Autocrine motility factor promotes epithelial-mesenchymal transition in endometrial cancer via MAPK signaling pathway

Autocrine motility factor (AMF) as a cytokine and a growth factor, is known to regulate tumor cell growth and motility in the progress of various human malignant tumors, however, its role in endometrial cancer (EC) has not been fully studied. In the present study, using immunohistochemistry, we found that AMF was highly expressed in EC tissues compared with normal endometrial tissues and tissue micrioarray technology showed positive correlation between AMF expression and epithelial-to-mesenchymal transition (EMT) related markers E-cadherin, vimentin and Snail. Next, we detected that silencing of AMF by stable transfection with shRNA induced mesenchymal-to-epithelial transition phenotype in Ishikawa and HEC-1B cells by qRT-PCR, western blotting and immunofluorescence. Gene expression profile revealed that AMF silencing resulted in altered expression of EMT related molecular mediators including Snail and transforming growth factor β receptor 1, and involvement of mitogen-activated protein kinase (MAPK) signaling pathway. Additionally, we found that EMT related markers were downregulated with pretreatment of the MAPK-specific inhibitor U0126 by western blotting. The present study is the first to support a role for AMF mediating EMT in endometrial cancer through MAPK signaling. Therefore, AMF may provide a potential prognostic and therapeutic target in preventing EC progression.