Objective   To study the difference in gene expression profile in human HepG2 cells treated with low dose arsenic trioxide, and to explain the molecular biological mechanisms of inorganic arsenic treating in malignant cell.

  Methods   cDNA microarray technology was employed to detect gene profile expression differences from HepG2 cells treated with low dose arsenic trioxide and 0.9 percent sodium chloride.

  Results   Among 4 096 genes which were got from gene expression profile analysis, there were 137 different from those in GenBank in which 53 genes were up-regulated such as IGF2R, TXNRF2 DI, IL-18, HSPA1A, DDITA, DDIT4MAP2 K6, MAP2K2 and so on, also 75 genes were down-regulated such as CYP4B1, APOB, APOH, and SEPP1 so on in HepG2 cells treated with 5μmol/L arsenic trioxide than those treat with 0.9 percent sodium chloride.These genes differentially regulated by arsenic included human genes encoding proteins involved in, cell signal transduction related gene, immune regulation, cell proliferation and differentiation, oncongenes and tumor supptession genes, cell cycle related genes, extracellular matrix and skeleton related genes, suppression genes, cell cycle related genes, extracellular matrix and skeleton related genes, transcription factors, DNA damage and repair related gemes, apoptosis related gemes, and ribosomal protein related genes.

  Conclusion   cDNA microarray technology was successfully used to screen the genes eifferentially expressed in HepG2 cells treated with arsenic trioxide, which brought some new clues for studying the regulation mechanisms of arsenic in liver.These results pave a new evidence to readily explore molecular biologocal mechanisms and biomarkers seeking of arsenism.