Optimizing biologically-based rational polytherapy in ALK+ lung cancer

肺癌是全世界癌症死亡率的主要原因，其中非小细胞肺癌（NSCLC）是最常见的癌症。 肺癌和肺腺癌的主要组织学亚型是NSCLC的主要亚群。尽管 随着特异性靶向治疗的使用，最近的临床进展，耐药性仍然是一个问题， 限制了患者的生存。对抗癌症耐药性的一个有希望的策略是预先部署合理的药物， 抑制耐药肿瘤细胞的存活和出现的多种疗法。然而，在大多数肿瘤中， 致癌受体激酶，最佳的初始多药治疗策略尚不清楚，因为受体激酶 通常涉及多个效应器通路，以及这些单独的通路中的哪一个（如果有的话）对 肿瘤细胞存活率定义不明确。我们最近在NSCLC模型中证实， 致癌ALK受体激酶融合（EML 4-ALK或ALK+）即RAS-MAPK通路，而非其他已知 ALK效应子是肿瘤细胞存活所必需的。我们发现EML 4-ALK通过以下方式驱动RAS-MAPK信号传导： 通过EML 4的HELP结构域接合所有三种主要RAS同种型（H、N-、K-RAS）。MAPK途径 通过KRASWT（野生型）的基因组扩增或MAPK的下调而重新激活 磷酸酶DUSP 6促进对ALK抑制的抗性。因此，前期ALK和MEK共抑制 在体外和体内模型中，EML 4-ALK NSCLC的初始缓解幅度和持续时间均增加。 此外，KRASWT的基因组扩增（或基因复制）或DUSP 6的下调也可能是一种基因突变。 在具有获得性ALK抑制剂耐药的ALK+肺腺癌患者中观察到。我们的发现 为RAS-MAPK信号传导在EML 4-ALK NSCLC中的功能提供了新的见解， ALK + MEK抑制剂联合治疗以改善患者结局，这是我们正在领导的一项新的临床试验。 此外，研究结果表明EML 4伴侣在EML 4-ALK癌基因功能中的作用出乎意料 和RAS信令。在这里，我们将进一步扩展我们的初步发现，以测试整体假设，即RAS 活化和信号传导是NSCLC中致癌ALK功能的标志。在目标1中，我们将定义 RAS-MAPK信号传导和EML 4-ALK NSCLC依赖性的生物学基础，剖析了EML 4-ALK NSCLC的分子和 在ALK+肿瘤中控制RAS激活和信号传导的细胞生物学控制机制。在目标2中，我们将 定义可能限制ALK+ NSCLC患者对ALK + MEK抑制剂综合治疗的疗效的机制 患者，勒韦林尖端的基于CRISPR的遗传筛查研究和来自我们的患者肿瘤样本， ALK + MEK抑制剂临床试验。总的来说，这些多学科，协作，以患者为中心的研究 涵盖生物化学、遗传学、药理学、细胞生物学、患者队列和肿瘤分子分析 将为癌症中RAS和致癌ALK信号传导的功能和控制提供基本见解 并进一步加强我们新的合理的综合治疗策略。我们的最终目标是确保我们将ALK+ 通过基于生物的精准医学，NSCLC从致命疾病转变为慢性或可治愈的疾病。

Lung cancer is the leading cause of cancer mortality worldwide, with non-small cell lung cancer (NSCLC) the predominant histologic subtype of lung cancer and lung adenocarcinoma the major subset of NSCLC. Despite recent clinical progress with the use of specific targeted therapies, drug resistance remains a problem that limits patient survival. A promising strategy to combat cancer drug resistance is to deploy rational upfront polytherapies that suppress the survival and emergence of resistant tumor cells. However, in most tumors with oncogenic receptor kinases, the optimal initial polytherapy strategy is unclear because receptor kinases typically engage multiple effector pathways, and which of these individual pathways, if any, is most critical to tumor cell survival is poorly defined. We recently demonstrated in models of NSCLC harboring the recurrent oncogenic ALK receptor kinase fusion (EML4-ALK or ALK+) that the RAS-MAPK pathway, but not other known ALK effectors, is required for tumor cell survival. We revealed that EML4-ALK drives RAS-MAPK signaling by engaging all three major RAS isoforms (H, N-, K-RAS) via the HELP domain of EML4. MAPK pathway reactivation via either genomic amplification of KRASWT (wild-type) or downregulation of the MAPK phosphatase DUSP6 promoted resistance to ALK inhibition. Accordingly, upfront ALK and MEK co-inhibition enhanced both the magnitude and duration of initial response in EML4-ALK NSCLC in vitro and in vivo models. Furthermore, genomic amplification (or gene duplication) of KRASWT or downregulation of DUSP6 was observed in ALK+ lung adenocarcinoma patients with acquired ALK inhibitor resistance. Together, our findings provided new insight into the function of RAS-MAPK signaling in EML4-ALK NSCLC and the rationale for upfront ALK + MEK inhibitor co-treatment to improve patient outcomes, a novel clinical trial we are leading. Moreover, the findings indicated an unanticipated role of the EML4 partner in EML4-ALK oncogene function and RAS signaling. Here, we will further extend our initial discovery to test the overall hypothesis that RAS activation and signaling is a hallmark of oncogenic ALK function in NSCLC. In Aim 1, we will define the biological basis of RAS-MAPK signaling and dependence in EML4-ALK NSCLC, dissecting the molecular and cell biological control mechanisms governing RAS activation and signaling in ALK+ tumors. In Aim 2, we will define the mechanism(s) that may limit curative response to ALK + MEK inhibitor polytherapy in ALK+ NSCLC patients, levering cutting-edge CRISPR-based genetic screening studies and patient tumor samples from our ALK + MEK inhibitor clinical trial. Overall, these multi-disciplinary, collaborative, patient-focused studies spanning biochemical, genetic, pharmacologic, cell biological, and patient cohort and tumor molecular analysis will provide fundamental insight into the function and control of RAS and oncogenic ALK signaling in cancer and further enhance our novel rational polytherapy strategy. Our ultimate goal is to ensure we transform ALK+ NSCLC from a lethal disease into a chronic or curable condition through biologically-based precision medicine.