Identification of Ferroptosis Biomarker in AHH-1 Lymphocytes Associated with Low Dose Radiation

The impact of long-term low-dose radiation on human health has always been a concern. Long-term low-dose gamma radiation causes cells continuous injury and causes chromosomal mutations to greatly increase the chance of cancer. Because it is significant to identify biomarkers for long-term low-dose gamma radiation, we investigate the influence of low dose rate on the gene expressions in the AHH-1 lymphocytes cell line (AHH-1 cells) for long-term irradiation. Different dose rates (7, 14, 26, 34, and 43 μGy h-1) of irradiation from gamma radiation in uranium tailings powder were used to irradiate AHH-1 lymphocytes. We used flow cytometry to test the apoptosis of AHH-1 lymphocytes at different dose rates and irradiation times (7-84 d). It was found that 14 μGy h-1 is the most sensitive dose rate of AHH-1 lymphocyte irradiation. The 7-, 14-, and 21-d (2.4, 4.8, and 7.2 mGy) irradiation groups were sensitive, and the 84-d (28.8 mGy) irradiation group was insensitive to low dose gamma radiation. Microarray analysis was conducted on the significantly differentially expressed genes (p<0.05) in the 2.4, 4.8, 7.2, and 28.8 mGy irradiation groups. We found that TFRC1, SLC3A2, SLC39A8, FTH1, ACSL4, and GPX4 are significant genes with low-dose radiation and were constituents of the ferroptosis signaling pathway. In the range of 0-4.8 mGy radiation dose, the expressions of these genes were downregulated with increasing radiation dose, while in the range of 4.8-28.8 mGy, its expression increased with increasing radiation dose. RT-PCR and Western blot were used to detect the mRNA and protein expression of these genes. The results were consistent with those from microarray analysis. Our findings indicate that expression of the TFRC, SLC3A2, SLC39A, FTH1, ACSL4, and GPX4 genes is sensitive to low-dose radiation, and they are main members of the ferroptosis signaling pathway. Therefore, there is a very important connection between ferroptosis and low-dose radiation, which has become a hot topic in international research. These results can provide reference to the effect of ferroptosis on human health with low-dose radiation.