miR‑28‑5p suppresses cell proliferation and weakens the progression of polycystic ovary syndrome by targeting prokineticin‑1.

Prokineticin‑1 (PROK1) serves important roles in the pathogenesis of polycystic ovary syndrome (PCOS); however, the association between microRNA (miR)‑28‑5p and PROK1 remains unclear. In the present study, the roles of miR‑28‑5p and PROK1, and their interaction in PCOS were investigated. Rat ovary granule cells were transfected with miR‑28‑5p mimics, and PROK1 expression levels were measured by reverse transcription‑quantitative PCR and western blotting. A dual‑luciferase reporter assay was performed to determine the association between miR‑28‑5p and PROK1. Additionally, pcDNA‑PROK1 was co‑transfected into rat ovary granule cells with miR‑28‑5p mimics. Cell proliferation, apoptosis, cell cycle and the expression of signaling proteins were investigated using Cell Counting Kit‑8 assays, 5‑ethynyl‑2'‑deoxyuridine staining, flow cytometry and western blotting, respectively. PROK1 expression was suppressed in rat ovary granule cells by miR‑28‑5p mimics, but upregulated following transfection with miR‑28‑5p inhibitors. The dual‑luciferase reporter assay revealed that miR‑28‑5p binds to the 3'‑untranslated region of PROK1. Proliferation activity was increased in PROK1‑overexpressing cells; this effect was eliminated by co‑transfection with miR‑28‑5p mimics. PROK1‑overexpressing rat ovary granule cells exhibited significantly suppressed cell apoptosis and a decreased number of cells in G1; miR‑28‑5p mimics reversed these effects. Western blotting revealed that the PI3K/AKT/mTOR signaling pathway was activated by PROK1. The present results suggested that miR‑28‑5p attenuated the progression of PCOS by targeting PROK1, which may promote the pathogenesis of PCOS via the PI3K/AKT/mTOR pathway, indicating that the miR‑28‑5p/PROK1 axis may be a potential therapeutic target for patients with PCOS.