The novel lysine methyltransferase ILSE1 controls castration-resistant prostate cancer

新型赖氨酸甲基转移酶 ILSE1 控制去势抵抗性前列腺癌

• 批准号: 389637042
• 负责人: Professor Dr. Roland Schüle
• 金额: --
• 依托单位: Arbeitsgruppe Hormone Dependent Cancer
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/389637042?language=en
• 关键词: novel; lysine; methyltransferase; ILSE1; controls

Epigenetic writers such as histone methyltransferases play key roles in the control of physiology and pathology. Consequently, small molecule inhibitors of various histone methyltransferases have been developed and entered clinical evaluation. To further expand our knowledge on the molecular functions of this important class of epigenetic enzymes we combined bioinformatic approaches such as homology prediction and cheminformatics with 3D structural information to identify novel histone methyltransferases (HMTs) with putative clinical relevance. One of the interesting lysine methyltransferases, hereafter named ILSE1 presents as an epigenetic enzyme writing the chromatin mark histone H4 monomethylated at lysine 12 (H4K12me) to which no function has been assigned so far. Introduction of a single point mutation in the catalytic center or treatment with the S-adenosyl methionine (SAH)-competitive inhibitor sinefungin abrogates methylation by ILSE1 in vitro. Accordingly, depletion or ectopic expression of ILSE1 results in reduced and elevated H4K12me levels in cultured cells, respectively. Of note, ILSE1 RNAi most robustly impairs proliferation of both androgen-dependent and castration-resistant prostate cancer cell lines. In contrast, growth of non-transformed cells and various other tumor cells is not regulated by ILSE1 uncovering unprecedented specificity of action. Finally, depletion of ILSE1 results in severely retarded growth of androgen-dependent and castration-resistant prostate cancer cell in mouse xenograft models. In summary, our preparatory work demonstrates that ILSE1 is the first H4K12 methyltransferase robustly impairing proliferation of castration-resistant prostate cancer in vitro and in vivo. Thus, our data identify ILSE1 as a target for potential therapeutic intervention of castration-resistant prostate cancer by small molecule inhibitors. Consequently, we propose to (1) determine the 3D crystal structure of ILSE1 and use the structural information to design and characterize chemical probes that inhibit ILSE methyltransferase activity. We shall (2) unravel the function of ILSE1 in physiology and pathology by the identification and characterization of target genes. Finally, we plan to (3) determine how the information stored in the chromatin mark H4K12me is interpreted and transduced into physiological and pathological traits by characterization of reader and eraser proteins.

表观遗传的作家，如组蛋白甲基转移酶在生理和病理的控制中发挥关键作用。因此，各种组蛋白甲基转移酶的小分子抑制剂已被开发并进入临床评价。为了进一步扩展我们对这类重要的表观遗传酶的分子功能的了解，我们将生物信息学方法如同源性预测和化学信息学与3D结构信息相结合，以鉴定具有推定临床相关性的新型组蛋白甲基转移酶（HMT）。感兴趣的赖氨酸甲基转移酶之一（下文称为ILSE 1）作为表观遗传酶存在，其书写在赖氨酸12处单甲基化的染色质标记组蛋白H4（H4 K12 me），迄今为止尚未对其分配功能。在催化中心引入单点突变或用S-腺苷甲硫氨酸（SAH）竞争性抑制剂sinefungin处理可在体外消除ILSE 1的甲基化。因此，ILSE 1的耗竭或异位表达分别导致培养细胞中H4 K12 me水平的降低和升高。值得注意的是，ILSE 1 RNAi最强烈地损害雄激素依赖性和去势抵抗性前列腺癌细胞系的增殖。相反，非转化细胞和各种其他肿瘤细胞的生长不受ILSE 1的调节，从而揭示了前所未有的作用特异性。最后，ILSE 1的缺失导致小鼠异种移植模型中雄激素依赖性和去势抵抗性前列腺癌细胞的生长严重迟缓。总之，我们的准备工作表明，ILSE 1是第一个H4 K12甲基转移酶在体外和体内强烈损害去势抵抗性前列腺癌的增殖。因此，我们的数据确定ILSE 1作为小分子抑制剂对去势抵抗性前列腺癌的潜在治疗干预的靶点。因此，我们建议（1）确定ILSE 1的三维晶体结构，并使用结构信息来设计和表征抑制ILSE甲基转移酶活性的化学探针。我们将（2）通过对靶基因的鉴定和鉴定，阐明ILSE 1在生理和病理上的功能。最后，我们计划（3）确定存储在染色质标记H4 K12 me中的信息是如何被解释并通过表征读取器和擦除器蛋白转换成生理和病理特征的。