Small molecule approaches to studying tumor metabolism

项目总结/摘要 人们早就知道肿瘤细胞会重新调整其代谢以确保增殖和生存。新兴 遗传学证据已经证明了许多代谢酶在支持癌症中的重要性 代谢，特别是氧化还原酶，催化电子转移反应，是最大的 代谢酶家族。然而，结合和调节这类代谢酶的代谢物是 没有完全表征，并且对于大多数氧化还原酶没有小分子抑制剂。 因为几乎在每一种代谢途径中都存在氧化还原酶，所以可以使用氧化还原酶的小分子抑制剂。 氧化还原酶可用于研究代谢在多种肿瘤模型中的作用。 作为靶向氧化还原酶的起点，我们开发了3-磷酸甘油酸抑制剂 脱氢酶（PHGDH），丝氨酸生物合成途径中的第一种酶，并表明这些 化合物对PHGDH依赖性雌激素受体阴性细胞系具有选择性毒性，即使在 外源丝氨酸的存在。这些化合物阻止了内源性产生的 和外源丝氨酸，通过一个碳单位，到增殖所需的核苷酸，这意味着丝氨酸， 合成不仅控制生产，而且控制丝氨酸衍生的一碳单元的命运， 生物合成虽然这可能解释了在PHGDH存在下PHGDH敲低或抑制的毒性， 丰富的外源丝氨酸，丝氨酸合成途径活性确保可用性的机制 生物合成的一个碳单位是未知的。 在这个建议中，基于我以前的工作，我们将测试丝氨酸合成途径 代谢物协调一碳单位的命运（目标1），并定义内源性代谢物的光谱。 结合和调节氧化还原酶和其他代谢酶的代谢物（目的2）。延长 将用于靶向PHGDH的技术扩展到其他氧化还原酶，我们将构建工具， 氧化还原酶抑制剂的系统发现（目标3）。这些努力产生的化合物将 推进我们对各种细胞环境中代谢的机械理解，并可能作为 新抗代谢药开发的概念验证。

Project Summary / Abstract It has long been known that tumor cells rewire their metabolism to ensure proliferation and survival. Emerging genetic evidence has demonstrated the importance of many metabolic enzymes in supporting cancer metabolism, in particular the oxidoreductases, which catalyze electron transfer reactions and are the largest family of metabolic enzymes. Yet, the metabolites that bind and regulate this class of metabolic enzymes are not fully characterized, and there are no small molecule inhibitors for the majority of the oxidoreductases. Because there is an oxidoreductase in nearly every metabolic pathway, small molecule inhibitors of the oxidoreductases would be useful for studying the role of metabolism in a variety of tumor models. As a starting point for targeting the oxidoreductases, we have developed inhibitors of 3-phosphoglycerate dehydrogenase (PHGDH), the first enzyme in the serine biosynthesis pathway, and shown that these compounds are selectively toxic towards PHGDH-dependent, estrogen receptor-negative cell lines, even in the presence of exogenous serine. These compounds prevent the incorporation of both endogenously produced and exogenous serine, via one-carbon units, into nucleotides needed for proliferation, implying that serine synthesis not only controls the production but also the fate of serine-derived one-carbon units needed for biosynthesis. While this may account for the toxicity of PHGDH knockdown or inhibition in the presence of abundant exogenous serine, the mechanism by which serine synthesis pathway activity ensures the availability of one-carbon units for biosynthesis is unknown. In this proposal, building on my previous work, we will test the hypothesis that a serine synthesis pathway metabolite coordinates the fate of one-carbon units (Aim 1), and define the spectrum of endogenous metabolites that bind and regulate the oxidoreductases and other metabolic enzymes (Aim 2). To extend extend the techniques used to target PHGDH to other oxidoreductases, we will build tools to enable the systematic discovery of oxidoreductase inhibitors (Aim 3). Compounds emerging from these efforts will advance our mechanistic understanding of metabolism in a variety of cellular contexts, and might serve as proof of concept for the development of novel antimetabolites.