Research Center for Women's Diseases and Department of Biological Sciences, Sookmyung Women's University, Seoul, Republic of Korea.
Oncol Rep. 2012 Sep;28(3):1022-8. doi: 10.3892/or.2012.1865. Epub 2012 Jun 14.
Aberrant activation of the Wnt/β-catenin signaling pathway is common in human cervical cancers. However, the mechanisms of Wnt activation in cervical cancer remain largely unknown. In the present study, we demonstrate that Klotho, a Wnt antagonist, is downregulated in invasive human cervical tumors and in a cell line we analyzed. Our data demonstrated that in vivo Klotho expression was not observed in invasive cervical carcinoma. In vitro restoration of Klotho expression in SiHa cells resulted in a decreased cell motility and invasiveness through upregulation of E-cadherin, downregulation of N-cadherin and reduced expression of MMP7 and -9. Ectopic expression of Klotho also reduced the expression of the epithelial-to-mesenchymal transition (EMT) transcription factors Slug and Twist. Furthermore, Klotho causes a significant inhibition of the Wnt/β-catenin pathway in cervical cancer cells, as supported by the expression of Wnt/β-catenin transcriptional target genes such as c-Myc and cyclin D1. Consequently, our findings demonstrate for the first time that Klotho regulates tumor invasion through the EMT process and provide novel mechanistic insights into the role of Klotho in cervical cancer progression and contribute to treatment for metastatic cervical cancer patients.
Wnt/β-连环蛋白信号通路的异常激活在人类宫颈癌中很常见。然而,宫颈癌中 Wnt 的激活机制在很大程度上仍不清楚。在本研究中,我们证明了 Wnt 拮抗剂 Klotho 在侵袭性人宫颈肿瘤和我们分析的细胞系中下调。我们的数据表明,Klotho 在侵袭性宫颈癌中不能在体内观察到表达。在 SiHa 细胞中恢复 Klotho 的表达导致细胞迁移和侵袭性降低,这是通过上调 E-钙黏蛋白、下调 N-钙黏蛋白以及降低 MMP7 和 MMP9 的表达来实现的。Klotho 的异位表达还降低了 EMT 转录因子 Slug 和 Twist 的表达。此外,Klotho 导致宫颈癌细胞中 Wnt/β-连环蛋白途径的显著抑制,这得到了 Wnt/β-连环蛋白转录靶基因如 c-Myc 和细胞周期蛋白 D1 的表达的支持。因此,我们的研究结果首次表明,Klotho 通过 EMT 过程调节肿瘤侵袭,并为 Klotho 在宫颈癌进展中的作用提供了新的机制见解,并有助于治疗转移性宫颈癌患者。