Endometrial E-cadherin and N-cadherin Expression during the Mid-Secretory Phase of Women with Ovarian Endometrioma or Uterine Fibroids

Background: Endometriosis and uterine fibroids are benign conditions frequently linked to subfertility/infertility. Recent research has highlighted the importance of epithelial-mesenchymal transition between embryonic and endometrial cells in the context of embryo implantation. Additionally, the adverse endometrial environment during implantation has been proposed as a mechanism contributing to infertility in endometriosis. Nevertheless, the role of cadherin molecule alterations in relation to endometrial receptivity and embryo invasion remains a subject of controversy.

Methods: We investigated the expression patterns of E-cadherin and N-cadherin in the endometria of women with ovarian endometrioma or uterine fibroids and assessed whether they differed from those of healthy women. We enrolled 17 women with ovarian endometrioma, 16 with uterine fibroids, and 6 healthy women. Endometrial tissues were obtained at the mid-secretory phase on days 19-24 of the menstrual cycle. The E-cadherin and N-cadherin mRNA and protein expression levels were measured using quantitative reverse transcriptase polymerase chain reaction and Western blot analysis, respectively.

Results: The E-cadherin and N-cadherin mRNA expression levels were higher and lower, respectively, in the endometrium of women with ovarian endometrioma than in those of the controls. In the endometrium of women with uterine fibroids, similar patterns with higher E-cadherin and lower N-cadherin levels were observed compared with that of the controls. Protein expression showed similar patterns.

Conclusions: Our findings revealed higher E-cadherin expression and lower N-cadherin expression in the endometria of women with infertility-related diseases than in those of healthy women in the mid-secretory phase. This suggests a resistance to endometrial receptivity, potentially reflecting mesenchymal-epithelial transition properties.