Feasibility Study Of Radiation - Sensitive Genes As Biomarkers Of Radiation Damage Molecules

OBJECTIVE: Explore the does and time effects of radiation-sensitive genes in human peripheral blood after irradiation, and its distribution in healthy background levels, as well find the experimental evidences to confirm whether those radiation-sensitive genes could become a new molecular biomarker for early radiation injury.METHODS:1. Using primers and peobes specific validation, optimization of reaction temperature to establish a real-time PCR detection methods,then build the plasmid standards of candidate gene and establish standard curve. 2. After radiation with dose of 0, 0.5, 1, 2, 4, 6, 10 Gy by 60 Co γ-rays, total RNA was extracted from peripheral blood of three healthy adults at 0, 2, 4, 8, 12, 24 h post-radiation. Expression levels of TRAF4, DDB2, POLH, GADD45 A, TNFSF9 were measured by real-time PCR. 3. 29 healthy donors’ peripheral blood were collected as the background group to measure the expression levels of radiation-sensitive genes(TRAF4, DDB2, POLH, GADD45A)in different individuals. 4. C57BL/6 male mice were irradiated with 60 Co γ-rays at 0, 2, 8Gy in vivo. The gene expression changes were analyzed by real-time quantitative PCR at 0, 4, 8, 12, 24, 48, 72 h post-radiation.Result: 1. Established the Real Time PCR detection method successfully, constructed the plasmid standard of candidate genes, and established standard curve, these all laid the foundation for follow-up study. 2. TRAF4, DDB2, POLH, GADD45 A genes in human peripheral blood induced by radiation was increased in dose-dependent and time-dependent manners. It may have great potential as a molecular biomarker for the study of radiation injury. 3. The basal level of DDB2, POLH, GADD45 A were uniform distribution, which not affected by gender, age and other factors. However, TRAF4 were greatly influenced by age. 4. The time effect of TRAF4, DDB2, GADD45 A were differently between C57BL/6 male mice and human peripheral blood, it be caused by different species or differences in vivo and in vitro.CONCLUSION:The expression changes of TRAF4, DDB2, POLH, GADD45 A have potential to become a molecular biomarker for early radiation injury. Real Time PCR detection method established in this article is simple and fast, it will be hopefully developed into a new detection method for dose radiation diagnosis.