Markwalder Jay A, Arnone Marc R, Benfield Pamela A, Boisclair Michael, Burton Catherine R, Chang Chong-Hwan, Cox Sarah S, Czerniak Philip M, Dean Charity L, Doleniak Deborah, Grafstrom Robert, Harrison Barbara A, Kaltenbach Robert F, Nugiel David A, Rossi Karen A, Sherk Susan R, Sisk Lisa M, Stouten Pieter, Trainor George L, Worland Peter, Seitz Steven P
Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543-4000, USA.
J Med Chem. 2004 Nov 18;47(24):5894-911. doi: 10.1021/jm020455u.
Using a high-throughput screening strategy, a series of 1-aryl-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-4-ones was identified that inhibit the cyclin-dependent kinase (CDK) 4/cyclin D1 complex-mediated phosphorylation of a protein substrate with IC(50)s in the low micromolar range. On the basis of preliminary structure-activity relationships (SAR), a model was proposed in which these inhibitors occupy the ATP-binding site of the enzyme, forming critical hydrogen bonds to the same residue (Val96) to which the amino group in ATP is presumed to bind. X-ray diffraction studies on a later derivative bound to CDK2 support this binding mode. Iterative cycles of synthesis and screening lead to a novel series of potent, CDK2-selective 6-(arylmethyl)pyrazolopyrimidinones. Placement of a hydrogen-bond donor in the meta-position on the 6-arylmethyl group resulted in approximately 100-fold increases in CDK4 affinity, giving ligands that were equipotent inhibitors of CDK4 and CDK2. These compounds exhibit antiproliferative effects in the NCI HCT116 and other cell lines. The potency of these antiproliferative effects is enhanced in anilide derivatives and translates into tumor growth inhibition in a mouse xenograft model.
采用高通量筛选策略，鉴定出一系列1-芳基-4,5-二氢-1H-吡唑并[3,4-d]嘧啶-4-酮，它们能抑制细胞周期蛋白依赖性激酶（CDK）4/细胞周期蛋白D1复合物介导的蛋白底物磷酸化，半数抑制浓度（IC50）在低微摩尔范围内。基于初步的构效关系（SAR），提出了一个模型，其中这些抑制剂占据酶的ATP结合位点，与ATP中氨基假定结合的同一残基（Val96）形成关键氢键。对一种与CDK2结合的后续衍生物进行的X射线衍射研究支持了这种结合模式。合成和筛选的迭代循环产生了一系列新型的强效、CDK2选择性的6-（芳基甲基）吡唑并嘧啶酮。在6-芳基甲基的间位放置一个氢键供体导致CDK4亲和力增加约100倍，得到对CDK4和CDK2具有同等效力的抑制剂配体。这些化合物在NCI HCT116和其他细胞系中表现出抗增殖作用。这些抗增殖作用的效力在酰苯胺衍生物中增强，并转化为小鼠异种移植模型中的肿瘤生长抑制。
