Targeting VCAM1-a4b1 Signaling to Ameliorate Pulmonary Osteosarcoma Metastasis

项目总结/摘要 骨肉瘤（OS）是一种侵袭性恶性原发性骨癌， 转移OS经常在骨快速生长期间起源于长骨。因此，OS 是影响儿童、青少年和年轻人（AYA）的最常见骨癌， 每年约400-600例，约占美国诊断的所有OS新病例的一半。 尽管积极的联合化疗和手术，转移性OS的结果仍然令人沮丧， 儿童和转移性OS的AYA患者的总生存率在2008年至2009年期间没有显著改善。 过去30年高比例的OS患者发生肺转移（pOS）， 诊断（20%）或开始多模式治疗后，包括联合化疗和手术。 不幸的是，几乎所有的病人谁开发手术不可切除的pOS总是屈服于这一点 毁灭性的疾病因此，pOS代表一种需求未得到满足的疾病。由于操作系统包含了 复杂的遗传改变，分子靶向精确治疗已被证明具有挑战性。近期精彩 科学发展暗示免疫系统作为一种潜在的重要的新的医疗设备， 控制或减少pOS的方法。在目前的提案中，我们鉴定了肿瘤表达的血管细胞， 粘附分子-1（tVCAM-1）通过与肿瘤细胞相互作用，在免疫介导的肿瘤转移中发挥关键作用。 与α4β1整合素在肺巨噬细胞（MAC）上，从而暗示肺巨噬细胞作为主要的 与非转移性亲代肿瘤（K7）相比，转移性肿瘤（K7）是转移性OS病理生理学的罪魁祸首。 鼠OS细胞（K7 M2）表达高表面VCAM-1，并且tVCAM-1或MAC的缺乏阻止了OS细胞（K7 M2）的增殖。 发展和改善大部分已建立的pOS。因此，我们希望进一步研究我们的 一种可靶向的细胞和分子机制，VCAM-1/ α4β1，是OS-MAC的主要驱动力， 相互作用，为体内pOS提供合适的肺组织生态位。我们的假设是干扰VCAM- 通过下调VCAM-1、耗尽MAC或破坏VCAM-1，pOS和MAC之间的1/α4β1信号传导 1-α4β1信号转导可减少肺转移并提高生存率。具体目标1：我们将描述 MACS和其他免疫细胞在VCAM-1/α4β4信号转导参与后的功能结果 POS.我们将比较VCAM-1 lo和VCAM-1hi pOS细胞的体内生长和相关的免疫应答 在肺部，并扩大我们的观察，包括测试其他人的肺转移潜力， 小鼠pOS细胞系和PDX可通过我们自己的PDX库和我们的合作者在 德州儿童医院我们将描述各种髓系和 VCAM-1 lo和VCAM-1hi pOS细胞的肺组织中的其它免疫细胞区室， 分子和成像方法。具体目标2：我们将测试VCAM功能性阻断的功效， 1/α4β1相互作用，通过鼻内氯膦酸脂质体治疗消耗MAC或通过抑制分子 使用VCAM-1特异性抑制肽（iVCAM-1 p）或鼻内/鼻腔内施用 抗A4封闭抗体。在涉及抗α4阻断抗体的后一种情况下，我们设定了一个目标， 用于监测全身和局部毒性并优化最佳治疗方案的基础临床前IND支持数据 剂量，以迅速转化的发现，从目前的赠款到I期研究使用FDA批准的 抗α4抗体，那他珠单抗，通过鼻内和吸入途径治疗晚期 pOS期患者，没有其他可证明治疗获益的治疗选择。成功 在这一高度优先的努力中， 和患有这种毁灭性疾病的AYA患者。

Project Summary / Abstract Osteosarcoma (OS) is an aggressive malignant primary bone cancer with a high propensity for lung metastasis. OS frequently originates in the long bones during periods of rapid bone growth. Consequently, OS represents the most prevalent bone cancers affecting children and adolescent and young adults (AYA), with ~400-600 cases a year and accounts roughly half of all new cases of OS diagnosed in the United States. Despite aggressive combination chemotherapy and surgery, the outcome for metastatic OS remains dismal, and the overall survival in children and AYA patients with metastatic OS has not improved significantly over the past 3 decades. A high proportion of OS patients develop pulmonary metastasis (pOS) either at the time of diagnosis (20%) or after initiation of multimodal therapy including combination chemotherapy and surgery. Unfortunately, almost all of the patients who develop surgically un-resectable pOS invariably succumb to this devastating disease. Therefore, pOS represent a disease with unmet needs. As OS contains extremely complex genetic alterations, molecular targeted precision therapy has proven challenging. Recent exciting scientific development implicates the immune system as a potential important new armamentarium as a novel approach to control or reduce pOS. In the current proposal, we identified tumor-expressed Vascular Cell Adhesion Molecule-1 (tVCAM-1) as playing a pivotal role in immune-mediated cancer metastasis by interacting with α4β1 integrin on lung macrophages (MACs), thereby implicating the pulmonary macrophages as a major culprit in the pathophysiology of metastatic OS. Compared to non-metastatic parental tumor (K7), metastatic murine OS cells (K7M2) express high surface VCAM-1, and absence of either tVCAM-1 or MACs prevents the development and ameliorates a large proportion of established pOS. Therefore, we wish to further examine our proposal that a targetable cellular and molecular mechanism, VCAM-1/ α4β1, is a primary driver of OS-MAC interaction, providing the suitable lung tissue niche for pOS in vivo. Our hypothesis is that interfering VCAM- 1/α4β1 signaling between pOS and MACs by down-regulating VCAM-1, depleting MACs or disrupting VCAM- 1-α4β1 signaling will reduce pulmonary metastasis and improve survival. Specific Aim 1: We will characterize functional outcomes of MACS and other immune cells following VCAM-1/α4β4 signaling engagement with pOS. We will compare VCAM-1lo and VCAM-1hi pOS cells for in vivo growth and associated immune responses in the lungs, and expand our observation to include testing lung metastatic potential of other human and mouse pOS cell lines and PDXs available through our own PDX repository and that of our collaborator at Texas Children's Hospital. We will characterize phenotypic and functional outcomes of various myeloid and other immune cellular compartment in the lung tissue of VCAM-1lo and VCAM-1hi pOS cells using cellular, molecular and imaging approaches. Specific Aim 2: We will test the efficacy of functional blockade of VCAM- 1/α4β1 interaction by depleting MACs with intranasal liposomal clodronate treatment or by inhibiting molecular interactions using VCAM-1 specific inhibitory peptide (iVCAM-1p) or intranasal / intratracheal administration of anti-a4 blocking antibody. In the latter scenario involving anti-α4 blocking antibody, we set a goal to obtain foundational pre-clinical, IND-enabling data for monitoring systemic and local toxicities and refining optimal dosing in order to rapidly translate findings from this current grant into Phase I studies using the FDA-approved anti-α4 antibody, Natalizumab, via the intratracheal and inhalation routes for the treatment of patients with late- stage pOS, for whom no other treatment options with demonstrable therapeutic benefits are available. Success in this high priority effort could have a profound effect in improving the outcome and quality of life for children and AYA patients afflicted with this devastating disease.