miRNA-558 promotes tumorigenesis and aggressiveness of neuroblastoma cells through activating the transcription of heparanase
miRNA-558 promotes tumorigenesis and aggressiveness of neuroblastoma cells through activating the transcription of heparanase
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miRNA-558 通过激活乙酰肝素酶的转录来促进神经母细胞瘤细胞的肿瘤发生和侵袭性。
DOI：
10.1093/hmg/ddv018
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发表时间：
2015-05-01
影响因子：
3.5
通讯作者：
Tong, Qiangsong
中科院分区：
文献类型：
--
作者：
Qu, Hongxia;Zheng, Liduan;Tong, Qiangsong
乙酰肝素酶（HPSE）是一种内源性内切糖苷酶，可降解硫酸乙酰肝素蛋白多糖，促进肿瘤生长、侵袭、转移和血管生成。我们以前的研究表明HPSE在神经母细胞瘤（NB）中高度表达，NB是儿童时期最常见的颅外实体瘤。然而，基本的监管机制在很大程度上仍然未知。在这项研究中，我们确定了HPSE启动子内microRNA-558（miR-558）的一个结合位点。在NB组织和细胞系中，miR-558表达上调，且与HPSE表达呈正相关。功能获得和丧失研究表明，miR-558促进NB细胞系中HPSE及其下游基因血管内皮生长因子的转录和蛋白水平。此外，miR-558增强HPSE的启动子活性，并且这些作用通过miR-558结合位点的突变而消除。在机制上，miR-558以Argonaute 1依赖性方式诱导NB细胞中HPSE启动子上活性表观遗传标记和RNA聚合酶II的富集，这通过抑制miR-558-启动子相互作用而被消除。内源性miR-558的敲低在体外和体内降低NB细胞的生长、侵袭、转移和血管生成。相反，miR-558过表达可促进SH-SY 5 Y和SK-N-SH细胞的生长、侵袭、转移和血管生成。HPSE表达的恢复阻止了NB细胞由miR-558的敲低或过表达诱导的这些生物学特征的变化。这些数据表明，miR-558通过启动子内的结合位点诱导HPSE的转录激活，从而促进NB的肿瘤发生和侵袭性。
Heparanase (HPSE) is the endogenous endoglycosidase that degrades heparan sulfate proteoglycans and promotes the tumor growth, invasion, metastasis and angiogenesis. Our previous studies have shown that HPSE is highly expressed in neuroblastoma (NB), the most common extracranial solid tumor in childhood. However, the underlying regulatory mechanisms remain largely unknown. In this study, we identified one binding site of microRNA-558 (miR-558) within the HPSE promoter. In NB tissues and cell lines, miR-558 was up-regulated and positively correlated with HPSE expression. Gain-and loss-of-function studies demonstrated that miR-558 facilitated the transcript and protein levels of HPSE and its downstream gene, vascular endothelial growth factor, in NB cell lines. In addition, miR-558 enhanced the promoter activities of HPSE, and these effects were abolished by the mutation of the miR-558-binding site. Mechanistically, miR-558 induced the enrichment of the active epigenetic marker and RNA polymerase II on the HPSE promoter in NB cells in an Argonaute 1-dependent manner, which was abolished by repressing the miR-558-promoter interaction. Knockdown of endogenous miR-558 decreased the growth, invasion, metastasis and angiogenesis of NB cells in vitro and in vivo. In contrast, over-expression of miR-558 promoted the growth, invasion, metastasis and angiogenesis of SH-SY5Y and SK-N-SH cells. Restoration of HPSE expression prevented the NB cells from changes in these biological features induced by knockdown or over-expression of miR-558. These data indicate that miR-558 induces the transcriptional activation of HPSE via the binding site within promoter, thus facilitating the tumorigenesis and aggressiveness of NB.