"As the community of scientists on the front lines of the battle against cancer, we are firm in our belief that continued experimentation with human stem cells is necessary to improve evaluation of anti-cancer drugs, to identify markers for early detection of cancer, and to illuminate the path to novel, targeted treatments," said Lynn M. Matrisian, Ph.D., AACR past president and Ingram Distinguished Professor of Cancer Research at Vanderbilt University in Nashville, Tenn.
"Our belief is based on the results of peer-reviewed research, the strength of professional integrity and long-standing ethical principles, and profound respect for human life," added Matrisian, who also is professor and chair of the department of cancer biology at Vanderbilt.
The association's statement is equally vehement in its rejection of any technology, including stem cell technology, used in human reproductive cloning, noting that, "such attempts have no beneficial goal and can be reasonably assumed to cause harm." At the same time, the AACR position supports the "ethical use of somatic cell nuclear transfer," noting that the technique, "promises to reveal the role of specific genetic alterations in tumorigenesis and further refine evaluations of drug activity, as well as generate immune-compatible material for transplant therapies."
The primary points of the AACR position on stem cell biology are:
# Human stem cell research will elucidate critical aspects of cell growth and differentiation that are altered during the formation and growth of tumors.
# Research on tissue-specific stem cells from adults may reveal the body's innate maintenance and repair mechanisms.
# Embryonic stem cells have the ability to transform into the cells of every major organ system in the human body. If this characteristic can be controlled, then medical researchers could determine the signals that direct the development of human tissues, including cancers.
# Bone marrow stem cells already have demonstrated their value in replenishing blood and immune systems damaged by cancer or cancer treatment. Research on human embryonic stem cells may extend this promise by providing a transplantable cell source that avoids the problems of immune rejection.
# Cancer stem cells have been described as the progenitors of breast, prostate, brain and other malignant tumors, raising the prospect of eliminating tumor recurrence following initial treatment and developing cancer therapies that are truly curative.
# Embryonic stem cells' ability spontaneously to form tumors should not hinder the progress of stem cell research, since these cells will be used only as precursors to the differentiated cells needed to replenish damaged tissue.
In light of the recent cloning of patient-specific human embryonic stem cells by researchers in South Korea, AACR Science Policy and Legislative Affairs Committee Chairman William G. Nelson V, M.D., Ph.D., pointed to the clause in the AACR position statement encouraging grant-making institutions to "work toward stable and sufficient funding for meritorious stem cell projects, free of political uncertainty, so that young investigators are encouraged to devote their careers to this important field."
Said Nelson, professor in the departments of Oncology, Urology, Pharmacology and Molecular Sciences, Medicine, Pathology, and Radiation Oncology and Molecular Radiation Sciences, at Johns Hopkins University, "The United States is so closely associated with scientific advancements that the first question on everyone's mind was, 'why wasn't this huge medical breakthrough made by Americans?'
"Sadly," he continued, "American stem c ell biology suffers from a small and unsteady flow of graduate students, post-doctoral fellows and early-career faculty. No scientific discipline can grow without the constant infusion of new talent and new ideas."