Role of Foxm1 in Lung Cancer Microenvironment

描述(申请人提供)：肺癌由基因改变的上皮性肿瘤细胞和各种间质和炎性细胞组成，包括巨噬细胞、内皮细胞、成纤维细胞、淋巴细胞和其他一些细胞。在肺癌发生发展过程中，肿瘤微环境发生动态变化。这些变化的结果是肿瘤病变中的非肿瘤细胞被激活。巨噬细胞的持续激活会导致局部慢性炎症，从而促进肺部肿瘤的发生。肿瘤中内皮细胞的激活导致肿瘤血管生成。FOXM1转录因子在所有增殖细胞中都有表达，包括上皮细胞、巨噬细胞和内皮细胞。FOXM1蛋白在包括非小细胞肺癌在内的多种人类癌症中都有表达。尽管我们实验室以前的研究表明FOXM1在肺肿瘤发生中发挥了关键作用，但体内不同群体的呼吸道细胞对FOXM1转录因子的具体要求仍然未知。在这项拨款提案中，我们提供了初步的数据，表明肺上皮细胞中FOXM1的有条件删除，肿瘤细胞的前体，导致肺癌的发生和发展显著延迟。然而，肺癌病变中不仅含有肿瘤细胞，还含有多种促进肿瘤微环境的间质细胞和炎性细胞。为了研究FOXM1在肿瘤微环境中的细胞自主作用，我们建议利用内皮细胞特异性或巨噬细胞特异性FOXM1缺失的新小鼠模型。这项建议的目的是同时使用遗传学和药理学方法来验证这样的假设，即在肿瘤微环境的特定细胞中灭活FOXM1转录因子会降低肺癌的发生。提出了三个具体目标。在目标1中，我们将使用内皮特异性FOXM1缺失的小鼠来确定内皮细胞中FOXM1缺失是否通过减少肿瘤血管生成来抑制肺癌的形成。在内皮特异性FOXM1基因敲除小鼠和对照小鼠中，将比较肺肿瘤的数量和大小、肿瘤细胞增殖和血管生成。在目标2中，我们将确定巨噬细胞中FOXM1基因的特异性缺失是否可以减轻由三种典型的致癌方案：乌拉坦、MCA/BHT和诱导性K-ras诱导的肺部炎症和减少肺肿瘤的形成。在目标3中，我们将通过已知的FOXM1抑制剂ARF 26-44肽对FOXM1转录活性的药物抑制来开发治疗肺癌荷瘤小鼠的方法。我们的初步数据显示，鼻腔给药的InFasurf(表面活性物质)和荧光标记的ARF26-44肽的混合物有效地输送到所有类型的肺细胞。用ARF多肽对荷肺肿瘤小鼠进行治疗，以确定该ARF多肽是否能抑制肿瘤细胞的增殖，减少肿瘤血管生成，减轻小鼠肺肿瘤的炎症反应。这些拟议研究的完成将使我们能够确定FOXM1是否在肿瘤微环境中发挥关键作用，以及FOXM1是否是肺癌治疗的重要靶点。 公共卫生相关性：本研究试图确定FOXM1在巨噬细胞和内皮细胞中在肺癌发生和发展中的直接作用，并通过用已知的FOXM1抑制剂ARF 26-44肽药物抑制FOXM1转录活性来开发治疗肺癌荷瘤小鼠的方法。将研究肺癌发生和发展中的新的信号通路，这将使我们更好地了解导致这种疾病的分子机制。这些拟议研究的完成将使我们能够确定FOXM1的细胞特异性抑制是否将为预防慢性肺部炎症和血管生成提供新的策略，并确定FOXM1的药理抑制是否将为治疗肺癌的药物设计提供潜在的新靶点的信息。

DESCRIPTION (provided by applicant): Lung cancers consist of genetically altered epithelial tumor cells and a diverse array of stromal and inflammatory cells, including macrophages, endothelial cells, fibroblasts, lymphocytes and some others. During lung cancer initiation and progression, the microenvironment of the tumors changes dynamically. The result of the changes is the activation of non-tumor cells in tumor lesions. Persistent activation of macrophages causes local chronic inflammation that promotes lung tumorigenesis. Activation of endothelial cells in the tumors results in tumor angiogenesis. The FoxM1 transcription factor is expressed in all proliferating cells, including epithelial cells, macrophages and endothelial cells. The Foxm1 protein is induced in a variety of human cancers, including non-small cell lung cancers. Although previous studies from our laboratory demonstrated a critical role of Foxm1 in lung tumorigenesis, specific requirements for the Foxm1 transcription factor in different populations of respiratory cells in vivo remain unknown. In this grant proposal, we provide preliminary data demonstrating that conditional deletion of Foxm1 in lung epithelial cells, the precursors of tumor cells, causes striking delay in initiation and progression of lung tumors. However, lung cancer lesions contain not only tumor cells, but also diverse stromal and inflammatory cells of tumor promoting microenvironment. To study the cell autonomous role of Foxm1 in the tumor microenvironment, we propose to utilize new mouse models with endothelial cell-specific or macrophage-specific Foxm1 deletion. The goal of this proposal is to use both genetic and pharmacological approaches to test the hypothesis that inactivation of Foxm1 transcription factor in specific cells of tumor microenvironment decreases lung tumorigenesis. Three specific aims are proposed. In Aim 1 we will use mice with endothelial-specific Foxm1 deletion to determine whether Foxm1-deficiency in endothelial cells inhibits formation of lung cancer by decreasing tumor angiogenesis. Number and sizes of lung tumors, tumor cell proliferation and angiogenesis will be compared in endothelial-specific Foxm1 knockout mice versus control mice. In Aim 2 we will establish whether specific deletion of Foxm1 gene in macrophages diminishes lung inflammation and decrease lung tumor formation induced by three well-characterized carcinogenesis protocols: urethane, MCA/BHT and inducible K-ras. In Aim 3 we will develop the therapeutic treatment for lung tumor bearing mice using pharmacological inhibition of Foxm1 transcriptional activity with ARF 26-44 peptide, a known Foxm1 inhibitor. Our preliminary data show that nasal administration of a mixture of InfaSurf (Surfactant) and fluorescently tagged ARF 26-44 peptide is effectively delivered to all cell types of the lung. The lung tumor-bearing mice will be treated with ARF peptide to determine whether this ARF peptide diminishes proliferation of tumor cell, decreases tumor angiogenesis and decreases inflammation in mouse lung tumors. Completion of the proposed studies will enable us to determine whether Foxm1 plays critical role in tumor microenvironment and whether Foxm1 is an important target for lung cancer treatment. PUBLIC HEALTH RELEVANCE: The present study seeks to identify the direct role of Foxm1 in macrophages and endothelial cells during initiation and progression of lung cancer and to develop the therapeutic treatment for lung tumor bearing mice using pharmacological inhibition of Foxm1 transcriptional activity with ARF 26-44 peptide, a known Foxm1 inhibitor. The novel signaling pathways in lung cancer initiation and progression will be studied, which will allow us to better understand the molecular mechanisms responsible for this disease. Completion of the proposed studies will enable us to determine whether the cell specific inhibition of Foxm1 will offer new strategies to prevent chronic lung inflammation and angiogenesis and to determine whether pharmacological inhibition of Foxm1 will provide information regarding potential novel targets for drug design to treat lung cancer.