Perez Damon S, Handa Robert J, Yang Raymond S H, Campain Julie A
Quantitative and Computational Toxicology Group, Center for Environmental Toxicology and Technology, Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA.
J Appl Toxicol. 2008 May;28(4):491-508. doi: 10.1002/jat.1301.
Both arsenic and benzo[a]pyrene (BaP) inhibit terminal differentiation and alter growth potential in normal human epidermal keratinocytes (NHEK) in vitro. To identify molecular alterations that may be involved in these cellular processes, microarray analysis was carried out on NHEK treated with BaP or arsenic. The gene expression microarray results measuring mRNA levels were as follows: (1) in total, the expression of 85 genes was induced and 17 genes was suppressed by 2.0 microm BaP. (2) Arsenic at an equitoxic dose (5.0 microm) induced the expression of 106 and suppressed 15 genes. Quantitative real-time RT-PCR was used subsequently to confirm microarray findings on selected genes involved in keratinocyte growth and differentiation pathways. These studies confirmed increased mRNA levels in NHEK by BaP of alpha-integrin binding protein 63 (AIBP63) (2.48-fold), retinoic acid- and interferon-inducible protein (IFIT5) (2.74-fold), interleukin-1 alpha (IL1A) (2.64-fold), interleukin-1 beta (IL1B) (2.84-fold) and Ras guanyl releasing protein 1 (RASGRP1) (3.14-fold). Real-time RT-PCR confirmed that arsenic increased mRNA levels of the following genes: retinoblastoma 1 (RB1) (5.4-fold), retinoblastoma-binding protein 1 (ARID4A) (6.8-fold), transforming growth factor beta-stimulated protein (TSC22D1) (6.84-fold), MAX binding protein (MNT) (2.44-fold), and RAD50 (4.24-fold). Collectively, these results indicate that these chemicals target different genes and molecular pathways involved in the regulatory processes controlling NHEK proliferation and differentiation. Mechanistic studies with a subset of genes may allow the correlation of alterations in these molecular markers with chemical-specific blocks to differentiation in NHEK.
砷和苯并[a]芘（BaP）均可在体外抑制正常人表皮角质形成细胞（NHEK）的终末分化并改变其生长潜能。为了确定可能参与这些细胞过程的分子改变，对用BaP或砷处理的NHEK进行了微阵列分析。测量mRNA水平的基因表达微阵列结果如下：（1）总体而言，2.0微摩尔BaP诱导了85个基因的表达并抑制了17个基因的表达。（2）等毒性剂量（5.0微摩尔）的砷诱导了106个基因的表达并抑制了15个基因的表达。随后使用定量实时RT-PCR来确认微阵列对参与角质形成细胞生长和分化途径的选定基因的发现。这些研究证实，BaP使NHEK中α-整合素结合蛋白63（AIBP63）（2.48倍）、视黄酸和干扰素诱导蛋白（IFIT5）（2.74倍）、白细胞介素-1α（IL1A）（2.64倍）、白细胞介素-1β（IL1B）（2.84倍）和Ras鸟苷释放蛋白1（RASGRP1）（3.14倍）的mRNA水平升高。实时RT-PCR证实，砷使以下基因的mRNA水平升高：视网膜母细胞瘤1（RB1）（5.4倍）、视网膜母细胞瘤结合蛋白1（ARID4A）（6.8倍）、转化生长因子β刺激蛋白（TSC22D1）（6.84倍）、MAX结合蛋白（MNT）（2.44倍）和RAD50（4.24倍）。总体而言，这些结果表明这些化学物质靶向参与控制NHEK增殖和分化的调节过程的不同基因和分子途径。对一部分基因进行的机制研究可能有助于将这些分子标志物的改变与NHEK中化学物质特异性的分化阻滞相关联。
