Targeting the RUNX1 protein – a transcription factor that helps regulate blood cell development – may provide a new approach to treating acute myeloid leukemia (AML), according to a study led by researchers at Cincinnati Children’s.

The findings, posted online Aug. 27, 2013, in the Journal of Clinical Investigation, found that RUNX1 plays an unexpected role in supporting the growth of AML when the condition is fueled by fusion proteins.

“RUNX1 is generally considered a tumor suppressor in myeloid neoplasms, but our study found that inhibiting its activity rather than enhancing it could be a promising therapeutic strategy for AMLs driven by fusion proteins,” said James Mulloy PhD, a researcher in the Division of Experimental Hematology and Cancer Biology at Cincinnati Children’s and lead investigator.

AML develops and progresses rapidly, requiring prompt treatment with chemotherapy, radiation or bone marrow transplant. These treatments can be risky or only partially effective depending on the patient as well as the variation and progression of disease. Mulloy and colleagues are searching for targeted molecular approaches that could be more effective and carry fewer side effects.

The research team developed a mouse model of AML that is driven by fusion proteins and a mixed-lineage leukemic gene called MLL-AF9. When researchers genetically inhibited RUNX1 and an associated protein called core-binding factor subunit beta (Cbfb) in these mice, it stopped the development of leukemia cells.

While findings based on mouse models do not always translate to human disease, the findings demonstrate that RUNX1 merits further research as a potential therapeutic target for AML.