Chen H, Liu J, Merrick B A, Waalkes M P
Laboratory of Comparative Carcinogenesis, NIEHS, Research Triangle Park, North Carolina 27709, USA.
Mol Carcinog. 2001 Feb;30(2):79-87. doi: 10.1002/1098-2744(200102)30:2<79::aid-mc1016>3.0.co;2-f.
Arsenic is a human carcinogen. Our recent work showed that chronic (>18 wk), low-level (125-500 nM) arsenite exposure induces malignant transformation in normal rat liver cell line TRL1215. In these arsenic-transformed cells, thecellular S-adenosylmethionine pool was depleted from arsenic metabolism, resulting in global DNA hypomethylation. DNA methylation status in turn may affect the expression of a variety of genes. This study examined the aberrant gene expression associated with arsenic-induced transformation with the use of Atlas Rat cDNA Expression microarrays. Poly(A(+)) RNA was prepared from arsenic-transformed cells and passage-matched control cells, and (32)P-labeled cDNA probes were synthesized with Clontech Rat cDNA Synthesis primers and moloney murine leukemia virus reverse transcriptase. The hybrid intensity was analyzed with AtlasImage software and normalized with the sum of the four housekeeping genes. Four hybridizations from separate cell preparations were performed, and mean and SEM for the expression of each gene were calculated for statistical analysis. Among the 588 genes, approximately 80 genes ( approximately 13%) were aberrantly expressed. These included genes involved in cell-cycle regulation, signal transduction, stress response, apoptosis, cytokine production and growth-factor and hormone-receptor production and various oncogenes. These initial gene expression analyses for the first time showed potentially important aberrant gene expression patterns associated with arsenic-induced malignant transformation and set the stage for numerous further studies. Mol. Carcinog. 30:79-87, 2001. Published 2001 Wiley-Liss, Inc.
砷是一种人类致癌物。我们最近的研究表明，长期（>18周）、低水平（125 - 500 nM）的亚砷酸盐暴露可诱导正常大鼠肝细胞系TRL1215发生恶性转化。在这些砷转化细胞中，细胞内的S-腺苷甲硫氨酸池因砷代谢而耗尽，导致全基因组DNA低甲基化。DNA甲基化状态反过来可能影响多种基因的表达。本研究使用Atlas大鼠cDNA表达微阵列检测了与砷诱导转化相关的异常基因表达。从砷转化细胞和传代匹配的对照细胞中制备多聚腺苷酸（Poly(A+)）RNA，并用Clontech大鼠cDNA合成引物和莫洛尼鼠白血病病毒逆转录酶合成32P标记的cDNA探针。用AtlasImage软件分析杂交强度，并用四个管家基因的总和进行标准化。对来自单独细胞制备物的四次杂交进行了检测，并计算每个基因表达的平均值和标准误用于统计分析。在588个基因中，约80个基因（约13%）表达异常。这些基因包括参与细胞周期调控、信号转导、应激反应、细胞凋亡、细胞因子产生以及生长因子和激素受体产生的基因，还有各种癌基因。这些初步的基因表达分析首次显示了与砷诱导的恶性转化相关的潜在重要异常基因表达模式，并为众多进一步的研究奠定了基础。《分子致癌学》30:79 - 87，2001年。2001年由Wiley-Liss公司出版。
