Studies on the effects of a novel intermittent therapy on intratumoral clonal architecture and resistance

摘要 虽然众所周知，肿瘤是随着它们适应环境线索而进化的，但这个过程到底是如何 事件仍在调查中。精准药物对消费者施加了相对均匀的选择压力 并具有描述良好的作用机制，这使我们有机会研究 进化选择的决定因素。通过将这种治疗与新建立的 能够实现单细胞测序和亚克隆种群的前瞻性跟踪的方法，这 该提案旨在提供对指导选择引起阻力的变更的原则的洞察。 BRAF突变肿瘤被选为实验模型系统，因为这些肿瘤是在 约7%的癌症患者，包括恶性黑色素瘤、甲状腺、结直肠癌和肺癌患者 癌症。虽然RAF和/或MEK抑制剂在临床上对这些肿瘤有效，但耐药性是 几乎所有的患者都不可避免地死于他们的疾病，这表明有必要确定改进的治疗方法。在……里面 在最近的工作中，我们建立了一个概念框架，解释了 耐药引起的改变，并确定了一种间歇性的三药联合疗法，它有一个 在BRAF V600E突变肺癌和黑色素瘤患者来源的异种移植模型中具有强大的抗肿瘤作用。 基于这些进展，我们现在建议研究这种治疗对肿瘤内克隆的影响。 异质性和抗性的出现。在目标1中，我们将确定导致 对间歇联合治疗的抵抗力，并确定该治疗对肿瘤内的影响 异质性。在目标2中，我们将前瞻性地评估治疗对克隆选择的影响。在《目标3》中，我们将 研究在治疗过程中选择的亚克隆的适合性机制。网络的影响 这项建议的核心是促进我们对推动选择 具有抗性变异的亚群及其对新的和更有效的鉴定的影响 BRAF突变肿瘤患者的治疗。

ABSTRACT While it is well established that tumors evolve as they adapt to environmental cues, exactly how this process occurs remains under investigation. Precision medicines impose a relatively uniform selective pressure on the tumor and have well-described mechanisms of action, which enable a unique opportunity to study the determinants of evolutionary selection. By utilizing such treatments in conjunction with newly established methodologies that enable single-cell sequencing and prospective tracking of subclonal populations, this proposal aims to provide insight into the principles that govern the selection of resistance-causing alterations. BRAF mutant tumors were selected as an experimental model system because these are found in approximately 7% of cancer patients, including those with malignant melanoma, thyroid, colorectal and lung cancers. While RAF and/or MEK inhibitors are clinically effective active against these tumors, resistance is inevitable and almost all patients die from their disease, indicating the need to identify improved therapies. In recent work, we have established a conceptual framework that explains the selection and propagation of resistance-causing alterations and identified an intermittent three-drug combination therapy, which has a potent antitumor effect in BRAF V600E mutant lung cancer and melanoma patient-derived xenograft models. Based on these advances, we now proposed to study the effect of this treatment on intratumoral clonal heterogeneity and the emergence of resistance. In aim 1 we will determine genetic alterations that confer resistance to the intermittent combination treatment and determine the effect of this therapy on the intratumoral heterogeneity. In aim 2 we will prospectively evaluate the effect of therapy on clonal selection. In aim 3 we will investigate the mechanisms that confer fitness to the subclones that are selected during therapy. The impact of this proposal centers on advancing our understanding of the dynamics that drive the selection of subpopulations harboring resistance-causing alterations and on the identification of novel and more effective treatments for patients with BRAF mutant tumors.