PTTG Role in Ovarian Tumorigenesis and Matastasis

卵巢癌是女性第五种最常见的癌症，也是最常见的 在美国死于妇科恶性肿瘤。启动和支持的分子机制 卵巢肿瘤的发生还没有很好的定义。我们克隆了一个新的癌基因“PTTG”，也称为securin。 并研究其在肿瘤发生中的作用。PTTG是一种多功能蛋白质 并在许多肿瘤中高表达，包括卵巢肿瘤。在NIH3T3和NIH3T3中引入PTTG HEK293细胞诱导细胞转化并促进裸鼠成瘤，提示其 具有较强的致癌作用。值得注意的是，PTTG已被证明抑制姐妹染色单体的分离，并 促进碱性成纤维细胞生长因子、血管内皮生长因子和白介素8的合成和分泌，并激活血管内皮细胞的表达 癌基因、c-myc和PI3K/AKT信号通路，提示PTTG的致癌活性可能 包括诱导非整倍体和染色体不稳定，增加血管生成，以及产生 促生长癌基因产品。卵巢癌细胞PTTG表达下调的体外实验研究 在动物中它的缺失(基因敲除)导致肿瘤发展的减少，这表明它很重要 在维持癌症表型中的作用。这个应用程序的长期目标是理解 PTTG在卵巢肿瘤发生中的作用及作为抗卵巢癌分子靶点的验证 肿瘤剂。在本应用中，我们建议：i)确定PTTG过表达在 卵巢上皮细胞对裸鼠细胞转化和肿瘤发生的影响 卵巢表面上皮细胞PTTG过表达对卵巢肿瘤发生、发展的影响 以及转基因动物的转移，并确定支持肿瘤生长和转移的机制； 以及iii)确定卵巢肿瘤细胞中PTTG表达下调对肿瘤的影响 抑制和转移，并确定导致抑制肿瘤生长和转移的机制 转移。这些研究将为卵巢中PTTG的机制提供关键信息。 肿瘤的发生和转移，为开发抑制PTTG的小分子奠定基础 具有抗肿瘤作用。此外，根据我们的研究开发的转基因动物模型可以 加强努力，开发检测、预防和治疗卵巢癌的新方法。

Ovarian cancer is the fifth most commonly diagnosed cancer among women and the most frequent cause of death from gynecologic malignancies in the United States. Molecular mechanisms that initiate and support ovarian tumorigenesis are not well defined. We cloned a novel oncogene "PTTG" also known as securin from human testis and ovarian tumors and studied its function in tumorigenesis. PTTG is a multifunctional protein and is highly expressed in many tumors, including tumors of ovary. Introduction of PTTG into NIH3T3 and HEK293 cells induces cellular transformation and promotes tumor formation in nude mice, suggesting its strong oncogenic function. Notably, PTTG has been shown to inhibit separation of sister chromatids, and to increase the synthesis and secretion of bFGF, VEGF, and IL-8 as well as activate the expression of the oncogene, c-myc and PI3K/AKT signaling pathway, suggesting that the oncogenic activity of PTTG may involve induction of aneuploidy and chromosomal instability, increased angiogenesis, and production of growth promoting oncogene products. Down-regulation of PTTG expression in ovarian tumor cells in vitro and its deletion in animals (Knockout) results in reduction of tumor development, suggesting its important role in maintenance of cancer phenotype. The long-term objectives of this application are to understand the role of PTTG in ovarian tumorigenesis and validate PTTG as a molecular target for the development of anti- neoplastic agents. In this application we propose: i) to determine the effect of overexpression of PTTG in ovarian epithelial cells on cellular transformation and tumor development in nude mice; ii) to determine the effect of overexpression of PTTG in ovarian surface epithelial cells on ovarian tumor initiation, progression and metastasis in transgenic animals and determine mechanisms that support tumor growth and metastasis; and iii)to determine the effect of down-regulation of PTTG expression in ovarian tumor cells on tumor suppression and metastasis and determine mechanisms that lead to suppression of tumor growth and metastasis. These studies will provide critical information regarding the mechanisms of PTTG in ovarian tumorigenesis and metastasis and set up basis for the development of small molecules to inhibit PTTG function as anti-neoplastic agents. In addition transgenic animal model developed from our studies could enhance efforts aimed at developing new methods for detection, prevention, and treatment of ovarian cancer.