Hypoxia and HIF in Sarcomagenesis

描述（由申请人提供）：软组织肉瘤是来源于肌肉、结缔组织和软骨间充质细胞的实体瘤。恶性纤维组织细胞瘤（MFH），最具侵袭性和最常见的肉瘤亚型，具有高度转移性。已经提出瘤内缺氧促进肉瘤（包括MFH）向远处转移。然而，这个过程的分子基础是未知的。最近，缺氧诱导因子（HIF）11和它的几个转录靶点，包括转录因子FOXM 1，已被确定为转移性MFH肉瘤的标志物，通过微阵列分析。FOXM 1表达的调节在肉瘤中可能特别重要，因为FOXM 1与许多其他人类癌症中的肿瘤形成和转移有关。HIF和FOXM 1都是Ras通路的潜在下游效应子，并且在高达50%的MFH肿瘤中发现Ras突变。这一建议的中心假设是缺氧肉瘤中HIF活性增加，促进FOXM 1表达和转移。基于这一假设，我将追求三个具体目标。具体目标1：探讨低氧和缺氧诱导因子对体外培养的肉瘤细胞增殖、凋亡和衰老的影响及其分子机制。具体目标二：明确低氧和HIF介导的肉瘤细胞迁移/侵袭和氧化应激反应的作用和分子基础。具体目标3：使用肉瘤和人异种移植肿瘤的诱导型小鼠模型来检查HIF和FOXM 1在体内的作用。为了完成这些研究，我将结合联合收割机在体外和体内的细胞生物学，生物化学，免疫组织化学，遗传学和动物模型的方法。本研究的目的是阐明缺氧和HIF依赖性肉瘤形成和发展的潜在机制。这些研究的长期目标将是确定新的治疗靶点，这将促进肉瘤的新治疗，并提供有关一般肿瘤形成和转移到肺的重要线索。 公共卫生相关性：MFH是50 - 70岁成人中最常见的肉瘤类型。它也是最具侵袭性的肉瘤类型，五年生存率仅为24%。目前肉瘤的治疗方法有手术、放疗和化疗。然而，这种疾病的靶向治疗是有限的，因为它在分子水平上的特征很差。也没有专门针对转移性肉瘤细胞的治疗方法。因此，我建议研究肉瘤形成和发展的机制，以促进靶向治疗的发展。

DESCRIPTION (provided by applicant): Soft tissue sarcomas are solid tumors derived from mesenchymal cells of muscle, connective tissue, and cartilage. Malignant fibrous histiocytoma (MFH), the most aggressive and most commonly diagnosed subtype of sarcoma is highly metastatic. Intratumoral hypoxia has been proposed to facilitate metastasis of sarcomas, including MFH, to distant sites. However, the molecular basis of this process is unknown. Recently, hypoxia inducible factor (HIF)11 and several of its transcriptional targets, including the transcription factor FOXM1, have been identified as markers of metastatic MFH sarcoma by microarray analysis. Regulation of FOXM1 expression may be particularly important in sarcomas, as FOXM1 has been associated with tumor formation and metastasis in numerous other human cancers. Both HIF and FOXM1 are potential downstream effectors of the Ras pathway and Ras mutations are found in up to 50% of MFH tumors. The central hypothesis of this proposal is that HIF activity is increased in hypoxic sarcomas, promoting expression of FOXM1 and metastasis. Based on this hypothesis I will pursue three specific aims. Specific Aim 1: To determine the effects and underlying molecular mechanisms of hypoxia and HIF on proliferation, apoptosis, and senescence of sarcoma cell lines in vitro. Specific Aim 2: To define the effects and molecular basis of hypoxia and HIF- mediated migration/invasion and oxidative stress responses in sarcoma cell lines. Specific Aim 3: To examine the role of HIFs and FOXM1 in vivo using an inducible mouse model of sarcoma and human xenograft tumors. To complete these studies I will combine in vitro and in vivo methods of cell biology, biochemistry, immunohistochemistry, genetics, and animal modeling. The objective of this research proposal is to elucidate the underlying mechanisms of hypoxia and HIF-dependent sarcoma formation and progression. The long-term goal of these studies will be to identify novel therapeutic targets, which will facilitate new treatments for sarcoma and provide important clues about general tumor formation and metastasis to the lung. PUBLIC HEALTH RELEVANCE: MFH is the most commonly diagnosed type of sarcoma in adults ages 50 -70. It is also the most aggressive type of sarcoma and has a five-year survival rate of only 24%. The current treatments for sarcoma are surgery, radiation, and chemotherapy. However, targeted treatments for this disease are limited because it is poorly characterized at the molecular level. There are also no treatments that specifically target metastatic sarcoma cells. Therefore, I propose to investigate the mechanisms of sarcoma formation and progression in order to facilitate the development of targeted therapeutics.