INTRODUCTION: Endometrial cancer (EC) is a growing global health concern. Understanding the molecular mechanisms driving EC is crucial for developing effective diagnostic and therapeutic strategies. This study investigates the roles of DLL3 and miR-508-5p in EC progression and explores a therapeutic approach using engineered exosomes to modulate their expression. METHODS: TCGA data were analyzed, RESULTS: Elevated DLL3 and downregulated miR-508-5p were observed in EC and correlated with poor outcomes. miR-508-5p directly targets DLL3. Engineered exosomes restored miR-508-5p, inhibited DLL3, and reduced tumor growth and metastasis in mouse models. DISCUSSION: The findings highlight the roles of DLL3 and miR-508-5p in EC. Targeting the miR-508-5p/DLL3 axis via exosome-mediated delivery represents a promising therapeutic strategy for EC.