Abstract:
Cysteine-rich angiogenic factor 61 (CCN1/Cyr61) is a matricellular protein that is induced and secreted in response to growth factors. Our previous work showed that 18:1-lysophosphatidic acid (LPA), which activates the G protein-coupled receptor LPAR1, induces CCN1 between 2-4 h in PC-3 human prostate cancer cells in a manner than enhances cell-substrate adhesion. While the time course of induction suggests that CCN1 contributes to intermediate events in LPA action, the roles of CCN1 in LPA-mediated signal transduction have not been fully elucidated. This study utilized a comprehensive global proteomics approach to identify proteins up- or down-regulated in response to treatment of PC-3 cells with LPA for three hours, during the time of peak CCN1 levels. In addition, the effects of siRNA-mediated CCN1 knockdown on LPA responses were analyzed. The results show that, in addition to CCN1, LPA increased the levels of multiple proteins. Proteins up-regulated by LPA included metastasis-associated in colon cancer protein 1 (MACC1) and thrombospondin-1 (TSP1/THBS1); both MACC1 and TSP1 regulated cancer cell adhesion and motility. LPA down-regulated thioredoxin interacting protein (TXNIP). CCN1 knockdown suppressed the LPA-induced up-regulation of 30 proteins; these included MACC1 and TSP1, as confirmed by immunoblotting. Gene ontology and STRING analyses revealed multiple pathways impacted by LPA and CCN1. These results indicate that CCN1 contributes to LPA signaling cascades that occur during the intermediate phase after the initial stimulus. The study provides a rationale for the development of interventions to disrupt the LPA-CCN1 axis.
摘要:
富含半胱氨酸的血管生成因子61(CCN1/Cyr61)是响应于生长因子而被诱导和分泌的基质细胞蛋白。我们以前的工作表明,18:1-溶血磷脂酸(LPA),激活G蛋白偶联受体LPAR1,在PC-3人前列腺癌细胞中以增强细胞-底物粘附的方式在2-4小时内诱导CCN1。虽然诱导的时间过程表明CCN1有助于LPA作用的中间事件,CCN1在LPA介导的信号转导中的作用尚未完全阐明。这项研究利用全面的全球蛋白质组学方法来鉴定响应于LPA处理3小时的PC-3细胞而上调或下调的蛋白质。在CCN1峰值水平期间。此外,分析了siRNA介导的CCN1敲低对LPA应答的影响.结果表明,除CCN1外,LPA还增加了多种蛋白质的水平。LPA上调的蛋白质包括结肠癌蛋白1(MACC1)和血小板反应蛋白1(TSP1/THBS1)中的转移相关蛋白;MACC1和TSP1均调节癌细胞粘附和运动。LPA下调硫氧还蛋白相互作用蛋白(TXNIP)。CCN1敲低抑制了LPA诱导的30种蛋白质的上调;如通过免疫印迹证实的,这些包括MACC1和TSP1。基因本体论和STRING分析揭示了受LPA和CCN1影响的多个途径。这些结果表明,CCN1有助于在初始刺激后的中间阶段发生的LPA信号级联。该研究为开发破坏LPA-CCN1轴的干预措施提供了理论基础。