Improving targeted therapy in KRAS mutant lung cancers

摘要/摘要 肺癌是美国最主要的死亡原因，每年影响16万名患者，为期五年 存活率为17%。大多数肺癌都含有KRAS突变，这种突变过度激活了肺癌中的RAS激酶 在MAPK信号通路中，Ras-RAF-MEK-ERK。针对血管紧张素转换酶关键效应因子的激酶抑制物(Kis) 癌症信号通路，构成了治疗KRAS驱动的肺癌的主要策略。强效MEK 在许多肿瘤中，存在抑制下游ERK信号的抑制剂，但这些抑制剂也抑制 正常细胞，使其剂量受到毒性的限制，导致治疗指数狭窄。抗肿瘤 MEK抑制剂的作用也因代偿或平行的FGFR1通路的激活而减弱， 导致抗药性和肿瘤复发。FGFR1的第二个KI的联合管理 途径可以减轻这种耐药性，但许多这样的KI组合是剧毒的。纳米级药物 递送是一种很有前途的策略，可以克服KRAS突变株应用联合KI疗法的局限性 肺癌。我们已经发现，带电染料之间的相互作用可以稳定不同的药物货物 形成纳米颗粒。这些染料具有硫酸盐化的表面，表现出对高密度的细胞类型的选择性吸收 CAV1表达--如KRAS肺癌血管内皮细胞。在目标1中，我们建议调查 该CAV1靶向的机制和评价其改变药物动力学和生物分布的可能性 包装药品与免费药品。我们计划使用不同内吞作用途径的药物抑制剂。 在体外内皮细胞中证实纳米颗粒摄取的主要机制是小窝蛋白介导的 内吞作用。我们还将使用Transwell分析来了解CAV1如何在肺内皮细胞中敲除 会改变纳米粒子进入肿瘤环境的能力。然后我们将在体内进行 时间推移活体显微镜观察纳米颗粒治疗的小鼠肺肿瘤微环境 实时了解纳米颗粒如何靶向、相互作用和穿过肿瘤内皮。在目标2中，我们将评估 纳米粒传递的KIS与游离KIS的药效学以及评估对 纳米颗粒介导的RAS和FGFR通路抑制的治疗指数。此前，我们发现， 纳米粒导致对肿瘤中PERK的长期抑制，并显著减弱对肿瘤的抑制 这一策略可能会消除MEK抑制剂的一个主要副作用--皮肤毒性。vt.在.的基础上 该项目的完成将带来新的发现，可能会产生治疗KRAS的新疗法 肺癌。该项目将确定，联合疗法可以在纳米颗粒中提供 选择性地只针对肿瘤微环境。这种选择性给药将改变剂量限制 这些药物全身给药时出现的毒性。从长远来看，这些结果可以用来告知 未来对犬类患者的研究、IND使能研究和临床试验。

SUMMARY/ABSTRACT Lung cancer is the leading cause of mortality in the US, affecting 160,000 patients annually with a five-year survival of 17%. The majority of lung cancers harbor KRAS mutations that overactivate the RAS kinase in the in the MAPK signaling pathway, RAS-RAF-MEK-ERK. Kinase inhibitors (KIs), which target key effectors of cancer signaling pathways, constitute a major strategy to treat KRAS-driven lung cancers. Potent MEK inhibitors exist that inhibit downstream ERK signaling in many tumors, but these also suppress signaling in normal cells so that their dosing is limited by toxicity, resulting in a narrow therapeutic index. The anti-tumor effects of MEK inhibitors are also diminished by the activation of the compensatory or parallel FGFR1 pathway, resulting in drug resistance and tumor resurgence. The co-administration of a second KI of the FGFR1 pathway can mitigate this resistance, but many such combinations of KI are highly toxic. Nanoscale drug delivery is a promising strategy to overcome the limitations of applying combination KI therapy to KRAS mutant lung cancer. We have discovered that interactions between charged dyes can stabilize diverse drug cargoes to form nanoparticles. These dyes have a sulfated surface that exhibits selective uptake by cell types with high CAV1 expression – such as KRAS lung tumor endothelium. In Aim 1, we propose to investigate the mechanism of this CAV1 targeting and assess its potential to alter the pharmacokinetic and biodistribution of packaged drugs versus free drugs. We plan to use pharmacological inhibitors of various endocytosis pathways in endothelial cells in vitro to confirm that the primary mechanism of nanoparticle uptake is caveolin-mediated endocytosis. We will also use transwell assays to understand how CAV1 knock out in lung endothelial cells would alter the ability of nanoparticles to transcytose into the tumor environment. We will then conduct in vivo time lapse intravital microscopy of the lung tumor microenvironment in mice treated with nanoparticles to see in real-time how the nanoparticles target, interact, and cross the tumor endothelium. In Aim 2, we will assess the pharmacodynamics of nanoparticle delivered KIs versus free KIs as well as assess improvements to therapeutic index of nanoparticle-mediated RAS and FGFR pathway inhibition. Previously, we have found that nanoparticles resulted in long-term inhibition of pERK in tumors and significantly attenuated inhibition in the skin, demonstrating that this strategy may obviate a major side-effect of MEK inhibitors – skin toxicities. Upon completion, this project will result in new findings that may produce novel therapies for the treatment of KRAS lung cancers. This project would establish that combination therapies could be delivered in nanoparticles that selectively target only the tumor microenvironment. This selective delivery would alter the dose limiting toxicities seen by these drugs upon systemic administration. Long term, these results can be used to inform future investigations in canine patients, IND-enabling studies, and clinical trials.