The kynurenine-AHR pathway in biomass production

项目摘要 增加摄取和合成的大分子是必不可少的，以维持过度增殖的需求， 癌细胞因此，开发专门限制肿瘤中生物质产生的方法可能具有 对癌症治疗的深远影响。虽然开创性的研究表明， MYC促进癌细胞中的蛋白质合成，但我们对MYC分子如何合成的理解仍存在差距 在致癌转化过程中控制翻译。我们发现转录因子芳烃 受体（AHR）及其配体犬尿氨酸（氨基酸色氨酸的副产物）由MYC诱导， 结肠癌细胞我们的初步结果表明，AHR是必要的基因表达有关 在增殖细胞的核糖体生物发生和蛋白质合成中。我们的假设是，AHR的感觉和 通过易位到细胞核中并诱导以下转录来响应来自于Dahan的犬尿氨酸： 在结肠癌细胞中介导核糖体生物合成和翻译的基因。目标1将直接测试 AHR在结肠癌细胞蛋白质合成中的作用，使用人类结肠癌等基因系中的遗传沉默 上皮细胞和小鼠类器官的肿瘤进展为结肠癌。目标2将确定 犬尿氨酸对AHR调节的蛋白质合成和细胞增殖的影响 犬尿氨酸用于AHR靶基因的表达、蛋白质合成和生长。我们将利用AHR击倒 细胞和动物以及阻止犬尿氨酸与AHR结合以定义AHR的竞争性抑制剂。 由犬尿氨酸调节的特定功能。目标3将直接检验糖代谢的重要性 这些酶在产生犬尿氨酸和调节结肠细胞增殖中的作用。我们将确定 敲低或敲除犬尿氨酸途径中的酶，以确定它们对AHR的需求 活性、蛋白质合成和结肠癌细胞和类器官的增殖。这项研究有可能 定义犬尿氨酸-AHR途径在驱动增加的生物质生产中的直接生理作用， 结肠癌的细胞增殖。而且，本研究将拓宽对犬尿氨酸作用的认识 作为肿瘤代谢物。我们的发现可能成为开发新方法的基础， 犬尿氨酸产生和AHR活性作为治疗MYC依赖性肿瘤的手段。

PROJECT SUMMARY Increased uptake and synthesis of macromolecules is essential to sustain the demands of hyperproliferative cancer cells. Therefore, developing approaches to limit biomass production specifically in tumors could have profound implications for cancer treatment. While seminal studies have shown that the universal oncogene MYC promotes protein synthesis in cancer cells, there is still a gap in our understanding of how MYC molecularly controls translation during oncogenic transformation. We found that the transcription factor aryl hydrocarbon receptor (AHR) and its ligand kynurenine, a byproduct of the amino acid tryptophan, are induced by MYC in colon cancer cells. Our preliminary results indicate that AHR is necessary for the expression of genes involved in ribosomal biogenesis and protein synthesis in proliferating cells. Our hypothesis is that AHR senses and responds to tryptophan-derived kynurenine by translocating into the nucleus and inducing the transcription of genes that mediate ribosome biogenesis and translation in colon cancer cells. Aim 1 will directly test the role of AHR in protein synthesis in colon cancer cells, using genetic silencing in isogenic lines of human colonic epithelial cells and of mouse organoids progressed to colon cancer. Aim 2 will establish the contribution of kynurenine to AHR-regulated protein synthesis and cell proliferation by examining the requirement for kynurenine for the expression of AHR target genes, protein synthesis, and growth. We will utilize AHR knockout cells and animals and a competitive inhibitor that prevents the binding of kynurenine to AHR to define AHR- specific functions regulated by kynurenine. Aim 3 will directly test the importance of tryptophan-metabolizing enzymes in generating kynurenine and in regulating proliferation of colonic cells. We will determine the effects of knocking down or knocking out enzymes in the kynurenine pathway to define their requirement for AHR activity, protein synthesis, and proliferation of colon cancer cells and organoids. This study has the potential to define a direct physiological role for the kynurenine-AHR pathway in driving increased biomass production and cell proliferation in colon cancer. Moreover, this study will broaden the understanding of the role of kynurenine as an oncometabolite. Our findings could become the basis for the development of novel approaches to limit kynurenine production and AHR activity as a means to treat MYC-dependent tumors.