Metapristone (RU486 derivative) inhibits endometrial cancer cell progress through regulating miR-492/Klf5/Nrf1 axis
Abstract Background: Endometrial cancer is the prevalent invasive gynecological cancer in the world. The pathogenesis of endometrial cancer involves many signaling pathways which are related with transcription factors or microRNAs. Metapristone is a hormone related drug and widely used in endometrial cancer clinical therapeutics. However, the deep regulatory mechanism of metapristone is not clear. In this research, we aimed to figure out the specific molecular mechanism during the treatment of endometrial cancer with metapristone.Methods: In this study, RL95-2 cells and Ishikawa cells were used as the endometrial cancer cell models. miR-492 was transfected into RL95-2 cells and Ishikawa cells. The miRNA expression was measured by qRT-PCR. Moreover, the mice tumor model was used to confirm the function of metapristone and the regulating process by miR-492/Klf5/Nrf1 axis in vivo. The protein expression was measured by western blot. Cell proliferation and apoptosis was monitored using the MTT assay, cell colony formation assay and EdU assay.Results: Firstly, the results indicated that metapristone as a kind of hormone-related drugs could significantly inhibit the endometrial cancer cell growth through regulating cell apoptosis-related gene expression. Meanwhile, miR-492 was detected to be highly expressed in the endometrial cancer cell lines. Overexpression of miR-492 could promote the cell proliferation and inhibit the cell apoptosis. Furthermore, the results demonstrated that the downstream target genes of miR-492 were Klf5 and Nrf1, which were inhibited by metapristone. At the animal level, metapristone also inhibited the endometrial cancer cell growth through down-regulating the expression of miR-492 and decreasing the protein level of Klf5 and Nrf1. Conclusion: Taken together, this study indicated that metapristone inhibited the endometrial cancer cell growth through regulating the cell apoptosis related signaling pathway and the expression of miR-492 and its downstream target genes (Klf5 and Nrf1), which provided the theoretical basis of endometrial cancer in clinical treatment.