Design and Development of Inhibitors of Methionine Adenosyltransferase for Cancer Treatment

项目摘要 S-腺苷甲硫氨酸（S-adenosyl-L-methionine，S-Met）是细胞表观遗传修饰中常见的甲基供体 大分子来调节基因表达。甲基腺苷转移酶（MAT）是 负责从ATP和甲硫氨酸底物合成蛋氨酸的唯一酶。三个MAT 同工酶存在于人类中，只有MAT 2A同工酶在大多数组织中表达 和癌细胞。MAT 2A在癌细胞中的过度表达已经被注意了一段时间。最近 研究表明，癌细胞中常见的5 '-甲硫基腺苷基因缺失 磷酸化酶（MTAP）由于细胞内的细胞增殖增加而产生对MAT 2A抑制的敏感性。 对蛋氨酸合成的依赖性。我们的实验室以前曾使用紧密结合的方法靶向MTAP 过渡态类似物成功地减少了细胞培养物中的癌细胞生长， 小鼠异种移植物。分析了对MTAP抑制剂抗性进行调节的癌细胞， 鉴定了MAT 2A基因座处的单基因扩增事件。在本提案中，我们将 采用点击化学和过渡态两种强有力的酶抑制剂设计方法 类似物，靶向MAT 2A。这些创新的化学方法已被应用于其他 酶靶向产生一些已知的最紧密结合的抑制剂。点击化学和 过渡态类似物方法允许产生双底物类似物， MAT 2A的ATP和甲硫氨酸结合位点。这种同时靶向两种酶 活性位点基团增加抑制剂亲和力，因为它类似于短寿命但高亲和力的 中间反应物种。通过这些方法产生的抑制剂将受到 结构、热力学和动力学分析。这些高亲和力MAT 2A抑制剂的功效 将在MTAP-/-和MTAP+/+癌细胞上分析对降低癌细胞生长和活力的影响 线用MTAP过渡态类似物共治疗癌细胞系将探索 MTAP和MAT 2A的协同作用。我们假设MAT 2A抑制剂产生于 这项工作将放大MTAP抑制剂的抗癌作用，并为癌症提供一种新的治疗方法。 MTAP-/-癌症。

Project Abstract S-adenosyl-L-methionine (AdoMet) is a common methyl donor in cellular epigenetic modification of macromolecules to regulate gene expression. Methionine adenosyltransferase (MAT) is the sole enzyme responsible for AdoMet synthesis from ATP and methionine substrates. Three MAT isozymes are found in humans, with only the MAT2A isoform being expressed in most tissues and cancer cells. Over expression of MAT2A in cancer cells has been noted for some time. Recent studies have shown that a common gene deletion in cancer cells of 5’-methylthioadenosine phosphorylase (MTAP) creates susceptibility to MAT2A inhibition due to increased cellular dependence on AdoMet synthesis. Our lab has previously targeted MTAP using tight-binding transition state analogues that were successful in reducing cancer cell growth in cell culture and mouse xenografts. Cancer cells conditioned to MTAP inhibitor resistance were analyzed and a single gene amplification event at the MAT2A gene locus was identified. In this proposal, we will use two powerful methods of enzyme inhibitor design, click chemistry and transition state analogues, to target MAT2A. These innovative chemistry approaches have been applied to other enzyme targets to generate some of the tightest binding inhibitors known. Click chemistry and transition state analogue approaches allow for creation of bisubstrate analogues that target both the ATP and methionine binding sites of MAT2A. This simultaneous targeting of two enzyme active site groups increases the inhibitor affinity, as it resembles the short-lived but high-affinity intermediate reaction species. Inhibitors generated through these methods will be subject to structural, thermodynamic, and kinetic analysis. Efficacy of these high affinity MAT2A inhibitors on reducing cancer cell growth and viability will be analyzed on MTAP-/- and MTAP+/+ cancer cell lines. Co-treatment of cancer cell lines with MTAP transition state analogues will explore synergistic effects of MTAP and MAT2A. We hypothesize that MAT2A inhibitors generated from this work will amplify the anti-cancer effects MTAP inhibitors and provide a novel treatment for MTAP-/- cancers.