Regulation of Metastasis and Angiogenesis by Autotaxin

自分泌运动因子对转移和血管生成的调节

• 批准号: 7291956
• 负责人: david d roberts
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7291956
• 关键词: Regulation; Metastasis; Angiogenesis; Autotaxin

The glycoprotein autotaxin (ATX) is a member of the ecto-nucleotide pyrophosphatase and phosphodiesterase (eNPP) family of proteins, which was initially cloned and purified in this laboratory as a tumor motility-stimulating factor. Recently, ATX was found to be identical to serum lysophospholipase D (LPLD). In addition, in experimental tumor models, ATX has been shown to enhance tumorigenesis, invasiveness, metastasis, and angiogenesis. We are studying the mechanisms by which ATX stimulates invasion, metastasis, and angiogenesis and how these biological functions relate to its enzymatic activity. Utilizing a series of point mutations within the LPLD active site, we found that motility stimulation requires intact enzyme activity. In fact, ATX motility stimulation appears to depend upon the production of LPA or S1P, depending upon which EDG receptors are present on the cell surface. We are continuing to study structure-function relationships within the ATX molecule. We have a number of new point mutations, including several within the enzyme active site and 6 that are part of a collaborative effort with Dr. Suk Woo Nam at the Catholic University of Korea who is looking at ATX mutations occurring in breast cancer patients. Among the active site point mutations that we have constructed are mutations that completely lack enzyme or motility activity and a mutation that retains both activities at an intermediate level. The mutations found in patients are now all in plasmids, and we are currently characterizing these mutant ATX's. A second major focus for our group has been to study how ATX regulates cell behavior and how it interacts with other essential cytokines and growth factors. Utilizing morpholino-oligonucleotides (ATX-specific vs mismatch controls), which reduce translation rather than transcription, we have decreased ATX secretion in two carcinoma cell lines to levels that are undetectable by immunoblot. One very important effect of the ATX knockdown in the human ovarian carcinoma cell line SKOV3 is significantly reduced motility response to multiple chemoattractants. We plan to determine if ATX knockdowns have a similar inhibitory effect with in vitro invasion assays.

糖蛋白自身酰胺（ATX）是蛋白质的核苷酸吡咯磷酸酶和磷酸二酯酶（ENPP）家族的成员，最初在该实验室中克隆并纯化，作为肿瘤运动刺激因子。最近，发现ATX与血清溶物磷脂酶D（LPLD）相同。另外，在实验性肿瘤模型中，ATX已被证明可以增强肿瘤发生，侵袭性，转移和血管生成。我们正在研究ATX刺激侵袭，转移和血管生成的机制，以及这些生物学功能如何与其酶活性相关。利用LPLD活性位点中的一系列点突变，我们发现运动刺激需要完整的酶活性。实际上，ATX运动刺激似乎取决于LPA或S1P的产生，具体取决于细胞表面上存在EDG受体。我们将继续研究ATX分子内的结构功能关系。我们有许多新的点突变，包括酶活性部位中的几个，这是与韩国天主教大学Suk Woo Nam博士进行合作的一部分，他们正在研究乳腺癌患者中发生的ATX突变。在我们构建的活跃位点突变中，它们完全缺乏酶或运动活性，以及​​一种将这两种活性保留在中间水平的突变。现在，患者发现的突变全部存在于质粒中，我们目前正在表征这些突变体ATX。我们小组的第二个主要重点是研究ATX如何调节细胞行为及其与其他必要的细胞因子和生长因子的相互作用。利用吗啡 - 寡核苷酸（ATX特异性与不匹配对照），减少翻译而不是转录，我们将两个癌细胞系中的ATX分泌降低到免疫印迹无法检测到的水平。 ATX敲低对人卵巢癌细胞系SKOV3的一个非常重要的效果是显着降低了对多种趋化剂的运动响应。我们计划确定ATX敲除与体外侵袭测定法是否具有相似的抑制作用。