Research Project 1: Diffuse Midline Glioma

项目摘要 传统观点认为，放射治疗是一种物理靶向的抗癌方式，其 癌症靶点在基因和生物学上都是一致的。然而，肿瘤的间质成分很复杂。 以及引起癌症靶点的外在可变性的变量。此外，最近使用单个细胞的研究 基因组学显示出内在的异质性，甚至在肿瘤细胞本身也是如此。我们的总体目标是 哈佛大学/加州大学旧金山分校的罗宾倡议是为了测试这样一个假设，即肿瘤内的可变性是抵抗- 以及放疗后的复发。为了实现这一目标，我们的中心选择专注于儿童癌症。 神经外胚层起源。与常见的成人癌症相比，儿童肿瘤的突变负担较低 从而为由指定的“低N/高含量”分子表征试验提供更清洁的遗传环境 罗宾·RFA。在此背景下，本项目聚焦于儿童弥漫性中线胶质瘤(DMG)。 大多数DMG最初对辐射有反应，但都有进展，而且没有一个被治愈。在预赛中 研究中，我们使用了单细胞基因组学来证明DMG内的恶性细胞是发育中的 异质的。我们的可检验假设是DMG肿瘤内的异质性超越了发育 包括常见DNA修复途径的差异表达/利用的标记。这一假设使得 通过对放疗前和放疗后肿瘤组织的配对样本进行评估的预测 来自前瞻性接受统一放射治疗方案的儿童，并在我们的《分子》杂志上进行了描述 特性试验(MCT)。我们有三个具体目标：目标1是测试肿瘤内的预测 异质性反映在高于和超出肿瘤细胞特异性发育标志物的水平上，我们的 初步研究；目标2是验证放射治疗降低DMG瘤内异质性的预测 通过选择复制能力强、抗辐射的干细胞样癌细胞；目标3是测试预测 肿瘤细胞内的异质性辐射反应是放射相关患者异质性的基础 毒性、神经认知效应和生活质量。 该研究计划结合了癌症基因组学、表观基因组学、染色质的当代方法 生物学和DNA酶学。我们将利用我们的临床人工智能和成像核心来 开发非侵入性方法来追踪这些(具有手术挑战性的)儿科患者的肿瘤内异质性 肿瘤。有了我们的分子数据科学和先进的剂量学核心，我们将开发计算 对肿瘤细胞进化和治疗反应的建模将对理解选择治疗方案至关重要 抗辐射亚克隆。该项目的共同负责人拥有互补的专业知识，以支持这项研究 计划。Daphne Haas-Kogan医学博士是一位治疗DMG患者的儿科放射肿瘤学家 在儿科临床试验的两个关键财团(COG和PNOC)担任领导职务。玛丽埃拉·菲尔宾 医学博士/博士是一名儿科神经肿瘤学家，擅长单细胞基因组学和DMG生物学。

Project Summary Conventional wisdom holds that radiation therapy is a physically targeted anti-cancer modality and that its cancer targets are genetically and biologically uniform. However, the stromal composition of tumors is complex and variable giving rise to extrinsic variability of the cancer target. Moreover, recent studies using single cell genomics show intrinsic heterogeneity even within the tumor cells per se. The broad goal of our Harvard/UCSF ROBIN initiative is to test the hypothesis that intra-tumoral variability underlies resistance to - and relapse from – radiotherapy. Towards this goal, our Center has chosen to focus on pediatric cancers of neuro-ectodermal origin. Pediatric tumors have a low mutational burden relative to common adult cancers and thus a cleaner genetic surround for the “low N/high content” Molecular Characterization Trials specified by the ROBIN RFA. Against this backdrop, this project focuses upon diffuse midline glioma (DMG) of children. The majority of DMGs initially respond to radiation, but all progress, and none are cured. In preliminary studies, we have used single cell genomics to show that the malignant cells within DMG are developmentally heterogeneous. Our testable hypothesis is that DMG intratumoral heterogeneity transcends developmental markers to include differential expression/utilization of common DNA repair pathways. This hypothesis makes predictions that will be assessed by drawing upon paired samples of pre-and post-radiotherapy tumor tissue from children treated prospectively with a uniform radiotherapy regimen and profiled in our Molecular Characterization Trial (MCT). We have three specific aims: Aim 1 is to test the prediction that intratumoral heterogeneity is reflected at levels above and beyond tumor cell-specific developmental markers noted our preliminary studies; Aim 2 is to test the prediction that radiotherapy reduces DMG intratumoral heterogeneity via selection of replication-competent, radio-resistant stem-like cancer cells; Aim 3 is to test the prediction that heterogeneous radiation responses within tumor cells underlie patient heterogeneity in radiation-associated toxicities, neurocognitive effects and quality of life. The study plan incorporates contemporary methods in cancer genomics, epigenomics, chromatin biology and DNA enzymology. We will draw upon our Clinical Artificial Intelligence and Imaging Core to develop non-invasive methods to track intra-tumoral heterogeneity in these (surgically challenging) pediatric tumors. With our Molecular Data Science and Advanced Dosimetry Core, we will develop computational modeling of tumor cell evolution and treatment response that will be critical to understanding selection for radioresistant subclones. The co-leaders of this Project have complementary expertise to enable the study plan. Daphne Haas-Kogan, M.D. is a pediatric radiation oncologist who treats patients with DMG and holds leadership positions in two key consortia (COG and PNOC) for pediatric clinical trials. Mariella Filbin, M.D./Ph.D. is a pediatric neuro-oncologist with expertise in single cell genomics and DMG biology.