Dicer Knockdown Inhibits Endothelial Cell Tumor Growth via MicroRNA 21a-3p Targeting of Nox-4
Dicer Knockdown Inhibits Endothelial Cell Tumor Growth via MicroRNA 21a-3p Targeting of Nox-4
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DOI：
10.1074/jbc.m113.519264
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发表时间：
2014-03-28
影响因子：
4.8
通讯作者：
Sen, Chandan K.
中科院分区：
文献类型：
--
作者：
Gordillo, Gayle M.;Biswas, Ayan;Sen, Chandan K.
背景：内皮细胞肿瘤是婴儿最常见的软组织肿瘤。结果：在体内，Dicer敲低上调靶向nox-4 mRNA的miR-21a-3p，阻止内皮细胞肿瘤的形成。结论：一氧化氮-4沉默抑制内皮细胞肿瘤的形成。Dicer敲低上调miR 21a-3p，其靶向Nox-4 3-UTR。意义：报告了内皮细胞肿瘤形成的新驱动因素。MicroRNAs （miR）作为生物标志物和潜在的肿瘤治疗靶点正在逐渐兴起。内皮细胞肿瘤是婴儿最常见的软组织肿瘤，miR在其生长调控中的作用尚不清楚。通过验证的小鼠内皮细胞（EOMA）肿瘤模型，研究人员证实了转录后基因沉默dicer（将pre-miR转化为成熟miR的酶）可以在体内阻止肿瘤的形成。注射了转染了对照shRNA的EOMA细胞的8只小鼠中有8只形成了肿瘤，而注射了转染了肿瘤shRNA的EOMA细胞的10只小鼠中只有4只形成了肿瘤。dicer shRNA组形成的肿瘤明显小于对照组。这种对dicer敲低的反应是通过上调靶向nox-4 3-UTR的miR 21a-3p活性介导的。用miR21a-3p模拟物和荧光素酶报告质粒转染EOMA细胞，这些质粒含有完整的ox-4 3-UTR或含有所提出的3-UTR miR21a-3p结合位点突变的质粒。与位点突变载体相比，完整载体的平均荧光素酶活性降低了85% （p < 0.01）。一氧化氮-4活性减弱导致细胞过氧化氢产生减少，氧化诱导的单核细胞化学引诱蛋白-1的产生减少，我们之前已经证明这是内皮细胞肿瘤形成所必需的。这些发现首次证明了dicer和microRNA在促进内皮细胞肿瘤生长中的重要作用。
Background: Endothelial cell tumors are the most common soft tissue tumor in infants. Results: Dicer knockdown up-regulated miR-21a-3p that targeted nox-4 mRNA preventing endothelial cell tumor formation in vivo. Conclusion: Nox-4 silencing inhibits endothelial cell tumor formation. Dicer knockdown up-regulates miR 21a-3p, which targets the Nox-4 3-UTR. Significance: Novel drivers of endothelial cell tumor formation are reported.MicroRNAs (miR) are emerging as biomarkers and potential therapeutic targets in tumor management. Endothelial cell tumors are the most common soft tissue tumors in infants, yet little is known about the significance of miR in regulating their growth. A validated mouse endothelial cell (EOMA) tumor model was used to demonstrate that post-transcriptional gene silencing of dicer, the enzyme that converts pre-miR to mature miR, can prevent tumor formation in vivo. Tumors were formed in eight of eight mice injected with EOMA cells transfected with control shRNA but formed in only four of ten mice injected with EOMA cells transfected with dicer shRNA. Tumors that formed in the dicer shRNA group were significantly smaller than tumors in the control group. This response to dicer knockdown was mediated by up-regulated miR 21a-3p activity targeting the nox-4 3-UTR. EOMA cells were transfected with miR 21a-3p mimic and luciferase reporter plasmids containing either intact nox-4 3-UTR or with mutation of the proposed 3-UTR miR21a-3p binding sites. Mean luciferase activity was decreased by 85% in the intact compared with the site mutated vectors (p < 0.01). Attenuated Nox-4 activity resulted in decreased cellular hydrogen peroxide production and decreased production of oxidant-inducible monocyte chemoattractant protein-1, which we have previously shown to be critically required for endothelial cell tumor formation. These findings provide the first evidence establishing the significance of dicer and microRNA in promoting endothelial cell tumor growth in vivo.