Fengxian District Center Hospital Graduate Student Training Base, Jinzhou Medical University, Shanghai, China.
Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
Acta Biochim Biophys Sin (Shanghai). 2018 Jul 1;50(7):693-700. doi: 10.1093/abbs/gmy050.
Breast cancer is one of the most common malignancies in women. ERα, PR, and HER2 triple negative breast cancer (TNBC) is the current research focus because of the lack of effective targeted therapies. In our study, lentivirus systems were used to overexpress EZH2 and miR-1301 in TNBC cell lines. Western blot analysis and RT-qPCR were used to detect the protein and microRNA levels. The TCGA and Kaplan Meier plotter databases were used to analyze the EZH2 and miR-1301 expression levels in breast cancer. The effect of miR-1301 overexpression on cell proliferation, migration and colony formation were determined by using the sulforhodamine B (SRB) assay, wound healing assay and colony formation assay, respectively. Furthermore, an xenograft mouse model was used to investigate the function of miR-1301 overexpression in vivo. Finally, dual luciferase reporter assay was used to verify the binding site of EZH2 and miR-1301. We found that EZH2 induced the expression of miR-1301 in two TNBC cell lines, HCC1937 and HCC1806. Overexpression of miR-1301 suppressed TNBC cell proliferation, migration and colony formation, as well as the xenograft tumor growth in immunodeficient mice. Interestingly, miR-1301 inhibited the expression of EZH2 by binding to the 3'-UTR of EZH2 gene. These data suggest that EZH2 induces the expression of miR-1301 as a negative feedback control mechanism in TNBC.
乳腺癌是女性最常见的恶性肿瘤之一。由于缺乏有效的靶向治疗方法，ERα、PR 和 HER2 三阴性乳腺癌（TNBC）是目前的研究热点。在我们的研究中，使用慢病毒系统在 TNBC 细胞系中过表达 EZH2 和 miR-1301。使用 Western blot 分析和 RT-qPCR 检测蛋白和 microRNA 水平。使用 TCGA 和 Kaplan Meier plotter 数据库分析乳腺癌中 EZH2 和 miR-1301 的表达水平。使用磺酰罗丹明 B（SRB）测定、划痕愈合测定和集落形成测定分别确定 miR-1301 过表达对细胞增殖、迁移和集落形成的影响。此外，还使用异种移植小鼠模型在体内研究 miR-1301 过表达的功能。最后，使用双荧光素酶报告基因测定验证 EZH2 和 miR-1301 的结合位点。我们发现 EZH2 在两种 TNBC 细胞系 HCC1937 和 HCC1806 中诱导 miR-1301 的表达。miR-1301 的过表达抑制了 TNBC 细胞的增殖、迁移和集落形成，以及免疫缺陷小鼠中的异种移植肿瘤生长。有趣的是，miR-1301 通过结合 EZH2 基因的 3'-UTR 抑制 EZH2 的表达。这些数据表明，EZH2 通过作为 TNBC 的负反馈控制机制诱导 miR-1301 的表达。
