Mir-302a-3p targets RUNX1 to inhibit the malignancy and epithelial-mesenchymal transition in endometrial cancer cells

Abstract

Abstract Background Runt related transcription factor 1 (RUNX1), a member of the RUNX family, is differentially expressed in various tumors. MicroRNA (Mir)-302a-3p, a member of the mir-302 family, is expressed at various levels in many tumors. We hypothesized that mir-302a-3p and its target RUNX1 jointly affected biological behavior of endometrial carcinoma.Method The binding sites of RUNX1 and mir-302a-3p were predicted by biological software and verified by luciferase assay. Real-time quantitative PCR was used to verify the expression of mir-302a-3p and RUNX1 at mRNA level. Western blotting was used to analyze the expression of RUNX1 and EMT-related proteins. The expression of RUNX1 was also validated by immunohistochemistry. The combined effect of Mir-302a-3p and RUNX1 on endometrial cancer was assessed in in vivo and in vitro models.Results RUNX1 was upregulated in endometrial cancer tissues, consistent with results from the TCGA database. RUNX1 knockdown can inhibit proliferation and promote apoptosis of endometrial cancer cells, as well as affect the G0-G1 phase of the cell cycle. Our previous results indicate that mir-302a-3p is down-regulated in endometrial cancer tissues. Bioinformatics analysis predicted a binding site between mir-302a-3p and RUNX1, which was validated by dual luciferase assays. We confirmed by quantitative real-time PCR and western blot that overexpression or knockdown of mir-302a-3p can affect the expression of RUNX1.Similarly, overexpression of mir-302a-3p inhibited proliferation, promoted apoptosis, and affected the G0-G1 phase of the cell cycle in endometrial cancer cells; these effects were more profound with co-transfection of mir-302a-3p agomir and shRUNX1.Further, mir-302a-3p and RUNX1 affected EMT in endometrial cancer, and the tumor-reducing effect of both RUNX1 knockdown and mir-302a-3p overexpression were confirmed in vivo.Conclusions Our results demonstrate that downregulation of mir-302a-3p promotes malignant biological behaviors and EMT in endometrial cancer cells by targeting RUNX1, and the miR-302a-3p/RUNX1 axis may be a potential therapeutic target for endometrial cancer.