Abstract: Objective To explore the expression of CCN5 in endometriotic tissues and its impact on proliferation, migration and invasion of human endometrial stromal cells (HESCs).Methods We collected ovarian endometriosis samples from 20 women receiving laparoscopic surgery and eutopic endometrium samples from 15 women undergoing IVF-ET for comparison of CCN5 expression. Cultured HESCs were transfected with a recombinant adenovirus Ad-CCN5 for CCN5 overexpression or with a CCN5-specific siRNA for knocking down CCN5 expression, and the changes of cell proliferation, migration and invasion were evaluated using CCK-8 assay, wound healing assay and Transwell chamber assay. RT-qPCR and Western blotting were used to examine the expression levels of epithelial-mesenchymal transition (EMT) markers including E-cadherin, N-cadherin, Snail-1 and vimentin in HESCs with CCN5 overexpression or knockdown. Results CCN5 expression was significantly decreased in ovarian endometriosis tissues as compared with eutopic endometrium samples (P<0.01). CCN5 overexpression obviously inhibited the proliferation, migration and invasion of HESCs, significantly increased the expression of E-cadherin and decreased the expressions of N-cadherin, Snail-1 and vimentin (P<0.01). CCN5 knockdown significantly enhanced the proliferation, migration and invasion of HESCs and produced opposite effects on the expressions of E-cadherin, N-cadherin, Snail-1 and vimentin (P<0.01).Conclusion CCN5 can regulate the proliferation, migration and invasion of HESCs and thus plays an important role in EMT of HESCs, suggesting the potential of CCN5 as a therapeutic target for endometriosis.

Key words: endometriosis; CCN5; human endometrial stromal cell; proliferation; migration; invasion; epithelial-mesenchymal transition