Methylation-mediated silencing of miR-133a-3p promotes breast cancer cell migration and stemness via miR-133a-3p/MAML1/DNMT3A positive feedback loop
Methylation-mediated silencing of miR-133a-3p promotes breast cancer cell migration and stemness via miR-133a-3p/MAML1/DNMT3A positive feedback loop
复制标题
甲基化介导的 miR-133a-3p 沉默通过 miR-133a-3p/MAML1/DNMT3A 正反馈环促进乳腺癌细胞迁移和干性。
DOI：
10.1186/s13046-019-1400-z
复制
发表时间：
2019-10-28
影响因子：
11.3
通讯作者：
Pan, Yi
中科院分区：
文献类型：
--
作者：
Shi, Wanyue;Tang, Tingting;Pan, Yi
背景资料：最近发现miR-133 a-3 p在包括乳腺癌在内的各种人类恶性肿瘤中下调，并且降低的miR-133 a-3 p水平与乳腺癌细胞生长和侵袭显著相关。方法：采用qRT-PCR方法检测miR-133 a-3 p在乳腺癌组织和细胞系中的表达。亚硫酸氢盐测序用于检测miR-133 a-3 p启动子的甲基化程度。通过细胞增殖实验、transwell实验、流式细胞术和western blotting检测miR-133 a-3 p对乳腺癌的体外作用。采用生物信息学分析、双荧光素酶法和RIP法检测miR-133 a-3 p与MAML 1的相互作用。结果：我们证实miR-133 a-3 p在乳腺癌细胞系和组织中通过DNA高甲基化而沉默，这预示着乳腺癌患者的预后不良，并且miR-133 a-3 p表达降低导致乳腺癌细胞在体外的迁移、侵袭、增殖和干细胞性显著增加。已证实MAML 1是miR-133 a-3 p调控乳腺癌转移的靶点。结论：在乳腺癌细胞中，miR-133 a-3 p/MAML 1/DNMT 3A正反馈环可能成为乳腺癌治疗的新靶点。
Background: miR-133a-3p has been recently discovered to be down-regulated in various human malignancies, including breast cancer, and reduced miR-133a-3p levels have been significantly associated with breast cancer cell growth and invasion. However, the regulatory mechanisms leading to abnormal expression of miR-133a-3p in breast cancer remain obscure.Methods: qRT-PCR was applied to detect the expression of miR-133a-3p in breast cancer tissues and cell lines. Bisulfite sequencing was used to detect the degree of methylation of the miR-133a-3p promoter. The effects of miR-133a-3p on breast cancer in vitro were examined by cell proliferation assay, transwell assay, flow cytometry, and western blotting. Bioinformatic analysis, dual-luciferase assay and RIP assay were employed to identify the interaction between miR-133a-3p and MAML1. A xenograft model was used to show the metastasis of breast cancer cells.Results: We confirmed that miR-133a-3p was silenced by DNA hypermethylation in breast cancer cell lines and tissues, which predicted poor prognosis in breast cancer patients, and reducing miR-133a-3p expression led to a significant increase in the migration, invasion, proliferation, and stemness of breast cancer cells in vitro. Mastermind-like transcriptional coactivator 1 (MAML1) was confirmed to be a target of miR-133a-3p involved in regulating breast cancer metastasis both in vitro and in vivo. Moreover, a series of investigations indicated that MAML1 initiated a positive feedback loop, which could up-regulate DNA methyltransferase 3A (DNMT3A) to promote hypermethylation of the miR-133a-3p promoter.Conclusion: Taken together, our findings revealed a novel miR-133a-3p/MAML1/DNMT3A positive feedback loop in breast cancer cells, which may become a potential therapeutic target for breast cancer.