Genetic and epigenetic profile changes associated with individual radiation sensitivity are well documented and have led to enhanced understanding of the mechanisms of the radiation-induced DNA damage response. However, the search continues to identify reliable biomarkers of individual radiation sensitivity. Herein, we report on a multi-biomarker approach using traditional cytogenetic biomarkers, DNA damage biomarkers and transcriptional microRNA (miR) biomarkers coupled with their potential gene targets to identify radiosensitivity in ataxia-telangiectasia mutated (ATM)-deficient lymphoblastoid cell lines (LCL); ATM-proficient cell lines were used as controls. Cells were 0.05 and 0.5 Gy irradiated, using a linear accelerator, with sham-irradiated cells as controls. At 1 h postirradiation, cells were fixed for γ-H2AX analysis as a measurement of DNA damage, and cytogenetic analysis using the G2 chromosomal sensitivity assay, G-banding and FISH techniques. RNA was also isolated for genetic profiling by microRNA (miR) and RT-PCR analysis. A panel of 752 miR were analyzed, and potential target genes, phosphatase and tensin homolog (PTEN) and cyclin D1 (CCND1), were measured. The cytogenetic assays revealed that although the control cell line had functional cell cycle checkpoints, the radiosensitivity of the control and AT cell lines were similar. Analysis of DNA damage in all cell lines, including an additional control cell line, showed elevated γ-H2AX levels for only one AT cell line. Of the 752 miR analyzed, eight miR were upregulated, and six miR were downregulated in the AT cells compared to the control. Upregulated miR-152-3p, miR-24-5p and miR-92-15p and all downregulated miR were indicated as modulators of PTEN and CCDN1. Further measurement of both genes validated their potential role as radiation-response biomarkers. The multi-biomarker approach not only revealed potential candidates for radiation response, but provided additional mechanistic insights into the response in AT-deficient cells.

中文翻译：

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ATM缺陷细胞的MicroRNA分析表明PTEN和CCDN1是潜在的放射反应生物标志物。

与个体辐射敏感性相关的遗传和表观遗传学变化已得到充分记录，并导致人们进一步认识了辐射诱导的DNA损伤反应的机制。但是，搜寻仍在继续寻找各个辐射敏感性的可靠生物标记。在本文中，我们报告了一种使用传统细胞遗传学生物标志物，DNA损伤生物标志物和转录微RNA（miR）生物标志物及其潜在基因靶标的多重生物标志物方法，以识别共济失调-毛细血管扩张突变（ATM）缺陷型淋巴母细胞系（LCL）的放射敏感性; 将ATM熟练的细胞系用作对照。使用线性加速器，将细胞以0.05和0.5Gy辐射，以假辐射细胞作为对照。照射后1小时，固定细胞进行γ-H2AX分析，以测量DNA损伤，并使用G2染色体敏感性测定，G带和FISH技术进行细胞遗传学分析。还通过microRNA（miR）和RT-PCR分析分离了RNA进行基因分析。分析了一组752 miR，并测量了潜在的靶基因，磷酸酶和张力蛋白同源物（PTEN）和细胞周期蛋白D1（CCND1）。细胞遗传学分析显示，尽管对照细胞​​系具有功能性细胞周期检查点，但对照细胞和AT细胞系的放射敏感性相似。所有细胞系（包括其他对照细胞系）中DNA损伤的分析表明，仅一种AT细胞系的γ-H2AX水平升高。与对照组相比，在分析的752 miR中，AT细胞中的8个miR被上调，而六个miR被下调。miR-152-3p上调，miR-24-5p和miR-92-15p以及所有下调的miR被指示为PTEN和CCDN1的调节剂。对这两个基因的进一步测量证实了它们作为辐射反应生物标记物的潜在作用。多种生物标志物方法不仅揭示了潜在的辐射反应候选者，而且还提供了对AT缺陷细胞反应的更多机制的见解。