Expression Changes And Correlation Analysis Of LncRNA-mRNA In UVC-radiated CD4 Cells

Long non-coding RNAs(IncRNAs)are a class of non-coding RNAs(>200 nt in length),which can affect gene expression and participate in the regulation of various cellular processes.However,it is not clear which genes or signaling pathways are regulated by IncRNA in radiation-induced DNA damage response.The tumor suppressor gene p53 can respond to DNA damage,regulating the transcription and translation of its downstream genes.A number of key genes on the p53 signaling pathway can be used as radiation biological dosimeters.In previous studies human lymphocytes(CD4 cells)were treated with ultraviolet radiation(UVC),and the results showed that UVC caused DNA damage within the optimal dose range(4-64 J/m2).In this study,the expression changes and the correlation between IncRNA-mRNA were analyzed in UVC-radiated CD4 cells,and the regulation relationship between lncRNA and genes related to p53 signaling pathway was explored to reveal the possible role and regulation mechanism of lncRNA in DNA damage response.In the present study,the intracellular reactive oxygen species(ROS)were first detected to analyze the oxidative stress levels in CD4 cells at 24 h after UVC radiation.The results showed that UVC significantly increased endogenous ROS production in a dose-dependent manner within the UVC(4-32 J/m2)dose range.Microarray analysis of gene expression profiles and lncRNA expression profiles showed that the number of both differentially expressed mRNA and lncRNA increased accompanied with the increase of UVC radiation dose.Stem analysis performed to observe the trend of genes and lncRNAs expression changes,and the results showed that the expression levels of 1372 genes and 133 lncRNAs were significantly decreased,while the expression levels of 729 genes and 797 lncRNAs were significantly increased.Real-time quantitative PCR results confirmed the expression changes of partial mRNAs and lncRNAs,consistent with the microarray results.Regression analysis showed that the expression of PLK2,ISCU,LCE1F and TRIAP1 showed a power or exponential trend within the UVC(4-32 J/m2)dose range.Low-dose(45 8 J/m2)and high-dose(16,32,64 J/m2)data were analyzed seprarately.The results showed that 159 and 788 genes appeared co-expression changes in the low-dose and high-dose groups,respectively.Sequently,MetaCore database was utilized to analyze p53 regulatory network based on these genes,and the results revealed that 38 genes were regulated by p53 gene in both high and low dose groups.LncRNA Disease database was used to screen lncRNAs possibly involving in human diseases from the upregulated-lncRNAs.Four IncRNAs(TP53TG1,LINC00115,GAS6-AS1,TERC)were found to be associated with human diseases,particularly cancer.Analysis of the most relevant top 200 IncRNA-mRNA co-expression showed that the p53 signaling pathway was the most relevant signaling pathway in the low-dose group.Cytoscape software was used to analyze the regulatory relationship between lncRNA-mRNA.The results showed that there were positive and negative regulatory relationships between one lncRNA and multiple mRNAs.Further,lncRNA-mRNA correlation analysis revealed that 13 lncRNAs such as LOC338799 were most likely involved in the regulation of p53 signaling pathway.In summary,lncRNAs were differentially expressed in response to UVC-induced DNA damage,and may play a role in DNA damage response through the p53 signaling pathway.This study provides important experimental guide for screening lncRNA as new radiation dosimeters in the future.