Microarray analysis of hub genes, non-coding RNAs and pathways in lung after whole body irradiation in a mouse model

Objective:Biomarkers of radiation injury are needed in planning therapeutic measures for cancer patients receiving radiation therapy and civilians exposed to nuclear events. Previous research has highlighted the impact of radiation damage, with cancer patients developing acute disorders including radiation induced pneumonitis or chronic disorders including pulmonary fibrosis months after radiation therapy ends. Discovery of biomarkers that predict these injuries will offer the potential to treat people proactively to mitigate this damage and improve quality of life. Recent research has highlighted the potential for messenger RNA (mRNA), microRNA (miRNA), and long non-coding RNA (lncRNA) to be used as radiation biomarkers. Our study focused on the changes in these RNAs at 48h after radiation exposure of mouse lung tissue to define biological pathway changes and determine potential biomarkers. Result: We observed sustained dysregulation of specific mRNAs, lncRNAs, and miRNAs across all doses. We observed gene dysregulation which can be used to develop both markers to identify no-exposure vs radiation exposure including Hba and Hbb mRNA which were dysregulated even at 1 Gy. We also observed genes which can indicate high dose exposure including Cpt1c and Pdk4. Gdf15, and Eda2r, mRNA markers of senescence and fibrosis, were the most significantly upregulated. Only three miRNAs were significantly dysregulated across all radiation doses, with miRNA-142-3p and miRNA-142-5p downregulated and miRNA-34a-5p upregulated. IPA analysis indicated that numerous pathways relevant to immune function, cell proliferation and survival decreased with increasing doses of radiation. This data highlighted early pathways of dysregulation depending on dose of exposure. This data will help with development of treatments and in medical decision-making. Further experiments are planned to develop medical countermeasures based on this early dysregulation. Six- to 8-week old female C57BL/6 J mice were given total-body irradiation (TBI) with X-rays using the Small Animal Radiation Research Platform (SARRP Xstrahl Ltd.). Mice were placed in plastic containers and exposed to a single surface dose of 1, 2, 4, 8, or 12 Gy at a dose rate of 1.05 Gy/min. Control mice (0 Gy) were placed in the same type of plastic container and sham irradiated. Three animals per dose were included in the study. Hearts of irradiated and control animals were harvested 48 h after TBI. Organs were snap frozen in liquid nitrogen and stored at − 80 °C until processed for RNA isolation. All animal experiments were performed at the Department of Pathology at New York University (NYU) Langone Medical Center under an approved IACUC protocol as part of a collaborative study.