Ibrutinib targets mutant-EGFR kinase with a distinct binding conformation.
Ibrutinib targets mutant-EGFR kinase with a distinct binding conformation.
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依鲁替尼以具有独特结合构象的突变型 EGFR 激酶为靶点。
DOI：
10.18632/oncotarget.11951
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发表时间：
2016-10-25
期刊：
影响因子：
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通讯作者：
Liu Q
中科院分区：
文献类型：
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作者：
Wang A;Yan XE;Wu H;Wang W;Hu C;Chen C;Zhao Z;Zhao P;Li X;Wang L;Wang B;Ye Z;Wang J;Wang C;Zhang W;Gray NS;Weisberg EL;Chen L;Liu J;Yun CH;Liu Q
依鲁替尼是一种临床批准的不可逆 BTK 激酶抑制剂，用于治疗套细胞淋巴瘤 (MCL) 和慢性淋巴细胞白血病 (CLL) 等，据报道对 EGFR 突变激酶有效，目前正在临床评估用于治疗非小细胞肺癌 (NSCLC)。通过 EGFR wt/突变体工程化同基因 BaF3 细胞系，我们证实了依鲁替尼通过 Cys797 与 EGFR wt/突变体激酶的不可逆结合模式。然而，与典型的不可逆 EGFR 抑制剂（例如 WZ4002）相比，洗脱实验显示依鲁替尼的共价结合效率要低得多。 EGFR L858R/T790M 激酶的生化结合亲和力检查表明，与更有效的不可逆抑制剂 WZ4002（Kd：0.074 μM）相比，依鲁替尼的结合效率较低（Kd：0.18 μM）。 EGFR (T790M) 与依鲁替尼复合物的 X 射线晶体结构表现出独特的 DFG-in/c-Helix-out 无活性结合构象，这部分解释了共价结合效率较低的原因，并为进一步开发针对 EGFR 突变激酶的高效不可逆结合抑制剂提供了见解。这些结果还意味着，与经典的不可逆抑制剂不同，伊布替尼可能需要持续的有效浓度，才能在临床应用中针对 EGFR 驱动的 NSCLC 实现最大疗效。
Ibrutinib, a clinically approved irreversible BTK kinase inhibitor for Mantle Cell Lymphoma (MCL) and Chronic Lymphocytic Leukemia (CLL) etc, has been reported to be potent against EGFR mutant kinase and currently being evaluated in clinic for Non Small Cell Lung Cancer (NSCLC). Through EGFR wt/mutant engineered isogenic BaF3 cell lines we confirmed the irreversible binding mode of Ibrutinib with EGFR wt/mutant kinase via Cys797. However, comparing to typical irreversible EGFR inhibitor, such as WZ4002, the washing-out experiments revealed a much less efficient covalent binding for Ibrutinib. The biochemical binding affinity examination in the EGFR L858R/T790M kinase revealed that, comparing to more efficient irreversible inhibitor WZ4002 (Kd: 0.074 μM), Ibrutinib exhibited less efficient binding (Kd: 0.18 μM). An X-ray crystal structure of EGFR (T790M) in complex with Ibrutinib exhibited a unique DFG-in/c-Helix-out inactive binding conformation, which partially explained the less efficiency of covalent binding and provided insight for further development of highly efficient irreversible binding inhibitor for the EGFR mutant kinase. These results also imply that, unlike the canonical irreversible inhibitor, sustained effective concentration might be required for Ibrutinib in order to achieve the maximal efficacy in the clinic application against EGFR driven NSCLC.