Screening On High-through Differential Expressive Genes In Radon-exposed Mouse And Rat

Objective Based on the experimental animal model of radon exposure, the research is to screen and identify differentially expressed genes in peripheral blood cells, bone marrow and bronchi-bronchiole epithelial cells of mouse and rat, to provide with imformation in exploring molecule mechanism of radon induced lung cancer.Methods BALB/c mice and Wistar rats were exposed in a type HD-3 multifunctional radon-room, with the accumulative doses of radon-exposure group at 100WLM and control group at 0.8WLM. Each group of four mice or rats was exposed eight hours a day, six days a week. The animal model was confirmed by biological and pathological changes induced by radon. The total RNA was extracted from peripheral blood cells, bone marrow cells and bronchi-bronchiole epithelial cells respectively, and methods of SMART for dscDNA synthesis and supprssion subtractive hybridization (SSH) for gene screening were applied. Upon the contruction of the cDNA library enriched with differentially expressed genes, the pMD 18-T plasmid containing LacZ operator at the multiple cloning site was operated to allow a blue white screening. The TA clones were amplified by nested PCR and the reverse Northern dot blot was used to identify up and down regulation of the clones. The differently expressed cDNA was then sequenced and analyzed through the Genbank. Finally, some of the differentially expressed genes were further identified by Quantitative real-time PCR.Results A total of 1004 recombinant white colonies were randomly selected. Among 837 cDNA monoclones selected from both forward- and reverse-subtracted libraries, 126 were chosen to sequence for their differential expressions based on reverse Northern blot. Among the 126 sequenced clones, 44 clones were obtained to have function/annotation. 39 known fragments with unknown function/ annotation, 24 with repeated fragments and 19 unknown ESTs with the GenBank accessing numbers. Most of the known function/annotation genes were revealed to be related with oxidative damage, cell proliferation, cellular apoptosis, DNA damages and carcinogenesis. These results of the screened genes may provide important clues for further investigations of the adversemolecular events induced by radon exposure.Conclusions1. The animal model of radon exposure was established and the cDNA libraries of peripheral blood cells, bone marrow cells and epithelial cells was constructed successfully.2. Fourty four known function/annotation genes were found related to oxidative damages, cell proliferation, cellular apoptosis, DNA damages and tumor promotion, and fifteen unknown ESTs were obtained the GenBank accessing numbers.3. Radon exposure could up and down regulate a series of genes, result in pathological damages and promotion of cancer.