Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, 20025, People's Republic of China.
Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, 20025, People's Republic of China.
Mol Cancer. 2019 Nov 14;18(1):161. doi: 10.1186/s12943-019-1088-x.
Dynamic N-methyladenosine (mA) RNA modification generated and erased by N-methyltransferases and demethylases regulates gene expression, alternative splicing and cell fate. Ocular melanoma, comprising uveal melanoma (UM) and conjunctival melanoma (CM), is the most common primary eye tumor in adults and the 2nd most common melanoma. However, the functional role of mA modification in ocular melanoma remains unclear.
mA assays and survival analysis were used to explore decreased global mA levels, indicating a late stage of ocular melanoma and a poor prognosis. Multiomic analysis of miCLIP-seq, RNA-seq and Label-free MS data revealed that mA RNA modification posttranscriptionally promoted HINT2 expression. RNA immunoprecipitation (RIP)-qPCR and dual luciferase assays revealed that HINT2 mRNA specifically interacted with YTHDF1. Furthermore, polysome profiling analysis indicated a greater amount of HINT2 mRNA in the translation pool in ocular melanoma cells with higher mA methylation.
Here, we show that RNA methylation significantly inhibits the progression of UM and CM. Ocular melanoma samples showed decreased mA levels, indicating a poor prognosis. Changes in global mA modification were highly associated with tumor progression in vitro and in vivo. Mechanistically, YTHDF1 promoted the translation of methylated HINT2 mRNA, a tumor suppressor in ocular melanoma.
Our work uncovers a critical function for mA methylation in ocular melanoma and provides additional insight into the understanding of mA modification.
动态 N6-甲基腺苷(mA)RNA 修饰由 N 甲基转移酶和去甲基酶产生和消除,调节基因表达、选择性剪接和细胞命运。眼黑素瘤包括葡萄膜黑素瘤(UM)和结膜黑素瘤(CM),是成人中最常见的原发性眼部肿瘤,也是第二常见的黑素瘤。然而,mA 修饰在眼黑素瘤中的功能作用尚不清楚。
mA 分析和生存分析用于探索降低的全局 mA 水平,表明眼黑素瘤处于晚期且预后不良。miCLIP-seq、RNA-seq 和无标记 MS 数据的多组学分析显示,mA RNA 修饰在后转录水平促进 HINT2 的表达。RNA 免疫沉淀(RIP)-qPCR 和双荧光素酶测定显示 HINT2 mRNA 与 YTHDF1 特异性相互作用。此外,多核糖体分析表明在具有更高 mA 甲基化的眼黑素瘤细胞中,HINT2 mRNA 更多地存在于翻译池中。
在这里,我们表明 RNA 甲基化显著抑制 UM 和 CM 的进展。眼黑素瘤样本显示 mA 水平降低,预示预后不良。全局 mA 修饰的变化与体外和体内肿瘤进展高度相关。机制上,YTHDF1 促进了 HINT2 mRNA 的翻译,HINT2 mRNA 是眼黑素瘤中的一种肿瘤抑制因子。
我们的工作揭示了 mA 甲基化在眼黑素瘤中的关键功能,并为理解 mA 修饰提供了更多的见解。