Abstract
Objective To investigate the impact of miR-146a on tamoxifen treatment sensitivity in patients with estrogen receptor alpha-positive(ERα+)breast cancer.Methods A total of 48 patients with breast cancer who underwent surgical resec-tion in our hospital from January 2018 to December 2019 were enrolled,and cancerous tissue samples and corresponding paracan-cerous tissue samples were collected,as well as clinicopathological features including age,pathological classification,lymph node metastasis,immunohistochemistry results,and molecular subtyping.RT-qPCR was used to measure the level of miR-146a in the cancerous and paracancerous tissue samples of 48 patients with breast cancer,the ERα+human breast cancer cell line(MCF-7),and the human breast epithelial cell line(MCF-10A),and the Kaplan-Meier plotter online database was used to analyze the associa-tion between the expression level of miR-146a and the prognosis of patients with breast cancer.MCF-7 cells were used to construct an ERα+breast cancer tamoxifen-resistant cell line(TAM-R),and then the cells were divided into untransfected group(TAM-R group),empty vector transfection group(mimic-NC group),and hsa-miR-146a mimic transfection group(mimic group).CCK-8 assay was used to measure cell proliferation at 0,24,48,72,and 96 hours of culture,and flow cytometry was used to measure cell apoptosis rate.The online prediction tools were used to predict the target genes of miR-146a,and dual-luciferase reporter assay was used to investigate the interaction between miR-146a and predicted target genes.Results RT-qPCR showed that the expression level of miR-146a in cancerous tissue of breast cancer patients and MCF-7 cells was significantly lower than that in the correspon-ding paracancerous tissue and MCF-10A cells(t=4.02,50.47,P＜0.05).The analysis of clinicopathological features showed that the expression level of miR-146a was significantly upregulated in Lumi-nal A-type,HER-2+,VEGF+,and ERα+breast cancer tissue(F=10.79,t=2.23-11.08,P＜0.05).In all patients with ERα+breast cancer and those receiving endocrine therapy,the patients with high miR-146a expression had a significantly lower survival rate than those with low miR-146a expression(HR=0.58,0.66,95％CI=0.41-0.84,0.41-0.89,P＜0.05).CCK-8 assay showed that the mimic group had a significantly lower absorbance value than the TAM-R and mimic-NC groups at each time point from 24-96 hours of culture(F=25.09-92.17,q=5.09-12.17,P＜0.05),and flow cytometry showed that compared with the mimic-NC group,the mimic group had a significant increase in cell apoptosis rate(F=38.24,q=5.60,P＜0.05).The results of online prediction tools screening showed that CARD10 was the potential target gene of miR-146a,and dual-luciferase reporter assay showed that the CARD10-wt+hsa-miR-146a mimic group had a significantly lower luciferase activity than the CARD10-mut+hsa-miR-146a mimic group,the CARD10-wt+miR-146a mimic negative control vector group,and the CARD10-mut+miR-146a mimic negative control vector group(F=51.93,q=4.16-5.41,P＜0.05).Conclusion The high expression of miR-146a enhances tamoxifen treatment sensitivity in ERα+breast cancer patients,thereby improving the survival rate of patients.关键词
乳腺肿瘤/微RNAs/雌激素受体α/基因表达调控/他莫昔芬/敏感性Key words
Breast neoplasms/MicroRNAs/Estrogen receptor alpha/Gene expression regulation/Tamoxifen/Sensitivity分类
医药卫生
