Identification of specific gene expression after exposure to low dose ionizing radiation revealed through integrative analysis of cDNA microarray data and the interactome

Background: accumulating reports suggest that the biological effects of low- and high- dose ionizing radiation (ldir and hdir) are qualitatively different and might cause different effects in human skin. materials and methods: to better understand the potential risks of ldir, we analyzed three cdna microarray datasets from the gene expression omnibus database. results: a pathway analysis showed that genes in immune-associated pathways were upregulated while those in cancer-associated pathways were downregulated in skin exposed to ldir as compared with non-irradiated control skin. consistently, according to a comparative gene ontology analysis, “antigen presentation and processing” was the most different gene ontology between the lidr and hdir transcriptomes. to identify key molecules regulated by ldir, we constructed a protein-protein interaction network analysis using topological metrics. one of the key molecules with a high network scores was e1a binding protein p300 (ep300), which is a potential target of a new therapeutic strategy to promote anti-tumor immunity. conclusion: our results showed that ldir exposure mainly induced the upregulation of immune-related genes including chemokines (cxcl1, cxcl2, and cxcl5) and interleukins (il1b, il11, il6, il15, and il7). additionally, ldir induced the upregulation of antigen processing and presentation-related genes including ciita, hla-dqb1, and kif26a, but these genes were downregulated in hdir-exposed skin. our protein network interaction results indicated that ep300 is downregulated by the immune response in skin after ldir exposure.