Abstract: People who exposed to low-dose ionizing radiation chronically could have an increased risk of lens opacity. It is very important to clarify the mechanism of lens opacity induced by low-dose ionizing radiation for the prevention and early intervention of cataract. This paper describes the experiments that human lens epithelial cells SRA01/04 were irradiated with 0.2 Gy ¹³⁷Cs and 2 Gy ⁶⁰Co γ-rays. Differentially expressed mRNAs were screened by gene chip technology at 48 h after irradiation, 3 690, 3 304, and 3 970 differentially expressed genes were identified in 0.2 Gy vs 2 Gy, 0.2 Gy vs 0 Gy, 2 Gy vs 0 Gy groups respectively. Bioinformatic analysis showed that the majority of these genes are associated with oxidative phosphorylation, cell proliferation and adhesion pathways. The expression of genes (PIM1, HMGB1, BRE, JUN) related to cell proliferation in SRA01/04 and HLE-B3 cells were verified by real-time PCR at 24 h and 48 h after different doses of γ-rays. The results showed that in both cell lines, the expression levels of PIM1, HMGB1, and BRE at most low-dose irradiated groups were significantly higher than those in the non-irradiated group at 24 h after irradiation, and still showed an increasing trend at 48 h after irradiation. However, at 48 h after 2 Gy irradiation, gene expression levels decreased significantly or returned to baseline. The results showed that low-dose ionizing radiation induces significant alterations of mRNAs expression in human lens epithelial cells, the differentially expressed genes play some roles in series of important biological processes and functional pathways, which could be useful to reveal molecular mechanisms of low-dose ionizing radiation induced lens opacification or cataract.

Key words: low-dose ionizing radiation, lens opacity, bioinformatics, proliferation