The effect of oxygen gradients on sarcoma invasiveness through dynamic collagen modulation

项目3摘要 肉瘤是一种起源于间充质来源的转化细胞的恶性肿瘤。进展和 肉瘤的转移受微环境信号的调控。肿瘤内低氧(缺氧)最多 显著增加肺转移和不良的临床结果，尽管我们还没有完全 了解低氧对肉瘤细胞和微环境的关键影响。因此，定义了主要的 肿瘤细胞在其微环境中对氧气的反应对于了解转移和鉴定是必不可少的 新的治疗靶点。 我们最近的工作表明，低氧通过诱导HIF1PLOD2促进肉瘤转移 以及随后异常的胶原蛋白沉积，导致远处转移。然而，我们还没有 了解在肿瘤中存在O2梯度时，细胞迁移/侵袭是如何改变的，2) 胶原蛋白修饰-酶定义细胞外基质，以及3)细胞的运动性如何被精确地修改以响应 改变了微环境中的胶原结构。拟议的研究解决了这些未知因素中的每一个。至 模拟肿瘤中的O2-梯度，当肿瘤生长超过血管供应时，我们开发了新的O2- 控制可作为3D低氧微环境的水凝胶。 我们假设肉瘤细胞的侵袭和迁移是由氧分压升高引导和促进的 通过低氧诱导的ECM重塑。我们将确定氧气梯度是否调节方向、速度和 迁移肉瘤细胞的距离，这些因素如何依赖于低氧的ECM重塑，重点是胶原 微观结构。我们的方法将把数学建模和体内外实验模型结合起来， 连接O2-ECM-肉瘤中的细胞侵袭和迁移。其具体目的是：(1)确定肉瘤 细胞和肿瘤移植物对空间氧梯度的反应；(2)表征 低氧梯度下肉瘤的侵袭；(3)确定胶原纤维组织如何调节低氧 入侵和迁徙。这里提出的实验结果将确定分子和物理 转移、侵袭和迁移初始步骤的潜在机制并开发预测模型 对于这些机制，所有这些都导致了新的治疗靶点。

Project 3 Summary Sarcoma is a malignant cancer derived from transformed cells of mesenchymal origin. Progression and metastasis of sarcomas is regulated by microenvironmental cues. Low intratumoral O2 (hypoxia) most dramatically increases pulmonary metastasis, and poor clinical outcomes, though we do not yet completely understand the critical effects of hypoxia on sarcoma cells and the microenvironment. Thus, defining how primary tumor cells respond to O2 in their microenvironment is essential for understanding metastasis and identification of novel therapeutic targets. Our recent work has shown that hypoxia promotes sarcoma metastasis, through induction of HIF1PLOD2 and the subsequent deposition of aberrant collagen that leads to distant metastasis. However, we do not yet know 1) how cell migration/invasion is altered in the presence of the O2 gradients that occur in tumors, 2) which collagen modifying-enzymes define the ECM, and 3) precisely how cells’ motility is modified in response to altered collagen structure in the microenvironment. The proposed studies address each of these unknowns. To model the O2-gradients that develop in tumors as they outgrow their vascular supply we developed novel O2- controlling hydrogels that can serve as 3D hypoxic microenvironments. We hypothesize that sarcoma cell invasion and migration is guided by increased O2 tension and facilitated by hypoxia-induced ECM remodeling. We will determine if O2 gradients regulate the direction, speed and distance of migrating sarcoma cells, how these factors depend on hypoxic ECM remodeling, focusing on collagen microstructure. Our approach will integrate mathematical modeling and experimental in vitro and in vivo models, linking O2-ECM-cellular invasion and migration in sarcomas. The specific aims are: (1) To determine sarcoma cell and tumor graft responses to spatial oxygen gradients; (2) To characterize collagen remodeling during sarcoma invasion under hypoxic gradients; (3) To determine how collagen fiber organization regulates hypoxic invasion and migration. The results of the experiments proposed here will identify the molecular and physical mechanisms underlying the initial steps of metastasis, invasion and migration, and develop predictive models for these mechanism, all leading to novel therapeutic targets.