Effect of miR-21 Inhibitor Coated with Ferric Oxide on Ovarian Cancer Cells Through Mitogen-Activated Protein Kinase Signaling Pathway

Ovarian cancer (OC) incidence has in recent years been on the rise among common gynecological cancers. Iron oxide nanoparticles (IONPs), as emerging nanomedicines, have been widely used in research on cancer therapy. However, with in-depth research on microRNA (miRNA), the effect of combining miRNA with nanoparticles on ovarian cancer is not yet clear. We deeply explored the mechanism of IONPs loading miRNA to regulate ovarian cancer cells. In this study, novelmiR-21 inhibitor-IONPs nanoparticles were prepared by loading miR-21 inhibitor into IONPs. Electron microscopy was used to observe nano-encapsulation and miR-21 expression was measured along with analysis of cell proliferation, apoptosis by flow cytometry, and phosphorylation of apoptotic proteins and mitogen-activated protein kinase (MAPK) signaling pathways by Western blot. Our results showed that miR-21 inhibitor-IONPs reduced miR-21 expression, thereby inhibiting ovarian cancer cells activities and promoting apoptosis. miR-21 inhibitor-IONPs also inhibited p-p38MAPK and p-ERK levels, which were increased after addition of MAPK agonist (U-46619). Moreover, ovarian cancer cell proliferation increased and apoptosis decreased. miR-21 inhibitor-IONPs can thus inhibit MAPK signaling, thereby reducing the activities of ovarian cancer cells. This study provides theoretical support for application of miR-21 inhibitor-IONPs as novel nanoparticles for the treatment of ovarian cancer.