TEAD4 modulated LncRNA MNX1-AS1 contributes to gastric cancer progression partly through suppressing BTG2 and activating BCL2
TEAD4 modulated LncRNA MNX1-AS1 contributes to gastric cancer progression partly through suppressing BTG2 and activating BCL2
复制标题
TEAD4调节的LncRNA MNX1-AS1部分通过抑制BTG2和激活BCL2促进胃癌进展
DOI：
10.1186/s12943-019-1104-1
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发表时间：
2020-01-10
期刊：
影响因子：
37.3
通讯作者：
Shu, Yongqian
中科院分区：
文献类型：
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作者：
Shuai, You;Ma, Zhonghua;Shu, Yongqian
背景胃癌（GC）是全球第三大癌症相关死亡原因。长链非编码RNA（lncRNA）在胃癌等恶性肿瘤中表达异常，探讨其表达的调控机制是一个有吸引力的研究领域。然而，这些分子机制需要进一步澄清，特别是上游mechanism.MethodsLncRNA MNX1-AS1在GC组织样品中的表达进行了研究，通过微阵列分析，并进一步确定在一个队列的GC组织通过定量逆转录聚合酶链反应（qRT-PCR）测定。通过细胞增殖和流式细胞术检测MNX1-AS1在胃癌细胞增殖、细胞周期调控和凋亡中的作用。用Transwell法检测MNX1-AS1对胃癌细胞迁移和侵袭的影响。建立异种移植肿瘤模型以验证MNX1-AS1对体内肿瘤发生的作用。通过ChIP和荧光素酶报告基因分析探讨了MNX1-AS1的TEAD 4上游调控机制。结果MNX1-AS1在胃癌组织和细胞中表达明显上调，且异位表达预示着胃癌患者预后不良。MNX1-AS1过表达可明显促进胃癌细胞增殖、迁移和侵袭，而MNX1-AS1过表达则可明显抑制胃癌细胞增殖、迁移和侵袭。与体外结果一致，MNX1-AS1耗竭有效抑制体内异种移植肿瘤的生长。TEAD 4直接与MNX1-AS 1的启动子区结合，刺激MNX1-AS 1的转录。此外，MNX1-AS1还能海绵化miR-6785 - 5p，上调胃癌细胞BCL 2的表达。同时，MNX1-AS1通过募集多梳抑制复合物2到BTG2启动子区域来抑制BTG2的转录。结论我们的研究结果表明，MNX1-AS1可以作为胃癌患者的预后指标，TEAD 4激活的MNX1-AS1可以通过EZH2/BTG2和miR-6785 - 5p/BCL 2轴促进胃癌的进展。暗示其为治疗GC的新的和有效的靶点。
BackgroundGastric cancer (GC) is the third leading cause of cancer-related mortality globally. Long noncoding RNAs (lncRNAs) are dysregulated in obvious malignancies including GC and exploring the regulatory mechanisms underlying their expression is an attractive research area. However, these molecular mechanisms require further clarification, especially upstream mechanisms.MethodsLncRNA MNX1-AS1 expression in GC tissue samples was investigated via microarray analysis and further determined in a cohort of GC tissues via quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Cell proliferation and flow cytometry assays were performed to confirm the roles of MNX1-AS1 in GC proliferation, cell cycle regulation, and apoptosis. The influence of MNX1-AS1 on GC cell migration and invasion was explored with Transwell assays. A xenograft tumour model was established to verify the effects of MNX1-AS1 on in vivo tumourigenesis. The TEAD4-involved upstream regulatory mechanism of MNX1-AS1 was explored through ChIP and luciferase reporter assays. The mechanistic model of MNX1-AS1 in regulating gene expression was further detected by subcellular fractionation, FISH, RIP, ChIP and luciferase reporter assays.ResultsIt was found that MNX1-AS1 displayed obvious upregulation in GC tissue samples and cell lines, and ectopic expression of MNX1-AS1 predicted poor clinical outcomes for patients with GC. Overexpressed MNX1-AS1 expression promoted proliferation, migration and invasion of GC cells markedly, whereas decreased MNX1-AS1 expression elicited the opposite effects. Consistent with the in vitro results, MNX1-AS1 depletion effectively inhibited the growth of xenograft tumour in vivo. Mechanistically, TEAD4 directly bound the promoter region of MNX1-AS1 and stimulated the transcription of MNX1-AS1. Furthermore, MNX1-AS1 can sponge miR-6785-5p to upregulate the expression of BCL2 in GC cells. Meanwhile, MNX1-AS1 suppressed the transcription of BTG2 by recruiting polycomb repressive complex 2 to BTG2 promoter regions.ConclusionsOur findings demonstrate that MNX1-AS1 may be able to serve as a prognostic indicator in GC patients and that TEAD4-activatd MNX1-AS1 can promote GC progression through EZH2/BTG2 and miR-6785-5p/BCL2 axes, implicating it as a novel and potent target for the treatment of GC.