Carcinoma Cell Hyaluronan as a Therapeutic Target in Metastasis

 描述（由申请人提供）：转移是治疗失败和失败的主要原因，仍然是癌症进展中最不了解的阶段。研究晚期转移的困难之一是缺乏合适的转移模型。 复杂的转移过程为了克服这一挑战，我们已经开发了一种微流体系统，该系统重现了转移的关键阶段，同时允许真实的时间刺激肿瘤细胞。 细胞表型和转移过程的真实的实时成像。微流体模型概括了异位部位的关键方面，包括具有生理流动和功能性内皮的血管隔室和固体ECM丰富的组织隔室。在这项工作中，我们将使用这个平台来阐明HA依赖性机制在肿瘤细胞中作为转移驱动因素的重要性，并最终开发微流体模型系统作为识别新型抗转移试剂的筛选工具。我们的工作假设是，HA合成和转移癌细胞形成的细胞外被赋予一个“基质独立”的表型，以增强转移形成。从机制上预测，这有利于循环中的存活，并促进癌细胞粘附于内皮细胞，随后外渗，以及在携带转移性病变的组织的实质内侵袭和生长。在这项工作中，我们将具体：（1）优化我们的微流体 平台来量化乳腺癌细胞的转移潜力;（2）量化改变转移性癌细胞的HA合成对体外和体内肿瘤细胞停滞、外渗和生长的影响。虽然HA合成癌已与恶性进展，我们假设，这是一个细胞周丰富的基质，定位质膜受体，组织细胞骨架和功能，以维持生存的形成。初步数据支持这一假设，这将通过限制HA合成和人工恢复细胞周围基质，使用脂质偶联的HA，将嵌入质膜进一步测试。我们将评估具有或不具有内源性或人工富含HA的细胞周基质的细胞（悬浮和粘附）中的关键致癌信号传导和存活途径。预测是，具有细胞周HA基质的细胞事实上将维持激活的致癌途径，而不依赖于粘附，这将通过防止细胞周富含HA的基质的形成而被抑制。除了这种特定的转移机制，这种模型应该有助于关注转移中的关键事件，并最终加速发现新的治疗靶点，以阻断这一过程中的限速步骤。

 DESCRIPTION (provided by applicant): Metastasis, which represents the major cause of frustration and failure in therapy, remains the least understood stage of cancer progression. One of the difficulties in studying later stages of metastasis is the lack of appropriate models of the complex metastatic process. To overcome this challenge, we have developed a microfluidic system that recapitulates critical stages of metastasis while allowing for real time stimulation of cell phenotype and real time imaging of the metastatic process. The microfluidic model recapitulates critical aspects of the ectopic site, including a vascular compartment with physiologic flow and functional endothelium and a solid ECM-rich tissue compartment. In this work, we will use this platform to elucidate the importance of HA-dependent mechanisms in tumor cells as drivers of metastasis and ultimately to develop the microfluidic model system as a screening tool for identifying novel anti-metastatic reagents. Our working hypothesis is that HA synthesis and pericellular coat formation by metastatic carcinoma cells confers a `stromal independent' phenotype to enhance metastasis formation. Mechanistically the prediction is that this facilitates survival in the circulation and promotes carcinoma cell adhesion to endothelial cells, subsequent extravasation, and invasion and growth within the parenchyma of tissues harboring metastatic lesions. Within this work, we will specifically: (1) optimize our microfluidic platform to quantify the metastatic potential of breast cancer cells; (2) quantify the effects of altering HA synthesis by metastatic carcinoma cells on tumor cells arrest, extravasation and growth both in vitro and in vivo. While HA synthesis by carcinomas has been linked with malignant progression, we hypothesize that it is the formation of a pericellular rich matrix that positions plasma membrane receptors, organizes the cytoskeleton and functions to maintain survival. Preliminary data support this hypothesis and this will be further tested by limiting HA synthesis and artificially restoring the pericellular matrix, using lipid coupled HA that will intercalate into the plasma membrane. We will evaluate key oncogenic signaling and survival pathways in cells (both suspended and adherent) that have, or do not have, an endogenous or artificial HA rich pericellular matrix. The prediction is that cells with a pericellular HA matrix ill in fact maintain activated oncogenic pathways, independent of adhesion, that will be inhibited by preventing the formation of a pericellular HA rich matrix. Beyond this specific mechanism of metastasis, this model should help focus on critical events in metastasis and ultimately speed the discovery of new therapeutic targets to block rate limiting steps in this process.