Work underway at St. Jude Children's Research Hospital seeks to harnesses the body's own immune cells known as natural killer, or NK, cells to help children battle cancer. NK cells are the immune system's warriors. The cells circulate widely in the body, armed with proteins, called enzymes, capable of delivering a deadly one-two punch to viruses and cancer cells.
The cancer-fighting potential of NK cells was recognized more than 30 years ago, but until recently efforts to exploit them were hampered because there were too few NK cells and those that could be isolated from donors did not always target tumor cells. St. Jude has emerged as a leading center of research into NK cells as a possible cancer treatment, particularly in children. St. Jude investigators are pioneering efforts on both the clinical and basic scientific fronts.
Dario Campana, M.D., Ph.D., St. Jude Oncology department vice chair for laboratory research, led the successful effort to develop techniques to increase the supply of NK cells available to treat patients. He also directed the successful push to re-engineer NK cells to include an artificial cell surface receptor. The receptor helps the NK cells recognize and target acute lymphoblastic leukemia cells.
NK cells now play a role in at least four St. Jude protocols for patients battling different types of leukemia as well as certain tumors of the bone, muscle and connective tissue known as sarcomas. Another St. Jude trial using NK cells is expected to open later this year. Investigators hope NK cells will extend cures by targeting cancer cells that survive chemotherapy.
"Immune therapies, including NK cells, promise to be able to treat patients who are resistant to chemotherapy because they work in a totally different way," Campana said. NK cells are also being tried against a variety of adult cancers, including multiple myeloma, the brain tumor neuroblastoma as well as cancer of the head and neck. Campana's laboratory is collaborating in those efforts with centers in the U.S. and Japan.