MiR-30a upregulates BCL2A1, IER3 and cyclin D2 expression by targeting FOXL2

FOXL2 is a transcription factor that is essential for ovarian development. Somatic mutations of FOXL2 are associated with ovarian granulosa cell tumorigenesis. In the present study, the expression of FOXL2 was suppressed by microRNAs using the Ago2 knockdown method in COV434 cells. Online bioinformatics tools were utilized to predict that FOXL2 expression may be repressed by miR-30 family members, and dual luciferase assay and western blotting were performed to demonstrate that FOXL2 is a target gene of miR-30a, which is relatively abundant in COV434 cells. Furthermore, miR-30a overexpression upregulates BCL2A1, IER3 and cyclin D2 expression by inhibiting FOXL2. miR-30a is known to function as a tumor suppressor in breast cancer, small cell lung cancer and colorectal carcinoma; however, the present study revealed an opposing function of miR-30a as an oncogene.