Oxymatrine induces anti-tumor response in cervical cancer by modulating circ_0008460/miR-197-3p/ribonucleotide reductase subunit M2 (RRM2)

Oxymatrine (OMT) has exhibited an anti-cancer role in human cancers, including cervical cancer (CC). The dysregulated circular RNAs (circRNAs) are key regulators in cancer biology, and circ_0008460 was upregulated in CC. This study was performed to investigate the circRNA-based molecular mechanism for OMT in CC. RNA detection for circ_0008460, microRNA-197-3p (miR-197-3p), or ribonucleotide reductase subunit M2 (RRM2) was completed using reverse transcription-quantitative polymerase chain reaction assay. Cell behaviors were assessed by Cell Counting Kit-8 assay for cell viability, colony formation assay or Edu assay for cell proliferation, flow cytometry for cell apoptosis, and wound healing assay/transwell assay for migration/invasion. Protein expression examination was conducted using western blot. Dual-luciferase reporter assay and RNA pull-down assay were applied to confirm target binding. Tumor xenograft assay was performed for OMT research in vivo. OMT induced circ_0008460 downregulation in CC cells. OMT-induced inhibitory effects on cell growth, migration, and invasion but promoting effect on cell apoptosis were attenuated by circ_0008460. Circ_0008460 directly interacted with miR-197-3p, and OMT inhibited malignant behaviors of CC cells via mediating circ_0008460/miR-197-3p axis. RRM2 acted as a target for miR-197-3p and circ_0008460 affected the RRM2 level through absorbing miR-197-3p. OMT upregulated miR-197-3p to inhibit RRM2 expression to impede CC cell development. CC tumorigenesis was suppressed by OMT via targeting circ_0008460/miR-197-3p/RRM2 axis in vivo. These results suggested that OMT restrained CC cell progression in vitro and tumor growth in vivo by downregulating circ_0008460 to mediate miR-197-3p/RRM2 axis.