miRNA-224-5p靶向JAG1抑制乳腺癌细胞自噬活性的机制研究

MiRNA-224-5p inhibits autophagy in breast cancer cells via targeting JAG1

目的探讨miRNA-224-5p靶向JAG1抑制乳腺癌细胞自噬活性的机制。方法收集2017年1月至2018年9月在台州市中心医院接受手术治疗的40例乳腺癌患者(乳腺癌组)及同期性别、年龄相匹配的40例健康体检者(健康对照组)的血清。采用实时定量逆转录-聚合酶链反应检测血清中miRNA-224-5p的表达;采用免疫印迹试验检测乳腺癌细胞MDA-MB-231中miRNA-224-5p的表达与自噬活性的关系。采用生物信息学的软件TargetScan 7.2和MiRDB预测miRNA-224-5p作用的下游靶基因,双荧光素酶报告基因实验对预测的靶基因进行验证。结果乳腺癌组血清miRNA-224-5p相对表达量为188.51±59.26,明显高于健康对照组的41.63±14.29,差异有统计学意义(P<0.05)。在MDA-MB-231细胞中,抑制miRNA-224-5p的表达后自噬活性增加。双荧光素酶报告基因实验验证JAG1为miRNA-224-5p的靶基因。结论miRNA-224-5p在乳腺癌患者血清中高表达,在MDA-MB-231细胞中miRNA-224-5p通过靶向JAG1抑制自噬活性。

Objective To investigate the effect of miRNA-224-5p on autophagy in breast cancer cells and its relation with JAG1 gene.Methods The expression of miRNA-224-5p was detected with RT-PCR in serum samples from 40 breast cancer patients and 40 age and gender-matched healthy subjects.The autophagy activity in MDA-MB-231 breast cancer cells was studied by Western blotting.Bioinformatics software(TargetScan 7.2 and MiRDB)was used to predict the downstream target gene of miRNA-224-5p,and double luciferase reporter gene experiment was used to verify the predicted target gene.Results The relative expression level of serum miRNA-224-5p in breast cancer patients was significantly higher than that in healthy controls(88.51±59.26 vs.41.63±14.29,P<0.05).By inhibiting the expression of miRNA-224-5p in MDA-MB-231 cells,autophagy activity was increased.Double luciferase reporter assay confirmed that JAG1 was the target gene of miRNA-224-5p.Conclusion The expression of miRNA-224-5p in serumof patients with breast cancer is higher than that in control.MiRNA-224-5p inhibits autophagy in MDA-MB-231 cells by targeting JAG1.