S55746 (BCL201) 是一种有效、可口服、选择性的 BCL-2 抑制剂，其 Ki 值和 Kd 值分别为 1.3 nM 和 3.9 nM。S55746 (BCL201) 具有抗肿瘤活性且毒性低。 Information S55746 (S 055746,BCL201) is a novel, orally activeBCL-2specific inhibitor (Ki = 1.3 nM) with poor affinity for BCL-XL and no significant binding to MCL-1, BFL-1 (BCL2A1/A1). The selectivity of S55746 for BCL-2 versus BCL-XL ranges from ~70 to 400 folds. Targets Bcl-2 (Cell-free assay) 1.3 nM(Ki) In vitro S55746 occupies the hydrophobic groove of BCL-2. In a panel of hematological cell lines, S55746 induces hallmarks of apoptosis including externalization of phosphatidylserine, caspase-3 activation and PARP cleavage. S55746 potently induces RS4;11 cell killing after 72 h of treatment with an IC50 of 71.6 nM and exhibits a much weaker activity in H146 (IC50 = 1.7 μM), a BCL-XL-dependent cell line, which expresses a low level of BCL-2 and high level of BCL-XL. It has no cytotoxic activity on BCL-XL-dependent cells, such as platelets. In vivo S55746 administered by oral route daily in mice demonstrates robust anti-tumor efficacy in two hematological xenograft models (RS4;11 and Toledo models) with no weight lost and no change in behavior. Cell Research(from reference) Cell lines：RS4;11 cells Concentrations：0.01, 0.03, 0.1, 0.3, 1 μM Incubation Time：2 hours