| Objectives: The cyclical changes in proliferation and differentiation of endometrial cells are regulated by
estrogen and progesterone via modulating Wnt/b-catenin signaling. Imbalance in the expression of
estrogen and progesterone receptors causes progesterone resistance in endometriosis patients. The aim
of this study was to investigate the expression of some main components of Wnt/b-catenin signaling
including WNT7a, DKK-1, b-catenin, and GSK-3b in eutopic endometrium and peritoneal endometriotic
lesions of endometriosis patients compared to healthy endometrium in the mid-secretory phase of
menstrual cycle.
Study Design: This prospective study was performed, during a 12 months period from December 2015 to
November 2016, on healthy women as the control group (n = 14) and endometriosis patients (n = 34). We
used real-time polymerase chain reaction and Western blot techniques.
Results: Protein and mRNA expression of DKK-1 were significantly down-regulated in both endometriotic
lesions and eutopic endometrium of endometriosis group. We also demonstrated that the expression of
non-phosphorylated b-catenin (active form) and phosphorylated GSK-3b (inactive form) were upregulated
in endometriosis patients. The mRNA levels of b-catenin, GSK-3b, and WNT7a, as well as the
protein levels of total b-catenin, total GSK-3b, and WNT7a in endometriosis group, were not significantly
different with those in control group. The patterns of mRNA and protein expression of all interested
factors in the lesions were similar to those in the eutopic endometrium of same patients.
Conclusions: It seems that the aberrant activation of Wnt/b-catenin signaling in the secretory phase of the
menstrual cycle in endometriosis has two essential elements: excessive inactivation of GSK-3b and
suppression of the expression of Wnt signaling inhibitor DKK-1. Interventions in this signaling pathway
may allow for the exploration of potential new targets for the control of development and progression of
endometriosis. |