INTRODUCTION Leptomeningeal carcinomatosis (LMC) occurs frequently in anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) and develops acquired resistance to ALK tyrosine kinase inhibitors (ALK-TKIs). This study aimed to clarify the resistance mechanism to alectinib, a second generation ALK-TKI, in LMC and test a novel therapeutic strategy. METHODS We induced alectinib-resistance in an LMC mouse model with ALK-rearranged NSCLC cell line, A925LPE3, by continuous oral alectinib treatment, established A925L/AR cells. Resistance mechanisms were analyzed using several assays, including western blot and receptor tyrosine kinase array. We also measured amphiregulin concentrations in cerebrospinal fluid (CSF) from ALK-rearranged NSCLC patients with alectinib-refractory LMC by ELISA. RESULTS A925L/AR cells were moderately resistant to various ALK-TKIs, such as alectinib, crizotinib, ceritinib, and lorlatinib, compared with parental cells in vitro. A925L/AR cells acquired the resistance by epidermal growth factor receptor (EGFR) activation due to amphiregulin overexpression caused by decreased expression of microRNA-449a. EGFR-TKIs and anti-EGFR antibody re-sensitized A925L/AR cells to alectinib in vitro. In the LMC model with A925L/AR cells, combined treatment with alectinib and EGFR-TKIs, such as erlotinib and osimertinib, successfully controlled progression of LMC. Imaging mass spectrometry showed accumulation of the EGFR-TKIs in the tumor lesions. Moreover, notably higher amphiregulin levels were detected in CSF from alectinib-resistant ALK-rearranged NSCLC patients with LMC (N=4), compared with those in EGFR-mutated NSCLC patients with EGFR-TKI-resistant LMC (N=30) or patients without LMC (N=24). CONCLUSIONS These findings indicate the potential of novel therapies targeting both ALK and EGFR for the treatment of ALK-TKI-resistant LMC in ALK-rearranged NSCLC.

中文翻译：

---

奥希替尼在 ALK 重排肺癌的软脑膜癌病模型中克服双调蛋白引起的艾乐替尼耐药

介绍 软脑膜癌病 (LMC) 经常发生在间变性淋巴瘤激酶 (ALK) 重排的非小细胞肺癌 (NSCLC) 中，并对 ALK 酪氨酸激酶抑制剂 (ALK-TKI) 产生获得性耐药。本研究旨在阐明 LMC 对第二代 ALK-TKI 艾乐替尼的耐药机制，并测试一种新的治疗策略。方法 我们通过持续口服艾乐替尼治疗，在具有 ALK 重排 NSCLC 细胞系 A925LPE3 的 LMC 小鼠模型中诱导艾乐替尼耐药，建立 A925L/AR 细胞。使用多种检测方法分析了耐药机制，包括蛋白质印迹和受体酪氨酸激酶阵列。我们还通过 ELISA 测量了来自具有艾乐替尼难治性 LMC 的 ALK 重排 NSCLC 患者的脑脊液 (CSF) 中的双调蛋白浓度。结果 与体外亲本细胞相比，A925L/AR 细胞对各种 ALK-TKI（如艾乐替尼、克唑替尼、色瑞替尼和劳拉替尼）具有中度耐药性。A925L/AR 细胞通过表皮生长因子受体 (EGFR) 激活获得抗性，这是由于 microRNA-449a 表达降低导致双调蛋白过表达。EGFR-TKIs 和抗 EGFR 抗体在体外使 A925L/AR 细胞对艾乐替尼重新敏感。在A925L/AR细胞的LMC模型中，艾乐替尼与厄洛替尼、奥希替尼等EGFR-TKI联合治疗成功控制了LMC的进展。成像质谱显示 EGFR-TKI 在肿瘤病变中积累。此外，在艾乐替尼耐药的 ALK 重排的 LMC NSCLC 患者（N=4）的 CSF 中检测到明显更高的双调蛋白水平，与具有 EGFR-TKI 耐药 LMC 的 EGFR 突变 NSCLC 患者（N=30）或无 LMC 的患者（N=24）相比。结论 这些发现表明，针对 ALK 和 EGFR 的新型疗法在治疗 ALK 重排 NSCLC 中对 ALK-TKI 耐药的 LMC 方面具有潜力。