Mechanism of miR-339-5p influencing chemotherapy resistance of breast cancer cells via regulating EMT
Objective To analyze the mechanism of miR-339-5p influencing chemotherapy resistance of breast cancer cells via regulating epithelial mesenchymal transformation(EMT).Methods From February 2023 to February 2024,MCF10A mammary epithelial cells and MCF-7 breast cancer cell lines were cultured in vitro.The paclitaxel resistant breast cancer cell line(MCF-7/paclitaxel)was constructed.The MCF-7/paclitaxel cells were divided into a miR-339-5p mimics group,a miR-339-5p mimetic negative control group(miR-NC group),a miR-339-5p inhibitor group,and a miR-339-5p inhibitor control group(NC group).The real-time fluorescence quantitative reverse transcription polymerase chain reaction(qRT-PCR)was used to detect the expression level of miR-339-5p.The methyl thiazolyl tetrazolium(MTT)assay was used to determine the inhibition rate of cell proliferation.The flow cytometry was used to determine cell apoptosis.The expression of EMT related proteins[E-cadherin(E-cad)and Vimentin(Vim)]was detected using the Western blot method.The independent sample t test,one-way ANOVA,and LSD-t test were used for the statistical analysis of the obtained data.Results The expression level of miR-339-5p in the MCF-7 cells was lower than that in the MCF10A cells[(0.36±0.07)vs.(0.73±0.08);P＜0.05].Forty-eight h after transfection,the proliferation inhibition rate and apoptosis rate in the miR-339-5p mimics group were higher than those in the miR-NC group[(45.86±4.92)％vs.(20.44±2.16)％and(16.54±1.67)％vs.(4.23±0.45)％;both P＜0.05].The cell proliferation inhibition rate and apoptosis rate of the miR-339-5p inhibitor group were lower than those of the NC group[(9.74±1.05)％vs.(17.18±1.84)％and(2.28±0.46)％vs.(5.43±0.59)％,both P＜0.05].The E-cad level in the miR-339-5p mimics group was higher than that in the miR-NC group[(0.78±0.07)vs.(0.42±0.05);P＜0.05];the Vim level in the miR-339-5p mimics group was lower than that in the miR-NC group[(0.42±0.05)vs.(0.61±0.07);P＜0.05].The E-cad level in the miR-339-5p inhibitor group was lower than that in the NC group[(0.23±0.04)vs.(0.34±0.05);P＜0.05];the Vim level in the miR-339-5p inhibitor group was higher than that in the NC group[(0.84±0.09)vs.(0.69±0.08);P＜0.05].Conclusions MiR-339-5p can reduce chemotherapy resistance of breast cancer cells,inhibit cell proliferation,and promote cell apoptosis.The mechanism may be that it inhibits EMT regulating EMT related proteins——E-cad and Vim.
Breast cancerMiR-339-5pEpithelial mesenchymal transformationChemotherapy resistanceMechanism
万方数据
维普
