Tumor DNA in CSF and novel modeling decode breast cancer - brain metastases

 描述(申请人提供)：脑脊液中的肿瘤DNA和新的模型解码乳腺癌脑转移项目摘要描述：治疗转移到中枢神经系统(CNS)的癌症的进展需要诊断和科学工具的范式转变，有忠实的模型重述人类疾病。我正在开发一种创新的、侵入性较小的方法来识别脑瘤突变，并跟踪转移到中枢神经系统的肿瘤的遗传谱如何随着时间和治疗的变化而变化。肿瘤细胞和无细胞DNA(CfDNA)起到指纹的作用，允许检测标志着疾病变异和进展的基因变化。脑脊液(CSF)中的肿瘤DNA将根据脑内实体和软脑膜(LM)乳腺癌转移中包含的突变建议有针对性的治疗。新发现的脑脊液肿瘤突变将详细说明脑转移瘤如何在治疗后获得有利的突变。与疾病的LM传播相一致的突变将揭示这种脑转移亚型的潜在病理生理学，并建议有效的、有针对性的治疗。由于缺乏可靠反映人类疾病的细胞培养和动物异种移植模型，对乳腺癌转移到脑内的固体转移和转移到脑内的转移研究严重不足。我将创建一种新的、可翻译的异种移植模型，涉及直接来自人脑转移的乳腺癌细胞的原代培养物脑内移植。这些主要的人脑转移特异性工具将允许进行新的药物筛选，并通过对脑脊液中肿瘤DNA的测序来验证确定的遗传靶点。具体目标1：为了建立一种识别和表征实体和LM乳腺癌脑转移患者脑脊液中脑肿瘤特异性突变的方法I)将：a)对肿瘤细胞和cfDNA进行测序，以寻找原发乳腺癌中的已知突变，并确定突变部分，b)将整个外显子测序应用于脑瘤DNA，以确定更多的突变基因，以及c)建立一个由乳腺癌中已知的、有针对性的突变组成的癌症测序小组。具体目标2：为了确定乳腺癌原发肿瘤、实体脑瘤转移和软脑膜转移在肿瘤生物学和药物治疗反应上的不同，我将利用新的原代细胞培养和乳腺癌中枢神经系统转移的颅内异种移植模型来验证在脑脊液中发现的肿瘤突变和筛选治疗方法。摘要：建议的目标是互补的，但不是相互依赖的，如果成功地结合在一起，将极大地提高我们对这种最常见的转移到中枢神经系统的癌症的理解。我们的发现将为改善这些患者的治疗提供潜在的治疗途径。识别和跟踪患者脑脊液中的脑瘤DNA指纹最终将使更复杂、个性化和有针对性的治疗成为可能。我们的转化性研究将彻底改变对转移瘤和转移瘤的认识和治疗，并加深我们对转移癌进展的理解。测试脑转移新疗法的假设需要更具体、快速和可翻译的细胞培养和动物模型。通过发展细胞系和植入人乳腺癌脑肿瘤的小鼠异种移植模型，我们可以测试治疗方法，并促进我们对实体和光镜下中枢神经系统肿瘤的理解。我是一名执业神经外科医生，在我职业生涯的早期，临床实践专注于脑瘤患者的手术治疗。我的实验室专注于神经肿瘤学的基础科学，项目重点是直接影响患者护理，并揭示脑肿瘤生物学的新研究领域。我在手术室和诊所照顾脑瘤患者，在实验室努力了解推动中枢神经系统肿瘤发生的遗传和表观遗传机制。这一指导培训奖对于保护我的研究时间至关重要，使我能够进一步发展我的实验室对脑脊液中细胞和cfDNA的关注，并推动已建立的颅内转移的工作模型。我的系主任为我提供了50%的受保护的研究时间，我完全致力于这个项目。

 DESCRIPTION (provided by applicant): Tumor DNA in CSF and novel modeling decode breast cancer brain metastases Project Summary DESCRIPTION: Advances in the treatment of cancer metastatic to the central nervous system (CNS) require paradigm shifts in diagnostic and scientific tools, with faithful models recapitulating the human disease. I am developing an innovative, less invasive method to identify brain tumor mutations and track how the genetic spectrum of tumors metastatic to the CNS changes over time and with therapy. Tumor cellular and cell-free DNA (cfDNA) acts as a fingerprint, allowing detection of genetic alterations that mark the variation and progression of disease. Tumor DNA in cerebral spinal fluid (CSF) will suggest targeted therapies based on the mutations contained in solid and leptomeningeal (LM) breast cancer metastases within the brain. Newly identified tumor mutations in CSF will detail how brain metastases acquire advantageous mutations in response to therapy. Mutations consistent with LM spread of disease will unveil the underlying pathophysiology of this brain metastasis subtype, and suggest effective, targeted therapies. Solid and LM metastases to the brain from breast cancer are woefully understudied, in part due to a lack of cell culture and animal xenograft models that reliably reflect the human disease. I will create a novel, translatable, xenograft model, involving the intracerebral transplantation of primary cultures of breast cancer cells derived directly from human brain metastases. These primary, human brain metastases-specific tools will allow for novel drug screens and validation of genetic targets identified through sequencing of tumor DNA in CSF. Specific Aim 1: To create a method of identifying and characterizing brain tumor-specific mutations in the CSF of patients with solid and LM breast cancer brain metastases, in CSF I will: a) sequence tumor cellular and cfDNA for known mutations in the primary breast tumor, and determine the mutant fraction, b) apply whole exome sequencing to brain tumor DNA to identify additional mutated genes, and c) develop a cancer sequencing panel consisting of known, targetable mutations in breast cancer. Specific Aim 2: To determine how breast cancer primary tumors, solid brain tumor metastases, and leptomeningeal metastases differ in tumor biology and response to medical therapy, I will utilize novel primary cell culture and intracranial xenograft models from breast cancer CNS metastases to validate tumor mutations identified in CSF and screen therapeutics. Summary: The proposed aims are complimentary yet not reliant on each other, and if successful in combination have substantial potential to exponentially advance our understanding of one of the most common cancers to metastasize to the CNS. Our findings would propose potential therapeutic avenues to improve treatment for these patients. Identifying and following the brain tumor DNA fingerprint in patient CSF will ultimately enable more sophisticated, personalized, and targeted therapies. Our translational study will revolutionize the recognition and treatment of solid and LM metastases, and deepen our understanding of metastatic cancer progression. Testing hypotheses of novel therapeutics for brain metastases requires more specific, rapid, and translatable cell culture and animal models. By developing cell lines and implanting mouse xenograft models intracranial with human breast cancer brain tumors we can test therapeutics and advance our understanding of solid and LM CNS tumors. I am a practicing neurosurgeon, in the early stage of my career, with a clinical practice focused on the surgical treatment of patients with brain tumors. My laboratory focuses on the basic science of neuro-oncology, with a project focus to directly impact patient care and unveil new areas of study in brain tumor biology. I care for brain tumor patients in the operating room and in the clinic, striving in the laboratory to understand the genetic and epigenetic mechanisms that drive tumor genesis in the CNS. This mentored training award is crucial to protect my research time and allow me to further develop my laboratory focus on cellular and cfDNA in CSF, and to advance a working model for established intracranial metastases. My department chair has provided me with 50% protected research time, and I am fully committed to this project.