracts more than 15,000 participants who share new and significant discoveries in the cancer field. Specialty meetings, held throughout the year, focus on the latest developments in all areas of cancer research.