Role of Foxm1 in Lung Cancer Microenvironment

描述（由申请人提供）：肺癌由遗传改变的上皮肿瘤细胞和各种基质和炎性细胞组成，包括巨噬细胞、内皮细胞、成纤维细胞、淋巴细胞和其他细胞。 在肺癌的发生和发展过程中，肿瘤的微环境发生动态变化。 这些变化的结果是肿瘤病变中非肿瘤细胞的激活。 巨噬细胞的持续激活引起促进肺肿瘤发生的局部慢性炎症。 肿瘤中内皮细胞的活化导致肿瘤血管生成。 FoxM 1转录因子在所有增殖细胞中表达，包括上皮细胞、巨噬细胞和内皮细胞。 Foxm 1蛋白在多种人类癌症中被诱导，包括非小细胞肺癌。 虽然我们实验室以前的研究证明了Foxm 1在肺肿瘤发生中的关键作用，但体内不同呼吸道细胞群体对Foxm 1转录因子的具体要求仍然未知。 在这项资助提案中，我们提供了初步数据，证明肺上皮细胞（肿瘤细胞的前体）中Foxm 1的条件性缺失会导致肺肿瘤发生和进展的显著延迟。 然而，肺癌病变不仅含有肿瘤细胞，而且还含有多种促肿瘤微环境的基质细胞和炎性细胞。 为了研究Foxm 1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Foxm 1缺失的新小鼠模型。 该提案的目的是使用遗传学和药理学方法来检验肿瘤微环境中特定细胞中Foxm 1转录因子失活降低肺肿瘤发生的假设。 提出了三个具体目标。 在目标1中，我们将使用内皮特异性Foxm 1缺失的小鼠来确定内皮细胞中Foxm 1缺陷是否通过减少肿瘤血管生成来抑制肺癌的形成。 将比较内皮特异性Foxm 1敲除小鼠与对照小鼠中肺肿瘤的数量和大小、肿瘤细胞增殖和血管生成。 在目的2中，我们将确定巨噬细胞中Foxm 1基因的特异性缺失是否减少肺部炎症并减少由三种充分表征的致癌方案诱导的肺部肿瘤形成：乌拉坦，MCA/BHT和诱导型K-ras。 在目标3中，我们将开发使用ARF 26-44肽（一种已知的Foxm 1抑制剂）药理学抑制Foxm 1转录活性来治疗荷肺肿瘤小鼠的治疗性治疗。 我们的初步数据显示，鼻内给药InfaSurf（表面活性剂）和荧光标记的ARF 26-44肽的混合物可有效地递送至肺的所有细胞类型。 将用ARF肽处理携带肺肿瘤的小鼠以确定该ARF肽是否减少肿瘤细胞的增殖、减少肿瘤血管生成和减少小鼠肺肿瘤中的炎症。 这些研究的完成将使我们能够确定Foxm 1是否在肿瘤微环境中起关键作用，以及Foxm 1是否是肺癌治疗的重要靶点。 公共卫生相关性：本研究旨在确定Foxm 1在肺癌发生和发展过程中在巨噬细胞和内皮细胞中的直接作用，并开发使用ARF 26-44肽（一种已知的Foxm 1抑制剂）药理学抑制Foxm 1转录活性的肺肿瘤荷瘤小鼠的治疗方法。 将研究肺癌发生和发展中的新信号通路，这将使我们能够更好地了解这种疾病的分子机制。 完成拟议的研究将使我们能够确定Foxm 1的细胞特异性抑制是否将提供预防慢性肺部炎症和血管生成的新策略，并确定Foxm 1的药理学抑制是否将提供有关治疗肺癌的药物设计的潜在新靶点的信息。

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.