St. Jude Unlocks Mystery of Very Aggressive Leukemia

- Loss of Arf gene in acute lymphoblastic leukemia makes some forms of this cancer resistant to treatment with imatinib, but blocking JAK kinases can restore the sensitivity of cells to this drug
Investigators at St. Jude have used mouse models to determine why some forms of acute lymphoblastic leukemia (ALL) are very aggressive and resistant to a drug that is effective in treating a different type of leukemia.
The investigators found that the combination of a mutation called Bcr-Abl and the loss of both copies of the tumor suppressor gene Arf in bone marrow cells triggers an aggressive form of ALL. Inactivation of both Arf genes allowed the multiplication of leukemic cells that did not respond to the drug imatinib (Gleevec