Interaction Between lncRNA SEMA3B-AS1 and CDK4 Mediated by mir-545 Regulates the Proliferation of Triple-Negative Breast Cancer Cells

Abstract

BackgroundAlthought lncRNA SEMA3B-AS1 was known to be involved in the development of many types of cancer, the role of SEMA3B-AS1 in triple-negative breast cancer (TNBC) remains unknown. This study was to investigate the role and underlying mechanism of SEMA3B-AS1 in TNBC.The mRNA expression of SEMA3B-AS1, miR-545 and CDK4 in TNBC tissues and non-cancer tissues of TNBC patients (n = 69) was detected by RT-qPCR. The protein expression of CDK4 was detected by Western blot. Cell proliferation were evaluated by CCK-8 assay.ResultsWe found that the expression of SEMA3B-AS1 was downregulated in TNBC tissues. The expression of SEMA3B-AS1 was positively correlated with the expression of miR-545 and inversely correlated with the expression of CDK4. Overexpression of SEMA3B-AS1 or miR-545 resulted in the downregulation of CDK4. Moreover, miR-545 inhibitor attenuated the effect of SEMA3B-AS1 overexpression on CDK4 expression. SEMA3B-AS1 overexpression also resulted in the upregulation of miR-545. Overexpression of SEMA3B-AS1 or miR-545 decreased the rate of TNBC cell proliferation, while overexpression of CDK4 increased the rate of TNBC cell proliferation. In addition, miR-545 inhibitor attenuated the effect of SEMA3B-AS1 overexpression on cell proliferation.Interaction between SEMA3B-AS1 and CDK4 mediated by miR-545 regulates the proliferation of TNBC cells.