Molecular Basis of Slits as Tumor Suppressors Controlling CXCR4/SDF1 in Breast

狭缝作为肿瘤抑制因子控制乳腺 CXCR4/SDF1 的分子基础

• 批准号: 8063686
• 负责人: LINDSAY E HINCK
• 金额: $ 3.33万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA CRUZ
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8063686
• 关键词: Address; Animal Model; Biological Assay; Biological Models; Blood Vessels; Breast; Breast Cancer Cell; CXCL12 gene; CXCR4 gene; Cancer Biology; Carcinoma; Cell Proliferation; Cells; Conflict (Psychology); Cues; Data; Development; Disease; Distant Metastasis; Down-Regulation; Ductal Epithelial Cell; Endothelial Cells; Environment; Epigenetic Process; Epithelial; Epithelial Cells; Epithelium; Fibroblasts; G-Protein-Coupled Receptors; Gene Expression; Gene Mutation; Generations; Genes; Genetic; Gland; Goals; Growth; Human; Hyperplasia; Immunoblotting; Immunohistochemistry; Knock-out; Lead; Lesion; Ligands; Link; Literature; Malignant - descriptor; Malignant Neoplasms; Mammary Neoplasms; Mammary gland; Matrix Metalloproteinases; Mediating; Molecular; Mutation; Neoplasm Metastasis; Organoids; Pathway interactions; Phenotype; Phosphorylation; Physiology; Plastics; Play; Primary Lesion; Primary Neoplasm; Process; Proteins; Research; Roche brand of trastuzumab; Role; Signal Transduction; Site; Source; Staging; Surveys; Tars; Tissues; Transplantation; Trastuzumab; Tumor Angiogenesis; Tumor Suppressor Proteins; Up-Regulation; Vascular Endothelial Growth Factors; angiogenesis; base; cell motility; chemokine; genetic profiling; in vivo; inhibitor/antagonist; loss of function; loss of function mutation; malignant breast neoplasm; mammary epithelium; neoplastic; neovascularization; null mutation; overexpression; public health relevance; receptor; response; therapeutic target; tumor; tumor growth; tumor progression; tumorigenesis; tumorigenic

DESCRIPTION (provided by applicant): The goal of cancer biology is to understand the progression of genetic and epigenetic changes occurring in cells as they become tumorigenic. Many studies have demonstrated a critical role for CXCR4 in guiding metastasizing breast cancer cells to sites with high levels of its ligand SDF1 (CXCL12). In contrast, relatively few studies have explored the consequences of having this pathway deregulated early in lesion development, even though a large fraction (>90%) of human breast tumors display inappropriate CXCR4 expression at very early stages of transformation. The observation that CXCR4 is upregulated early in the disease process, combined with recent studies demonstrating that carcinoma associated fibroblasts serve as a local source of its ligand SDF1, have fueled speculation that CXCR4 may also play a pivotal role in primary tumor growth. We have identified such a disease signature in hyperplastic lesions of mammary glands harboring loss-of-function in Slit2 and Slit3 or its Robo1 receptor, giving us the unique opportunity to understand the function of CXCR4 and SDF1 in the early stages of breast transformation within the integrated physiology of an animal model. Our preliminary data demonstrate that loss-of-function mutations in Slits or their Robo1 receptor lead to loss of tissue organization, elevated proliferation and a host of changes in the microenvironment, including increased angiogenesis. Based on our preliminary data, the overall hypothesis of the application is that loss of SLIT/ROBO1 signaling in breast leads to upregulated SDF1/CXCR4, which, in turn, contributes to epithelial transformation and generation of the tumor microenvironment. To address this hypothesis, the Specific Aims of this proposal are three-fold. In Aim I, we propose to investigate the role SDF1/CXCR4 signaling plays in early lesion development by determining the signaling status of CXCR4 in Slit2-/-;Slit3-/- and Robo1-/- tissue using both gain- and loss-of-function approaches. We will also evaluate whether similar expression changes occur between Slits, Robo1 and Cxcr4 in human breast tumors. In Aim II, we propose to define the cross talk that occurs between mammary epithelia and stroma by generating glands in which SLIT/ROBO1 signaling is selectively eliminated in the epithelia or stroma. In Aim III, we investigate the pro-angiogenic environment that arises in the absence of SLIT/ROBO1 signaling. We propose to elucidate the role of SDF1, alone, in promoting neoangiogenesis by eliminating VEGF activation in the Robo1-null background. We also propose to explore the role of Slit2 and Slit3 as tumor suppressors by re-expressing the genes in breast cancer cells and evaluating the effects on tumor growth and tumor angiogenesis. In summary, we have identified SDF1/CXCR4 as key, downstream regulatory targets of SLIT/ROBO1 signaling in vivo. We propose to elucidate how misregulation of this chemokine axis orchestrates inappropriate interactions between cells and their environment, leading to transformation of the tissue and surrounding microenvironment. PUBLIC HEALTH RELEVANCE: The genesis of breast cancer has remained elusive. Even though it is considered a heritable disease, it is estimated that only 5-10% of all human breast cancers are causally linked to known genetic mutations. Identifying genes whose mutations allow a lesion to progress and become malignant is crucial for identifying potential therapeutic targets. For a number of cancers, prominently breast, a candidate target with an established role in metastasis is the G-protein coupled receptor CXCR4. The goal of this application is to understand how CXCR4 contributes to tumor progression using breast as a model system.

描述（由申请人提供）：癌症生物学的目的是了解细胞变成肿瘤性时发生的遗传和表观遗传变化的进展。 许多研究表明，CXCR4在引导乳腺癌细胞转移到具有高水平配体SDF1（CXCL12）的位点的关键作用。 相比之下，相对较少的研究探讨了在病变发育初期消除该途径的后果，即使大量的人类乳腺肿瘤在很早的转化阶段表现出不适当的CXCR4表达。 CXCR4在疾病过程的早期被上调的观察与最近的研究相结合，表明癌相关的成纤维细胞是其配体SDF1的局部来源，这激发了人们的猜测，即CXCR4也可能在原发性肿瘤生长中起关键作用。 我们已经在乳腺的增生病变中确定了这种疾病特征，该病变在SLIT2和SLIT3或其ROBO1受体中具有功能丧失的功能丧失，这为我们提供了独特的机会，可以理解CXCR4和SDF1在乳房转化的早期阶段的功能。 我们的初步数据表明，缝隙或其ROBO1受体的功能丧失突变导致组织组织的损失，增殖升高和微环境的许多变化，包括血管生成增加。 基于我们的初步数据，应用的总体假设是乳房中的狭缝/robo1信号的丧失导致SDF1/CXCR4上调，这反过来又有助于上皮转化和肿瘤微环境的产生。 为了解决这一假设，该提案的具体目的是三倍。 在目标I中，我们建议通过确定slit2 - / - ; slit3 - / - 和robo1-/ - 组织使用增益和功能丧失方法来研究早期病变发育中SDF1/CXCR4信号传导的作用。 我们还将评估人类乳腺肿瘤中狭缝，robo1和cxcr4之间是否发生类似的表达变化。 在AIM II中，我们建议通过产生腺体或基质信号在上皮或基质中有选择地消除乳腺上皮和基质之间发生的串扰。 在AIM III中，我们研究了在没有缝隙/Robo1信号传导的情况下产生的促血管生成环境。 我们建议单独阐明SDF1在促进新血管生成中的作用，以消除在Robo1-Null背景中VEGF激活。 我们还建议通过重新表达乳腺癌细胞中的基因并评估对肿瘤生长和肿瘤血管生成的影响，探索SLIT2和SLIT3作为肿瘤抑制子的作用。 总而言之，我们已经将SDF1/CXCR4确定为体内狭缝/ROBO1信号的钥匙，下游调节靶标。 我们建议阐明这种趋化因子轴的正调如何策划细胞与环境之间的不适当相互作用，从而导致组织和周围的微环境的转化。 公共卫生相关性：乳腺癌的起源仍然难以捉摸。 即使被认为是一种可遗传的疾病，据估计，所有人类乳腺癌中只有5-10％与已知的遗传突变有因果关系。 鉴定突变允许病变发展并变恶的基因对于识别潜在的治疗靶标至关重要。 对于许多癌症，乳腺癌的癌症是G蛋白偶联受体CXCR4。 该应用的目的是了解CXCR4如何使用乳腺作为模型系统促进肿瘤进展。