miR-205 promotes tumor proliferation and invasion through targeting ESRRG in endometrial carcinoma

Increasing evidence suggests that miR-205 is frequently dysregulated in many types of human cancers, suggesting its important roles in the initiation and progression of cancer. However, the functions of miR-205 in human endometrial endometrioid carcinoma (EEC) are still unknown. In this study, we investigated the expression of miR-205 in both normal endometrium and EEC tissues using TaqMan PCR. Compared to normal tissues, miR-205 was significantly upregulated in EEC (P<0.001). After transfection of miR-205 inhibitors into Ishikawa cells (or transfection of miR-205 mimics into AN3CA cells), we demonstrated that the cellular proliferation, migration and invasion properties were negatively regulated by miR-205. Moreover, by combination of microRNA target prediction algorithms and luciferase reporter system, we identified estrogen-related receptor-gamma (ESRRG) as a target of miR-205. In conclusion, we demonstrated frequent upregulation of miR-205 in EEC. In gain-of-function and loss-of-function assays, inhibition of miR-205 reduced cellular proliferation, migration and invasion; vice versa, increased levels of miR-205 led to upregulated cellular proliferation, migration and invasion. Nonetheless, we identified the ESRRG gene to be a novel target, which could be helpful to elucidate mechanisms underlying the tumorigenesis of EEC.