BETd-260 (ZBC260; Compound 23) is capable of inducing degradation of BRD2, BRD3, and BRD4 proteins at 30–100 pM in the RS4;11 leukemia cells. BETd-260 shows inhibitory activity against the growth of RS4;11 leukemia cells and MOLM-13 cells with IC50s of 51 pM and 2.2 nM, respectively, and induces apoptosis in both RS4;11 and MOLM-13 cell lines at 3-10 nM.
BETd-260 reciprocally modulates the expression of several apoptotic genes in HCC cells, i.e., suppressing the expression of anti-apoptotic Mcl-1, Bcl-2, c-Myc, and XIAP, whereas increasing the expression of pro-apoptotic Bad.