Identification of Metabolic Liabilities in Breast Cancer

乳腺癌代谢负担的识别

• 批准号: 8352910
• 负责人: Richard Lewis Possemato
• 金额: $ 11.4万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8352910
• 关键词: Address; Bioinformatics; Biological Assay; Biomass; Blood Circulation; Breast Cancer Cell; Breast Cancer Model; Cancer cell line; Cell Proliferation; Cells; Collaborations; DNA Sequence; Data; Dependency; Disinhibition; Environment; Enzymes; Essential Genes; Estrogen Receptor Status; Exhibits; Future; Gene Expression; Genes; Glucose; Glutamine; Goals; Growth; Human; In Vitro; Individual; Institutes; Malignant Neoplasms; Measures; Mentors; Metabolic; Metabolic Pathway; Metabolism; Methods; Modeling; Molecular Profiling; Mus; Normal Cell; Normal tissue morphology; Nutrient; Oncogene Activation; Oxygen; Pathway interactions; Patients; RNA Interference; RNAi vector; Research; Resources; Sampling; Screening procedure; Serine; Solutions; System; Techniques; Time; Tissues; Work; Xenograft Model; arm; base; biological systems; cancer cell; cancer therapy; career; cell transformation; deprivation; design; enzyme pathway; experience; follow-up; in vivo; loss of function; malignant breast neoplasm; meetings; metabolic abnormality assessment; metabolomics; novel; response; skills; tool; tumor; tumor xenograft; uptake

DESCRIPTION (provided by applicant): Tumors exhibit altered uptake and utilization of nutrients, such as glucose and glutamine, to accommodate the tumor's need to accumulate biomass. In contrast to normally proliferative tissues, cells within a tumor are frequently starved for nutrients due to their high proliferation rate and unreliable vasculature. Therefore, the rewiring of cancer cell metabolism that occurs in response to nutrient limitation may present cancer specific vulnerabilities that can be the target of future anti-cancer therapies. Here, we propose to gain a better understanding of cancer metabolism by meeting the challenges of (1) determining how the tumor nutrient environment impacts cancer cell metabolism and (2) defining pathways which can be targeted as a consequence of this altered metabolism. In meeting these challenges, we will enable the fulfillment of our long-term goal: to characterize the metabolism of cancer in vivo and take advantage of the liabilities present due to this altered metabolism to identify essential genes which can be the target of future cancer therapies. We propose to address these challenges by two complementary Aims: (1) Determine those enzymes and pathways specifically essential to breast cancer cells in an orthotopic model of breast cancer and (2) using defined metabolic environments, determine those enzymes and pathways specifically essential to breast cancer cells in nutrient limited conditions. Completion of these first two Aims will give us the opportunity to (3) integrate the results from the two cancr cell systems and conduct targeted follow-up. Accomplishing the First Aim will require the implementation of an in vivo RNAi-based loss-of-function screen. This screen will be conducted using a pool of RNAi vectors targeting metabolic genes, enabling the construction of a pool of breast cancer cells, each of which exhibits suppression of a single enzyme. Upon in vivo or in vitro culture, the change in abundance of the RNAi construct will be measured by massively parallel DNA sequencing, and allow us to determine the essentiality of the gene which that construct suppresses. In the Second Aim we propose assessing the metabolite composition of murine or xenograft tumor models and patient tumor samples to identify key nutrients provided by the circulation that are depleted from individual tumors. Then, implementing a continuous medium replacement system that we have developed to grow cells in defined conditions where such key nutrients are limiting, we will define the adaptation to limiting key nutrients using a combination of expression profiling, metabolite profiling and RNAi-based screening, ultimately uncovering those enzymes or pathways essential for growth upon nutrient limitation. Finally, in the Third Aim we will have the opportunity to integrate the data from the first two Aims and identify metabolite, gene expression, or gene dependency profiles which are common or unique to the environments studied, with the goal of engaging in a targeted follow-up to gain a detailed mechanistic understanding of individual genes or pathways identified as essential in these environments. PUBLIC HEALTH RELEVANCE: Understanding how cancer cells adapt to nutrient limiting conditions will enable the identification of metabolic genes and pathways specifically required in the transformed state. The identification of these essential metabolic genes and pathways is anticipated to facilitate the discovery of novel anti-cancer targets, and in combination with bioinformatic methods, identify patients who would be most likely to benefit from inhibition of such targets. Finally, identificatin of those key nutrients limiting in human tumors and the impact of this nutrient limitation on overall cancer cell metabolism will increase understanding of any limitations in the in vitro use o patient derived cell lines for cancer metabolism research.

描述(申请人提供)：肿瘤表现出对营养物质的吸收和利用的改变，如葡萄糖和谷氨酰胺，以适应肿瘤积累生物量的需要。与正常增殖的组织不同，肿瘤内的细胞经常挨饿。 对于营养物质，因为它们的高增殖率和不可靠的血管系统。因此，对营养限制作出反应的癌细胞代谢的重新连接可能会呈现出癌症特有的脆弱性，这可能是未来抗癌治疗的目标。在这里，我们建议通过应对以下挑战来更好地了解癌症新陈代谢：(1)确定肿瘤营养环境如何影响癌细胞新陈代谢；(2)确定作为这种新陈代谢改变结果的靶向途径。在迎接这些挑战时，我们将能够实现我们的长期目标：确定癌症在体内的代谢特征，并利用由于这种代谢变化而存在的风险来识别可能成为未来癌症治疗目标的基本基因。我们建议通过两个互补的目标来应对这些挑战：(1)在乳腺癌的原位模型中确定对乳腺癌细胞特定必需的酶和途径；(2)使用定义的代谢环境，在营养有限的条件下确定对乳腺癌细胞特定必需的酶和途径。前两个目标的完成将使我们有机会(3)整合两个癌症细胞系统的结果，并进行有针对性的后续行动。要实现第一个目标，将需要实施基于体内RNAi的功能丧失筛查。这一筛选将使用靶向代谢基因的RNAi载体池进行，从而能够构建乳腺癌细胞池，每个细胞池都显示出对单一酶的抑制。在体内或体外培养后，RNAi构建体的丰度变化将通过大规模平行DNA测序来测量，并使我们能够确定该构建体抑制的基因的重要性。在第二个目标中，我们建议评估小鼠或异种移植肿瘤模型和患者肿瘤样本的代谢物成分，以确定从单个肿瘤中耗尽的循环提供的关键营养物质。然后，实施我们开发的连续培养基替换系统，以在限定的条件下培养细胞，其中这些关键营养物质是有限的，我们将使用表达谱分析、代谢物谱分析和基于RNAi的筛选相结合的方法来定义对限制关键营养物质的适应，最终揭示那些对营养限制时生长至关重要的酶或途径。最后，在第三个目标中，我们将有机会整合来自前两个目标的数据，并确定所研究环境中常见或独特的代谢物、基因表达或基因依赖谱，目标是参与有针对性的后续行动，以获得对这些环境中被确定为必需的单个基因或途径的详细机制理解。 公共卫生相关性： 了解癌细胞如何适应营养限制条件将有助于识别 在转化状态下特别需要的代谢基因和途径。这些重要代谢基因和途径的识别有望促进新的抗癌靶点的发现，并与生物信息学方法相结合，识别最有可能从抑制这些靶点中受益的患者。最后，确定那些限制人类肿瘤的关键营养物质，以及这种营养限制对整个癌细胞代谢的影响，将增加对患者来源细胞系体外用于癌症代谢研究的任何限制的理解。