RESUMO
Endometriosis is an estrogen-dependent disease associated with pain and infertility. The objective of this study was to determine the expression of ZEB1 in endometriosis and its role in 17ß-estradiol (E2)-induced epithelial-mesenchymal transition (EMT). 25 patients with endometriosis and 16 endometriosis-free patients were recruited for the study. Tissue expression of EMT makers was investigated by immunohistochemistry, then the expression of ZEB1 was quantified by qRT-PCR, immunohistochemistry, and western blot. The proliferation, DNA replication, and migration and invasion in ZEB1 knockdown Ishikawa cells were further respectively performed by MTS, Edu, wound healing and transwell assays. Luciferase assay was used to measure the ZEB1 promoter activity. Our results show that protein levels of E-cadherin and Keratin 18 decreased in endometriotic tissues. Meanwhile the expressions of ZEB1, Vimentin, and N-cadherin were significantly increased in endometriotic tissues. Down-regulation of ZEB1 inhibited Ishikawa cells proliferation, migration, invasion and EMT. E2 promoted the expression of ZEB1 through the ER genomic pathway, which contributed to the EMT process. The -1401 bp - -1901 bp region in the ZEB1 promoter was the main target of the E2 activity. The present results suggest that a high expression of ZEB1 plays an important role in the pathogenesis of endometriosis, and it may serve as a potential therapeutic target for endometriosis.