Integration of Glycolysis with the Epithelial-Mesenchymal Transition

项目总结 锌指E盒结合同源盒1(ZEB1)在肿瘤细胞中的过表达促进上皮细胞- 间充质转化(EMT)与增强的侵袭和转移能力相关，以及 获得癌症干细胞的特性。了解ZEB1是如何受到监管的应该允许 确定可用于治疗转移性癌症的可用药靶点。 表达ZEB1，包括胰腺癌和非小细胞肺癌(NSCLC)。低氧诱导因子-1诱导的6- Phosphofructo-2-kinase/fructose-2，6-bisphosphase-3(PFKFB3)在肿瘤中高表达，激活 糖酵解通过其产物果糖-2，6-二磷酸，最近被发现是周期蛋白的激活剂- 依赖蛋白激酶(CDK)。鉴于越来越多的证据表明细胞周期调节因子，如 对于EMT中的CDK，我们推测PFKFB3可能是获得/维持 肿瘤细胞的间质特征。在初步研究中，我们证明了PFKFB3在A549中的沉默 NSCLC细胞和MIA Paca-2胰腺癌细胞导致ZEB1表达显著降低 逆转EMT，通过增加E-钙粘素(一种上皮标志物)和降低E-钙粘素来评估 波形蛋白/纤维连接蛋白(间质标记物)水平。我们进一步表明，PFKFB3的敲除降低了 视网膜母细胞瘤(RB)蛋白的磷酸化，CDK的靶标，以及STAT3蛋白的表达， 最近发现这两种基因都可以调节ZEB1的表达。因此，我们假设 肿瘤细胞中PFKFB3的上调通过依赖Rb和/或STAT3增加ZEB1的表达 机制，导致获得/维持与增加相关的间充质表型 转移能力和茎。为了检验这一假说，我们将追求以下具体目标：(1)研究 PFKFB3与ZEB1的功能相互作用及其对肿瘤细胞侵袭和肿瘤干细胞特性的影响 (2)研究PFKFB3与ZEB1在肿瘤转移过程中的功能相互作用。 活体胰腺癌。在这些研究的最后，我们期望建立一个新的功能 PFKFB3在调控ZEB1基因和EMT中的作用，这可能对卵巢癌具有治疗意义 治疗侵袭性、转移性癌症，如胰腺癌。

PROJECT SUMMARY Overexpression of Zinc finger E-box binding homeobox 1 (ZEB1) in tumor cells promotes the epithelial- mesenchymal transition (EMT) that is associated with enhanced invasive and metastatic capabilities and the acquisition of cancer-stem cell characteristics. Understanding how ZEB1 is regulated should permit the identification of druggable targets that can be exploited for the treatment of metastatic cancers that over- express ZEB1, including pancreatic and non-small cell lung cancers (NSCLC). The HIF-1¿-inducible 6- phosphofructo-2-kinase/fructose-2,6-bisphosphase-3 (PFKFB3) is over-expressed in tumors, activates glycolysis via its product fructose-2,6-bisphosphate and was recently found to be an activator of cyclin- dependent kinases (Cdks). Given the accumulating evidence suggesting a role for cell cycle regulators such as the Cdks in the EMT, we postulated that PFKFB3 may be essential for the acquisition/maintenance of mesenchymal traits in tumor cells. In preliminary studies, we demonstrate that PFKFB3 silencing in A549 NSCLC cells and MIA PaCa-2 pancreatic cancer cells causes a marked decrease in ZEB1 expression and reverses the EMT, as assessed by increased E-cadherin (an epithelial marker) and decreased vimentin/fibronectin (mesenchymal markers) levels. We further show that knockdown of PFKFB3 decreases the phosphorylation of the retinoblastoma (RB) protein, a Cdk target, and the expression of the STAT3 protein, both of which have recently been found to regulate ZEB1 expression. We therefore hypothesize that upregulation of PFKFB3 in tumor cells increases ZEB1 expression via an RB and/or STAT3-dependent mechanism, leading to the acquisition/maintenance of a mesenchymal phenotype associated with increased metastatic ability and stemness. The following specific aims will be pursued to test this hypothesis: (1) To study the functional interaction of PFKFB3 with ZEB1 and its effect on invasion and cancer stem cell properties in vitro; and (2) To examine the functional interaction of PFKFB3 with ZEB1 in the progression of metastatic pancreatic adenocarcinoma in vivo. At the end of these studies, we expect to have established a novel function for PFKFB3 in the regulation of the ZEB1 gene and EMT, which may have therapeutic implications for the treatment of aggressive, metastatic cancers such as pancreatic adenocarcinoma.