Sorafenib inhibits imatinib-resistant KIT and platelet-derived growth factor receptor β gatekeeper mutants
Sorafenib inhibits imatinib-resistant KIT and platelet-derived growth factor receptor β gatekeeper mutants
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DOI：
10.1158/1078-0432.ccr-06-2667
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发表时间：
2007-06-01
影响因子：
11.5
通讯作者：
Carlomagno, Francesca
中科院分区：
文献类型：
--
作者：
Guida, Teresa;Anaganti, Suresh;Carlomagno, Francesca
目的：伊马替尼靶向 KIT 和血小板衍生生长因子受体 (PDGFR) 酪氨酸激酶是一种有效的抗癌策略。然而，看门残基（KIT 中的 T670 和 PDGFR beta 中的 T681）的突变使这两种激酶对伊马替尼产生耐药性。本研究的目的是评估索拉非尼 (BAY 43-9006)（一种 KIT 和 PDGFR 的多靶点 ATP 竞争性抑制剂）是否对伊马替尼耐药的 KIT 和 PDGFR β 激酶具有活性。 实验设计：我们使用体外激酶测定和磷酸特异性抗体免疫印迹来确定索拉非尼对 KIT 和 PDGFR β 激酶的活性。我们还利用报告荧光素酶测定来测量索拉非尼对 KIT 和 PDGFR β 下游信号转导事件的影响。还测试了索拉非尼对表达致癌 KIT 或其伊马替尼耐药 T6701 突变体的 Ba/F3 细胞的白细胞介素 3 独立增殖的活性。 结果：索拉非尼有效抑制 KIT 和 PDGFR β 的看门突变体（KIT T6701 的 IC50，60 nmol/L；PDGFR β T681I 的 IC50，110 nmol/L）。相反，它对同样具有伊马替尼耐药性的两种受体激活环突变体（KIT D816V 的 IC50，3.8 μ mol/L；PDGFR beta D850V 的 IC50，1.17 μ mol/L）活性较低。索拉非尼阻断完整细胞中 KIT 和 PDGFR β 守门突变体的受体自身磷酸化和信号传导，以及 AP1 反应性和细胞周期蛋白 D1 基因启动子的激活。最后，该化合物抑制表达携带 T6701 突变的致癌 KIT 突变体的 Ba/F3 细胞的 KIT 依赖性增殖。结论：对于携带 KIT 和 PDGFR β 守门突变的患者，索拉非尼可能是一种有前景的抗癌药物。
Purpose: Targeting of KIT and platelet-derived growth factor receptor (PDGFR) tyrosine kinases by imatinib is an effective anticancer strategy. However, mutations of the gatekeeper residue (T670 in KIT and T681 in PDGFR beta) render the two kinases resistant to imatinib. The aim of this study was to evaluate whether sorafenib (BAY 43-9006), a multitargeted ATP-competitive inhibitor of KIT and PDGFR, was active against imatinib-resistant KIT and PDGFR beta kinases.Experimental Design: We used in vitro kinase assays and immunoblot with phosphospecific antibodies to determine the activity of sorafenib on KIT and PDGFR beta kinases. We also exploited reporter luciferase assays to measure the effects of sorafenib on KIT and PDGFR beta downstream signaling events. The activity of sorafenib on interleukin-3- independent proliferation of Ba/F3 cells expressing oncogenic KIT or its imatinib-resistant T6701 mutant was also tested.Results: Sorafenib efficiently inhibited gatekeeper mutants of KIT and PDGFR beta (IC50 for KIT T6701, 60 nmol/L; IC50 for PDGFR beta T681I, 110 nmol/L). Instead, it was less active against activation loop mutants of the two receptors (IC50 for KIT D816V, 3.8 mu mol/L; IC50 for PDGFR beta D850V, 1.17 mu mol/L) that are also imatinib-resistant. Sorafenib blocked receptor autophosphorylation and signaling of KIT and PDGFR beta gatekeeper mutants in intact cells as well as activation of AP1-responsive and cyclin D1 gene promoters, respectively. Finally, the compound inhibited KIT-dependent proliferation of Ba/F3 cells expressing the oncogenic KIT mutant carrying the T6701 mutation.Conclusions: Sorafenib might be a promising anticancer agent for patients carrying KIT and PDGFR beta gatekeeper mutations.