HYALURONAN TURNOVER IN PROSTATE CANCER

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 前列腺癌是美国男性癌症死亡的第二大原因。超过80%的死亡是由骨转移并发症引起的。我们的实验室研究细胞外成分调节肿瘤发展和转移扩散的机制。我们即将推出的R01应用集中在透明质酸(HA)上，这是一种对细胞生长和发育过程中的迁移至关重要的聚合物糖胺聚糖。HA在正常前列腺组织中含量很低，但在前列腺癌和骨转移瘤中含量较高。肿瘤相关HA及其周转酶Hyal1的定量可以预测前列腺癌的侵袭进展，并为前列腺癌患者的预后提供临床读数。肿瘤相关的透明质酸聚合物由透明质酸合成酶(HAS)合成，并被透明质酸酶(Hyaluronidase，即Hyal1)切割。在细胞和组织水平对HA的反应受控于HA的大小和HA受体的特定分布，如CD44和HA内吞受体(HARE)。 我们的这一应用假说建立在先前数据的三个关键结果基础上：(1)外源性HA对肿瘤细胞没有影响，而诱导内源性HA的产生则降低了整合素和钙粘附素的表面表达，从而降低了肿瘤细胞的生长速度和运动性；(2)诱导肿瘤细胞表达Hyal1，这是一种分泌和溶酶体酶，可增加肿瘤细胞对内细胞性HA的摄取速率；(3)系统地给药一种抗HARE的抗体，这种抗体存在于小鼠的肝、淋巴结和骨的内皮细胞中，可阻断小鼠前列腺癌细胞的自发转移。根据这些观察，我们推测，肿瘤细胞携带的表面HA通过促进表达HARE的血管系统的停滞和/或肿瘤细胞进入淋巴和骨髓组织来提高转移效率。此外，我们认为，过量的肿瘤携带的HA可以加速肿瘤细胞的内吞和/或内吞循环，如果存在Hyal1，则激活淋巴重塑。细胞内循环的速度决定了细胞黏附受体的表面密度，从而影响肿瘤细胞的运动和转移生存。这一假说是新颖、创新和简明的：以前没有任何解释将HA在肿瘤生长和转移中的复杂作用结合在共同的内吞过程中，该过程由肿瘤细胞和基质细胞上不同的受体类别触发，导致不同但同时发生的结果。积极地定义这些独特的机制可以通过拮抗肿瘤细胞严重依赖的内吞吸收或循环途径来开辟治疗途径。 我们在过渡性筹资期间的目标是收集更多的初步数据，以支持以下目标： 目的1：确定HA是如何控制淋巴导航和骨转移的。透明质酸可能是前列腺癌细胞转移偏好的一个因素，而透明质酸1是启动转移的重要因素。我们知道HA受体连接所依赖的HA聚合物的大小和数量取决于Has和Hyal1酶的相对表达。HARE在前列腺中不表达，但存在于淋巴结和骨组织中的内皮细胞上，HA包裹的肿瘤细胞向这些组织转移的频率增加。我们有可诱导的系统，允许我们以实验控制的方式刺激或抑制HAS或Hyal1，我们还开发了非侵入性近红外成像方法来监测小鼠的肿瘤生长。我们将使用小鼠的原位和心内注射来量化HA、Hyal1和Hare操作对转移过程的影响

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Prostate cancer is the second leading cause of cancer death in U.S. men. Over 80% of mortality results from complications of bone metastasis. Our lab studies mechanisms by which extracellular components regulate tumor development and metastatic dissemination. Our upcoming R01 application centers on hyaluronan (HA), a polymeric glycosaminoglycan essential for cell growth and migration in development. HA is negligible in normal prostate, but abundant in prostate tumors and bone metastases. Quantification of tumor-associated HA and its turnover enzyme, Hyal1, predicts invasive progression and provides a clinical readout for prostate cancer patient prognosis. Tumor-associated HA polymers are synthesized by HA synthases (HAS) and cleaved by hyaluronidases (i.e.; Hyal1). Response to HA at the cellular and tissue level is controlled by HA size and by specific distribution of HA receptors such as CD44 and the HA receptor for endocytosis (HARE). Our hypothesis for this application is built on three key results from our previous data: (1) exogenous HA has no effect on tumor cells, while induced endogenous HA production lowers surface expression of integrins, and cadherins, which reduces growth rate and motility of tumor cells; (2) induced expression of Hyal1, which is both a secreted and a lysosomal enzyme, increases the rate of endocytic HA intake in tumor cells; and (3) systemic administration of an antibody against HARE, found in endothelial cells of liver, lymph node and bone, blocks spontaneous metastasis of prostate tumor cells in mice. From these observations, we postulate that surface HA borne by tumor cells increases metastatic efficiency by facilitating arrest in HARE-expressing vasculature and/or entry of the tumor cells into lymph and marrow tissue. In addition, we suggest excess tumor-borne HA can accelerate tumor cell endocytosis and/or endocytic recycling if Hyal1 is present, activating lymphatic remodeling. Rate of endocytic recycling determines the surface density of cell adhesion receptors and thereby impacts tumor cell motility and metastatic survival. This hypothesis is novel, innovative and parsimonious: no previous explanation has incorporated the complex actions of HA in tumor growth and metastasis under the common process of endocytosis, triggered by distinct receptor classes on tumor cells versus stromal cells, leading to different but concurrent outcomes. Positively defining these unique mechanisms could open avenues of therapy through antagonism of endocytic uptake or recycling pathways more heavily relied upon by tumor cells. Our goal in the bridge funding period is to collect additional preliminary data to support the following aims: Aim 1: Determine how HA controls lymphatic navigation and bone metastasis. HA is a likely factor in metastatic preference of prostate tumor cells, while Hyal1 is important for metastasis initiation. We know the size and quantity of HA polymers, on which HA receptor ligation depends, are determined by the relative expression of HAS and Hyal1 enzymes. HARE is not expressed in prostate, but is present on endothelial cells in lymph node and bone, tissues to which HA-enveloped tumor cells show increased frequency of metastasis. We have inducible systems that allow us to stimulate or inhibit either HAS or Hyal1 in an experimentally controlled fashion and we have developed non-invasive near-infrared imaging methods for monitoring tumor growth in mice. We will use orthotopic and intracardiac injection in mice to quantify effects of HA, Hyal1 and HARE manipulation on the metastatic process