Radiation-Induced changesin expression of genes related to DNA damage response in lymphocytes of human peripheralblood

Abstract

：Objective To detect the expression of DNA damage responsegenes induced by radiation in human peripheral blood lymphocyte,and to explore the newbiomarkers of radiation.Methods The human peripheral blood cells were irradiated to X-raysat different doses of 0,1,2,3,4,and 5 Gy.The quantitative real.time qPCR wag used todetect the expressions of cyclin-dependent kinase inhibitor l a gene(Cdknl a)and growtharrest and DNA damage inducible gene(Gadd45a)in lymphoeytes at 4 and 24 hpost-irradiation,respectively.The method of CB mieronucleus was used to determine thechange of micronucleus ratio.Results The expression of Cdknl a in peripheral bloodlymphocytes wag increased significantly at 4 and 24 h post-irradiation to 0-5 Gy.reachedthe peak at 4 Gy and began to decrease at 5 Gy,which showed a dose-dependentmanner(r=0.946,0.975,P<0.05).Similarly,the expression of Gadd45α in human peripheralblood lymphocytes was also increased significantly at 4 and 24 h post-irradiation to 0-5Gy in a dose-dependent manner,while the expression of Gadd45a at 4 h wag higher than thatat 24 h(r=0.936,0.797,P<0.05).The ratio of micronuclei wag increased significantly at 4and 24 h post-irradiation to 0-5 Gy(r=0.990,0.984,P<0.05).Conciusions Cdknl a andGadd45α expression could be increaged significandy at 4 and 24 h post-irradiation to 0-5Gy,showing a good linear relationship.which might be candidate for radiation biologicaldosimeter. Key words: Radiation; Human peripheral blood lymphocytes; Cdknla; Gadd45