CCNG1 and FDXR gene expression levels after radiation therapy in breast cancer patients

Introduction: Radiation biomarkers represent parameters which, through their quan­ti­fication, reflect the interaction of the biological system with ionizing radiation (IR) as а physical agent in the environment and are object of study of the biological dosimetry. Of all identified radioresponsive genes that consist “gene signatures” of IR, the gene for ferredoxin reductase, FDXR, is prominent with its promptness and relevance in estimation of exposition to IR. It is also known as adrenodoxin reductase. The gene for CCNG1 represents another in vitro and in vivo validated radiation biomarker involved. Materials and methods: In this non-randomized, controlled open-trial clinical study, 57 patients with diagnosed breast cancer and 50 healthy individuals were included. Isolation of RNA from 3 mL peripheral blood and gene expression analysis with qRT-PCR were performed for detection of expression of FDXR and CCNG1 genes. Results: A statistically significant difference in the threshold cycle was confirmed for FDXR and CCNG1 in the analyzed period between 24 and 48 h after radiation. Conclusion: Gene expression is emerging as a highly powerful readout for biodosimetry. Exposure to IR leads to many cellular responses including modification of gene expression. Many genes have been reported to be radiation-responsive at the transcriptional level and monitoring of their expression in blood samples can potentially be used for rapid, minimally invasive high-throughput biological dosimetry purposes.