According to McGowan Institute for Regenerative Medicine
faculty members Vera Donnenberg, PhD (pictured top), assistant professor of surgery in the school of medicine at the University of Pittsburgh, Albert Donnenberg, PhD (pictured center), professor of medicine at the University of Pittsburgh, J. Peter Rubin, MD (pictured bottom), associate professor of plastic surgery at the University of Pittsburgh, and researchers at the University of Pittsburgh School of Medicine, fat-derived stem cells can be safely used to aid reconstruction of breast tissue after mastectomy as long as there is no evidence of active cancer.
Plastic surgeons have long moved fat from one part of the body into the breasts for reconstruction, but with some complications and a varying success rate, explained senior author Dr. Vera Donnenberg. More recently, they have considered adding stem cells derived from adipose, or fat, tissue (ADSC) or the bone marrow to the transferred fat with the aim of supporting graft integration by enhancing new blood vessel formation.
“But it has not been clear whether these stem cells are safe for breast cancer patients because they could send growth signals that promote tumor reactivation or provide new blood vessels for the tumor,” Dr. Vera Donnenberg said. “Our research suggests that this risk is real if the patient still has active tumor cells, but is safe when the cells are inactive or resting.”
For the study, the researchers collected adipose tissue that would have been discarded during “tummy tuck” procedures performed by study co-author Dr. Rubin, whose team has several federally funded projects underway to develop fat grafting and stem cell therapies for reconstruction of a variety of tissues.
The researchers isolated ADSC from normal fat and mixed them with human breast cancer cells obtained directly from patients. After 2 weeks in culture they found that ADSC greatly encouraged the growth of tumor cells. In a follow-up experiment, the researchers injected small numbers of highly purified active or resting tumor cells under the skin of mice either with ADSC or with previously irradiated tumor cells. The combination of active tumor cells and ADSC led to dramatic tumor growth, while injections of resting tumor cells were not affected by co-injection of either ADSC or irradiated tumor cells.
“There is already some clinical evidence that breast reconstruction with transplanted fat is safe. Our findings lead us to conclude that augmentation of fat grafts with additional ADSC should be postponed until there is no evidence of active cancer,” Dr. Vera Donnenberg said. “Our data in the mouse suggest that dormant cancer cells are not sensitive to the growth signals sent by the ADSC.”
The study was funded by grants from the U.S. Department of Defense, the National Institutes of Health, the Hillman Foundation, the University of Pittsburgh Cancer Institute, the Glimmer of Hope Foundation, and the Commonwealth of Pennsylvania through the McGowan Institute for Regenerative Medicine.
Illustration: McGowan Institute for Regenerative Medicine.
University of Pittsburgh Schools of the Health Sciences Media Relations News Release (09/15/10)
Bioscience Technology (09/16/10)
Science Daily (09/17/10)
Bio: Dr. Vera Donnenberg
Bio: Dr. Albert Donnenberg
Bio: Dr. J. Peter Rubin
Abstract (Tissue Engineering Part A. Online Ahead of Print: September 17, 2010.)