INTRODUCTION The highly selective ALK inhibitor alectinib is standard therapy for ALK-positive lung cancers; however, some tumors quickly develop resistance. Here, we investigated the mechanism associated with rapid acquisition of resistance using clinical samples. METHODS Autopsied samples were obtained from lung, liver, and renal tumors from a 51-year-old male patient with advanced ALK-positive lung cancer and who had acquired resistance to alectinib in only 3 months. We established an alectinib-resistant cell line (ABC-14) from pleural effusion and an alectinib/crizotinib-resistant cell line (ABC-17) and patient-derived xenograft (PDX) model from liver tumors. Additionally, we performed next-generation sequencing (NGS), direct DNA sequencing, and quantitative real-time reverse-transcription polymerase chain reaction. RESULTS ABC-14 cells harbored no ALK mutations and were sensitive to crizotinib while also exhibiting MET geneamplification and amphiregulin overexpression. Additionally, combined treatment with crizotinib/erlotinib inhibited cell growth. ABC-17 and PDX tumors harbored ALK G1202R, and PDX tumors metastasized to multiple organs in vivo, whereas the third generation ALK-inhibitor, lorlatinib, diminished tumor growth in vitro and in vivo. NGS indicated high tumor mutation burden (TMB) and heterogeneous tumor evolution. The autopsied lung tumors harbored ALK G1202R (c. 3604 G>A) and the right renal metastasis harbored ALK G1202R (c. 3604 G>C); the mutation thus comprised different codon changes. CONCLUSIONS High TMB and heterogeneous tumor evolution might be responsible for rapid acquisition of alectinib resistance. Timely lorlatinib administration or combined therapy with an ALK inhibitor and other receptor tyrosine-kinase inhibitors might constitute a potent strategy.

中文翻译：

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简报：ALK阳性肺癌高肿瘤突变负担快速获得艾乐替尼耐药

引言 高选择性 ALK 抑制剂艾乐替尼是 ALK 阳性肺癌的标准疗法；然而，一些肿瘤很快就会产生耐药性。在这里，我们使用临床样本研究了与快速获得耐药性相关的机制。方法 从一名患有晚期 ALK 阳性肺癌的 51 岁男性患者的肺、肝和肾肿瘤中获取尸检样本，该患者仅在 3 个月内就对艾乐替尼产生了耐药性。我们建立了来自胸腔积液的艾乐替尼耐药细胞系 (ABC-14) 和来自肝脏肿瘤的艾乐替尼/克唑替尼耐药细胞系 (ABC-17) 和患者来源的异种移植 (PDX) 模型。此外，我们还进行了新一代测序 (NGS)、直接 DNA 测序和定量实时逆转录聚合酶链反应。结果 ABC-14 细胞没有 ALK 突变，对克唑替尼敏感，同时还表现出 MET 基因扩增和双调蛋白过表达。此外，克唑替尼/厄洛替尼联合治疗抑制了细胞生长。ABC-17 和 PDX 肿瘤含有 ALK G1202R，PDX 肿瘤在体内转移到多个器官，而第三代 ALK 抑制剂劳拉替尼在体外和体内减少了肿瘤生长。NGS 表明高肿瘤突变负荷 (TMB) 和异质性肿瘤进化。尸检的肺肿瘤含有 ALK G1202R (c. 3604 G>A)，右侧肾转移瘤含有 ALK G1202R (c. 3604 G>C)；因此，突变包括不同的密码子变化。结论 高 TMB 和异质性肿瘤进化可能是艾乐替尼耐药性快速获得的原因。