INTEGRIN SIGNALING DURING BREAST TUMORIGENESIS

乳腺癌肿瘤发生过程中的整合素信号传导

• 批准号: 7749542
• 负责人: FILIPPO G GIANCOTTI
• 金额: $ 38.96万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 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/7749542
• 关键词: 1-Phosphatidylinositol 3-Kinase; Ablation; Adherens Junction; Adhesions; Apoptosis; Biochemical; Biological Assay; Breast Cancer Cell; Breast Carcinoma; Bypass; Cancer cell line; Carcinoma; Cells; Complex; ERBB2 gene; Endothelial Cells; Epithelial; Epithelial Cells; Extracellular Matrix; Fatty acid glycerol esters; Fibroblasts; Focal Adhesion Kinase 1; Genetic; Goals; Growth; Image; In Vitro; Integrins; Invaded; JUN gene; Laboratories; Maintenance; Malignant Epithelial Cell; Malignant Neoplasms; Mammary Neoplasms; Mammary Tumorigenesis; Mammary gland; Mediating; Modeling; Molecular; Molecular Target; Mus; Mutagenesis; Mutation; NOD/SCID mouse; Null Lymphocytes; Oncogenes; Oncogenic; Pathogenesis; Pathway interactions; Play; Polyomavirus; Proliferating; Public Health; Role; STAT3 gene; Signal Pathway; Signal Transduction; Specificity; Testing; Transgenic Mice; Tumorigenicity; adhesion receptor; breast tumorigenesis; cancer cell; cell transformation; design; imaging modality; in vivo; knock-down; macrophage; malignant breast neoplasm; mouse model; mutant; neoplastic cell; novel; reconstitution; research study; response; senescence; transcription factor; tumor; tumor initiation; tumor progression; tumorigenesis; tumorigenic

DESCRIPTION (provided by applicant): We hypothesize that integrin signaling plays key roles during tumor initiation and progression. To study the role of the ¿4 integrin during ErbB2-mediated mammary tumorigenesis, we introduced a targeted deletions of the ¿4 signaling domain in MMTV-Neu mice. Loss of ¿4 signaling delayed tumor onset and inhibited invasive growth. Ex vivo studies indicated that ¿4 forms a complex with ErbB2 and enhances activation of STAT3 and c-Jun. STAT3 contributes to disrupt epithelial adhesion and promote invasion, whereas c-Jun is required for hyperproliferation. To examine the role of Focal Adhesion Kinase (FAK) in mammary tumorigenesis, we introduced a mammary gland-specific ablation of FAK in MMTV-PyMT mice. Notably, deletion of FAK completely suppressed mammary tumorigenesis. In addition, silencing of FAK induced Ras- and PI-3K-transformed mammary carcinoma cells to undergo growth arrest and senescence or apoptosis in vitro. These results suggest that ¿4 promotes tumor progression by amplifying ErbB2 signaling, whereas FAK is required for Ras- and PI-3K-mediated mammary tumorigenesis. We propose: 1) To examine the oncogene specificity of the pro-tumorigenic effects of ¿4 and FAK. Normal mammary epithelial cells will be altered in vitro to suppress FAK or ¿4 signaling and then subjected to transformation assays with various oncogenes. Conversely, mammary tumor cells carrying distinct oncogenes will be genetically manipulated in vitro to suppress FAK or ¿4 signaling and subjected to assays designed to examine their ability to proliferate, to resist apoptosis, to invade in vitro, and to form orthotopic tumors in NOD/SCID mice. Key observations will be confirmed using selected human breast cancer cell lines and transgenic mouse models; 2) To elucidate the mechanisms through which ¿4 signaling disrupts epithelial adhesion and promotes invasion. The mechanism by which ¿4 amplifies ErbB2 signaling will be examined by using mutagenesis in combination with biochemical analysis and iRNA-mediated inhibition. The signaling pathways through which hyperactivation of Rac causes disassembly of adherens junctions will be studies by using biochemical analysis, silencing, and imaging methods; 3) To study the molecular mechanisms through which FAK promotes mammary tumorigenesis. Silencing will be used to confirm that CAS mediates the pro-tumorigenic effect of FAK. Biochemical analysis of control and CAS-silenced tumor cells will then be used to identify CAS-dependent pathways. Inhibition of key downstream effectors will be used to identify the major signaling pathways through which CAS promotes mammary tumorigenesis; 4) To examine the mechanisms through which ¿4 and FAK cooperate to sustain ErbB2-initiated mammary tumorigenesis. Biochemical experiments will be conducted to identify signaling components jointly activated by ¿4 and FAK in mammary tumor cells. Silencing will be used to test the pro-tumorigenic role of potential key signaling integrators. Mouse genetics will be used to determine if ¿4 and FAK cooperate in vivo to promote ErbB2-initiated mammary tumorigenesis. PUBLIC HEALTH RELEVANE: Breast carcinoma cells evolve toward increasing malignancy in response to signals from their microenvironment, which include carcinoma-associated fibroblasts, macrophages, angiogenic endothelial cells, and the extracellular matrix that these cells produce. The integrin adhesion receptors are critical players in this signaling network. Yet, their role in breast tumorigenesis is incompletely understood. Our preliminary studies suggest that the ¿4 integrin promote breast carcinoma progression by amplifying ErbB2 signaling, whereas Focal Adhesion Kinase (FAK) is required for Ras- and Pi-3K-mediated tumor initiation and maintenance. We propose to examine the mechanisms through which ¿4 and FAK promote breast tumorigenesis. These studies will contribute to our understanding of the pathogenesis of breast cancer and to the identification of novel molecular targets for its therapy.

描述（由申请人提供）：我们研究整合素信号在肿瘤发生和进展过程中发挥的关键作用。 4 整合素在 ErbB2 介导的乳腺肿瘤发生过程中，我们引入了 ¿ MMTV-Neu 小鼠中 4 信号结构域丢失。 4 信号传导可延迟肿瘤发生并抑制侵袭性生长。 4 与 ErbB2 形成复合物并增强 STAT3 和 c-Jun 的激活，有助于破坏上皮粘附并促进侵袭，而 c-Jun 是过度增殖所必需的。我们在 MMTV-PyMT 小鼠中引入了 FAK 的乳腺特异性消融，值得注意的是，FAK 的缺失完全抑制了乳腺。此外，FAK 沉默可诱导 Ras 和 PI-3K 转化的乳腺癌细胞在体外发生生长停滞和衰老或凋亡。 4 通过放大 ErbB2 信号传导促进肿瘤进展，而 FAK 是 Ras 和 PI-3K 介导的乳腺肿瘤发生所必需的。我们建议：1) 检查 ¿ 促肿瘤作用的癌基因特异性。 4 和 FAK 会在体外发生改变以抑制 FAK 或 ¿ 4 信号传导，然后用各种癌基因进行转化，携带不同癌基因的乳腺肿瘤细胞将在体外进行基因操作以抑制 FAK 或 ¿ 4 信号传导，并进行旨在检查其增殖、抗凋亡、体外侵袭以及在 NOD/SCID 小鼠中形成原位肿瘤的能力的测定。关键观察结果将使用选定的人乳腺癌细胞系和转基因小鼠模型进行证实。 ; 2) 阐明 ¿ 4 信号传导破坏上皮粘附并促进侵袭的机制 ¿ 4 将通过结合生化分析和 iRNA 介导的抑制来检查放大 ErbB2 信号传导 将通过生化分析、沉默和成像方法来研究 Rac 过度激活导致粘附连接分解的信号传导途径 3)；为了研究FAK促进乳腺肿瘤发生的分子机制，将使用沉默来确认CAS介导FAK的促肿瘤作用。然后，对照和 CAS 沉默的肿瘤细胞将用于识别 CAS 依赖性通路，而对关键下游效应器的抑制将用于识别 CAS 促进乳腺肿瘤发生的主要信号通路。 4 和 FAK 合作维持 ErbB2 引发的乳腺肿瘤发生，将进行生化实验来鉴定 ¿ 联合激活的信号成分。 4 和 FAK 在乳腺肿瘤细胞中的沉默将用于测试潜在关键信号整合因子的促肿瘤作用，以确定是否 ¿ 4 和 FAK 在体内协同促进 ErbB2 引发的乳腺肿瘤发生。 公共卫生相关：乳腺癌细胞响应微环境（包括癌相关成纤维细胞、巨噬细胞、血管生成内皮细胞和细胞外基质）的信号，向恶性程度增加的方向进化。这些细胞产生的整合素粘附受体是该信号网络中的关键参与者，但它们在乳腺肿瘤发生中发挥着重要作用。我们的初步研究表明 ¿ 4 整合素通过放大 ErbB2 信号传导促进乳腺癌进展，而局灶粘附激酶 (FAK) 是 Ras 和 Pi-3K 介导的肿瘤发生和维持所必需的，我们建议检查 ¿ 4 和 FAK 促进乳腺肿瘤发生，这些研究将有助于我们了解乳腺癌的发病机制并确定其治疗的新分子靶点。