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。 在这种癌症中实施精准医学的努力受到其罕见性，疾病异质性，时间 需要收集信息丰富的临床数据，以及化疗耐药性的出现。液体活检是 一种有前途的新技术，允许对血浆中循环的肿瘤DNA进行测序， 肿瘤活检这种非侵入性技术有很大的潜力，以改善病人的结果， 纵向监测然而，为了将这项技术应用于临床，关键问题是， 必须回答其最佳使用问题。我建议开发液体活检作为临床监测策略， 以宠物狗为模型的血管肉瘤 狗通常发展血管肉瘤，这是高度 在临床、组织病理学和基因组水平上与血管肉瘤相似。因此，狗模型提供了 有机会在大量患者人群中对罕见癌症进行快速临床试验。 目的/假设：我建议将液体活检作为一种可行的临床策略， 监测治疗反应，并通过利用犬的优势更早地发现复发 血管肉瘤模型。此外，我将通过描述患者死亡的主要原因， 阿霉素耐药机制。具体目的：（目的1）我将验证犬血管肉瘤作为 通过体细胞突变的详细表征在基因组水平上建立人血管肉瘤模型 全基因组和全外显子组测序。(Aim 2）我将在一个队列中优化液体活检方案， 犬血管肉瘤患者，以最大限度地提高样本的诊断质量，并实施 并完善跟踪微小残留病（MRD）的技术。(Aim 3）我将识别相关的突变 多柔比星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用现有的治疗方法来靶向。 研究设计： 诊断时将前瞻性入组30只脾血管肉瘤犬。肿瘤和正常 将在手术时采集样本，并在诊断、手术和每次手术时采集纵向血样。 阿霉素治疗直至复发。(Aim 1）我将对一个子集进行肿瘤/正常全基因组测序 的情况下，这将允许表征监管和结构变异，并将比较这些 结果与目前由血管肉瘤项目生成的整个外显子组数据相比较。(Aim（2）发展 并通过对不同的MRD进行测试， 静脉切开术方案和设计患者特异性杂交捕获探针。(Aim 3）识别突变 与多柔比星耐药相关，通过分析诊断时同一患者的体细胞突变， 再次复发。

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.