Carcinoma Cell Hyaluronan as a Therapeutic Target in Metastasis

 描述(由申请人提供)：转移，这是治疗失败和失败的主要原因，仍然是癌症进展过程中最不了解的阶段。研究晚期转移的困难之一是缺乏合适的模型。 复杂的转移过程。为了克服这一挑战，我们开发了一种微流控系统，它可以概括转移的关键阶段，同时允许实时刺激 细胞表型和转移过程的实时成像。微流体模型概括了异位部位的关键方面，包括一个具有生理血流和功能内皮的血管隔室，以及一个固体的富含ECM的组织隔室。在这项工作中，我们将利用这个平台来阐明肿瘤细胞中HA依赖的机制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筛选新的抗转移试剂的工具。我们的工作假设是，转移性癌细胞的HA合成和细胞周毛形成赋予了一种不依赖于间质的表型，以促进转移的形成。从机制上讲，这有助于在循环中存活，并促进癌细胞与内皮细胞的黏附，随后的渗出，以及在含有转移灶的组织的实质内的侵袭和生长。在这项工作中，我们将具体：(1)优化我们的微流体 (2)量化转移性癌细胞的HA合成在体内外对肿瘤细胞停滞、渗出和生长的影响。虽然癌症合成HA与恶性进展有关，但我们假设它是形成一种细胞周围丰富的基质，定位质膜受体，组织细胞骨架，并发挥维持生存的功能。初步数据支持这一假设，并将通过限制HA的合成和人工恢复细胞周围基质，使用插入质膜的脂质偶联HA来进一步验证这一假设。我们将评估细胞(包括悬浮细胞和贴壁细胞)中的关键致癌信号和存活途径，这些细胞具有或不具有内源性或人造的富含HA的细胞外基质。预测是，具有细胞周围HA基质的细胞实际上将维持激活的致癌途径，而不是黏附，这将通过阻止细胞周围富含HA基质的形成而被抑制。除了这种特定的转移机制，这个模型应该有助于专注于转移中的关键事件，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.