The Role of the Microenvironment in Early Ovarian Cancer Metastasis

描述(申请人提供)：卵巢癌(OvCa)最重要的特征之一是癌细胞转移到腹膜腔。OvCa转移的主要部位是大网膜。大网膜微环境由一层覆盖着基质的间皮细胞组成，基质由细胞外基质(ECM)和基质细胞(即成纤维细胞和脂肪细胞)组成。脂肪细胞是大网膜中的主要细胞类型(80%以上)。卵巢上皮细胞的转移需要癌细胞最初的黏附和侵袭进入大网膜表面。我们的初步结果表明，微环境中的一些因素调节OvCa向大网膜转移的初始步骤，包括基质细胞(即间皮细胞、成纤维细胞、脂肪细胞)、不同的细胞外基质(即纤维连接蛋白)、黏附分子(即a5？1-整合素)和蛋白酶(即基质金属蛋白酶2[MMP-2])。然而，OvCa细胞早期转移的机制尚未完全阐明。本项目在指导阶段的目标是确定基质金属蛋白酶-2的功能意义，区分FN及其受体a5？1-整合素的功能作用，并阐明脂肪细胞作为早期OvCa转移的导体的功能价值。在该奖项的独立阶段，目的是发现OvCa细胞黏附和转移的新抑制剂，并进一步研究和评估脂肪细胞作为OvCa早期转移调节因子的功能意义。我们的总体假设是，作为转移的第一步，OvCa的微环境在OvCa的黏附和侵袭中起着关键作用。 大多数卵巢癌患者处于晚期，癌细胞扩散至整个腹膜腔。即使在积极的手术切除后，肿瘤仍会在腹膜腔内重新生长，由于缺乏对OvCa转移的了解，治疗也受到阻碍。这项建议将研究黏附和侵袭，这是早期OvCa转移的最初限速步骤。为了设计新的有效的治疗方法，在建立单个转移瘤之前，我们必须了解OvCa细胞与大网膜的黏附机制。为了追求这一目标，我们设计了一个使用原代人间皮细胞和具有细胞外基质的成纤维细胞的大网膜表面的三维模型。这个模型使我们有机会在体外研究OvCa微环境中存在的每个细胞和ECM成分在转移中的不同作用。 相关性：我们研究的潜在长期临床应用是确定早期的腹膜腔内治疗可以抑制OvCa细胞(原发肿瘤或腹水来源)与腹膜腔的黏附(即基质金属蛋白酶-2选择性抑制物)和转移。将从早期治疗中受益的卵巢癌患者包括晚期疾病患者，他们在手术结束时肉眼看起来没有肿瘤(大约70%的FIGO期IIIB至IV期)，并且仅推测为“微观疾病”，以及腹水患者，其疾病仅限于卵巢(FIGO期IC至IIIA期)。

DESCRIPTION (provided by applicant): One of the most important characteristics of ovarian cancer (OvCa) is metastasis of cancer cells to the peritoneal cavity. The main site of OvCa metastasis is the omentum. The omental microenvironment is composed of a layer of mesothelial cells covering the underlying stroma composed of extra-cellular matrices (ECMs) and stromal cells (i.e. fibroblasts and adipocytes). Adipocytes are the main cell type (over 80%) present in omentum . OvCa metastasis requires the initial adhesion and invasion of cancer cells into the surface of the omentum. Our preliminary results show that a number of factors in the microenvironment regulate the initial steps of OvCa metastasis to the omentum including stromal cells (i.e. mesothelial cells, fibroblasts, adipocytes), different extra-cellular matrices (ECMs) (i.e. fibronectin), adhesion molecules (i.e. a5¿1-integrin), and proteases (i.e. matrix-metalloproteinase 2 [MMP-2]). However, the mechanisms involved in early OvCa cell metastasis have yet to be fully elucidated. The objectives of this project during the mentored phase are to determine the functional significance of MMP-2, to differentiate the functional roles of FN and its receptor, a5¿1-integrin, and to clarify the functional value of adipocytes as conductors of early OvCa metastasis. During the independent phase of the award, the intent is to discover new inhibitors of OvCa cell adhesion and metastasis and to further investigate and evaluate the functional significance of adipocytes as regulators of early OvCa metastasis. Our overall hypothesis is that the OvCa microenvironment plays a critical role in OvCa adhesion and invasion as the first step of metastasis. Most patients with OvCa present in an advanced stage that involves the dissemination of cancer cells throughout the peritoneum cavity. Even after aggressive surgical debulking, tumors repopulate the abdominal cavity, and treatment is hampered by a lack of understanding of OvCa metastasis. This proposal will investigate adhesion and invasion, the initial rate-limiting steps of early OvCa metastasis. To design new and effective treatments, it is important that we understand the mechanisms of OvCa cell adhesion to the omentum, prior to establishment of single metastases. In pursuit of this goal, we have designed a three dimensional model of the surface of the omentum using primary human mesothelial cells and fibroblasts with ECM. This model gives us the opportunity to study in vitro the distinct roles of each cellular and ECM component present in the OvCa microenvironment on metastasis. RELEVANCE: The potential long-term clinical application of our studies is to identify early intraperitoneal treatment that inhibits OvCa cell (primary tumor or ascites-derived) adhesion (i.e. MMP-2 selective inhibitor) to the peritoneal cavity and metastasis. The OvCa patients that will benefit from early treatment include patients with advanced disease who, at the end of surgery, were rendered macroscopically tumor free (approximately 70% of FIGO stage IIIB to IV) and have only presumed "microscopic disease", and patients with ascites whose disease is limited to the ovary (FIGO stage IC to IIIA).