METTL14 suppresses proliferation and metastasis of colorectal cancer by down-regulating oncogenic long non-coding RNA XIST
METTL14 suppresses proliferation and metastasis of colorectal cancer by down-regulating oncogenic long non-coding RNA XIST
复制标题
METTL14通过下调致癌长非编码RNA XIST抑制结直肠癌的增殖和转移
DOI：
10.1186/s12943-020-1146-4
复制
发表时间：
2020-02-28
期刊：
影响因子：
37.3
通讯作者：
Zheng, Minhua
中科院分区：
文献类型：
--
作者：
Yang, Xiao;Zhang, Sen;Zheng, Minhua
背景
N6-甲基腺苷（m6A）是真核细胞中最普遍的RNA表观遗传调控。然而，对结直肠癌（CRC）中m6A的了解非常有限。我们设计了这项研究，以探讨m6A在CRC中的作用。
方法
从公共数据库和组织芯片中提取胃L14的表达水平，以研究胃L14在结直肠癌中的临床相关性。接下来，使用功能获得/丧失实验来确定胃L14在CRC进展中的作用。此外，转录组测序（RNA-seq）被用来筛选潜在的目标，胃L14。通过RNA pull-down和RNA免疫沉淀（RIP）试验验证了胃L14与假定靶点之间的特异性结合。并通过拯救实验和甲基化RNA免疫沉淀（Me-RIP）等方法探讨其作用机制。
结果
在临床上，胃L14的丢失与结直肠癌患者的不良预后相关。在功能上，敲低胃L14显著增强了CRC细胞的体外增殖和侵袭能力，并促进了体内致瘤性和转移。在机械上，RNA-seq和Me-RIP将lncRNA XIST鉴定为胃L14的下游靶标。敲除胃L14基本上消除了XIST的m6A水平，并增强了XIST表达。此外，我们发现m6A-甲基化XIST被m6A阅读蛋白YTHDF 2识别，以介导XIST的降解。结论：XIST与胃L14、YTHDF 2在大肠癌组织中的表达呈负相关。
结论
我们的发现突出了胃L14在CRC中的功能和预后价值，并扩展了对RNA表观遗传学在癌症生物学中重要性的理解。
Background
N6-methyladenosine (m6A) is the most prevalent RNA epigenetic regulation in eukaryotic cells. However, understanding of m6A in colorectal cancer (CRC) is very limited. We designed this study to investigate the role of m6A in CRC.
Methods
Expression level of METTL14 was extracted from public database and tissue array to investigate the clinical relevance of METTL14 in CRC. Next, gain/loss of function experiment was used to define the role of METTL14 in the progression of CRC. Moreover, transcriptomic sequencing (RNA-seq) was applied to screen the potential targets of METTL14. The specific binding between METTL14 and presumed target was verified by RNA pull-down and RNA immunoprecipitation (RIP) assay. Furthermore, rescue experiment and methylated RNA immunoprecipitation (Me-RIP) were performed to uncover the mechanism.
Results
Clinically, loss of METTL14 correlated with unfavorable prognosis of CRC patients. Functionally, knockdown of METTL14 drastically enhanced proliferative and invasive ability of CRC cells in vitro and promoted tumorigenicity and metastasis in vivo. Mechanically, RNA-seq and Me-RIP identified lncRNA XIST as the downstream target of METTL14. Knockdown of METTL14 substantially abolished m6A level of XIST and augmented XIST expression. Moreover, we found that m6A-methylated XIST was recognized by YTHDF2, a m6A reader protein, to mediate the degradation of XIST. Consistently, XIST expression negatively correlated with METTL14 and YTHDF2 in CRC tissues.
Conclusion
Our findings highlight the function and prognostic value of METTL14 in CRC and extend the understanding of the importance of RNA epigenetics in cancer biology.