UCA1 Functions As A Competing Endogenous RNA To Suppress Epithelial Ovarian Cancer Metastasis

[Background]Epithelial ovarian cancer(EOC)is a prevalent malignancy and often associated with fatal outcome in women worldwide.Despite advances in treatment approaches over the last decades,the overall survival of epithelial ovarian cancer patients remains low due to the metastasis in the pelvic and abdominal cavity.Long noncoding RNAs(IncRNAs)have recently been discovered to play an important role in various kinds of tumors.Yet,it is not fully clear whether this unique function of IncRNAs is involved in the carcinogenesis and metastasis of EOC.Human urothelial carcinoma associated 1(UCA1),a newly identified IncRNA,had initially come to known for its involvement in oncogenesis of bladder cancer,wherein elevation of UCA1 promoted bladder cancer cell proliferation and metastasis.In this study,we found that UCA1 was aberrantly up-regulated in EOC tissues.Moreover,knockdown of UCA1 reduced the invasion and migration of EOC cells.Bioinformatics analysis and molecular biology experiments were applied to verify the lncRNA/miRNA interaction,further elucidating the effect on the expression of miRNA target gene,finally revealing the mechanism of metastasis in EOC.[Objectives]1.To elucidate verify the expression of UCAl in epithelial ovarian cancer.2.To study the role of UCA1 in the regulation of invasion and migration of epithelial ovarian cancer.3.To verify molecular mechanisms of IncRNA UCA1 in promoting metastasis of epithelial ovarian cancer.[Methods]The expression of UCA1 was verified by qRT-PCR in epithelial ovarian cancer.The Kaplan-Meier method and the Cox multivariate regression analysis were applied to analyze the effect of UCA1 on EOC patients.The role of UCA1 in metastasis of EOC was determined by the invasion and wound healing assay.Bioinformatics analysis was used to analysis UCA1/miRNA interaction.The UCA1/miRNA interaction was verified by dual luciferase reporter gene assay and RNA binding protein immunoprecipitation.Western blot elucidate the effect of miR-485-5p on the target gene MMP14.Furthermore,western blot experiment was applied to explore the role of miR-485-5p and UCA1 in the regulation of MMP14.The correlation between UCA1 and MMP14 was also analyzed.[Results]1.The qRT-PCR showed that UCA1 expressions were distinctly up-regulated in cases than in normal tissues.Kaplan-Meier method verified high expression of UCA1 was associated with poor outcome.Univariate and multivariate analyses showed that UCA1 was a prognostic factor for overall survival in EOC patients.2.Knockdown of UCA1 reduced the invasion and migration of EOC cells.3.UCA1 was predicted to contain miR-485-5p binding sites by miRBase.Dual luciferase reporter assay demonstrated that miR-485-5p can decrease the relative luciferase activity of UCA1.Relative to control immunoglobulin G(IgG)immunoprecipitates,anti-Ago2 antibody could significantly enrich the Ago2-UCAl-miR-485-5p complex.4.Luciferase reporter assay implied that miR-485-5p inhibited luciferase activity of WT reporter harboring coding region of MMP14 gene.Knockdown of UCAl or up-regulation of miR-485-5p could obviously reduce MMP14 expression at both mRNA and protein level.Bivariate correlation analysis implied that MMP14 expression was corresponded with UCA1 expression in normal and cancer ovarian samples.[Conclusion]UCA1 was upregulated in EOC cancer.Knockdown of UCA1 reduced the invasion and migration of EOC cells.As a ceRNA,UCA1 could combine with miR-485-5p,thereby modulating the derepression of miR-485-5p target MMP14.The derepression of MMP14 led to the involvement in cancer cell metastasis via degrading extracellular matrix.In summary,the elucidation of the UCA1-miR-485-5p-MMP14 pathway could function as a potential target for therapeutic therapy.