Intra-tumor Heterogeneity in Colorectal Cancer Progression and Treatment Response

项目概要： 结直肠癌（CRC）仍然是美国癌症相关死亡的第三大常见原因。 治疗取决于位置和阶段，通常包括放疗，化疗和手术。CRC 表型和对治疗的反应显著不同。CRCs的出现部分是由于体细胞的积累， 突变和拷贝数变体（CNV）。没有发现任何特别的变化可以完全预测 表型。我们和其他人已经确定了CRC中的遗传亚克隆。在其他肿瘤类型中，最近的研究 已经强调了遗传异质性在肿瘤表型中的潜在作用，但在CRC中， 在肿瘤进展和对治疗的反应中的异质性和肿瘤亚克隆仍然未知。因此，在本发明中， 我们假设如下：在原发性CRCs中，实质性肿瘤内遗传异质性是常见的， 存在于原发性病变中的不同亚克隆支持CRC生物学行为和临床表型。 原发病灶中不同的亚克隆引起CRC淋巴结（LN）和远处转移。该子- 存在于CRC病变中的克隆对化疗和放疗的反应不同。三个具体 提出了目标，以解决总体假设：具体目标1：我们将描述的程度和 通过研究多个不同地理区域的体细胞遗传改变， 目标2和3中使用的每个肿瘤的区域。我们将使用生物信息学工具整合突变， CNV用于定义每个肿瘤内的遗传亚克隆，并比较肿瘤间的亚克隆。具体目标二： 为了比较20例原发性结直肠癌患者与患者匹配的淋巴结转移患者的亚克隆， 目的是确定亚克隆群体在转移进展中的作用。我们提出的问题 答案是：1.转移到淋巴结的亚克隆是来自淋巴结中的多数克隆还是少数克隆， 原发性肿瘤？2.单个淋巴结转移瘤是由单个还是多个亚克隆组成？3.当有 单个患者的多个LN转移，它们是否来自原发性LN的相同亚克隆？ 肿瘤还是多个不同的亚克隆？具体目标3A：评估在基因组中亚克隆之间的关系。 直肠癌患者术前放化疗的疗效 治疗前后匹配的原发性直肠癌。我们假设一些直肠癌亚- 克隆对化疗和放疗敏感，而其他克隆对化疗和放疗有抗性。目标3B：同时，我们将创建 20种直肠癌的异种移植模型，并评估它们是否模拟了对标准 化疗和放射治疗。该提案将利用创新的排序， 生物信息学技术沿着患者样本和临床信息。最终， CRC进展和治疗反应的遗传机制将允许新的，靶向的 提出并测试的治疗方法。这个项目，多学科导师团队和教育计划 将准备候选人是一个完全独立的研究人员在结直肠癌遗传学领域。

PROJECT SUMMARY: Colorectal cancer (CRC) remains the 3rd most common cause of cancer-related death in the United States. Treatment depends on location and stage and often includes radiation, chemotherapy and surgery. CRC phenotype and response to therapy vary significantly. CRCs arise in part due to the accumulation of somatic mutations and Copy Number Variants (CNV's). No particular change has been found that fully predicts phenotype. We and others have identified genetic sub-clones in CRC. In other tumor types, recent studies have highlighted the potential role of genetic heterogeneity in tumor phenotype, but in CRC the role of heterogeneity and tumor sub-clones in tumor progression and response to therapy remains unknown. Thus, we hypothesize the following: Substantial intra-tumoral genetic heterogeneity is common in primary CRCs, and the distinct sub-clones present in a primary lesion underpin CRC biological behavior and clinical phenotype. Distinct sub-clones in the primary lesion give rise to CRC lymph node (LN) and distant metastases. The sub- clones present in a CRC lesion vary in their response to chemotherapy and radiation therapy. Three specific aims are proposed to address the overarching hypotheses: Specific Aim 1: We will characterize the extent and nature of genetic sub-clones in CRCs by studying somatic genetic alterations in multiple, distinct geographic regions from each tumor used in aims 2 and 3. We will use bioinformatics tools to integrate mutations and CNV's to define genetic sub-clones within each tumor and compare sub-clones across tumors. Specific Aim 2: To compare sub-clones in primary CRC's to those in patient-matched LN metastases in 20 patients with the goal of defining the role of sub-clonal populations in metastatic progression. The questions we propose to answer are these: 1. Are the sub-clones that metastasize to the LNs from the majority or minority clones in the primary tumor? 2. Are individual LN metastasis made up of single or multiple sub-clones? 3. When there are multiple LN metastasis in an individual patient, are they derived from the same sub-clone from the primary tumor or multiple different sub-clones? Specific Aim 3A: To assess relationships between the sub-clones in the tumor and the response of rectal cancer patients to pre-operative chemotherapy and radiation, by analyzing 40 matched primary rectal cancers before and after treatment. We hypothesize that some rectal cancer sub- clones are sensitive and others resistant to chemo- and radiation therapy. Aim 3B: In parallel, we will create xenograft models of 20 of the rectal cancers and assess whether they mimic the response to standard chemotherapy and radiation seen in the matched patients. This proposal will utilize innovative sequencing and bioinformatics techniques along with patient samples and clinical information. Ultimately, greater understanding of the genetic mechanisms underlying CRC progression and response to treatment will allow novel, targeted therapies to be proposed and tested. This project, the multidisciplinary mentorship team, and educational plan will prepare the candidate to be a fully independent investigator in the field of colorectal cancer genetics.