MINNEAPOLIS, May 7, 2008—Researchers at the University of Minnesota may have discovered what they are calling the 'Achilles’ heel" of leukemia.

The finding may represent a major step forward toward resolving the long-standing medical controversy about which cells are the source of leukemias, cancer of the blood and bone marrow, and possibly other cancers.

An article about this laboratory discovery is published today in the journal Cancer Cell. 

“Determining whether more mature progenitor cells or the younger stem cells in the process of forming are at greatest risk for leukemia has been a research controversy for a long time,” said John Kersey, M.D., pediatric cancer researcher at the Masonic Cancer Center and lead investigator on the study.

“We found that it is the young stem cells that are at greatest risk,” said Kersey. “The young at-risk cells are extremely rare – less than one in 1,000 stem cells – but it is in that one cell that leukemia starts. That stem cell is the Achilles’ heel of leukemias.”

Kersey and his colleagues made this discovery in connection with acute leukemia, the most common childhood cancer. Current treatments cure more than 80 percent of children older than two years when diagnosed with ALL. That cure rate drops to much lower levels in infants who have leukemia caused by the cancer gene MLL-AF9.

For this laboratory study, Kersey and his colleagues Weili Chen, M.D., Ph.D., and Ashish Kumar, M.D., Ph.D., used stem cells from young mice created to contain abnormal cells with the rearranged gene called MLL-AF9. The researchers sorted the candidate cells into the young stem cells or the more mature progenitor cells. They found that the young stem cells containing the MLL-AF9 gene were the ones that caused leukemia in the mice that is similar to the type that affects infants.

“We believe our finding has significance for all types of cancer because stem cells may be the Achilles’ heel in most if not all human cancers,” said Kersey. “It points out the critical need for research to better understand the complicated intricacies of stem cells and their potential for healing as well as harm.”

University of Minnesota news release