Cbfbeta reduces Cbfbeta-SMMHC-associated acute myeloid leukemia in mice.

The gene encoding for core-binding factor beta (CBFbeta) is altered in acute myeloid leukemia samples with an inversion in chromosome 16, expressing the fusion protein CBFbeta-SMMHC. Previous studies have shown that this oncoprotein interferes with hematopoietic differentiation and proliferation and participates in leukemia development. In this study, we provide evidence that Cbfbeta modulates the oncogenic function of this fusion protein. We show that Cbfbeta plays an important role in proliferation of hematopoietic progenitors expressing Cbfbeta-SMMHC in vitro. In addition, Cbfbeta-SMMHC-mediated leukemia development is accelerated in the absence of Cbfbeta. These results indicate that the balance between Cbfbeta and Cbfbeta-SMMHC directly affects leukemia development, and suggest that CBF-specific therapeutic molecules should target CBFbeta-SMMHC function while maintaining CBFbeta activity.