SOX2 regulates multiple malignant processes of breast cancer development through the SOX2/miR-181a-5p, miR-30e-5p/TUSC3 axis.
SOX2 regulates multiple malignant processes of breast cancer development through the SOX2/miR-181a-5p, miR-30e-5p/TUSC3 axis.
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DOI：
10.1186/s12943-017-0632-9
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发表时间：
2017-03-14
期刊：
影响因子：
37.3
通讯作者：
Lan X
中科院分区：
文献类型：
--
作者：
Liu K;Xie F;Gao A;Zhang R;Zhang L;Xiao Z;Hu Q;Huang W;Huang Q;Lin B;Zhu J;Wang H;Que J;Lan X
SOX2蛋白的高水平与乳腺癌的扩散增加有关。然而，其潜在的分子机制尚不完全清楚。在这项研究中，我们通过多种体内外检测方法来研究SOX2在乳腺癌转移中的作用，包括细胞培养、shRNA介导的基因敲除、伤口愈合、克隆形成、Transwell小室、异种移植和尾静脉注射。采用蛋白质印迹、免疫染色、基因芯片和实时荧光定量聚合酶链式反应等方法检测细胞内蛋白质和miRNA水平的变化。用荧光素酶活性测定法评价TUSC3作为miR-181a-5p和miR-30e-5p靶点的活性，并用Kaplan-Meier分析进行临床生存相关性分析。我们发现了一种新的途径，涉及SOX2调节microRNAs来控制乳腺癌细胞的增殖和迁移。ShRNA介导的SOX2基因敲除可抑制乳腺癌细胞的扩张和迁移。更重要的是，我们发现这些变化伴随着两个microRNAs的水平显著降低，miR-181a-5p和miR-30e-5p。这两个microRNAs的过表达导致乳腺癌细胞中肿瘤抑制候选基因3(TUSC3)的蛋白水平降低；TUSC3的3‘-UTR区潜在结合位点的突变消除了microRNAs的抑制作用。我们进一步发现，上调TUSC3的表达导致乳腺癌细胞的增殖和迁移减少。在乳腺癌标本中，TUSC3蛋白水平与SOX2蛋白水平呈负相关。综上所述，我们的工作揭示了一个新的SOX2介导的调节轴，它在乳腺癌细胞的增殖、迁移和侵袭性中发挥关键作用。靶向这一轴可能在乳腺癌的治疗中提供有益的效果。本文的在线版本(doi：10.1186/s12943-0170632-9)包含补充材料，授权用户可以使用。
High levels of SOX2 protein are correlated with increased dissemination of breast cancer. However, the underlying molecular mechanisms are not fully understood. In this study we investigate the role of SOX2 in breast cancer metastasis using multiple in vitro and in vivo assays including cell culture, shRNA-mediated knockdown, wound healing, colony formation, transwell chamber, xenograft and tail vein injection. Moreover, western blot, immunostaining, microarray and real-time PCR were used to determine the change of protein and miRNA levels. Luciferase assays were also used to evaluate activity which TUSC3 is a target of miR-181a-5p and miR-30e-5p, and the clinical survival relevance was analyzed by Kaplan-Meier analysis. We identified a novel pathway involving SOX2 regulation of microRNAs to control the proliferation and migration of breast cancer cells. shRNA-mediated knockdown of SOX2 inhibits breast cancer cell expansion and migration. More importantly, we found that these changes are accompanied by significant reduction in the levels of two microRNAs, miR-181a-5p and miR-30e-5p. Overexpression of these two microRNAs leads to reduced protein levels of Tumor Suppressor Candidate 3 (TUSC3) in breast cancer cells; mutations of the potential binding sites in the 3’-UTR of TUSC3 abrogate the inhibitory effects of the microRNAs. We further found that upregulation of TUSC3 expression leads to reduced proliferation and migration of breast cancer cells. In human breast cancer samples the levels of TUSC3 protein are inversely correlated with those of SOX2 protein. Taken together, our work reveals a novel SOX2-mediated regulatory axis that plays critical roles in the proliferation, migration and invasiveness of breast cancer cells. Targeting this axis may provide beneficial effect in the treatment of breast cancer. The online version of this article (doi:10.1186/s12943-017-0632-9) contains supplementary material, which is available to authorized users.