MiR-410 Acts as a Tumor Suppressor in Estrogen Receptor-Positive Breast Cancer Cells by Directly Targeting ERLIN2 via the ERS Pathway
MiR-410 Acts as a Tumor Suppressor in Estrogen Receptor-Positive Breast Cancer Cells by Directly Targeting ERLIN2 via the ERS Pathway
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MiR-410 通过 ERS 途径直接靶向 ERLIN2，在雌激素受体阳性乳腺癌细胞中充当肿瘤抑制剂
DOI：
10.1159/000491777
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发表时间：
2018-01-01
影响因子：
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通讯作者：
Wang, Guohui
中科院分区：
文献类型：
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作者：
Wu, Hewen;Li, Junli;Wang, Guohui
背景/目的：据报道，内质网脂筏相关蛋白2 （ERLIN2）在人乳腺癌细胞中过表达，并在细胞增殖中起重要作用。MicroRNAs （miRNAs）作为基因表达的转录后调控因子，参与包括乳腺癌在内的多种恶性肿瘤的发展。然而，ERLIN2在人类乳腺癌中异常表达的分子机制仍然知之甚少。方法：Real-time PCR检测MiR-410表达水平，Western blot、Real-time PCR及免疫组化染色检测ERLIN2表达水平。使用荧光素酶测定miR-410对ERLIN2 3'UTR强度的影响。采用CCK-8和集落形成法分析细胞增殖，Annexin V-PE/7-AAD试剂盒检测细胞凋亡。采用Transwell迁移和侵袭试验检测细胞迁移和侵袭。采用甲基化特异性PCR检测miR-410启动子是否被去甲基化。结果：在本研究中，我们验证了ERLIN2是miR-410的直接靶点，miR-410在转录后水平抑制ERLIN2的表达。重要的是，miR-410对ERLIN2的调控依赖于雌激素受体（ER）。功能研究表明，miR-410抑制乳腺癌细胞的增殖、迁移和侵袭，但促进细胞凋亡。然而，抑制miR-410会产生相反的效果。异种移植裸鼠模型进一步证实miR-410抑制乳腺肿瘤生长。此外，miR-410调节上皮-间质转化（EMT）相关基因的表达水平。ERLIN2敲低抑制细胞增殖、迁移和侵袭，抑制EMT。ERLIN2过表达可以恢复被miR-410抑制的细胞增殖、迁移和侵袭。此外，我们的数据表明，miR-410抑制抑制内质网应激（ERS）相关基因的表达，而ERLIN2敲低消除了miR-410抑制剂的作用。最后，我们发现miR-410在人er阳性乳腺癌组织中下调，与ERLIN2呈负相关。我们进一步证明miR-410在乳腺癌中的下调可能是由于其启动子的高甲基化。结论：我们的研究表明，miR-410在ER阳性乳腺癌中通过直接下调ERLIN2抑制细胞生长、迁移和侵袭，起到抑瘤作用。我们的研究还表明，miR-410可能作为ER阳性乳腺癌患者的潜在治疗靶点。
Background/Aims: Endoplasmic reticulum lipid raft-associated 2 (ERLIN2) is reported to be overexpressed in human breast cancer cells and plays an important role in cell proliferation. MicroRNAs (miRNAs) act as post-transcriptional regulators of gene expression and are involved in the development of multiple malignancies, including breast cancer. However, the molecular mechanism of the aberrant ERLIN2 expression in human breast cancer remains poorly understood. Methods: MiR-410 expression level was analyzed using Real-time PCR, and ERLIN2 expression was analyzed using Western blot, Real-time PCR and immunohistochemical staining. The effect of miR-410 on ERLIN2 3’UTR intensity was performed using a luciferase assay. Cell proliferation was analyzed using CCK-8 and colony formation assay, together with an Annexin V-PE/7-AAD kit for cell apoptosis assay. Cell migration and invasion was detected using a Transwell migration and invasion assay. Methylation specific PCR was used to examine whether miR-410 promoter was demethylated. Results: In this study, we validated that ERLIN2 was a direct target of miR-410 and miR-410 suppressed ERLIN2 expression at the post-transcriptional level. Importantly, the regulation of ERLIN2 by miR-410 was estrogen receptor (ER) dependent. Functional studies demonstrated that miR-410 inhibited breast cancer cell proliferation, migration and invasion, but promoted cell apoptosis. However, inhibition of miR-410 resulted in opposite effects. A xenograft nude mouse model further confirmed that miR-410 suppressed breast tumor growth. In addition, miR-410 modulated the expression levels of epithelial-mesenchymal transition (EMT)-related genes. ERLIN2 knockdown suppressed cell proliferation, migration and invasion, as well as EMT. ERLIN2 overexpression can restore the cell proliferation, migration and invasion that were inhibited by miR-410. Furthermore, our data demonstrated that miR-410 inhibition suppressed the expression of endoplasmic reticulum-stress (ERS)-related genes, while ERLIN2 knockdown abrogated the effects of miR-410 inhibitor. Finally, we showed that miR-410 was downregulated in human ER-positive breast cancer tissues, inversely correlated with ERLIN2. We further demonstrated the downregulation of miR-410 in breast cancer might be due to the hypermethylation of its promoter. Conclusions: Our study indicates that miR-410 suppresses cell growth, migration and invasion by directly downregulating ERLIN2 in ER positive breast cancer, acting as a tumor suppressor. Our study also suggests that miR-410 may serve as a potential therapeutic target for patients with ER positive breast cancer.