(PQD-5) Patient derived orthotopic xenograft models for drug response prediction

描述(申请人提供)：缺乏准确预测人类治疗反应的动物模型系统阻碍了新的、更有效的抗癌疗法的发展。这项应用的目的是证明患者-肿瘤来源的恶性脑肿瘤原位异种移植小鼠模型可以准确地预测人类的药物反应，并且这些模型可以在短时间内(3-4个月)在临床环境中实时进行原发患者肿瘤的全球基因组分析的同时前瞻性地开发出来。我们的中心假设是，患者肿瘤来源的原位异种移植肿瘤对抗癌治疗的反应与相应的人类原发肿瘤相似，并可以可靠地预测患者的药物反应。此外，临床全外显子组测序和其他基因组方法的快速发展，为及时和定制的临床前药物筛选创造了对个性化动物模型的迫切需求。我们的第二个假设是，个性化的异种异种移植小鼠模型可以在3-4个月内为参加临床完整外显子组测序研究的患者开发，并用于测试基于每个患者的基因组数据选择的靶向治疗。为了检验这些假设，我们提出了两个具体目标。在目标1中，我们将用给予相应患者的相同化疗药物和/或电离辐射治疗每一种现有的异种移植小鼠模型，并直接比较异种移植反应(肿瘤体积缩小和生存时间延长)与在匹配的原始患者肿瘤中观察到的反应。患者治疗的剂量和时间表将被修改，使小鼠血清中的药物浓度与人类相似。我们还将通过分析肿瘤之间和肿瘤内在体外和体内治疗反应的差异，以及通过检查药物对小鼠脑内异种移植瘤的输送效率来研究肿瘤耐药性的潜在机制。在目标2中，我们将确定更高的细胞存活率和更多的肿瘤细胞数量对缩短同一脑瘤患者原位异种移植瘤形成时间框架的影响，这些患者来自NHGR/NCI资助的U01临床探索性测序研究(CSER)项目，该项目旨在对德克萨斯儿童医院所有新诊断的儿童实体瘤进行测序。我们将确认患者原发肿瘤基因突变在异种移植瘤中的保存；并通过靶向肿瘤特异性(和可治疗的)基因组异常(S)进行定制的临床前药物筛选，无论是否与标准治疗相结合。由于我们的所有模型都是特定于患者的，具有来自匹配的原始患者肿瘤的治疗历史和临床结果数据，并且我们已经优化了手术程序，允许将肿瘤细胞快速安全地注射到小鼠大脑的不同位置(&GT；160只/天)，因此我们处于有利地位，能够在与临床相关的环境中解决PQD-5问题，为该模型系统的预测能力提供准确和客观的评估。

DESCRIPTION (provided by applicant): Lack of animal model system that accurately predicts therapy responses in humans is blocking the development of new and more effective anti-cancer therapies. The objective of this application is to demonstrate that patient-tumor derived orthotopic xenograft mouse models of malignant brain tumors can accurately predict drug responses in humans, and that these models can be prospectively developed within a short time frame (3-4 months) concurrent with global genomic analysis of the primary patient tumors in real time in a clinical setting. Our central hypothesis is that patient tumor-derived orthotopic xenograft tumors will respond to anti-cancer therapies similarly to the corresponding human primary tumors and can reliably predict drug responses in the patients. Additionally, rapid advancement of clinical whole exome sequencing and other genomic methods has created an urgent need for personalized animal models for timely and customized preclinical drug screenings. Our second hypothesis is that personalized orthotopic xenograft mouse models can be prospectively developed within 3-4 months for patients enrolled in a clinical whole exome sequencing study and utilized to test targeted therapies selected based on each patient's genomic data. To test these hypotheses, we propose two Specific Aims. In Aim 1, we will treat each of the existing xenograft mouse models in vivo with the same chemotherapeutic agents and/or ionizing radiation that were administered to the corresponding patients and to compare xenograft responses (tumor size shrinkage and survival time extension) directly with that observed in the matched original patient tumors. The doses and schedule of the patient treatment will be modified so that the drug concentrations in mouse serum are similar to those in human beings. We will also examine the underlying mechanisms of tumor resistance by analyzing the inter- and intra-tumoral differences of therapy responses both in vitro and in vivo, and by examining the efficiency of drug delivery into xenograft tumors in vivo in mouse brains. In Aim 2, we will determine the impact of greater cell viability and increased tumor cell number on shortening time frame of orthotopic xenograft tumor formation from the same brain tumor patients enrolled in the NHGR/NCI funded U01 Clinical Exploratory Sequencing Research (CSER) project, which is aimed to sequence all the newly diagnosed pediatric solid tumors at Texas Children's Hospital. We will confirm the preservation of patient primary tumor gene mutations in the xenograft tumors; and conduct customized preclinical drug screenings by targeting the tumor-specific (and druggable) genomic aberration(s) with or without combination with the standard therapies. Since all our models are patient-specific with treatment history and clinical outcome data from the matched original patient tumors, and we have optimized surgical procedures that allows for rapid and safe injection of tumor cells into various locations in mouse brains (>160 mice/day), we are well positioned to address the PQD-5 in a clinically relevant setting to provide accurate and objective evaluation of the predicative power of this model system.