Abstract: OBJECTIVE: To use gene chip technology and bioinformatics to investigate PM_2.5-exposure on expression of genes related to carcinogenesis and mutagenesis in human bronchial epithelial (HBE) cells. METHODS: HBE cells were treated with 50 μg/mL water-soluble PM_2.5 for 24 h. Untreated cells were used as a blank control group,and three parallel samples were established. Extracted RNA samples were subjected to fluorescent-labeling,purification and hybridization to the chip. Collected data were pre-processed and statistically calculated using the Rosetta Resolver^® System (Rosetta Biosoftware) to analyze differentially expressed genes. The data were analyzed using the Cluster Profiler software for principal component and cluster analysis,and pathway and GO (Gene Ontolog) analysis. Differences in gene expression of HBE cells after PM_2.5 exposure were preliminarily investigated. Protein interaction relationships of differentially expressed genes were analyzed using the String protein interaction database,then the core protein with the largest number of nodes was selected. RESULTS: According to the preset screening conditions,245 differentially expressed genes were screened,including 27 up-regulated genes and 218 down-regulated genes. After further analyses,the top 10 up-regulated and down-regulated core genes such as PHACTR2,SFRP1,WFDC1 were screened out. The top 10 core differential gene by GO functional annotation enrichment analysis show that the differentially expressed genes were mainly enriched in molecular functions such as transmembrane receptor activity,receptor activity,cell signaling,and cell molecular conduction. Their mechanisms involved biological transmembrane transport,translocation of cells to lipopolysaccharide inorganic ions,and transport of cellular nutrients. The KEGG enrichment analyses show that the differentially expressed genes were mainly enriched in seven core pathways involved in tumor cell migration,bile metabolism related,neural activity,and genotoxicity. Protein interaction networking mapped out 5 core proteins including SST,BDNF,NCAM1,SSTR1 and Bcl2L11. CONCLUSION: Exposure of HBE cells to PM_2.5 showed differential expression of genes which are involved with carcinogenesis and mutagenesis. The information is useful for better understanding the carcinogenic effect of PM_2.5.

Key words: PM_2.5, human bronchial epithelial cells, gene chip, Gene Ontolog, KEGG enrichment analysis