| Glioma is an aggressive and poor prognosis tumor which account for more than50%of all primary brain tumors. The current standard treatment is surgical resection to the extent feasible, and follow by adjuvant radiotherapy plus temozolomide chemotherapy. But there are still90%of cases recurrent with strong radioresistance. In order to better understand the molecular mechanism of radioresistance of glioma, the study of expression profile and CNV were carried out to investigate the difference of gene expression and CNV regions before and after irradiation of gamma ray. We did our study with monoclone of T98G, and also selected eight monoclones which were used in expression and CNV array after irradiation of60Gy.The results showed that the different gene expression and CNV fragments in each monoclonal were different. The expression results showed that there were3473different gene expression in4b monoclone and168genes in In monoclone. The CNV results showed that there were380CNV regions in4d monoclone and235regions in In monoclone. In the expression array,4303differentially expressed genes were obtained among8monoclones, and199genes were significantly associated with survival of TCGA database, and the four genes, S100A4, BMP2, LGALS3, NNMT, were found in more than5monoclones. The results of CNV showed that there were14215different genes in the CNV regions among8monoclones. Compared with two platforms,1243genes were picked out from both arrays.The result of heatmap in expression profiles showed that there were two clusters in the8monoclones. The most significant difference of top30terms involving molecular function, biology process and cellular component were enriched in each monoclones with GO analysis. The enriched terms were lysosome, ECM-receptor interaction, focal adhesion, Wnt signaling, TGF-β signaling, hypoxia and p53, Aminoacyl-tRNA biosynthesis, and Glutathione metabolism. The results of pathway analysis were similar to GO.The LOH analysis showed that there were23LOH regions range from3M to108.9M in glioma, and21LOH regions range from4.2M to65.6M in lung cancer. Compared to control T98G, there were different LOH regions in each monoclone, and the regions mainly located in chromosome1,7,8and16. The UPD analysis showed that the UPDs existed in chromosome9and17in glioma, and no difference before and after irradiation.Based on the results of espression and CNV, LGALS3was picked out as candidate gene. The LGALS3was overexpression in5monoclones and amplified in5monoclones. The expression of LGALS3was significantly associated with survival, so we selected LGALS3 as candidate gene for function analysis. We also investigated the susceptibility between the polymorphism of LGALS3and glioma because radiation was the most important risk factor for glioma.LGALS3is a member of galectin family, and express in the cell cytoplasm and nucleus. LGALS3plays critical roles in proliferation, local adhesion, angiogenesis and apoptosis, but there are little studies in glioma.In order to investigate the relationship between genetic variants in LGALS3and glioma risk,961cases and1351controls were enrolled from East China.5tagSNPs in LGALS3were picked out for genotyping using the Illumina platform. Rs4644and rs4652were both missense mutation loci and located in exon3of LGALS3.The results showed that compared with wild genotype CC of rs4644, AA genotype could significantly increase the risk of glioma, adjusted OR=2.15,95%CI=1.25-3.72, P=0.006. In the recessive model, AA genotype could also significantly increase glioma risk compared with CC+CA genotype, adjusted OR=2.10,95%CI=1.22-3.62, P=0.007. The CC genotype of rs4652could significantly increase glioma risk compared with wild genotype AA, adjusted OR=1.29,95%CI=1.00-1.67, however, the P value is adjacent state0.054. Further stratified analysis revealed that rs4644was significantly associated both male and GBM, adjusted OR=2.07,95%CI=1.04-4.12for male, and adjusted OR=2.81,95%CI=1.46-5.38for GBM. Rs4652was significantly associated with female and GBM, adjusted OR=1.56,95%CI=1.03-2.37for female, and adjusted OR=1.44,95%CI=1.01-2.06for GBM. Our results showed that the two missense mutation loci rs4644and rs4652were significantly associated with the risk of glioma.According to the results of susceptibility, we reconstructed the Lentiviral expression plasmid A-C and C-A of rs4644-rs4652, and shRNA interference plasmid for LGALS3to study the functions in Cell proliferation, the chemosensitivity, migration, as well as cell cycle in glioma cell line T98G.The results indicated that changed the expression of LGALS3through either overexpression or interference could change the phenotype of T98G. The proliferation results showed overexpression of LGALS3could significantly improve the proliferative capacity of cells, but there were difference between control and interference cells. The survival rate of AC genotype was significantly higher than other groups after treated with TMZ, and the interference group was the lowest, and no difference between AC group and control. In migration experiments, the migration of overexpression of AC and CA were significantly faster than the control group and the interfering group, and interference cells almost no migration occurs. The cell cycle test results found that over-expression and interfere with LGALS3gene would cause the cells in S and G2phase increased, and the cells in G1phase decreased.In this study, we used microarray and CNV chip to explore the molecular mechanisms of glioma cells to radioresistance from the RNA and DNA levels, respectively, and obtained the genes and CNV fragments associated with radioresistance. We selected LGALS3gene as candidate gene to study its function in glioma cell, and found that LGALS3gene was significantly with glioma risk, and had critical roles in proliferation, migration and chemotherapy resistance of glioma cell line, and suggested that LGALS3was important in occurrence, development and prognosis of glioma, and the molecular mechamisms need further research.
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