Advancing precision medicine through development of the canine comparative cancer model

项目摘要 背景：血管肉瘤是一种罕见的侵袭性癌症，迫切需要新的治疗方法。 这种癌症的罕见、疾病的异质性、时间等因素阻碍了对其实施精确医学的努力 需要收集信息丰富的临床数据，以及化疗耐药的出现。液体活组织检查是 一种有希望的新技术，允许对血浆中循环的肿瘤DNA进行测序，作为检测 肿瘤活检。这种非侵入性技术具有巨大的潜力，可以通过允许 纵向监测。然而，为了将这项技术应用于临床，关键问题是 它的最佳使用必须得到回答。我建议发展液体活组织检查作为临床监测策略 以宠物狗为模型制作血管肉瘤模型。​犬通常会患上血管肉瘤，这是一种高度 在临床、组织病理学和基因组水平上与血管肉瘤相似。因此，狗狗模型提供了 在大量患者群体​中实施一种罕见癌症的快速临床试验的机会。 目标/假设：​I建议将液体活检作为一种可行的临床策略 监测治疗反应，并通过利用犬类的力量更早地识别复发 血管肉瘤模型。此外，我将通过以下特征来解决患者死亡的主要原因 阿霉素耐药机制的研究。具体目标：​(目标1)我将验证犬血管肉瘤是否为 通过详细描述体细胞突变在基因组水平上建立人类血管肉瘤模型 在全基因组和全外显子组测序中。(目标2)我将在一个队列中优化液体活检方案 为了最大限度地提高犬血管肉瘤患者的诊断质量，并实施 并改进跟踪微小残留病(MRD)的技术。(目标3)我将确定相关的突变 对阿霉素耐药。导致疾病进展的耐药性是患者死亡的主要原因， 我将确定这些机制是否可以利用现有的治疗方法进行靶向治疗。​研究设计： 30只患脾血管肉瘤的狗将在确诊时前瞻性入选。肿瘤与正常 在手术时采集样本，在诊断时、手术时和每次手术时抽取纵向血液样本。 阿霉素治疗直到复发。(目标1)我将执行一个子集的肿瘤/正常全基因组测序 案例，这将允许对监管和结构变体的特征，并将比较 目前由血管肉瘤项目生成的整个外显子组数据的结果。(目标2)我会发展 并改进了用于纵向监测MRD的cfDNA采样方法，通过测试不同的 采血方案，以及设计针对患者的杂交捕获探针。(目标3)​I将识别突变 与阿霉素耐药有关，通过分析同一患者在诊断和治疗时的体细胞突变 又是旧病复发。

Project Abstract Background: Angiosarcoma is a rare and aggressive cancer for which new treatments are urgently needed. Efforts to implement precision medicine in this cancer are hindered by its rarity, disease heterogeneity, the time needed to collect informative clinical data, and the emergence of chemotherapeutic resistance. Liquid biopsy is a promising new technique allowing the sequencing of tumor DNA circulating in the plasma as a proxy for tumor biopsy. This noninvasive technique has great potential to improve patient outcomes by allowing for longitudinal monitoring. However, in order for this technique to be applied in the clinic, key questions regarding its optimal use must be answered. I propose to develop liquid biopsy as a clinical monitoring strategy in angiosarcoma using the pet dog as a model. ​Dogs commonly develop hemangiosarcoma, which is highly similar to angiosarcoma at the clinical, histopathological, and genomic level. The dog model thus offers the opportunity to implement rapid clinical trials for a rare cancer in a large patient population​. Objective/Hypothesis: ​I propose to advance the use of liquid biopsy as a viable clinical strategy to monitor treatment response, and to identify relapse earlier, by harnessing the strengths of the canine angiosarcoma model. Furthermore, I will address a major cause of patient mortality by characterizing mechanisms of doxorubicin resistance. Specific Aims: ​(Aim 1) I will validate canine hemangiosarcoma as a model for human angiosarcoma at the genomic level through detailed characterization of somatic mutations in whole-genome and whole-exome sequencing. (Aim 2) I will optimize protocols for liquid biopsy in a cohort of canine hemangiosarcoma patients in order to maximize the diagnostic quality of the samples, and implement and refine techniques for tracking minimal residual disease (MRD). (Aim 3) I will identify mutations associated with doxorubicin resistance. Resistance leading to disease progression is a major cause of patient mortality, and I will determine whether these mechanisms can be targeted using existing therapeutics. ​Study Design: Thirty dogs with splenic hemangiosarcoma will be enrolled prospectively at diagnosis. Tumor and normal samples will be collected at surgery, and longitudinal blood samples drawn at diagnosis, surgery, and at each doxorubicin treatment until relapse. (Aim 1) I will perform tumor/normal whole genome sequencing of a subset of cases, which will allow for characterization of regulatory and structural variants, and will compare these results to the whole exome data currently being generated by The Angiosarcoma Project. (Aim 2) I will develop and refine methods for sampling cfDNA for longitudinal monitoring of MRD, through testing of different phlebotomy protocols, and designing patient-specific hybrid capture probes. (Aim 3) ​I will identify mutations associated with doxorubicin resistance, by analyzing somatic mutations in the same patient at diagnosis and again at relapse.