Purpose: Endometriosis is a chronic gynecological disorder associated with pain symptoms and infertility. The expression of microRNA miR-29c-3p is dysregulated in endometriosis. We aimed to identify novel molecular targets of miR-29c-3p functionally linked to proliferation and invasive growth in endometriosis.

Methods: The epithelial endometriotic cell line 12Z and primary endometriotic stromal cells (PESC) were transfected with control miRNA or pre-miR-29c-3p, and subjected to cell cycle analysis, cell viability, wound healing, and Matrigel invasion assays. Expression of bioinformatically predicted miR-29c-3p targets was analyzed by qPCR and western blot. Target gene expression in endometriotic lesions and healthy endometrium was studied in the EndometDB endometriosis database.

Results: miR-29c-3p decreased 12Z and PESC cell viability and the proportion of PESC in the S-phase. 12Z cell invasion, but not migration, was decreased after miR-29c-3p upregulation. miR-29c-3p decreased the mRNA expression of CDK6, BCCIP, TCF7L1, TCF7L2, PTEN, COL4A1, E-Cadherin, and N-Cadherin. A decrease of CDK6 and PTEN and an increase of p21 were confirmed at the protein level. EndometDB database analysis demonstrated dysregulated expression of the selected targets in both deep endometriosis and ovarian endometriosis.

Conclusions: miR-29c-3p effectively curbs endometriotic cell proliferation and invasion by combined inhibition of cell cycle regulators and transcription factors, unveiling a promising therapeutic strategy.