Proliferation of MicroRNA-365 and E74-like Factor 4 in Cervical Cancer Cells and Its Clinical Significance

Abstract

Objective To investigate the expressions,roles,and clinical significance of microRNA-365(miR-365)and E74-like factor 4(ELF4)in cervical cancer. Methods The expressions of miR-365 in normal cervical tissues(n=34),cervical intraepithelial neoplasia 1(CIN 1)(n=31),cervical intraepithelial neoplasia2-3(CIN 2-3)(n=37),squamous cell carcinoma of the cervix(SCC)(n=33),and three cervical cancer cell lines(C33A cells,Hela cells,and SiHa cells)were detected by real-time quantitative polymerase chain reaction(qPCR).Bioinformatic prediction and luciferase reporter gene assay were performed to verify whether ELF4 was a direct target of miR-365.Western blot and immunohistochemistry were used to detect ELF4 expression in cervical cancer cells and in different pathological cervix tissues.CCK8 assay was used to detect the effect of overexpression or inhibition of miR-365 on the proliferation of cervical cancer cells at different time points.The relationships among the miR-365 expression,ELF4 expression,and clinicopathological parameters of cervical cancer were analyzed by correlation analysis. Results qPCR results showed that compared with the normal cervical cell HcerEpic,the expressions of miR-365 in CIN1,CIN2-3,and cervical cancer tissues gradually decreased with the increased pathologic grade,and its expressions also decreased in different cervical cancer cell lines.The luciferase reporter gene assay confirmed that ELF4 was the direct target of miR-365.Western blot showed that the expression of ELF4 increased in all three cervical cancer cell lines compared with normal cervical epidermal cell(P=0.013,P=0.002,P=0.004).Immunohistochemistry showed that ELF4 expression was up-regulated in CIN and cervical cancer tissues.CCK8 assay showed that overexpression of miR-365 inhibited cell proliferation,while inhibition of miR-365 promoted the proliferation of three cervical cancer cells(P<0.05).Further analysis confirmed that there was a negative correlation between the expression levels of miR-365 and ELF4 in CIN2-3 and SCC(r=-0.351,P=0.045;r=-0.349,P=0.035).Clinical analysis showed that the expressions of both miR-365 and ELF4 were correlated with tumor size,pathological grade,and clinical stage in SCC(all P < 0.05).<b>Conclusion</b> The decreased expression of miR-365 in human cervical cancer cells relieves its inhibitory effect on ELF4,which promotes the proliferation of cervical cancer cells and the formation of tumor.