Long non-coding RNAs (lncRNAs) are emerging as key molecules in regulating many biological processes and have been implicated in development and disease pathogenesis. Biomarkers of cancer and normal tissue response to treatment are of great interest in precision medicine and for public health and medical management of disasters such as assessing radiation injury following accidental or intentional exposure. Circulating and functional RNAs, including microRNAs (miRNAs) and lncRNAs, in whole blood and other body fluids represent potential valuable candidates as biomarkers. Early prediction of possible acute, intermediate, and delayed effects of radiation exposure will enable timely therapeutic interventions. To address whether lncRNAs could serve as biomarkers for radiation bio-dosimetry, we performed whole genome transcriptome analysis in a mouse model after whole body irradiation. Differential lncRNA expression patterns were evaluated at 16-, 24-, and 48-hour time points post irradiation in total RNA isolated from whole blood of mice exposed to 1, 2, 4, 8, and 12 Gy of gamma-rays. Sham irradiated animals served as controls. Significant alterations in the expression patterns of lncRNAs were observed after different radiation doses at the various timepoints. We identified several lncRNAs known for DNA damage response as well as immune response as radiation induced biomarkers. Long non-coding RNA targets of tumor protein 53 (P53), Trp53cor1, Dino, Pvt1 and Tug1 and an upstream regulator of p53, Meg3 were altered in response to radiation. Gm14005 (Morrbid) and Tmevpg1 were regulated by radiation across all time points and doses. These two lncRNAs have important potential as blood based radiation biomarkers; Gm14005 (Morrbid) has recently been shown to play a key role in inflammatory response while Tmevpg1 has been implicated in the regulation of interferon-gamma. Precise molecular biomarkers will not only enable the development and effective use of medical countermeasures but also may be used to detect and circumvent or mitigate normal tissue injury in cancer radiotherapy treatments.
Overall design
48 samples of mouse whole blood in batches of 3 biological replicates taken 6, 16, 24, or 48 hr after irradiation dose 0, 1, 2, 4, 8, or 12 Gy.