Abnormal expression of Hippo-YAP1 signalling pathway and progesterone resistance mechanism in endometrial polyps.

BACKGROUND

Endometrial polyps (EPs) are a localised hyperproliferative disorder of the endometrium, and its pathogenesis remains unclear. Progesterone resistance may influence the recurrence rate of progesterone-treated EPs. Expression of the Hippo-YAP1 signalling pathway has been studied in various diseases. However, few studies have explored their expression in EPs and association with progesterone resistance. Prolactin (PRL), a molecular marker of endometrial mesenchymal cell metaplasia, indirectly reflects progesterone action in vivo. This study aimed to explore the role of Hippo-YAP1 signalling pathway in EPs.

METHODS

Endometrial tissue specimens obtained by surgical resection from 35 patients with a normal endometrium and 35 with EPs were collected between July 2023 and July 2024. Immunohistochemically, the expressions of mammalian STE20-like kinase 1 (MST1), Yes-associated protein 1 (YAP1), progesterone receptor (PR) and PRL in the normal endometrium and EPs tissues were detected.

RESULTS

Compared to normal endometrial tissues, the expression of MST1 was relatively low in EPs (p < .05), while the total and nuclear expression of YAP1 was relatively high in EPs (p < .0001). The expression of PR in EPs tissues was significantly lower than that in normal endometrial tissues (p < .05), and the expression level of PRL was lower than that of normal endometrium in EPs tissues (p < .001).

CONCLUSIONS

EPs have progesterone resistance, and the Hippo-YAP1 signalling pathway may be involved in the development and progression of EPs by acting on the progesterone resistance mechanism.