PROSAPOSIN, A PROMOTER OF PROSTATE CARCINOGENESIS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们已经发现了一种蛋白质，鞘脂激活蛋白原（PSAP），我们假设是一个主要的贡献者的生长和侵袭的人前列腺癌细胞。PSAP是我们实验室鉴定、克隆和表征的70-kDa蛋白，并且发现其增加PCa细胞的生长、迁移和侵袭。以前，我们发现PSAP表达在雄激素非依赖性（AI）进展后增加，在转移性人AI PCa细胞中显著过表达。我们目前的数据显示，通过shRNA下调PSAP表达导致（a）PCa细胞与基底膜蛋白的粘附，（B）蛋白水解酶MMP-9和uPA的表达，以及（c）PCa细胞的迁移和侵袭特性的显著降低。为了检验我们的假设，即PSAP实质上有助于人PCa细胞的侵袭，我们提出了以下具体目的： 1.定义PSAP调节体外PCa侵袭的机制。 我们将使用我们建立的具有增加或降低的PSAP表达水平的PCa细胞系（PC-3、DU-145、LNCaP）的稳定转染子来检查PSAP和PCa细胞粘附于细胞外基质蛋白（例如，层粘连蛋白-1，Matrigel）和下游信号传导途径与FAK活性状态、uPA/MMPs表达的关系。 2.确定PSAP与PCa体内生长和侵袭的关系。通过使用表达增加或减少量的PSAP的PCa细胞，我们将检查PSAP对PCa细胞生长、迁移和侵袭能力的影响，以及与已建立的原发性或转移性肿瘤中B1-整合素、FAK活性和uPA/MMPs的表达水平的关系。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have discovered a protein, prosaposin (PSAP), that we hypothesize to be a major contributor to the growth and invasion of human PCa cells. PSAP is a 70-kDa protein identified, cloned, and characterized by our laboratory and found to increase growth, migration, and invasion of PCa cells. Previously, we showed that PSAP expression increases upon androgen-independent (AI) progression, with marked overexpression in metastatic human AI PCa cells. Our current data show that down modulating PSAP expression by shRNA leads to a significant reduction of (a) PCa cells adhesion to basement membrane proteins, (b) the expression of the proteolytic enzymes MMP-9 and uPA, and (c) migratory and invasion properties of PCa cells. To test our hypothesis that PSAP contributes substantially to invasion of human PCa cells, we propose the following Specific Aims: 1. Define the mechanisms by which PSAP regulates PCa invasion in vitro. We will use our established stable transfectants of PCa cell lines (PC-3, DU-145, LNCaP) with an increased or a decreased level of PSAP expression to examine the cause and effect relationship between PSAP and PCa cell adhesion to extracellular matrix proteins (e.g., Laminin-1, Matrigel) and down stream signaling pathways in relation to FAK activity status,expression of uPA/MMPs . 2. Determine the relationship between PSAP and PCa growth and invasion in vivo. By using PCa cells expressing increased or decreased amounts of PSAP, we will examine the effect of PSAP on PCa cells growth, migratory, and invasive ability and in relation with expression level of B1-integrin, FAK activity, and uPA/MMPs in established primary or metastatic tumors.