Department of Biochemistry and Molecular Biology, University of Nebraska MedicalCenter, Omaha, NE 68198-5870, USA.
Carcinogenesis. 2012 Oct;33(10):1953-64. doi: 10.1093/carcin/bgs225. Epub 2012 Jul 12.
MUC4 is a type-1 transmembrane mucin differentially expressed in multiple cancers and has previously been shown to potentiate progression and metastasis of pancreatic cancer. In this study, we investigated the molecular mechanisms associated with the MUC4-induced invasion and metastasis in pancreatic cancer. Stable silencing of MUC4 in multiple pancreatic cancer cells resulted in the downregulation of N-cadherin and its interacting partner fibroblast growth factor receptor 1 (FGFR1) through downregulation of partly by pFAK, pMKK7, pJNK and pc-Jun pathway and partly through PI-3K/Akt pathway. The downregulation of FGFR1 in turn led to downregulation of pAkt, pERK1/2, pNF-κB, pIkBα, uPA, MMP-9, vimentin, N-cadherin, Twist, Slug and Zeb1 and upregulation of E-cadherin, Occludin, Cytokeratin-18 and Caspase-9 in MUC4 knockdown BXPC3 and Capan1 cells compared with scramble vector transfected cells. Further, downregulation of FGFR1 was associated with a significant change in morphology and reorganization of the actin-cytoskeleton, leading to a significant decrease in motility (P < 0.00001) and invasion (P < 0.0001) in vitro and decreased tumorigenicity and incidence of metastasis in vivo upon orthotopic implantation in the athymic mice. Taken together, the results of the present study suggest that MUC4 promotes invasion and metastasis by FGFR1 stabilization through the N-cadherin upregulation.
MUC4 是一种 1 型跨膜粘蛋白,在多种癌症中差异表达,先前已被证明可增强胰腺癌的进展和转移。在这项研究中,我们研究了与胰腺癌细胞中 MUC4 诱导的侵袭和转移相关的分子机制。在多种胰腺癌细胞中稳定沉默 MUC4 会通过下调部分 pFAK、pMKK7、pJNK 和 pc-Jun 通路以及部分通过 PI-3K/Akt 通路下调 N-钙粘蛋白及其相互作用伙伴成纤维细胞生长因子受体 1(FGFR1)。FGFR1 的下调反过来又导致 pAkt、pERK1/2、pNF-κB、pIkBα、uPA、MMP-9、波形蛋白、N-钙粘蛋白、Twist、Slug 和 Zeb1 的下调,以及 MUC4 敲低 BXPC3 和 Capan1 细胞中 E-钙粘蛋白、Occludin、细胞角蛋白-18 和 Caspase-9 的上调,与转染 scramble 载体的细胞相比。此外,FGFR1 的下调与肌动蛋白细胞骨架的形态和重排的显著变化相关,导致体外迁移(P < 0.00001)和侵袭(P < 0.0001)显著减少,以及在裸鼠原位植入后体内致瘤性和转移发生率降低。总之,本研究结果表明,MUC4 通过 N-钙粘蛋白的上调促进 FGFR1 稳定从而促进侵袭和转移。