Preliminary Study On The Expression Of CircRNA Circ-ZEB1 In Triple Negative Breast Cancer And Its Clinical Significance

Background and Objective:Triple negative breast cancer(TNBC)is the most invasive subtype of all breast cancer,with poor prognosis and unclear specific pathogenesis.Circular RNA(circRNA)are a new class of highlighted molecules,which have been found to play an important role in the development of breast cancer through a variety of mechanisms.Our previous study found that miR-448 had an inhibitory effect in breast cancer,and a database search showed that multiple circRNAs could bind to miR-448.Considering of this,a circRNA-circ-ZEB1 with miR-448 binding site and differentially expressed in TNBC was found by screening.To explore the expression of circ-ZEB1 and miR-448 in TNBC cancer tissues as well as the relationship between circ-ZEB1 and miR-448,and to find out the relationship between the expression of circ-ZEB1 and clinical characteristics.Besides,current study also aimed to provide new references and bases for TNBC treatment and prognosis in clinic.Methods:Several candidate circRNAs that may combine with miR-448 are predicted and selected by Starbase software.The tumor tissues and matched paracancerous tissues were collected from 30 patients admitted to the First Affiliated Hospital of Zhengzhou University who were pathologically confirmed to be TNBC patients.The expression levels of candidate circRNAs and miR-448 in tissues were detected by quantitative real-time PCR(qRT-PCR),and the relationship between the differentially expressed circRNAs and miR-448 and the relationship between their expression levels and the clinical characteristics of TNBC patients were analyzed.Results:1.The expression of candidate circRNAs and miR-448 in 30 TNBC cancer tissues and adjacent tissues were detected by qRT-PCR.We found that circ-ZEB1 was differentially expressed in samples from TNBC patients,and the expression of circ-ZEB1 in cancer tissues was significantly higher than that in adjacent tissues,while miR-448 in cancer tissues was significantly lower than that in adjacent tissues.2.Pearson correlation analysis was carried out to analyze the expression of circ-ZEB1 and miR-448 in TNBC cancer tissues by using qRT-PCR results.The results showed a negative correlation between them,with R=0.6775,p<0.0001.And the expression of circ-ZEB1 was negatively correlated with miR-448 in TNBC tumor tissues.3.Taking the average expression of circ-ZEB1 in TNBC as the boundary,TNBC patients were divided into high and low expression group,respectively.The results showed that the expression level of circ-ZEB1 was related to lymph node metastasis(p=0.024)and Ki-67 proliferation index(p=0.026).Conclusions:1.Circ-ZEB1 was upregulated in TNBC.2.The expression of circ-ZEB1 and miR-448 in TNBC is negatively correlated,which may affect the occurrence and development of TNBC by regulating the expression of miR-448.3.Circ-ZEB1 may be a potential target for TNBC therapy and associated with prognosis.