A KSHV microRNA Directly Targets G Protein-Coupled Receptor Kinase 2 to Promote the Migration and Invasion of Endothelial Cells by Inducing CXCR2 and Activating AKT Signaling.
A KSHV microRNA Directly Targets G Protein-Coupled Receptor Kinase 2 to Promote the Migration and Invasion of Endothelial Cells by Inducing CXCR2 and Activating AKT Signaling.
复制标题
KSHV microRNA 直接靶向 G 蛋白偶联受体激酶 2，通过诱导 CXCR2 和激活 AKT 信号传导促进内皮细胞的迁移和侵袭。
DOI：
10.1371/journal.ppat.1005171
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发表时间：
2015-09
期刊：
影响因子：
6.7
通讯作者：
Lu C
中科院分区：
文献类型：
--
作者：
Hu M;Wang C;Li W;Lu W;Bai Z;Qin D;Yan Q;Zhu J;Krueger BJ;Renne R;Gao SJ;Lu C
卡波西肉瘤（KS）是一种高度播散的血管生成性内皮细胞肿瘤，与卡波西肉瘤相关疱疹病毒（KSHV）感染有关。KSHV编码超过20种miRNAs，但它们在KSHV诱导的肿瘤扩散和转移中的作用仍然未知。在这里，我们发现miR-K12-3（miR-K3）的异位表达促进内皮细胞迁移和侵袭。生物信息学和荧光素酶报告基因分析表明，miR-K3直接靶向G蛋白偶联受体（GPCR）激酶2（GRK 2，官方基因符号ADRBK 1）。重要的是，GRK 2的过表达逆转了miR-K3对细胞迁移和侵袭的诱导。此外，趋化因子受体CXCR 2，这是负调控GRK 2，在miR-K3转导的内皮细胞上调。CXCR 2的敲低消除了miR-K3诱导的细胞迁移和侵袭。此外，GRK 2的miR-K3下调减轻了其对AKT的直接抑制作用。CXCR 2诱导和AKT从GRK 2的释放两者都是miR-K3最大化激活AKT和诱导细胞迁移和侵袭所需的。最后，从KSHV基因组中删除miR-K3消除了其对GRK 2/CXCR 2/AKT途径和KSHV诱导的迁移和侵袭的影响。我们的数据提供了一线证据，通过抑制GRK 2，miR-K3通过激活CXCR 2/AKT信号促进细胞迁移和侵袭，这可能有助于KSHV诱导的肿瘤的传播。卡波西肉瘤相关疱疹病毒（KSHV）是卡波西肉瘤（KS）的病原体。KS是一种高度播散的肿瘤，常累及内脏器官。实验上，KSHV感染诱导内皮细胞的侵袭性。KSHV编码12种前体miRNAs（pre-miRNAs），其被加工成至少25种成熟miRNAs。然而，这些miRNAs在KSHV诱导的肿瘤传播中的作用仍然未知。在这里，我们研究了KSHV编码的miR-K12-3（miR-K3）促进内皮细胞迁移和侵袭，这是肿瘤扩散的潜在机制。我们证明miR-K3通过直接靶向G蛋白偶联受体（GPCR）激酶2（GRK 2）促进细胞迁移和侵袭。此外，我们发现趋化因子受体CXCR 2，这是负调控GRK 2，其下游AKT信号正介导的miR-K3诱导的细胞迁移和侵袭。miR-K3下调GRK 2减轻了其对AKT的直接抑制作用，并且CXCR 2诱导和AKT从GRK 2释放都是miR-K3最大激活AKT和诱导细胞迁移和侵袭所必需的。这些结果表明miR-K3及其下游通路可能是治疗KSHV相关恶性肿瘤的潜在治疗靶点。
Kaposi's sarcoma (KS) is a highly disseminated angiogenic tumor of endothelial cells linked to infection by Kaposi's sarcoma-associated herpesvirus (KSHV). KSHV encodes more than two dozens of miRNAs but their roles in KSHV-induced tumor dissemination and metastasis remain unknown. Here, we found that ectopic expression of miR-K12-3 (miR-K3) promoted endothelial cell migration and invasion. Bioinformatics and luciferase reporter analyses showed that miR-K3 directly targeted G protein-coupled receptor (GPCR) kinase 2 (GRK2, official gene symbol ADRBK1). Importantly, overexpression of GRK2 reversed miR-K3 induction of cell migration and invasion. Furthermore, the chemokine receptor CXCR2, which was negatively regulated by GRK2, was upregulated in miR-K3-transduced endothelial cells. Knock down of CXCR2 abolished miR-K3-induced cell migration and invasion. Moreover, miR-K3 downregulation of GRK2 relieved its direct inhibitory effect on AKT. Both CXCR2 induction and the release of AKT from GRK2 were required for miR-K3 maximum activation of AKT and induction of cell migration and invasion. Finally, deletion of miR-K3 from the KSHV genome abrogated its effect on the GRK2/CXCR2/AKT pathway and KSHV-induced migration and invasion. Our data provide the first-line evidence that, by repressing GRK2, miR-K3 facilitates cell migration and invasion via activation of CXCR2/AKT signaling, which likely contribute to the dissemination of KSHV-induced tumors. Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS). KS is a highly disseminated tumor often involved with visceral organs. Experimentally, KSHV infection induces the invasiveness of endothelial cells. KSHV encodes twelve precursor miRNAs (pre-miRNAs), which are processed into at least 25 mature miRNAs. However, the roles of these miRNAs in KSHV-induced tumor dissemination remain unknown. Here, we investigated KSHV-encoded miR-K12-3 (miR-K3) promotion of endothelial cell migration and invasion, which are the underlying mechanisms of tumor dissemination. We demonstrated that miR-K3 promoted cell migration and invasion by directly targeting G protein-coupled receptor (GPCR) kinase 2 (GRK2). Furthermore, we found that the chemokine receptor CXCR2, which was negatively regulated by GRK2, and its downstream AKT signaling positively mediated miR-K3-induced cell migration and invasion. miR-K3 downregulation of GRK2 relieved its direct inhibitory effect on AKT, and both CXCR2 induction and the release of AKT from GRK2 were required for miR-K3 maximum activation of AKT and induction of cell migration and invasion. These results show that miR-K3 and its the downstream pathway may be potential therapeutic targets for the treatment of KSHV-associated malignancies.