Department of Pathology and Oncology, Wayne State University School of Medicine, Detroit, MI, USA.
Cancer Res. 2011 May 1;71(9):3400-9. doi: 10.1158/0008-5472.CAN-10-0965. Epub 2011 Mar 9.
Phosphoglucose isomerase/autocrine motility factor (PGI/AMF) plays an important role in glycolysis and gluconeogenesis and is associated with invasion and metastasis of cancer cells. We have previously shown its role in the induction of epithelial-mesenchymal transition (EMT) in breast cancer cells, which led to increased aggressiveness; however, the molecular mechanism by which PGI/AMF regulates EMT is not known. Here we show, for the first time, that PGI/AMF overexpression led to an increase in the DNA-binding activity of NF-κB, which, in turn, led to increased expression of ZEB1/ZEB2. The microRNA-200s (miR-200s) miR-200a, miR-200b, and miR-200c are known to negatively regulate the expression of ZEB1/ZEB2, and we found that the expression of miR-200s was lost in PGI/AMF overexpressing MCF-10A cells and in highly invasive MDA-MB-231 cells, which was consistent with increased expression of ZEB1/ZEB2. Moreover, silencing of PGI/AMF expression in MDA-MB-231 cells led to overexpression of miR-200s, which was associated with reversal of EMT phenotype (i.e., mesenchymal-epithelial transition), and these findings were consistent with alterations in the relative expression of epithelial (E-cadherin) and mesenchymal (vimentin, ZEB1, ZEB2) markers and decreased aggressiveness as judged by clonogenic, motility, and invasion assays. Moreover, either reexpression of miR-200 or silencing of PGI/AMF suppressed pulmonary metastases of MDA-MB-231 cells in vivo, and anti-miR-200 treatment in vivo resulted in increased metastases. Collectively, these results suggest a role of miR-200s in PGI/AMF-induced EMT and thus approaches for upregulation of miR-200s could be a novel therapeutic strategy for the treatment of highly invasive breast cancer.
磷酸葡萄糖异构酶/自分泌运动因子（PGI/AMF）在糖酵解和糖异生中发挥重要作用，并与癌细胞的侵袭和转移有关。我们之前已经证明了它在乳腺癌细胞中诱导上皮-间充质转化（EMT）中的作用，这导致了侵袭性的增加；然而，PGI/AMF 调节 EMT 的分子机制尚不清楚。在这里，我们首次表明，PGI/AMF 的过表达导致 NF-κB 的 DNA 结合活性增加，进而导致 ZEB1/ZEB2 的表达增加。miR-200s（miR-200a、miR-200b 和 miR-200c）已知负调控 ZEB1/ZEB2 的表达，我们发现 PGI/AMF 过表达 MCF-10A 细胞和高侵袭性 MDA-MB-231 细胞中 miR-200s 的表达丢失，这与 ZEB1/ZEB2 的表达增加一致。此外，沉默 MDA-MB-231 细胞中的 PGI/AMF 表达导致 miR-200s 的过表达，这与 EMT 表型的逆转（即间质-上皮转化）有关，这些发现与上皮（E-钙粘蛋白）和间充质（波形蛋白、ZEB1、ZEB2）标志物的相对表达的改变以及集落形成、迁移和侵袭测定判断的侵袭性降低一致。此外，miR-200 的重新表达或 PGI/AMF 的沉默均抑制了 MDA-MB-231 细胞在体内的肺转移，体内抗 miR-200 处理导致转移增加。总之，这些结果表明 miR-200s 在 PGI/AMF 诱导的 EMT 中的作用，因此上调 miR-200s 的方法可能是治疗高度侵袭性乳腺癌的一种新的治疗策略。
