Environmental Pollutants and AHR pathway in Uterine Leiomyoma

环境污染物与子宫平滑肌瘤的 AHR 通路

• 批准号: 10567192
• 负责人: Serdar E. Bulun
• 金额: $ 63.22万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-13 至 2027-10-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10567192
• 关键词: ARNT gene; ATAC-seq; Affect; Age; Amino Acid Transporter; Anemia; Apoptosis; Aryl Hydrocarbon Receptor; Bioinformatics; Biological Assay; Cell Proliferation; Cell Survival; Cells; ChIP-seq; Chemical Exposure; Chromatin; Development; Diet; Diethylhexyl Phthalate; Disease; Endocrine Disruptors; Environmental Pollutants; Environmental Risk Factor; Enzymes; Epidemiology; Exposure to; FDA approved; Fibroid Tumor; Future; Gene Expression; Gene Expression Profile; Gene Mutation; Genes; Genetic; Goals; Growth; Health; Human; Hysterectomy; In Vitro; Inhibition of Apoptosis; Kynurenine; Leiomyoma; Ligands; Link; Malignant Neoplasms; Maps; Masks; Mediating; Medical; Metabolism; Molecular; Mutation; Obstruction; Pathogenesis; Pathway interactions; Perimenopause; Pregnancy loss; Premenopause; Process; Production; Progesterone Receptors; Proliferating; Receptor Activation; Recurrence; Reporting; Risk Factors; Role; Sampling; Small Interfering RNA; Smooth Muscle Myocytes; Testing; Time; Tissues; Translational Research; Tryptophan; Tryptophan Metabolism Pathway; Tryptophanase; Up-Regulation; Urine; Uterine Fibroids; Uterine hemorrhage; Uterus; Woman; Xenograft procedure; amino acid metabolism; antagonist; aryl hydrocarbon receptor ligand; cell growth; consumer product; epidemiology study; genome-wide analysis; histone modification; in vivo; inhibitor; knock-down; mouse genome; mouse model; mutant; myometrium; novel; novel therapeutic intervention; novel therapeutics; pharmacologic; phthalates; reproductive; reproductive system disorder; research and development; response; small hairpin RNA; steroid hormone; therapeutic target; transcriptome; transcriptome sequencing; tumor; tumor growth; tumorigenesis; uptake

Uterine leiomyomas (LM, fibroids) disrupt uterine function and cause recurrent pregnancy loss, excessive uterine bleeding, and anemia in 15-30% of reproductive-age women. No long-term medical treatment is available. Understanding how a LM develops is essential for identifying new non-surgical treatments. MED12 mutations (mut-MED12) occur in 70% of all LM and drive LM growth in a steroid hormone-dependent manner. Pre- and peri-menopausal women are widely exposed to endocrine disrupting chemicals (EDCs), e.g., phthalates, which are found in many consumer products and associated with a number of reproductive diseases. How a mut- MED12 influences LM growth and whether this process is enhanced by exposure to EDCs remain unknown. We recently found that tryptophan (Trp) 2,3-dioxygenase (TDO2) gene expression is strikingly upregulated in mut- but not wild-type (wt)-MED12 LM. TDO2 catalyzes a critical step in Trp breakdown to kynurenine (Kyn), an endogenous ligand for the aryl hydrocarbon receptor (AHR) whose activation stimulates the expression of pro- growth genes to promote cell survival and proliferation in various tissues. Kyn levels are markedly higher in LM vs myometrium, particularly in mut-MED12 LM. Trp and Kyn treatments of LM cells activated AHR and increased cell survival; blocking the Trp-Kyn-AHR pathway by siRNA knockdown or inhibitors of TDO2 or AHR abolished these effects, with mutant LM cells showing higher sensitivity to the treatments. Epidemiological studies have shown positive associations between LM and exposure to di(2-ethylhexyl) phthalate (DEHP). In vitro, mono(2- ethyl-5-hydroxyhexyl) phthalate (MEHHP), a major metabolite of DEHP, stimulated the expression of Trp transporters (LAT1 and LAT2), increased Trp uptake and Kyn production, activated AHR, and promoted LM cell survival. In addition, progesterone receptor is crucial for the expression of AHR and its nuclear translocator ARNT. Thus, the Trp-Kyn-AHR pathway appears to be a hub at which mut-MED12, steroid hormone action, and EDC effects converge enabling LM growth. Our overall hypothesis is that increased Trp uptake and metabolism, Kyn production, and AHR pathway activation, as a result of mut-MED12 or high exposure to the environmental pollutant DEHP, promote cell survival and proliferation and lead to LM growth. Using a xenograft mouse model and genome-wide studies, we will test our hypothesis in the following Aims: (1) Define the functional role of the Trp-Kyn-AHR pathway in LM tumorigenesis. Hypothesis: elevated expression of the TDO2 enzyme in mut- MED12 LM causes Kyn overproduction that activates AHR and promotes proliferation and survival of smooth muscle cells and tumor growth. (2) Determine whether DEHP stimulates LM growth via activation of the Trp- Kyn-AHR pathway. Hypothesis: exposure to DEHP and its metabolite MEHHP upregulates the expression of Trp transporters to increase its uptake, resulting in increased Kyn production and AHR activation leading to LM cell survival and tumor growth. The study will link, for the first time, abnormal amino acid metabolism and LM growth, opening a new avenue for translational research and the development of novel therapeutics for LM.

子宫平滑肌瘤（LM，纤维瘤）破坏子宫功能，导致反复流产，过度子宫 15-30%的育龄妇女患有出血和贫血。没有长期的治疗。 了解LM如何发展对于确定新的非手术治疗方法至关重要。MED 12突变 （mut-MED 12）发生在所有LM的70%中，并以类固醇激素依赖性方式驱动LM生长。前和 围绝经期妇女广泛暴露于内分泌干扰化学品（EDCs），例如，邻苯二甲酸盐， 在许多消费品中发现，并与许多生殖疾病有关。怎么个混- MED 12影响LM生长，而暴露于EDCs是否会增强这一过程仍不清楚。我们 最近发现，色氨酸（Trp）2，3-双加氧酶（TDO 2）基因表达在突变体中显著上调， 而不是野生型（wt）-MED 12 LM。TDO 2催化Trp分解为犬尿氨酸（Kyn）的关键步骤， 芳烃受体（AHR）的内源性配体，其活化刺激前- 生长基因以促进各种组织中的细胞存活和增殖。LM中的Kyn水平明显较高 与子宫肌层相比，尤其是在mut-MED 12 LM中。Trp和Kyn处理LM细胞激活AHR，并增加 细胞存活;通过siRNA敲低阻断Trp-Kyn-AHR通路或TDO 2或AHR抑制剂被废除 突变LM细胞对治疗表现出更高的敏感性。流行病学研究 显示LM与邻苯二甲酸二（2-乙基己基）酯（DEHP）暴露之间存在正相关性。体外，单（2- 邻苯二甲酸乙酯（MEHHP），DEHP的主要代谢产物，刺激Trp的表达 转运蛋白（LAT 1和LAT 2），增加Trp摄取和Kyn产生，激活AHR，并促进LM细胞 生存此外，孕激素受体对AHR及其核转运蛋白的表达至关重要 ARNT。因此，Trp-Kyn-AHR途径似乎是mut-MED 12、类固醇激素作用和 EDC效应收敛，使LM增长。我们的总体假设是，增加色氨酸的吸收和代谢， 由于mut-MED 12或高暴露于环境中， 污染物DEHP，促进细胞存活和增殖并导致LM生长。使用异种移植小鼠模型 和全基因组研究，我们将测试我们的假设在以下目的：（1）定义的功能作用， Trp-Kyn-AHR通路在LM肿瘤发生中的作用假设：在突变体中TDO 2酶的表达升高， MED 12 LM导致Kyn过度生产，激活AHR并促进平滑肌细胞增殖和存活。 肌肉细胞和肿瘤生长。(2)确定DEHP是否通过激活Trp- Kyn-AHR途径。假设：暴露于DEHP及其代谢物MEHHP可上调Trp的表达 转运蛋白增加其摄取，导致Kyn产生增加和AHR激活，导致LM细胞 存活和肿瘤生长。这项研究将首次将异常氨基酸代谢和LM生长联系起来， 为LM的转化研究和新疗法的开发开辟了新的途径。