PDF(Pubmed)
Abstract：
Prostate cancer is a leading cause of cancer-related mortality in males. Dysregulation of RNA adenine N-6 methylation (m6A) contributes to cancer malignancy. m6A on mRNA may affect mRNA splicing, turnover, transportation, and translation. m6A exerts these effects, at least partly, through dedicated m6A reader proteins, including YTH domain-containing family protein 2 (YTHDF2). YTHDF2 is necessary for development while its dysregulation is seen in various cancers, including prostate cancer. However, the mechanism underlying the dysregulation and function of YTHDF2 in cancer remains elusive. Here, we find that the deubiquitinase OUT domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1) increases YTHDF2 protein stability by inhibiting its ubiquitination. With in vivo and in vitro ubiquitination assays, OTUB1 is shown to block ubiquitin transfer to YTHDF2 independent of its deubiquitinase activity. Furthermore, analysis of functional transcriptomic data and m6A-sequencing data identifies PRSS8 as a potential tumor suppressor gene. OTUB1 and YTHDF2 decrease mRNA and protein levels of PRSS8, which is a trypsin-like serine protease. Mechanistically, YTHDF2 binds PRSS8 mRNA and promotes its degradation in an m6A-dependent manner. Further functional study on cellular and mouse models reveals PRSS8 is a critical downstream effector of the OTUB1-YTHDF2 axis in prostate cancer. We find in prostate cancer cells, PRSS8 decreases nuclear β-catenin level through E-cadherin, which is independent of its protease activity. Collectively, our study uncovers a key regulator of YTHDF2 protein stability and establishes a functional OTUB1-YTHDF2-PRSS8 axis in prostate cancer.
摘要：
前列腺癌是男性癌症相关死亡率的主要原因。RNA的失调腺嘌呤N-6甲基化(m6A)有助于癌症的恶性程度。mRNA上的m6A可能影响mRNA的剪接，营业额，运输和翻译。M6A发挥这些作用，至少部分地,通过专用的m6A阅读器蛋白，包括YTHDF2。YTHDF2是发育所必需的,而其失调在包括前列腺癌的各种癌症中可见。然而,YTHDF2在癌症中失调和功能的潜在机制仍然难以捉摸。这里,我们发现去泛素酶OTUB1通过抑制YTHDF2蛋白的泛素化增加其稳定性。通过体内和体外泛素化试验，OTUB1显示阻断泛素向YTHDF2的转移，而与其去泛素酶活性无关。此外，功能转录组数据和m6A测序数据的分析确定PRSS8为潜在的抑癌基因。OTUB1和YTHDF2降低PRSS8的mRNA和蛋白质水平,PRSS8是胰蛋白酶样丝氨酸蛋白酶。机械上,YTHDF2结合PRSS8mRNA并以m6A依赖性方式促进其降解。对细胞和小鼠模型的进一步功能研究表明，PRSS8是前列腺癌中OTUB1-YTHDF2轴的关键下游效应物。我们在前列腺癌细胞中发现，PRSS8通过E-cadherin降低核β-catenin水平，这与它的蛋白酶活性无关。总的来说，我们的研究揭示了YTHDF2蛋白稳定性的关键调节因子,并在前列腺癌中建立了功能性OTUB1-YTHDF2-PRSS8轴.
