METTL3 in chromium-induced angiogenesis and carcinogenesis

METTL3 在铬诱导的血管生成和癌变中的作用

• 批准号: 10615806
• 负责人: STEVEN B. MCMAHON
• 金额: $ 51.95万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-29 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10615806
• 关键词: Adenosine; Animal Model; Biological Assay; Biological Markers; Blood; Blood specimen; CRISPR/Cas technology; CXCL5 gene; Cell Proliferation; Cells; Chromates; Chromium; Chronic; Development; Dose; Endothelial Cells; Environmental Carcinogens; Enzyme-Linked Immunosorbent Assay; Enzymes; Epithelial Cells; Exposure to; Future; Gene Chips; Goals; Hypoxia Inducible Factor; IL8 gene; IL8RA gene; Interleukin 8A Receptor; Knock-out; Lung; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of lung; Mediating; Messenger RNA; Metal exposure; Methylation; Methyltransferase; Modeling; Modification; Molecular; Mononuclear; Mus; Occupational Exposure; Peripheral Blood Mononuclear Cell; Play; RNA; RNA Interference; Role; SOX4 gene; Sampling; Signal Pathway; Signal Transduction; Structure of parenchyma of lung; Techniques; Testing; Tissue Sample; Tube; Tumor Angiogenesis; Up-Regulation; Vascular Endothelial Cell; angiogenesis; cancer prevention; cancer type; carcinogenesis; cell transformation; chemokine; chromium hexavalent ion; disorder prevention; early detection biomarkers; epidemiology study; exposed human population; human subject; hypoxia inducible factor 1; interest; non-smoking; novel; overexpression; paracrine; posttranscriptional; receptor; transcription factor; tumor; tumor growth; tumorigenesis; whole genome

Exposure of hexavalent chromium [Cr(VI)] is known to induce lung cancer. Although there is emerging interest in mechanisms of Cr(VI)-induced carcinogenesis, role of Cr(VI) in inducing RNA modification in carcinogenesis is unknown. Our preliminary studies found that higher levels of methyltransferase like 3 (METTL3) were found in lung tissues from Cr(VI)-exposed mice, samples from Cr(VI)-exposed nonsmoking workers, and Cr(VI)- transformed (Cr-T) cells. To study underlying mechanism, we found that METTL3 was induced by upregulation of Nrf2 and SOX4, two important transcription factors. We found that METTL3 was important in regulating Cr-T cell proliferation, tube formation and tumor angiogenesis. METTL3 induced hypoxia-inducible factor 1 (HIF- 1) expression through suppressing PHD2, suggesting METTL3/PHD2/HIF-1 signaling would be important in Cr(VI) carcinogenesis. C-X-C motif chemokine 5 (CXCL5) and IL-8 were downstream effectors of METTL3. Our whole genome expression array analysis of blood mononuclear cells (PBMCs) from Cr(VI)-exposed nonsmoking workers and control subjects showed that METTL3, CXCL5 and IL-8 were among the most upregulated molecules in Cr(VI) exposure group, which was validated using RT-qPCR and ELISA assays. We hypothesize that long-term Cr(VI) exposure induces METTLE3 overexpression to regulate cell transformation, tumor growth and angiogenesis through METTL3/PHD2/HIF-1 axis in lung epithelial cells, and SOX4 and NRF-2 are two key upstream inducers. In order to test this hypothesis, we will perform three specific aims: Aim 1) To determine role and mechanism of METTL3 upregulation in Cr(VI)-induced cell transformation, tumor growth and angiogenesis, and to identify upstream regulator(s) of METTL3 elevation in Cr-T cells. Aim 2) To investigate key downstream targets and molecules of METTL3 in Cr(VI)-induced cell transformation and tumor growth. Aim 3) To determine whether METTL3 upregulation in Cr-T cells induces tumor angiogenesis through CXCR1/2 receptors and paracrine effect using humanized chimeric tumor model; to determine expression levels of Nrf2, SOX4, METTL3, PHD2, HIF-1, CXCL5, and/or IL-8 in peripheral blood mononuclear cells (PBMCs) and lung tissues from the Cr(VI)-exposed mice and in PBMCs from workers with occupational exposure to Cr(VI). We will use a combination of molecular approaches, animal models, and blood and tissue samples from human subjects and mice to define the role and mechanisms of new METTL3/PDH2/HIF-1 axis induced by Nrf2 and SOX4 in mediating cell transformation, tumor growth and angiogenesis, and determine the possible correlations with Cr(VI) internal exposure doses in workers and in mice via levels of these molecules. We will also investigate the effects of downstream effectors of METTL3/PDH2/HIF-1 axis, and their receptors in Cr-T cell-inducing angiogenesis. These studies will help us understand underlying mechanisms of Cr(VI) in inducing tumor growth and angiogenesis, and identify new biomarkers for early detection of Cr(VI) exposure and cancer prevention.

已知接触六价铬 [Cr(VI)] 会诱发肺癌，尽管人们对此越来越感兴趣。 Cr(VI) 诱导致癌机制中 Cr(VI) 在诱导 RNA 修饰中的作用 我们的初步研究发现甲基转移酶样 3 (METTL3) 水平较高。 暴露于 Cr(VI) 的小鼠的肺组织、暴露于 Cr(VI) 的不吸烟工人的样本以及 Cr(VI)- 为了研究潜在机制，我们发现 METTL3 是由上调诱导的。 我们发现 METTL3 在调节 Cr-T 中发挥着重要作用。 METTL3 诱导的细胞增殖、管形成和肿瘤血管生成。 1) 通过抑制 PHD2 表达，表明 METTL3/PHD2/HIF-1 信号传导在 Cr(VI) 致癌作用。C-X-C 基序趋化因子 5 (CXCL5) 和 IL-8 是 METTL3 的下游效应子。 我们对 Cr(VI) 暴露的血液单核细胞 (PBMC) 进行全基因组表达阵列分析 不吸烟工人和对照受试者的结果表明，METTL3、CXCL5 和 IL-8 是最常见的 Cr(VI) 暴露组中的分子上调，并使用 RT-qPCR 和 ELISA 检测进行了验证。 长期接触 Cr(VI) 会诱导 METTLE3 过度表达以调节细胞 通过肺上皮中 METTL3/PHD2/HIF-1 轴的转化、肿瘤生长和血管生成 SOX4 和 NRF-2 是两个关键的上游诱导子，为了验证这一假设，我们将进行实验。 三个具体目标： 目标 1) 确定 METTL3 在 Cr(VI) 诱导的细胞中上调的作用和机制 转化、肿瘤生长和血管生成，并鉴定 METTL3 升高的上游调节因子 目标 2) 研究 Cr(VI) 诱导细胞中 METTL3 的关键下游靶点和分子。 目标 3) 确定 Cr-T 细胞中 METTL3 的上调是否会诱导转化和肿瘤生长。 使用人源化嵌合肿瘤模型通过CXCR1/2受体和旁分泌作用进行肿瘤血管生成； 确定 Nrf2、SOX4、METTL3、PHD2、HIF-1α、CXCL5 和/或 IL-8 的表达水平 Cr(VI) 暴露小鼠的外周血单核细胞 (PBMC) 和肺组织以及 来自职业接触 Cr(VI) 的工人的 PBMC 我们将使用分子组合。 方法、动物模型以及来自人类受试者和小鼠的血液和组织样本来定义作用 Nrf2和SOX4在介导细胞中诱导新METTL3/PDH2/HIF-1轴的机制及机制 转化、肿瘤生长和血管生成，并确定与 Cr(VI) 内部可能的相关性 我们还将通过这些分子的水平来研究工人和小鼠的暴露剂量。 METTL3/PDH2/HIF-1 轴的下游效应器及其在 Cr-T 细胞诱导血管生成中的受体。 这些研究将帮助我们了解 Cr(VI) 诱导肿瘤生长的潜在机制和 血管生成，并确定用于早期检测 Cr(VI) 暴露和癌症预防的新生物标志物。