Uncovering the Biology of Resistance to Tyrosine Kinase Inhibitors in EGFR Mutant Lung Cancer Patient-Derived Models.

项目总结 一个长期的临床观察是，转移性癌症是难以治疗的。即使有了新的 在分子靶向治疗中，几乎总是会出现耐药性，患者最终会屈服于 癌症的进一步转移扩散。在EGFR突变肺腺癌(LUAD)的情况下，肿瘤可以 获得对酪氨酸激酶抑制剂(TKI)的抵抗力，同时扩散到肝脏和大脑。其作用机制 人们对这些病态结果之间的联系仍知之甚少。在此，我们拟研究其生物学特性。 当EGFR突变肿瘤通过TKI治疗演变时，识别允许接受治疗的肿瘤细胞 持续以及转移的生态位特征与对TKIs的反应深度(或持久性)如何联系在一起。我们 假设：1)肿瘤微环境(TME)和肿瘤细胞外在因素是关键决定因素 TKI治疗后对播散性肿瘤细胞持久性的影响以及2)对这些因素的依赖程度降低 通过序贯TKI治疗发生高度耐药的转移。 为了研究这一假设，我们成功地建立了重复活组织检查计划来收集和分析 肺癌标本，包括TKI治疗前后的EGFR突变LUADs。通过这个项目，我们 已经建立了20个患者来源的EGFR突变LUAD模型，包括有机培养物和 皮下和原位患者来源的异种移植物(PDX)。在目标1中，我们将产生更多的患者- 来自10名患者的派生癌症模型(PDMC)，作为有机类、皮下或原位PDX 与EGFR突变体LUAD在TKI治疗之前纵向和获得性抗性TKI。这些PDMC 将具有基因组和组织学特征，而他们对TKI的敏感性将与患者进行比较 标本。在目标2中，我们将利用这些模型来确定TKI抵抗影响的机制 EGFR突变肿瘤的侵袭性。使用配对的TKI前后PDMC，我们将评估延迟 以及这些肿瘤的复发部位。我们还将确定已知的TKI耐药机制如何影响 EGFR突变型肿瘤的转移特性及新型耐药和耐药双分子介质的鉴定 转移。最后，在Aim3中，我们将确定TKI后肿瘤细胞持久性的组织特异性决定因素 治疗。聚焦于我们所知的对特定TKI有反应的肿瘤，我们将确定肿瘤 植入不同部位的转移灶对TKIs表现出不同的敏感性，并鉴定细胞、分子 以及这些差异的药理学决定因素。我们将测试间质的机械预测 细胞外基质调节肿瘤细胞在TKI治疗中持续存在的能力。 胸部恶性肿瘤是大多数与癌症相关的死亡原因。通过整合互补的专业知识 和2个主要研究人员和合作者的资源，我们的目标将提供对 治疗中EGFR突变型LUAD的纵向演变及药物间的机制关系 耐药性和肿瘤微环境，这将导致转移性癌症的新治疗策略。

PROJECT SUMMARY A long-standing clinical observation is that metastatic cancers are refractory to treatment. Even with the advent of molecularly targeted therapies, drug resistance almost always emerges and patients ultimately succumb to further metastatic spread of the cancer. In the case of EGFR mutant lung adenocarcinoma (LUAD), tumors can acquire resistance to tyrosine kinase inhibitors (TKI) while spreading to the liver and brain. The mechanisms linking these morbid outcomes remain poorly understood. Here, we propose to study the biological properties of EGFR mutant tumors as they evolve through TKI treatment, identify the factors that allow treated tumor cells to persist and how features of the metastatic niche and depth (or durability) of responses to TKIs are linked. We hypothesize that, 1) the tumor microenvironment (TME) and tumor cell extrinsic factors are critical determinants of disseminated tumor cell persistence following TKI treatment and 2) that the reliance on these factors decreases in highly resistant metastasis through sequential TKI treatment. To study this hypothesis, we have successfully established a repeat biopsy program to collect and analyze lung cancer specimens, including EGFR mutant LUADs before and after TKI treatment. Through this program we have established >20 patient-derived models of EGFR mutant LUAD, including organoid cultures and subcutaneous and orthotopic patient-derived xenografts (PDXs). In Aim 1, we will generate additional patient- derived models of cancer (PDMCs) as organoids, subcutaneous or orthotopic PDXs, collected from 10 patients with EGFR mutant LUAD longitudinally prior to TKI treatment and at acquired resistance to TKIs. These PDMCs will be genomically and histologically characterized, while their TKI sensitivity will be compared to the patient specimens. In Aim 2, we will leverage these models to determine the mechanisms by which TKI resistance affects the aggressiveness of EGFR mutant tumors. Using paired pre- and post-TKI PDMCs, we will evaluate the latency and site of relapse of these tumors. We will also determine how known mechanisms of TKI resistance affect the metastatic properties of EGFR mutant tumors and identify novel dual molecular mediators of resistance and metastasis. Finally, in Aim3, we will Identify tissue-specific determinants of tumor cell persistence following TKI treatment. Focusing on tumors that we know are responsive to specific TKIs, we will establish whether tumors implanted in different sites of metastases exhibit different sensitivity to TKIs and identify the cellular, molecular and pharmacological determinants of these differences. We will test the mechanistic prediction that the stromal extracellular matrix modulates the ability of tumor cells to persist upon TKI treatment. Thoracic malignancies account for most cancer-related deaths. By integrating the complementary expertise and resources of 2 principal investigators and collaborators, our aims will provide fundamental insights into the longitudinal evolution of EGFR mutant LUAD under treatment and the mechanistic relationship between drug resistance and the tumor microenvironment, which will lead to new therapeutic strategies for metastatic cancers.