Tumor suppressor promotes some acute myeloid leukemias, study reveals
AML accounts for over 1 percent of all cancer deaths in the United States and is characterized by an excessive proliferation of hematopoietic stem cells in the bone marrow and their subsequent failure to differentiate into white blood cells. AML can be caused by various combinations of gene mutations. One of the most common mutations is in the gene encoding the cell surface signaling protein FLT3, and patients with this mutation show poor rates of survival. The mutant form of FLT3 can promote cell proliferation, but experiments in mice have shown that it isn't sufficient to block white blood cell differentiation and induce AML on its own. Carol Stocking and colleagues at the Heinrich-Pette-Institute, Leibniz Institute for Experimental Virology in Hamburg noticed that many patients carrying the mutant form of FLT3 also showed increased levels of a transcription factor called RUNX1. "This was unexpected because up to 20 percent of AML patients carry mutations that inactiva...