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

描述（由申请人提供）：缺乏准确预测人类治疗反应的动物模型系统阻碍了新的和更有效的抗癌疗法的开发。本申请的目的是证明患者-肿瘤来源的恶性脑肿瘤原位异种移植小鼠模型可以准确预测人体中的药物反应，并且这些模型可以在临床环境中真实的时间内与原发性患者肿瘤的全球基因组分析同时在短时间范围（3-4个月）内前瞻性开发。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性肿瘤相似，并且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迫切需要个性化的动物模型，以进行及时和定制的临床前药物筛选。我们的第二个假设是，可以在3-4个月内为参加临床全外显子组测序研究的患者前瞻性地开发个性化原位异种移植小鼠模型，并用于测试基于每个患者的基因组数据选择的靶向疗法。为了验证这些假设，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剂和/或电离辐射在体内治疗每种现有异种移植小鼠模型，并将异种移植反应（肿瘤大小缩小和存活时间延长）直接与匹配的原始患者肿瘤中观察到的反应进行比较。将修改患者治疗的剂量和时间表，以使小鼠血清中的药物浓度与人类相似。我们还将通过分析体外和体内治疗反应的肿瘤间和肿瘤内差异，以及通过检查小鼠脑中体内异种移植肿瘤的药物递送效率，来研究肿瘤耐药的潜在机制。在目标2中，我们将确定更大的细胞活力和增加的肿瘤细胞数量对缩短来自NHGR/NCI资助的U 01临床探索性测序研究（CSER）项目中招募的相同脑肿瘤患者的原位异种移植肿瘤形成的时间范围的影响，该项目旨在对德克萨斯州儿童医院所有新诊断的儿科实体瘤进行测序。我们将确认异种移植肿瘤中患者原发性肿瘤基因突变的保留;并通过靶向肿瘤特异性（和可药物化）基因组畸变（与或不与标准疗法组合）进行定制的临床前药物筛选。由于我们所有的模型都是患者特异性的，具有来自匹配的原始患者肿瘤的治疗史和临床结果数据，并且我们优化了手术程序，可以快速安全地将肿瘤细胞注射到小鼠大脑的各个位置（>160只小鼠/天），我们已经做好了处理PQD的准备-5在临床相关的设置，以提供准确和客观的评价，该模型系统的预测能力。

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.