Objective:To explore the effects of circular non coding RNA(Circ)_BICD2 on the proliferation,apoptosis and epithe-lial mesenchymal transformation(EMT)of oral squamous cell carcinoma(OSCC)cells by regulating microRNA(miR)-218-5p/Ras homologous gene family member A(RHOA)axis.Methods:The mRNA expression level of Circ_BICD2,miR-218-5p and RHOA in OSCC cells of Cal-27,SCC-25,SCC-9 and HSC-3,and oral keratinocytes HOK was detected by qRT-PCR.SCC-25 cells were di-vided into control group,sh BICD2 group,sh NC group,sh BICD2+miR-218-5p inhibitor group and sh BICD2+inhibitor NC group.Apoptosis,proliferation,EMT-related protein and RHOA expression were respectively examined.The targeting relationship between miR-218-5p and Circ_BICD2 and RHOA respectively was verified.Results:miR-218-5p has targeted binding sites with Circ_BICD2 and RHOA,respectively.The expression levels of Circ_BICD2,RHOA mRNA and miR-218-5p were the most significant in SCC-25 cells(P＜0.05).Interference of BICD2 decreased Circ_BICD2 and RHOA expression,upregulated miR-218-5p,inhibited cell proliferation and EMT,and promoted apoptosis,miR-218-5p inhibitor reversed the malignant behavior inhibition effect by the in-terference of BICD2 on SCC-25 cells.Conclusion:Interference of Circ_BICD2 can inhibit the proliferation and EMT transformation of SCC-25 cells and induce their apoptosis,which may be related to the regulation of miR-218-5p/RHOA axis.

Objective:To explore the effects of circular non coding RNA(Circ)_BICD2 on the proliferation,apoptosis and epithe-lial mesenchymal transformation(EMT)of oral squamous cell carcinoma(OSCC)cells by regulating microRNA(miR)-218-5p/Ras homologous gene family member A(RHOA)axis.Methods:The mRNA expression level of Circ_BICD2,miR-218-5p and RHOA in OSCC cells of Cal-27,SCC-25,SCC-9 and HSC-3,and oral keratinocytes HOK was detected by qRT-PCR.SCC-25 cells were di-vided into control group,sh BICD2 group,sh NC group,sh BICD2+miR-218-5p inhibitor group and sh BICD2+inhibitor NC group.Apoptosis,proliferation,EMT-related protein and RHOA expression were respectively examined.The targeting relationship between miR-218-5p and Circ_BICD2 and RHOA respectively was verified.Results:miR-218-5p has targeted binding sites with Circ_BICD2 and RHOA,respectively.The expression levels of Circ_BICD2,RHOA mRNA and miR-218-5p were the most significant in SCC-25 cells(P＜0.05).Interference of BICD2 decreased Circ_BICD2 and RHOA expression,upregulated miR-218-5p,inhibited cell proliferation and EMT,and promoted apoptosis,miR-218-5p inhibitor reversed the malignant behavior inhibition effect by the in-terference of BICD2 on SCC-25 cells.Conclusion:Interference of Circ_BICD2 can inhibit the proliferation and EMT transformation of SCC-25 cells and induce their apoptosis,which may be related to the regulation of miR-218-5p/RHOA axis.