Preclinical Evaluation of the WEE1 Inhibitor MK-1775 as Single-Agent Anticancer Therapy
Preclinical Evaluation of the WEE1 Inhibitor MK-1775 as Single-Agent Anticancer Therapy
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DOI：
10.1158/1535-7163.mct-13-0025
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发表时间：
2013-08-01
影响因子：
5.7
通讯作者：
Shumway, Stuart D.
中科院分区：
文献类型：
--
作者：
Guertin, Amy D.;Li, Jing;Shumway, Stuart D.
抑制DNA损伤检查点激酶WEE1通过消除细胞周期停滞和适当的DNA修复来加强遗传毒性化疗。然而，在没有外在伤害的情况下，WEE1对于不受干扰的细胞分裂也是必不可少的。在这里，我们研究了WEE1抑制剂的抗癌潜力，独立于化疗，并探索了可能的细胞背景下对WEE1抑制的敏感性。我们发现，MK-1775，一种有效的和选择性的WEE1的ATP竞争抑制物，对广泛的肿瘤细胞系具有细胞毒性，并诱导DNA双链断裂。MK-1775诱导的S期细胞DNA损伤发生在不加化疗或放疗的情况下，依赖于活跃的DNA复制。在耐受剂量下，MK-1775治疗可导致异种移植瘤生长抑制或消退。为了开始寻找MK-1775单一疗法的潜在反应标记物，我们重点研究了PKMYT1，一种与WEE1功能相关的激酶。敲除PKMYT1可使MK-1775的EC50降低5倍，但不影响细胞对其他细胞毒药物的反应。此外，敲除PKMYT1增加了MK-1775诱导的DNA损伤的标志物--γ-H_2AX和pCHK1(S345)。在对用MK-1775处理的305个细胞株的事后分析中，我们发现在33个最敏感的细胞系中，有73%的细胞PKMYT1的表达低于平均水平。我们的发现为WEE1抑制作为一种独立于基因毒性伙伴的有效抗癌治疗提供了理论基础，并表明PKMYT1的低表达可以作为MK-1775敏感性的浓缩生物标志物。(C)2013年AACR。
Inhibition of the DNA damage checkpoint kinase WEE1 potentiates genotoxic chemotherapies by abrogating cell-cycle arrest and proper DNA repair. However, WEE1 is also essential for unperturbed cell division in the absence of extrinsic insult. Here, we investigate the anticancer potential of a WEE1 inhibitor, independent of chemotherapy, and explore a possible cellular context underlying sensitivity to WEE1 inhibition. We show that MK-1775, a potent and selective ATP-competitive inhibitor of WEE1, is cytotoxic across a broad panel of tumor cell lines and induces DNA double-strand breaks. MK-1775-induced DNA damage occurs without added chemotherapy or radiation in S-phase cells and relies on active DNA replication. At tolerated doses, MK-1775 treatment leads to xenograft tumor growth inhibition or regression. To begin addressing potential response markers for MK-1775 monotherapy, we focused on PKMYT1, a kinase functionally related to WEE1. Knockdown of PKMYT1 lowers the EC50 of MK-1775 by five-fold but has no effect on the cell-based response to other cytotoxic drugs. In addition, knockdown of PKMYT1 increases markers of DNA damage, gamma H2AX and pCHK1(S345), induced by MK-1775. In a post hoc analysis of 305 cell lines treated with MK-1775, we found that expression of PKMYT1 was below average in 73% of the 33 most sensitive cell lines. Our findings provide rationale for WEE1 inhibition as a potent anticancer therapy independent of a genotoxic partner and suggest that low PKMYT1 expression could serve as an enrichment biomarker for MK-1775 sensitivity. (C)2013 AACR.