U Researcher Proves Potency of Tumor-Killing Cells from Human Embryonic Stem Cells

Research shows the cells are effective in completely killing tumors and preventing organ metastasis 

Watch a video of Dr. Kaufman explaining his discovery

MINNEAPOLIS / ST. PAUL (May 4, 2009) — University of Minnesota researcher Dan Kaufman, M.D., Ph.D., a pioneer in deriving natural killer (NK) cells from human embryonic stem cells, has proven the effectiveness of those NK cells in killing human leukemia in a mouse model.  Furthermore, he has shown that these human embryonic stem cell-derived tumor-killing cells are highly effective in killing breast cancer, prostate cancer, testicular cancer, and brain tumor cells in the laboratory.

Natural killer (NK) cells are a naturally occurring type of cell that work as part of the human immune system to protect the body from invaders, such as viruses or tumors. However, when cancer overwhelms the immune system, scientists have sought other sources of NK cells as a targeted boost to immunity.

Kaufman and his team, who have published a broad range of leading-edge work in blood cell development from human embryonic stem cells, have now demonstrated that NK cells produced from human embryonic stem cells are more homogeneous, and thus more potent in killing those tumors in mice, thereby preventing the cancer from metastasizing in any of the animal’s organs. In addition, Kaufman and his team showed these cells were more effective than other NK cell populations, such as umbilical cord blood-derived NK cells, that were tested.

“These recent studies really advance previous work done in our lab to produce a population of natural killer cells from human embryonic stem cells,” Kaufman said. “We’ve now proven that these cells are much more potent and effective at killing tumor cells than those coming from other sources like human umbilical cord blood, and we’ve been able to identify some of the reasons why. With the recent rule changes surrounding embryonic stem cells in Washington, it is exciting that this work is now coming out.” 

When they compared the two types of NK cells, Kaufman and his team were able to determine that NK cells developed from human embryonic stem cells mature much earlier than those developed from umbilical cord blood, evident by the types of proteins and molecules the cells expressed; this allows them to function more effectively than NK cells from other sources. Human embryonic stem cell–derived NK cell populations were also found to have a higher percentage of highly potent NK cells with the ability to effectively attack and kill tumor cells.    

Kaufman is enthusiastic about the potential of human embryonic stem cell-derived NK cells to lead to the next generation of cancer therapy. He said, “The next key goal is to be able to produce enough of these cells to treat patients rather than just mice. Based on the history of cell-based therapies at the University, I see this as very feasible. But it will take time based on the resources available to get to the scale of human treatments.”

Kaufman’s paper, entitled, “Human embryonic stem cells differentiate into a homogeneous population of natural killer cells with potent in vivo anti-tumor activity,” will be published in an upcoming issue of Blood and is currently featured online as a First Look paper.

Kaufman is an associate professor in the Division of Hematology, Oncology, and Transplantation at the University of Minnesota Medical School, associate director of the Stem Cell Institute, and member of the Masonic Cancer Center.

Dedicated to excellence, diversity and service, the University of Minnesota Medical School educates the next generation of physicians, advances patient care, and discovers breakthroughs in biomedical research that enhance health in Minnesota and beyond. Its commitment to transform medical education, Rural Physician Associate Program, and success in training Native American physicians are well-known. More than 1,500 Medical School physicians and scientists provide world-class care and carry out nearly $200 million in research, which informs the treatments and care that patients receive. For more information, go to www.med.umn.edu.

Contact:          
Laura Stroup, Academic Health Center, 612-624-5680 or stro0481@umn.edu 
Nick Hanson, Academic Health Center, 612-624-2449 or hans2853@umn.edu