RESUMEN
Objective To compare the gene expression difference between 0.1 and 5 Gy X-ray irradiated cells,and to explore its possible mechanism.Methods A cDNA microarray corresponding to 45033 human genes was used to analyze the transcriptional profiles of normal human lymphoblastoid AHH-1 cells at 4 h after 0.1 or 5 Gy irradiation.The genes with a fold change ≥ 2.0 were identified as the differentially expressed genes.real-lime PCR and Western blot were used to confirm the expression of PERP.Results The microarray assay showed that there were 760 up-regulated genes and 1222 down-regulated genes in the cells at 0.1 Gy,while there were 744 genes down-regulated and 457 genes up-regulated in the cells at 5 Gy.In addition,55 genes were commonly up-regulated and 339 genes commonly down-regulated at 0.1 and 5 Gy.The predominant biological processes of the differential genes responding to low-dose radiation include cell-cell signaling transduction and DNA damage response,and the altered genes after 5 Gy irradiation were related to cell proliferation,differentiation,and apoptosis.Moreover,the expression of PERP gene was down regulated,which was consistent with the data of microarrey assay.Conclusions The quantitative and qualitative differences in the gene expressions may contribute to the diversed biological effects induced by low or high doses of ionizina radiation.