Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
Br J Pharmacol. 2018 Sep;175(17):3504-3515. doi: 10.1111/bph.14395. Epub 2018 Jul 19.
Alterations in the tyrosine kinase enzyme RET are found in thyroid and lung cancer. While RET TK inhibitors (TKIs) are used to treat thyroid cancer and are in clinical trials for RET fusion-positive non-small cell lung cancer, the impact of mutations in the RET kinase domain on drug sensitivity is largely uncharacterized.
We identified and analysed mutations in the RET kinase domain that conferred resistance to the TKIs cabozantinib, lenvatinib, vandetanib and nintedanib using RET kinase-dependent BaF3/KIF5B-RET (BaF3/KR) cells. We also examined the sensitivity of RET (M918T), a RET mutation prevalent in aggressive multiple endocrine neoplasia type 2B, to these TKIs in the context of BaF3/KR cells.
Fourteen mutations were analysed. Pan resistance to the four TKIs was found in six RET kinase domain mutations (L730I, V738A, V804L/M, Y806N, G810S). Seven RET kinase domain mutations (L730V, E732K, A807V, G810A, V871I, M918T, F998V) displayed selective resistance to one or more of these drugs. L730I/V and G810A/S had different drug resistance profiles. V871I, M918T and F998V mutations are located at distant sites away from the TKI binding pocket.
A panel of TKI-resistant RET mutations were identified, and their drug sensitivities were cross-profiled. The results provide a reference for selecting appropriate TKIs to inhibit RET kinase domain mutants. Besides changes in the drug-interacting residues, mutations at distant sites could exert long-range effects resulting in TKI resistance. Among the four TKIs analysed here, nintedanib remained unaffected by mutations at the three distant sites.
甲状腺癌和肺癌中发现了酪氨酸激酶酶 RET 的改变。虽然 RET 酪氨酸激酶抑制剂（TKI）被用于治疗甲状腺癌，并正在临床试验中用于治疗 RET 融合阳性的非小细胞肺癌，但 RET 激酶结构域突变对药物敏感性的影响在很大程度上尚未得到描述。
我们使用依赖 RET 激酶的 BaF3/KIF5B-RET（BaF3/KR）细胞鉴定并分析了导致对 TKI 卡博替尼、仑伐替尼、凡德他尼和尼达尼布耐药的 RET 激酶结构域突变。我们还在 BaF3/KR 细胞中检查了 RET（M918T）突变的敏感性，该突变在侵袭性多发性内分泌肿瘤 2B 中普遍存在。
分析了 14 个突变。在 6 个 RET 激酶结构域突变（L730I、V738A、V804L/M、Y806N、G810S）中发现了对这四种 TKI 的普遍耐药。7 个 RET 激酶结构域突变（L730V、E732K、A807V、G810A、V871I、M918T、F998V）对这些药物中的一种或多种显示出选择性耐药。L730I/V 和 G810A/S 具有不同的耐药谱。V871I、M918T 和 F998V 突变位于远离 TKI 结合口袋的远位。
鉴定了一组 TKI 耐药 RET 突变，并对它们的药物敏感性进行了交叉分析。结果为选择合适的 TKI 抑制 RET 激酶结构域突变体提供了参考。除了药物相互作用残基的变化外，远处的突变也可能产生远程影响，导致 TKI 耐药。在本文分析的四种 TKI 中，尼达尼布不受三个远位突变的影响。
