Project 1: Critical Events In The Transformation of Human Bladder Cells

项目1：人类膀胱细胞转化中的关键事件

• 批准号: 7936593
• 负责人: A J GANDOLFI
• 金额: $ 18.22万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7936593
• 关键词: Acids; Adult; Affect; Agar; Animal Model; Arsenic; Arsenicals; Arsenites; Biological Markers; Biological Markers; Bladder; Bladder Injury; Breathing; Cell Culture Techniques; Cells; Child; Chronic; DNA; Dust; Event; Exposure to; Female; Generations; Goals; Growth; Health; Hispanics; Human; Indigenous; Large T Antigen; Lead; Lung; MMA(III); Malignant - descriptor; Malignant neoplasm of urinary bladder; Mediating; Modeling; Monitor; Mus; Organ; Population; Primary Cell Cultures; Production; Proteins; Publishing; Reactive Oxygen Species; Sampling; Signal Transduction; Signaling Protein; Simian virus 40; Skin; System; TP53 gene; Time; Toxic effect; Tumor Suppressor Proteins; Urine; Urothelium; carcinogenesis; cell injury; cell transformation; cytotoxic; drinking water; exposed human population; immortalized cell; imprint; macromolecule; male; monomethylarsonous acid; particle; response; tumor

The human bladder is the most sensitive internal organ to arsenic-induced carcinogenesis. The bladder is exposed to inorganic arsenicals and methylated metabolites both systemically and via the urine. Methylated metabolites of arsenic have been found to be more cytotoxic than inorganic arsenicals. The UROtsa cell, an immortalized human urothelium cell, has become an accepted system for examining the toxic effects of arsenicals to the bladder. Year-long chronic low-level exposure of arsenite [1 microM As(III)] or the more toxic arsenic metabolite [monomethyl-arsonous acid; 50 nM MMA(III)] transformed UROtsa cells such that they formed tumors when injected into immuno-deficient mice. Current studies indicate that much shorter exposures (3 months) to low-level MMA(III) is sufficient to allow them to grown in soft agar and form tumors in immuno-deficient mice. These results indicate that MMA (III) causes critical, irreversible events in UROtsa cells in the first 3 months of exposure. Thus the Goal of this proposal is to find the critical events that short-term, low-level As(III) or MMA(III) causes in UROtsa cells resulting in their eventual transition into malignantly transformed cells. To accomplish this goal we will do low-level, short-term (0-3) exposures of UROtsa cells to arsenicals [1 microM As(III) and 50 nM MMA(III)] to determine the minimal exposure and time required to malignantly transform these cells. Once this minimal exposure time point is established we will examine the cells for changes in specific alterations in macromolecules, signaling systems, or regulatory systems resulting in the irreversible changes. Since previous studies have found reactive oxygen species (ROS) generation by low-level exposure to As(III) and MMA(III), we will determine if these early effects of arsenicals on UROtsa cells are mediated by ROS generation. To determine if low-level arsenicals can transform "normal" human bladder cells, primary cultures of human bladder cells will be similarly examined. Lastly pivotal events in the transformation of bladder cells by low-level arsenicals will be examined as possible biomarkers in exposed populations. Overall, these studies will clarify the toxic effects of low-level arsenic in a human bladder model and provide potential biomarkers for arsenic-induced bladder injury.

人膀​​胱是对砷诱导的致癌作用最敏感的内部器官。膀胱暴露于系统和通过尿液的无机砷和甲基化的代谢物中。已经发现，砷的甲基化代谢产物比无机砷更细胞毒性。 Urotsa细胞是一种永生的人尿皮细胞，已成为检查砷对膀胱的毒性作用的公认系统。砷[1 microm as（iii）]或更毒性的砷代谢产物[单甲基 - 近似酸； 50 nm MMA（iii）]转化了urrotsa细胞，因此当注射到免疫缺陷型小鼠中时会形成肿瘤。当前的研究表明，低水平MMA（III）的暴露较短（3个月）足以使它们在软琼脂中生长并在免疫缺陷型小鼠中形成肿瘤。这些结果表明，在暴露的前三个月中，MMA（III）在Urotsa细胞中引起关键的，不可逆的事件。因此，该提案的目的是找到一个关键事件，即短期，低水平为（III）或MMA（iii）引起的urrotsa细胞导致它们最终过渡到恶性转化的细胞。为了实现这一目标，我们将进行低水平的短期（0-3）暴露于urotsa细胞对砷[1 microm as（iii）和50 nm MMA（iii）]，以确定恶性转化这些细胞所需的最小暴露和时间。一旦建立了最小的暴露时间点，我们将检查细胞是否会改变大分子，信号系统或调节系统的特定变化，从而导致不可逆的变化。由于先前的研究发现通过低水平暴露于AS（III）和MMA（III）生成活性氧（ROS），因此我们将确定砷对urotsa细胞的这些早期作用是否由ROS的产生介导。为了确定低水平的砷是否可以转化“正常”的人膀胱细胞，将类似地检查人类膀胱细胞的主要培养物。最后，将在暴露群体中检查膀胱细胞转化中膀胱细胞转化的关键事件。总体而言，这些研究将阐明低级砷在人膀胱模型中的毒性作用，并为砷诱导的潜在生物标志物提供了潜在的生物标志物 膀胱受伤。