RNA N6-Methyladenosine Methyltransferase METTL3 Facilitates Colorectal Cancer by Activating the m6A-GLUT1-mTORC1 Axis and Is a Therapeutic Target
RNA N6-Methyladenosine Methyltransferase METTL3 Facilitates Colorectal Cancer by Activating the m6A-GLUT1-mTORC1 Axis and Is a Therapeutic Target
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DOI：
10.1053/j.gastro.2020.11.013
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发表时间：
2021-03-09
期刊：
影响因子：
29.4
通讯作者：
Yu, Jun
中科院分区：
文献类型：
--
作者：
Chen, Huarong;Gao, Shanshan;Yu, Jun
背景与目的：RNA N-6-甲基腺苷（m（6）A）修饰是近年来出现的一种新的肿瘤进展调控机制。我们的目的是探讨m（6）A调节酶胃L3在结直肠癌（CRC）发病机制中的作用及其作为治疗靶点的潜力。方法：在多个人类结直肠癌队列中研究胃L3的表达和临床意义。通过整合m（6）A测序、RNA测序和核糖体分析研究了胃L3在CRC中的潜在机制。在CRC细胞系、患者来源的CRC类器官和Mettl 3敲除小鼠模型中阐明了靶向胃L3在CRC治疗中的功效。研究结果：使用靶向成簇规则间隔短回文重复序列（CRISPR）/Cas9缺失筛选，我们将胃L3鉴定为CRC中最重要的m（6）A调节酶。在来自2个独立队列的原发性CRC中，62.2%（79/127）和88.0%（44/50）的胃癌L3过表达。在结直肠癌患者中，胃L3高表达预示着较差的生存率（n = 374，P <0.01）。在功能上，沉默胃L3抑制CRC细胞、人源性原发性CRC类器官和Mettl 3敲除小鼠模型中的肿瘤发生。我们通过聚焦结构域的CRISPR筛选和诱变分析在CRC细胞中发现了新的功能性m（6）A甲基转移酶结构域。从机制上讲，通过整合m6 A测序、RNA测序、核糖体测序和功能验证鉴定，胃L3直接诱导m（6）A-GLUT 1-mTORC 1轴。胃L3以m（6）A依赖性方式诱导GLUT 1翻译，随后促进葡萄糖摄取和乳酸产生，导致mTORC 1信号传导激活和CRC发展。此外，mTORC 1的抑制增强了CRC患者源性类器官和MTORC 3转基因小鼠模型中MTORC 3沉默的抗癌作用。结论：胃L3通过激活m（6）A-GLUT 1-mTORC 1轴促进CRC的发生。胃癌L3是一个很有前途的治疗CRC的治疗靶点。
BACKGROUND & AIMS: RNA N-6-methyladenosine (m(6)A) modification has recently emerged as a new regulatory mechanism in cancer progression. We aimed to explore the role of the m(6)A regulatory enzyme METTL3 in colorectal cancer (CRC) pathogenesis and its potential as a therapeutic target. METHODS: The expression and clinical implication of METTL3 were investigated in multiple human CRC cohorts. The underlying mechanisms of METTL3 in CRC were investigated by integrative m(6)A sequencing, RNA sequencing, and ribosome profiling analyses. The efficacy of targeting METTL3 in CRC treatment was elucidated in CRC cell lines, patient-derived CRC organoids, and Mettl3-knockout mouse models. RESULTS: Using targeted clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 dropout screening, we identified METTL3 as the top essential m(6)A regulatory enzyme in CRC. METTL3 was overexpressed in 62.2% (79/127) and 88.0% (44/50) of primary CRCs from 2 independent cohorts. High METTL3 expression predicted poor survival in patients with CRC (n = 374, P < .01). Functionally, silencing METTL3 suppressed tumorigenesis in CRC cells, human-derived primary CRC organoids, and Mettl3-knockout mouse models. We discovered the novel functional m(6) A methyltransferase domain of METTL3 in CRC cells by domain-focused CRISPR screening and mutagenesis assays. Mechanistically, METTL3 directly induced the m(6)A-GLUT1-mTORC1 axis as identified by integrated m6A sequencing, RNA sequencing, ribosome sequencing, and functional validation. METTL3 induced GLUT1 translation in an m(6)A-dependent manner, which subsequently promoted glucose uptake and lactate production, leading to the activation of mTORC1 signaling and CRC development. Furthermore, inhibition of mTORC1 potentiated the anticancer effect of METTL3 silencing in CRC patient-derived organoids and METTL3 transgenic mouse models. CONCLUSIONS: METTL3 promotes CRC by activating the m(6)A-GLUT1-mTORC1 axis. METTL3 is a promising therapeutic target for the treatment of CRC.