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Genetic events associated with arsenic‐induced malignant transformation: applications of cDNA microarray technology †
Author(s) -
Chen Hua,
Liu Jie,
Merrick Bruce A.,
Waalkes Michael P.
Publication year - 2001
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/1098-2744(200102)30:2<79::aid-mc1016>3.0.co;2-f
Subject(s) - biology , complementary dna , gene expression , gene , dna microarray , microbiology and biotechnology , housekeeping gene , microarray , gene expression profiling , dna methylation , malignant transformation , cancer research , genetics
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 (∼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.