Chromium in carcinogenesis and angiogenesis

铬在致癌和血管生成中的作用

• 批准号: 10328704
• 负责人: BingHua Jiang
• 金额: $ 30.78万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10328704
• 关键词: Chromium; carcinogenesis; angiogenesis

Hexavalent chromium [Cr(VI)] long-term exposure is associated with human lung cancer. Although there is emerging interest in the mechanism underlying Cr(VI)-induced carcinogenesis, the mechanism and role of Cr(VI) in inducing carcinogenesis still remains to be elucidated. In preliminary studies, we used human peripheral blood mononuclear cells (PBMC cells) from Cr(VI) exposed and control subjects to perform whole genome expression array analysis, and found that IL-8 and CXCL5 are the two most up-regulated genes detected in the exposure group compared with non-exposure subjects. We validated our findings by RT-qPCR and ELISA assay. Additionally, we found that miR-199a suppression and β-catenin upregulation are important for IL-8 and CXCL5 induction. Forced expression of miR-199a and knockdown of IL-8 or CXCL5 inhibited both cell transformation and angiogenesis. These findings are consistent with our results obtained from Cr(VI)- transformed cells and from in vitro studies. Furthermore, we found that β-catenin directly activated IL-8 expression at transcriptional level, while miR-199a directly targets hypoxia-inducible factor 1 (HIF-1) for inhibiting HIF-1 expression. We hypothesize that miR-199a suppression and β-catenin upregulation are important in Cr(VI)-induced tumorigenesis and angiogenesis through induction of IL- 8 and CXCL5 expression. Tumor cell growth and angiogenesis are the important characteristics of carcinogenesis, transformation from normal cells to cancer cells. In order to test this hypothesis, we will perform three specific aims: Aim 1) To determine role of miR-199a suppression and β-catenin upregulation in Cr(VI)-induced cell transformation, and identify the mechanism of IL-8 and CXCL5 elevation. Aim 2) To determine roles of miR-199a, β-catenin, IL-8, and CXCL5 in Cr(VI) transformed cell-induced tumor growth. Aim 3) To determine whether Cr-T cells induce tumor angiogenesis through IL-8 receptors using chimeric tumor model and determine expression levels of IL-8, CXCL5, β-catenin, and miR-199a in peripheral blood mononuclear cells (PBMCs) and plasma, and the possible correlations with Cr(VI) internal exposure doses in workers with occupational Cr(VI) exposure. We will use a combination of molecular approaches, a n animal model, and blood and tissue samples from human subjects to define roles and mechanisms of miR-199a, β- catenin, IL-8, and CXCL5 in Cr(VI)-induced cell transformation, tumor growth, and angiogenesis. These studies will not only help us understand the underlying mechanisms of Cr(VI) in inducing carcinogenesis, but also identify potential new biomarkers for early detection of Cr(VI) exposure of workers in electroplating factories in the future.

六价铬[CR（VI）]长期暴露与人类肺癌有关。虽然有 对CR（VI）诱导的癌变的机制的新兴兴趣，机制和作用 诱导的致癌作用中的Cr（VI）仍有待阐明。在初步研究中，我们使用了人类 暴露于CR（VI）和控制受试者的外周血单核细胞（PBMC细胞）进行整体 基因组表达阵列分析，发现IL-8和CXCL5是两个最上调的基因 与非暴露受试者相比，在暴露组中检测到。我们通过RT-QPCR验证了我们的发现 和Elisa分析。此外，我们发现miR-199a抑制和β-catenin上调很重要 对于IL-8和CXCL5诱导。 MiR-199a的强迫表达和IL-8或CXCL5的敲低抑制了这两者 细胞转化和血管生成。这些发现与我们从CR（VI）获得的结果一致 - 转化的细胞和体外研究。此外，我们发现β-catenin直接激活IL-8 转录水平的表达，而miR-199a直接靶向缺氧诱导因子1 （HIF-1）用于抑制HIF-1表达。我们假设miR-199a抑制和β-catenin 上调在CR（VI）诱导的肿瘤发生和血管生成中很重要 8和CXCL5表达。肿瘤细胞生长和血管生成是 癌变，从正常细胞转化为癌细胞。为了检验这一假设，我们将 执行三个具体目标：目标1）确定miR-199a抑制和β-catenin上调的作用 CR（VI）诱导的细胞转化，并确定IL-8和CXCL5升高的机理。目标2） 确定miR-199a，β-catenin，iL-8和CxCl5在CR（VI）转化细胞诱导的肿瘤生长中的作用。目的 3）确定CR-T细胞是否使用嵌合肿瘤通过IL-8受体诱导肿瘤血管生成 模型并确定外周血中IL-8，CXCL5，β-catenin和miR-199a的表达水平 单核细胞（PBMC）和血浆，以及与CR（VI）内部暴露剂量的可能相关性 有职业CR（VI）暴露的工人。我们将使用分子方法的组合，一种N动物 模型，以及来自人类受试者的血液和组织样本，以定义miR-199a，β-的作用和机制 CR（VI）诱导的细胞转化，肿瘤生长和血管生成中的Catenin，IL-8和CXCL5。这些 研究不仅会帮助我们了解诱导的癌变中Cr（VI）的潜在机制，而且还可以 还可以确定潜在的新生物标志物，以及早发现电镀中工人的CR（VI）暴露 未来的工厂。