The alpha2beta1 Integrin and Tumor Metastasis

α2β1整合素与肿瘤转移

• 批准号: 8009795
• 负责人: MARY M. ZUTTER
• 金额: $ 30.9万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8009795
• 关键词: Address; Animal Model; Animals; Behavior; Breast Cancer Cell; Burn injury; Cancer Etiology; Cell Survival; Cells; Cessation of life; Clinical; Collagen; Data; Disease; Environment; Epithelial; Epithelial Cells; Genes; Goals; Health; Human; Incidence; Integration Host Factors; Integrin alpha2beta1; Integrins; Laboratories; Laminin Receptor; Lead; Lewis Lung Carcinoma; Lung; Malignant - descriptor; Malignant Epithelial Cell; Malignant Neoplasms; Mammary gland; Mediating; Metastasis Suppression; Metastasis Suppressor Genes; Modeling; Molecular; Mouse Mammary Tumor Virus; Mus; Neoplasm Metastasis; Phenotype; Primary Neoplasm; Proteins; Relative (related person); Role; Sampling; Severities; Site; Soil; Specimen; Tail; Transgenic Organisms; Tumor Suppression; Tumor Suppressor Proteins; Veins; Xenograft Model; base; cancer cell; cell type; in vivo; in vivo Model; interest; intravenous injection; malignant breast neoplasm; metastatic process; neoplastic cell; tumor; tumor growth; tumor initiation; tumor progression

DESCRIPTION (provided by applicant): The goal of this proposal is to define the role of the a2¿1 integrin in tumor metastasis, with specific interest on the interplay between malignant mammary epithelial cells and the tumor microenvironment. Integrin-mediated interactions between tumor cells and their microenvironment are required for tumor progression and metastasis. Our earliest data derived from human pathological specimens demonstrated that the a2¿1 integrin was highly expressed on normal epithelial cells but was diminished or lost in cancer in a manner that correlated with cancer progression. We now present new and exciting preliminary data that lack of the a2¿1 integrin expression promotes tumor metastasis in an in vivo model of spontaneous breast cancer. Although primary tumor incidence and latency were similar, metastases were twice as frequent in transgenic MMTV-c-neu mice lacking the a2¿1 integrin relative to wild type MMTV-c-neu littermate controls. Thus, the a2¿1 integrin may function as a metastasis suppressor gene that alters the rate of metastasis but not tumor initiation. Metastatic disease is not solely dependent on the malignant epithelial cell, but is equally influenced by the tumor microenvironment. When wild type and a2-null were injected intravenously with Lewis Lung carcinoma cells, the a2-null animals harbored significantly increased metastatic disease. These data from the intravenous injection of tumor cells suggest that increased metastasis is a consequence of host factors influencing the later steps of the tumor metastatic process. We cannot exclude additional contributions from the a2-null tumor cells in the spontaneous metastasis model. Based on these data we propose the following hypotheses and aims to address the hypotheses: 1) The a2¿1 integrin is a metastasis suppressor gene and alters tumor progression and the metastatic phenotype; 2) the a2¿1 integrin modifies the tumor micro-environment to serve as a metastasis efficiency modifier gene. AIM #1: To define the independent or cooperative contributions mediated by the a2¿1 integrin when expressed by tumor cells alone, by the tumor microenvironment alone, or by both tumor and microenvironment that leads to suppression of metastasis. Focus - the interaction of the tumor cells and the microenvironment. AIM #2: To define the role and determine the molecular mechanisms by which the a2¿1 integrin expression by the tumor cells regulates tumor progression. Focus - the tumor cells. AIM #3: To determine the role of the a2¿1 integrin modifies the host microenvironment to suppress tumor metastasis. This aim will focus specifically on the lung and the steps of intravasation, cell survival, arrest and colonization. Focus - the microenvironment of the metastatic site in the lung. PUBLIC HEALTH RELEVANCE: Metastasis is the main cause of cancer death. We have identified a protein that may suppress the incidence and severity of breast cancer metastasis. This proposal will evaluate the way in which this protein suppresses tumor metastasis.

描述（由申请人提供）：本提案的目标是确定a2¿1整合素在肿瘤转移中的作用，特别关注恶性乳腺上皮细胞与肿瘤微环境之间的相互作用。整合素介导的肿瘤细胞及其微环境之间的相互作用是肿瘤进展和转移所必需的。我们从人类病理标本中获得的最早数据表明，a2¿1整合素在正常上皮细胞上高度表达，但在癌症中以与癌症进展相关的方式减少或丢失。我们现在提出了新的和令人兴奋的初步数据，在自发性乳腺癌的体内模型中，缺乏a2¿1整合素表达会促进肿瘤转移。虽然原发肿瘤发生率和潜伏期相似，但缺乏a2¿1整合素的转基因MMTV-c-neu小鼠的转移频率是野生型MMTV-c-neu小鼠的两倍。因此，a2¿1整合素可能作为转移抑制基因起作用，改变转移率，但不改变肿瘤起始。转移性疾病不仅依赖于恶性上皮细胞，而且同样受到肿瘤微环境的影响。当野生型和a2-null小鼠静脉注射Lewis肺癌细胞时，a2-null小鼠的转移性疾病明显增加。这些来自静脉注射肿瘤细胞的数据表明，转移增加是宿主因素影响肿瘤转移过程后期步骤的结果。我们不能排除自发转移模型中a2-null肿瘤细胞的额外贡献。基于这些数据，我们提出以下假设并旨在解决以下假设：1)a2¿1整合素是一种转移抑制基因，改变肿瘤的进展和转移表型；2) a2¿1整合素修饰肿瘤微环境，作为转移效率修饰基因。目的1：明确a2¿1整合素在肿瘤细胞单独表达、肿瘤微环境单独表达、肿瘤和微环境共同表达时，对肿瘤转移抑制的独立或协同作用。焦点-肿瘤细胞与微环境的相互作用。目的2：明确肿瘤细胞a2¿1整合素表达调控肿瘤进展的作用和分子机制。焦点-肿瘤细胞。目的3：确定a2¿1整合素修饰宿主微环境抑制肿瘤转移的作用。这一目标将特别关注肺和内渗、细胞存活、停搏和定植的步骤。病灶-肺转移部位的微环境。公共卫生相关性：转移是癌症死亡的主要原因。我们已经确定了一种可能抑制乳腺癌转移的发生率和严重程度的蛋白质。本提案将评估该蛋白抑制肿瘤转移的方式。