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.

Wing Leung, M.D., Ph.D., director of St. Jude Bone Marrow Transplantation and Cellular Therapy, has taken a different approach to developing NK cells as a weapon against cancer. Leung has published a series of papers focusing on the genes for assembling killer immunoglobulin-like receptors or KIRs. KIRs are carried on the surface of the NK cell and help the immune cells recognize and kill cancer cells.

Leung and his colleagues demonstrated KIR proteins help determine whether or not NK cells will target cancer cells. KIR proteins are now the basis of the NK donor selection Leung’s laboratory does for both St. Jude and the Children’s Oncology Group, the world’s largest cooperative childhood cancer research organization. Recently published work from Leung’s group hints that tracking tiny variations in the composition of KIR proteins might help further improve NK donor selection.

Earlier this year, Leung was senior author of a study of 10 young St. Jude patients with acute myeloid leukemia (AML) who were each treated with NK cells from a parent. The patients had completed standard therapy with anti-cancer drugs and were in remission when they received the donor NK cells. Nearly three years later, the patients are all alive and cancer free. An editorial that accompanied the report in the Journal of Clinical Oncology praised the St. Jude treatment approach, predicting it could have far-reaching implications for improving AML treatment.

St. Jude Children’s Research Hospital
St. Jude Children’s Research Hospital is internationally recognized for its pioneering research and treatment of children with cancer and other catastrophic diseases. Ranked the No. 1 pediatric cancer hospital by Parents magazine, St. Jude is the first and only National Cancer Institute-designated Comprehensive Cancer Center devoted solely to children, and has treated children from all 50 states and from around the world. St. Jude has developed research protocols that helped push overall survival rates for childhood cancer from less than 20 percent when the hospital opened to almost 80 percent today. St. Jude is the national coordinating center for the Pediatric Brain Tumor Consortium and the Childhood Cancer Survivor Study. In addition to pediatric cancer research, St. Jude is also a leader in sickle cell disease research and is a globally prominent research center for influenza.

Founded in 1962 by the late entertainer Danny Thomas, St. Jude freely shares its discoveries with scientific and medical communities around the world, publishing more research articles than any other pediatric cancer research center in the United States. St. Jude treats more than 5,400 patients each year and is the only pediatric cancer research center where families never pay for treatment not covered by insurance. St. Jude is financially supported by thousands of individual donors, organizations and corporations without which the hospital’s work would not be possible. In 2010, St. Jude was ranked the most trusted charity in the nation in a public survey conducted by Harris Interactive, a highly respected international polling and research firm. For more information, go to http://www.stjude.org.

Experts Available:
Dario Campana, M.D., Ph.D., is vice chair for Laboratory Research in the Oncology department and a member of the Pathology department at St. Jude Children’s Research Hospital. He can discuss the use of NK cells in cancer treatment as well as novel approaches to the classification, monitoring and treatment of leukemia and lymphoma.

Wing Leung, M.D., Ph.D., is the director of Bone Marrow Transplantation and Cellular Therapy at St. Jude Children’s Research Hospital. He can offer expertise in NK cell and stem cell transplantation as well as late effect and molecular epidemiology.

Source:  St. Jude Children’s Research Hospital