lncRNA MEG3 Suppresses the Tumorigenesis of Hemangioma by Sponging miR-494 and Regulating PTEN/ PI3K/AKT Pathway.
lncRNA MEG3 Suppresses the Tumorigenesis of Hemangioma by Sponging miR-494 and Regulating PTEN/ PI3K/AKT Pathway.
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DOI：
10.1159/000496040
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发表时间：
2018-01-01
期刊：
影响因子：
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通讯作者：
Ou, Jingmin
中科院分区：
文献类型：
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作者：
Dai, Yuxin;Wan, Yongkun;Ou, Jingmin
背景/目标：长链非编码RNA（lncRNA）的异常调控与多种肿瘤的增殖和转移有关，其中lncRNA母源表达基因3（MEG 3）在多种恶性肿瘤中被认为是肿瘤抑制基因。然而，MEG 3促进人类血管瘤（HAs）的潜在机制尚未确定。方法：采用qRT-PCR分析MEG 3和VEGF在增殖期或消退期HAs中的表达水平。采用MTT法、集落形成实验、流式细胞仪分析和皮下移植瘤模型研究MEG 3对HA成瘤的影响。通过生物信息学分析、荧光素酶报告试验、RNA免疫沉淀（RIP）试验证明MEG 3与miRNAs或其下游通路之间的相互作用。结果：增生期HA中MEG 3的表达明显低于退化期HA和正常皮肤组织，且与VEGF的表达呈负相关。MEG 3的异位表达在体外和体内抑制细胞增殖、集落形成和诱导周期阻滞，随后下调VEGF和cyclinD 1，但敲低MEG 3逆转了这些作用。MEG 3在HAs细胞中充当miR-494的“海绵”，miR-494通过调节PTEN/PI 3 K/AKT通路抵消MEG 3的抗增殖作用，并与增殖期HAs中MEG 3和PTEN的表达呈负相关。
BACKGROUND/AIMS: Dysregulation of long noncoding RNAs (lncRNAs) is associated with the proliferation and metastasis in a variety of cancers, of which lncRNA maternally expressed gene 3 (MEG3) has been indicated as a tumor suppressor in multiple malignancies. However, the underlying mechanisms by which MEG3 contributes to human hemangiomas (HAs) remain undetermined.METHODS: qRT-PCR analysis was performed to examine the expression levels of MEG3 and VEGF in proliferating or involuting phase HAs. MTT, colony formation assay, flow cytometry analysis and a subcutaneous xenograft tumor model were conducted to assess the effects of MEG3 on the HAs tumorigenesis. The interaction between MEG3 and miRNAs or their downstream pathways was evidenced by bioinformatic analysis, luciferase report assays, RNA immunoprecipitation (RIP) assay. and Western blot analysis.RESULTS: The expression of MEG3 was substantially decreased and had a negative correlation with VEGF expression in proliferating phase HAs, as compared with the involuting phase HAs and normal skin tissues. Ectopic expression of MEG3 suppressed cell proliferation, colony formation and induced cycle arrest in vitro and in vivo, followed by the downregulation of VEGF and cyclinD1, but knockdown of MEG3 reversed these effects. Furthermore, MEG3 was verified to act as a sponge of miR-494 in HAs cells, and miR-494 counteracted MEG3-caused anti-proliferative effects by regulating PTEN/PI3K/AKT pathway, and exhibited the negative correlation with MEG3 and PTEN expression in proliferating phase HAs.CONCLUSION: Our findings suggested that lncRNA MEG3 inhibited HAs tumorigenesis by sponging miR-494 and regulating PTEN/PI3K/AKT pathway.