β-catenin represses miR455-3p to stimulate m6A modification of HSF1 mRNA and promote its translation in colorectal cancer
β-catenin represses miR455-3p to stimulate m6A modification of HSF1 mRNA and promote its translation in colorectal cancer
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β-连环蛋白抑制 miR455-3p 刺激 HSF1 mRNA 的 m6A 修饰并促进其在结直肠癌中的翻译。
DOI：
10.1186/s12943-020-01244-z
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发表时间：
2020-08-24
期刊：
影响因子：
37.3
通讯作者：
Jin, Hongchuan
中科院分区：
文献类型：
--
作者：
Song, Ping;Feng, Lifeng;Jin, Hongchuan
背景热休克转录因子1(HSF1)在结直肠癌中过表达，促进谷氨酰胺分解，激活mTOR。方法采用染色质免疫沉淀、定量逆转录聚合酶链式反应、免疫组织化学和免疫印迹等方法检测HSF1的表达。通过多聚体谱分析和新生蛋白分析探讨HSF1的翻译。应用生物素下拉和m6A RNA免疫共沉淀法研究RNA/RNA相互作用和m6A修饰。结果吡喃或−-catenin基因敲除WnT/β-catenin信号后，HSF1的表达和活性降低，而被氯化锂或β-catenin过表达激活后，HSF1的表达和活性增加。与LiCl处理的WT MEF相比，LiCl处理的HSF1-KO MEF中上调的基因要少得多。HSF1蛋白表达与β-连环蛋白在细胞系和原代组织中的表达呈正相关。在β-连环蛋白缺失后，HSF1mRNA的翻译受损，伴随着其m6A修饰的减少和miR455-3p的上调，miR455-3p可以与HSF1mRNA的3‘端非编码区相互作用而抑制其翻译。有趣的是，抑制miR455-3p挽救了β-连环蛋白的耗竭，导致HSF1m6A修饰和METTL3相互作用减少。结论β-catenin可以抑制miR455-3p的生成，从而刺激m6A修饰和随后的HSF1mRNA的翻译。HSF1对β-连环蛋白促进结直肠癌的发展具有重要意义。靶向hsf1可能是干预β-连环蛋白驱动的癌症的一种潜在策略。
BackgroundHeat shock transcription factor1 (HSF1) was overexpressed to promote glutaminolysis and activate mTOR in colorectal cancer (CRC). Here, we investigated the mechanism for cancer-specific overexpression of HSF1.MethodsHSF1 expression was analyzed by chromatin immunoprecipitation, qRT-PCR, immunohistochemistry staining and immunoblotting. HSF1 translation was explored by polysome profiling and nascent protein analysis. Biotin pulldown and m6A RNA immunoprecipitation were applied to investigate RNA/RNA interaction and m6A modification. The relevance of HSF1 to CRC was analyzed in APCmin/+and APCmin/+HSF1+/−mice.ResultsHSF1 expression and activity were reduced after the inhibition of WNT/β-catenin signaling by pyrvinium or β-catenin knockdown, but elevated upon its activation by lithium chloride (LiCl) or β-catenin overexpression. There are much less upregulated genes in HSF1-KO MEF treated with LiCl when compared with LiCl-treated WT MEF. HSF1 protein expression was positively correlated with β-catenin expression in cell lines and primary tissues. After β-catenin depletion, HSF1 mRNA translation was impaired, accompanied by the reduction of its m6A modification and the upregulation of miR455-3p, which can interact with 3′-UTR of HSF1 mRNA to repress its translation. Interestingly, inhibition of miR455-3p rescued β-catenin depletion-induced reduction of HSF1 m6A modification and METTL3 interaction. Both the size and number of tumors were significantly reduced in APCmin/+mice when HSF1 was genetically knocked-out or chemically inhibited.Conclusionsβ-catenin suppresses miR455-3p generation to stimulate m6A modification and subsequent translation of HSF1 mRNA. HSF1 is important for β-catenin to promote CRC development. Targeting HSF1 could be a potential strategy for the intervention of β-catenin-driven cancers.