Discovery of a selective inhibitor of oncogenic B-Raf kinase with potent antimelanoma activity
Discovery of a selective inhibitor of oncogenic B-Raf kinase with potent antimelanoma activity
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DOI：
10.1073/pnas.0711741105
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发表时间：
2008-02-26
影响因子：
11.1
通讯作者：
Bollag, Gideon
中科院分区：
文献类型：
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作者：
Tsai, James;Lee, John T.;Bollag, Gideon
BRAF（V600 E）是已知最常见的致癌蛋白激酶突变。此外，靶向“活性”蛋白激酶的抑制剂已经在针对癌症的治疗谱中显示出显著的效用。因此，我们致力于开发靶向B-Raf，特别是V600 E等位基因的特异性激酶抑制剂。通过使用结构指导的发现方法，已经发现了活性B-Raf的有效和选择性抑制剂。PLX 4720是一种7-氮杂吲哚衍生物，其抑制B-Raf（V600 E）的IC 50为13 nM，定义了一类在生化和细胞测定中具有显著选择性的激酶抑制剂。与广谱其他激酶相比，PLX 4120优先抑制活性B-Raf（V600 E）激酶，并且强效细胞毒性作用也仅限于携带V600 E等位基因的细胞。与高度选择性一致，PLX 4720在携带B-Raf（V600 E）的肿瘤细胞系中有效抑制ERK磷酸化，但在缺乏致癌B-Raf的细胞中不抑制ERK磷酸化。在黑色素瘤模型中，PLX 4720仅在B-Raf（V600 E）阳性细胞中诱导细胞周期停滞和细胞凋亡。在B-Raf（V600 E）依赖性肿瘤异种移植模型中，PLX 4720经口给药可导致显著的肿瘤生长延迟，包括肿瘤消退，但无毒性证据。本文描述的工作代表了整个发现过程，从最初的鉴定到动物模型中的结构和生物学研究，再到在携带B-Raf（V600 E）驱动肿瘤的癌症患者中进行测试的有希望的治疗方法。
BRAF(V600E) is the most frequent oncogenic protein kinase mutation known. Furthermore, inhibitors targeting "active" protein kinases have demonstrated significant utility in the therapeutic repertoire against cancer. Therefore, we pursued the development of specific kinase inhibitors targeting B-Raf, and the V600E allele in particular. By using a structure-guided discovery approach, a potent and selective inhibitor of active B-Raf has been discovered. PLX4720, a 7-azaindole derivative that inhibits B-Raf(V600E) with an IC50 Of 13 nM, defines a class of kinase inhibitor with marked selectivity in both biochemical and cellular assays. PLX4120 preferentially inhibits the active B-Raf(V600E) kinase compared with a broad spectrum of other kinases, and potent cytotoxic effects are also exclusive to cells bearing the V600E allele. Consistent with the high degree of selectivity, ERK phosphorylation is potently inhibited by PLX4720 in B-Raf(V600E)-bearing tumor cell lines but not in cells lacking oncogenic B-Raf. In melanoma models, PLX4720 induces cell cycle arrest and apoptosis exclusively in B-Raf(V600E)-positive cells. In B-Raf(V600E)-dependent tumor xenograft models, orally dosed PLX4720 causes significant tumor growth delays, including tumor regressions, without evidence of toxicity. The work described here represents the entire discovery process, from initial identification through structural and biological studies in animal models to a promising therapeutic for testing in cancer patients bearing B-Raf(V600E)-driven tumors.