Expression data from RDI treated T-ALL cells

RUNX1 and CBFB, which encode subunits of the core binding factor, are frequent targets of chromosomal aberrations in hematological malignancies. We previously determined that CBF (encoded by CBFB) is important for the transforming activity of the chimeric protein AML1-ETO (RUNX1-RUNX1T1) generated by the t(8;21), and other studies showed that normal Runx1 functions are essential for survival and maintenance of some leukemias lacking RUNX1 or CBFB mutations. Thus, we hypothesized that we could achieve therapeutic efficacy in multiple leukemias by targeting the Runx1:CBF interaction with small molecule inhibitors. Using the structure of the DNA binding Runt domain (RD) of Runx1 and its interface with CBF, we employed a computational screen of a library of 78,000 drug-like compounds, and further optimized our initial hits. The Runt domain inhibitors (RDIs) bind directly to the RD and disrupt its interaction with CBF. These tool compounds reduced growth and induced apoptosis of t(8;21) acute myeloid leukemia (AML) cell lines, and reduced the progenitor activity of mouse and human leukemia cells harboring the t(8;21), but not normal bone marrow cells. The RDIs had similar effects on murine and human T cell acute lymphocytic leukemia (T-ALL) cell lines that did not harbor the t(8;21)

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