GAS41 Is Essential For The Growth Of Glioblastoma Cells

Background:Glioblastoma multiform is the most common malignant brain tumor in adults with high invasion,high mortality and poor prognosis.The survival of the patients is generally only 12 to 15 months.Because of the heterogeneity of glioblastoma multiform and the existence of stem cell-like cell groups,it is very difficult to treat it.Until now,there is still no effective treatment for GBM,so it is necessary to research the pathogenesis of glioblastoma multiform.GAS41 was discovered due to the amplification in glioblastoma multiform.Through the analysis of TCGA database,we find that GAS41 was amplified in various tumors and the m RNA expression level in glioblastoma multiform is significantly higher than that in normal neurons,which suggests that GAS41 protein may play an important regulatory role in glioblastoma multiforme.It can be seen that GAS41 may also become a new therapeutic target for glioblastoma multiform.Objective:The purpose of this study was to investigate the role of GAS41 in the growth and development of glioblastoma multiform.Methods:Firstly,through the TCGA database,we learned about the mutation and expression of GAS41 in glioblastoma.We selected two glioblastoma multiforme cell lines(U87,T98G)as experimental cell models,and then knocked down GAS41 by RNA interference technique.After getting the cell model with low GAS41,the cell phenotypes were detected by this cell model.We detected the tumor cell proliferation by MTS test,detected the tumor stem cell self-renewal ability by limiting dilution assay,detected the cell cycle and apoptosis by flow cytometry.At the same time,the GAS41 knocked-down cell line were analyzed by RNA high-throughput sequencing.We hope to find the regulatory mechanisms.Then the mechanism of hypothesis will be verified by western-blot.Results:1.GAS41 is amplified in glioblastoma multiforme and its expression level is higher.2.GAS41 protein level in glioblastoma multiform cell lines was knocked down by RNAi technique.3.When GAS41 is knocked down,the proliferation of glioblastoma multiform cells is obviously inhibited,the self-renewal of tumor stem cells is obviously inhibited,the cell cycle is arrested in G0/G1 phase.The percentage of early and late apoptosis cells increase significantly.4.RNA-seq analysis show that the co-upregulated genes in two U87-MG cells with low GAS41 are enriched in the Cell cycle pathway and the p53 gene is up-regulated,and the co-downregulated genes are enriched in the PI3K/AKT pathway.Conclusion:GAS41 plays an important role in the growth of glioblastoma multiforme.Through effecting the cell cycle and apoptosis of tumor cells,GAS41 regulates the growth of glioblastoma multiforme.