FOXA2 sensitizes endometrial carcinoma to progestin-mediated conservative therapy by triggering PR transcriptional activation.

Progesterone receptor (PR) expression correlates strongly with progestin sensitivity in fertility-sparing therapy for endometrial carcinoma (EC). However, the mechanisms governing PR expression remain incompletely defined. Here, by stratifying EC patients into PR-high and PR-low groups, we observe that PR-low tumors exhibit enhanced invasion and metastasis signatures, whereas PR-high tumors display increased fatty acid metabolism. Through integrated network analysis, transcriptional correlation across multiple cohorts, and single-cell transcriptomic profiling, FOXA2 is identified as a master regulator of PR expression. Specifically, FOXA2 directly binds the PR promoter, which, in turn, transcriptionally activates PR expression and increases the sensitivity of EC cells to medroxyprogesterone acetate (MPA), an oral progestin used in clinical. Overexpression of FOXA2 markedly inhibits tumor progression, evidenced with reduced cell proliferation and migration while elevated apoptosis. Moreover, FOXA2 is critically involved in lipid metabolic modulation and the administration of Orlistat, an FDA-approval inhibitor of fatty acid synthase, elevates FOXA2 and PR expression, subsequently enhancing progestin sensitivity both in vitro and in vivo. Collectively, our findings identify FOXA2 as a key regulator in controlling PR levels in EC cells and propose the activation of FOXA2-PR axis via Orlistat treatment as a promising therapeutic strategy to improve progestin responsiveness in EC patients.