Genetic background modulates lincRNA-coordinated tissue response to low dose ionizing radiation

Long noncoding RNAs (lncRNAs) are emerging as key regulators of diverse cell functions and processes. However, the relevance of lncRNAs in the cell and tissue response to ionizing radiation has not yet been characterized. Here we used microarray profiling to determine lncRNA and mRNA expression in mammary glands of BALB/c and SPRET/EiJ mice after low-dose ionizing radiation (LDIR) exposure. We found that unirradiated mammary tissues of these strains differed significantly in baseline expressions of 290 lncRNAs. LDIR exposure (10 cGy) induced a significant change in the expression of many lncRNAs. For BALB/c mice, a total of 357, 480, and 335 lncRNAs and 550, 911, and 389 coding RNAs were identified at 2, 4, and 8 weeks post-irradiation, respectively, while for SPRET/EiJ, a total of 327 lncRNAs and 424 mRNAs were identified at 4 weeks post-irradiation. Low dose radiation induced changes in mRNA and lncRNA expression were measured in mouse mammary gland tissues at 2,4 and 8 weeks after radiation exposure in BALB/c and 4 weeks after exposure in SPRET/EiJ mice. BALB/c: 3 timepoints (2wk, 4 wk, 8 wk); 3 replicates per timepoint; 2 treatments per timepoint (10 cGy x-ray and sham). SPRET/EiJ: 1 timepoint (4 wk); 3 replicates per timepoint; 2 treatments per timepoint (10 cGy x-ray and sham).