Preclinical studies of TW-37, a new nonpeptidic small-molecule inhibitor of Bcl-2, in diffuse large cell lymphoma xenograft model reveal drug action on both Bcl-2 and Mcl-1
Preclinical studies of TW-37, a new nonpeptidic small-molecule inhibitor of Bcl-2, in diffuse large cell lymphoma xenograft model reveal drug action on both Bcl-2 and Mcl-1
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DOI：
10.1158/1078-0432.ccr-06-1574
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发表时间：
2007-04-01
影响因子：
11.5
通讯作者：
Al-Katibl, Ayad
中科院分区：
文献类型：
--
作者：
Mohammad, Ramzi M.;Goustin, Anton Scott;Al-Katibl, Ayad
用途：在超过80%的B细胞淋巴瘤中观察到Bcl-2蛋白的过表达，包括弥漫性大细胞淋巴瘤（DLCL），非霍奇金淋巴瘤的最常见亚型。我们以前采用的天然产物（-）-棉酚，以测试其作为Bcl-2的小分子抑制剂的治疗B细胞lymphomas.Experimental Designs的治疗潜力：最近，我们已经使用了基于结构的策略来设计一类新的有效的小分子抑制剂作用于Bcl-2。一种这样的先导化合物是苯磺酰基衍生物TW-37，其被设计成靶向Bcl-2中的BH 3结合沟，其中促凋亡Bcl-2蛋白如巴克、Bax、Bid和Bim结合。在我们使用重组Bcl-2、Bcl-X-L和Mcl-1蛋白的基于荧光偏振的结合测定中，TW-37结合Bcl-2、Bcl-X-L、Mcl-1的Ki值分别为290、1、110和260 nmol/L。因此，TW-37是Bcl-2的有效抑制剂，并且具有超过Bcl-X-L>3倍的选择性。在体外，TW-37在从头化学抗性-WSU-DLCL 2淋巴瘤细胞系和从淋巴瘤患者获得的原代细胞中显示出显著的抗增殖作用，而对正常外周血淋巴细胞没有影响。免疫共沉淀实验表明TW-37破坏Bax或截短的Bid与抗凋亡蛋白之间的异二聚体形成，顺序为Mcl-1 > Bcl-2 >> Bcl-X-L。正如预期的那样，TW-37引起凋亡性死亡。TW-37预处理淋巴瘤细胞可显著增强环磷酰胺-阿霉素-长春新碱-泼尼松（CHOP）方案的杀伤作用。TW-37在严重联合免疫缺陷（SCID）小鼠中的最大耐受剂量为40 mg/kg（3次静脉注射）（单独给药）和20 mg/kg（3次静脉注射）（与CHOP联合给药）。使用WSU-DLCL 2 SCID小鼠异种移植模型，除了TW-37 CHOP导致更完全的肿瘤抑制相比，无论是CHOP或TW-37单用。结论：我们得出结论，TW-37，作为一个有效的Bcl-2和Mcl-1抑制剂，标准化疗的管理可能被证明是一种有效的策略，在治疗B细胞淋巴瘤。
Purpose: Overexpression of Bcl-2 protein has been observed in more than 80% of B-cell lymphomas, including diffuse large cell lymphoma (DLCL), the most common subtype of non-Hodgkin's lymphoma. We have previously employed the natural product (-) -gossypol to test its therapeutic potential as a small-molecule inhibitor of Bcl-2 for the treatment of B-cell lymphomas.Experimental Design: Recently, we have used a structure-based strategy to design a new class of potent small-molecule inhibitor acting on Bcl-2. One such lead compound is the benzenesulfonyl derivative TW-37, which was designed to target the BH3-binding groove in Bcl-2 where proapoptotic Bcl-2 proteins, such as Bak, Bax, Bid, and Bim bind.Results: In our fluorescence polarization - based binding assays using recombinant Bcl-2, Bcl-X-L, and Mcl-1 proteins,TW-37 binds to Bcl-2, Bcl-X-L, and Mcl-1 with K-i values of 290, 1,110 and 260 nmol/L, respectively. Hence,TW-37 is a potent inhibitor of Bcl-2 and has >3-fold selectivity over Bcl-X-L. In vitro,TW-37 showed significant antiproliferative effect in a de novo chemoresistant-WSU-DLCL2 lymphoma cell line and primary cells obtained from a lymphoma patient with no effect on normal peripheral blood lymphocytes. Coimmunoprecipitation experiments showed that TW-37 disrupted heterodimer formation between Bax or truncated-Bid and antiapoptotic proteins in the order Mcl-1 > Bcl-2 >> Bcl-X-L. As expected, TW-37 caused apoptotic death. Pre-exposure of lymphoma cells to TW-37 significantly enhanced the killing effect of cyclophosphamide-doxorubicin-vincristine-prednisone (CHOP) regimen. The maximum tolerated dose of TW-37 in severe combined immunodeficient (SCID) mice was 40 mg/kg for three i.v. injections when given alone and 20 mg/kg, x3 when given in combination with CHOP. Using WSU-DLCL2 SCID mouse xenograft model, the addition of TW-37 to CHOP resulted in more complete tumor inhibition compared with either CHOP or TW-37 alone.Conclusions: We conclude that the administration of TW-37, as a potent Bcl-2 and Mcl-1 inhibitor, to standard chemotherapy may prove an effective strategy in the treatment of B-cell lymphoma.