Molecular Mechanism of circRAPGEF5 in Regulating the Molecular Axis of microRNA-4712-5p/Tyrosine 3-Monooxygenase/Tryptophan 5-Monooxygenase Activation Protein Epsilon Affecting Cellular Proliferation and Apoptosis in Mammary Cancer
To understand the molecular mechanism of circRAPGEF5, its effect on the proliferation and apoptosis of mammary cancer cells, and its regulatory effect on the molecular axis of miRNA-4712-5p/YWHAE. qRT-PCR and Western blot were used to test circRAPGEF5, miRNA-4712-5p, and YWHAE expression in mammary cancer and paracancerous tissues. The human mammary cancer cell, MDA-MB-231, was cultured in vitro, and pcDNA-NC, pcDNA-circRAPGEF5, anti-miRNA-NC, anti-miRNA-4712-5p, pcDNA-circRAPGEF5, and miRNA-NC, pcDNA-circRAPGEF5 were transfected into MDA-MB-231 cells with miRNA-4712-5p mimics. qRT-PCR and Western blot were employed to detect circRAPGEF5, miRNA-4712-5p, and YWHAE expression in cells. The CCK-8 methodand plate clone formation experiment were conducted to test cellular proliferation ability. Flow cytometry was performed to detect apoptosis rate. Dual luciferase reporter assays were used to test the targeting association between circRAPGEF5 and miRNA-4712-5p, and the targeting association between miRNA-4712-5p and YWHAE. Western blot was utilized to detect Bcl-2, Bax, and Cleared Caspase-3 protein expression. In comparison with paracancerous tissues, circRAPGEF5 and YWHAE expression levels in mammary cancer tissues were significantly reduced (P < 0.05), and miRNA-4712-5p expression levels were significantly increased (P < 0.05). Transfection of pcDNA-circRAPGEF5 or trans-anti-miRNA-4712-5p could reduce the optical density (OD) value, Bcl-2 protein level and clonal formation number to a significant extent (P < 0.05), and it increases Bax and Cleaved Caspase-3 apoptosis rate and protein levels (P < 0.05). Dual luciferase reporter assays confirmed that there was target binding between circRAPGEF5 and miRNA-4712-5p and between miRNA-4712-5p and YWHAE. Co-transfection of pcDNA-circRAP GEF5 and miRNA-4712-5p could greatly reduce transfection of pcDNA-circRAP GEF5 and its effect on the proliferation and apoptosis of MDA-MB-231 cells. Overexpression of circRAPGEF5 can inhibit the proliferation of mammary cancer cells and induce apoptosis by regulating the molecular axis of miRNA-4712-5p/YWHAE.