Molecular Mechanisms Of Long Non-coding RNA CTBP1-AS In Regulation Of Biological Characteristics Of Breast Cancer Cells

Objective: The aim of current study is to investigate the expression of LncRNA CTBP1-AS in breast cancer tissues and association with the patient clinicopathological characteristics,explore the effect of LncRNA CTBP1-AS on the proliferation,apoptosis,migration and invasion of breast cancer cells,and further explore the regoulatory mechanism of LncRNA CTBP1.Methods:1.The expression level of LncRNA CTBP1-AS in breast cancer and adjacent tissues were measured by q RT-PCR.In addition,the correlation between LncRNA CTBP1-AS expression and the clinicopathological parameters of breast cancer patients was analyzed.2.The relative expression level of LncRNA CTBP1-AS in human breast cancer cell lines MCF-10 A,MCF-7,BT-549,MDA-MB-231 and MDA-MB-435 was determined by q RT-PCR.3.The effect of knockdown or overexpression of LncRNA CTBP1-AS on proliferation,apoptosis,migration and invasion of breast cancer cells was detected by CCK8,clone formation,flow cytometry,transwell migration and invasion,and wound-healing assays.4.The effect of knockdown or overexpression of LncRNA CTBP1-AS on apoptosis and expression of EMT-related proteins was evaluated by Western blot.5.The interaction between LncRNA CTBP1-AS and mi R-940 was predicted and verified by bioinformatics analysis,RNA immunocoprecipitation,dual luciferase reporter assay and q RT-PCR.The CCK8 and clone formation assays were performed to analyze the effect of LncRNA CTBP1-AS and mi R-940 on cell proliferation.6.The effect of LncRNA CTBP1-AS on xenograft tumor formation was evaluated by tumor transplantation in nude mice.Results:1.The analysis of 155 breast cancer tissues indicated that LncRNA CTBP1-AS expression in cancer tissue was significantly higher compared with adjacent tissues(P<0.05).In addition,the expression of LncRNA CTBP1-AS was closely related to tumor size(P<0.001),histological grade(P<0.001),Ki-67(P = 0.027)and HER-2(P<0.001).2.The q RT-PCR results showed that the expression level of LncRNA CTBP1-AS in breast cancer cell lines was significantly higher than that in MCF-10 A cell line(P<0.05).3.CCK-8 and clone formation assays demonstrated that LncRNA CTBP1-AS promoted the proliferation of breast cancer cells in vitro(P<0.05);Flow cytometry and Western blot results indicated that LncRNA CTBP1-AS inhibited the apoptosis of breast cancer cells(P<0.05);Wound-healing and transwell cell migration assays showed that LncRNA CTBP1-AS promoted the migration ability of breast cancer cells(P<0.05);Transwell cell invasion and Western blot results showed that LncRNA CTBP1-AS promoted the invasion ability of breast cancer cells(P<0.05).4.Bioinformatics analysis and further experiments verified that there is an interaction between LncRNA CTBP1-AS and mi R-940.Furthermore,LncRNA CTBP1-AS regulated the proliferation of breast cancer cells by targeting mi R-940.5.The results of nude mice xenograft experiments showed that compared with control group,the volume and weight of nude mice subcutaneous xenografts in the LncRNA CTBP1-AS downregulated group were significantly reduced(P<0.05).Conclusions:1.The expression of LncRNA CTBP1-AS in breast cancer tissues and cells increased dramatically.2.LncRNA CTBP1-AS can promote the proliferation,invasion and migration of breast cancer cells,and inhibit cell apoptosis.3.LncRNA CTBP1-AS affects the proliferation of breast cancer cells by targeting mi R-940.4.Down-regulation of LncRNA CTBP1-AS inhibited the growth of transplanted tumors in nude mice.