Immune Therapy Versus Leukemia Stem Cells
Via EurekAlert!, an example of progress in using the immune system to target specific cells for destruction: acute myeloid leukemia (AML) "is a cancer of the white blood cells that has an extremely poor prognosis and does not respond well to conventional chemotherapy. ... The cellular and molecular basis for this dismal picture is unclear. However, previous research has suggested that leukemia stem cells (LSCs) may lie at the heart of post-treatment relapse and chemoresistance ... [researchers] exploited the fact that the molecule CD123 is expressed at very high levels on LSCs but not on normal blood cells. CD123 is part of the interleukin-3 receptor, a protein that interacts with a growth factor (called a cytokine) that influences cell survival and proliferation. The researchers created a therapeutic antibody that recognized and bound to CD123 with the hope that this antibody would selectively interfere with AML-LSC survival. When AML-LSCs from human patients were transplanted into mice treated with the antibody, called 7G3, cytokine signaling in the tumor cells was blocked. Further, 7G3 impaired migration of the AML-LSCs to bone marrow and activated the innate immune system of the host mouse to destroy the AML-LSCs. Overall, treatment with 7G3 substantially improved mouse survival."
Link: http://www.eurekalert.org/pub_releases/2009-07/cp-ntt062409.php