The Role Of Ars2 On The Proliferation In Glioblastoma Cells

Glioblastoma(GBM) is the most common primary malignant brain tumor, representing 45.2% of malignant tumors and 15.6% of all primary brain tumors. It mainly occurred in the cerebral hemisphere. It is highly aggressive and deadly. At present, the main treatment is surgical resection, followed by adjuvant radiotherapy and chemotherapy, but the average survival of patients with glioma is still only 14 months. Therefore, in recent years a lot of research efforts to find a new therapy for glioblastoma.Arsenic resistance protein 2(Ars2) is as a gene product were isolated in hamster cell line for the first time, and found it is with arsenite resistant. Ars2 contains a number of domains, an amino terminal arginine rich domain, a central RNA binding domain, and a zinc finger domain, which are common in RNA-binding protein. Ars2 is a highly conserved gene, which is homologous to the plant and yeast. In recent years, studies found that Ars2 plays an important role in cell proliferation and biosynthesis of micro RNA, and it can bind to the promoter of Sox2 as a positive regulatory transcription factor in neural stem cells. However, there is little research on Ars2 in tumor, and its mechanism is rarely involved now. This paper mainly studies the effects of Ars2 on proliferation of glioma cell growth.Our results are as follows:1. Effects of Ars2 on the proliferation and growth of human glioblastoma cellsIn order to detect the effect of Ars2 on the proliferation of human glioblastoma cells,we used knockdown of Ars2 by infection with lentivirus-expressioning sh RNA in LN229 and U87. We used RT-PCR and Blot Western to detect the interference effect. After interfering with Ars2 in these two cell lines, the growth of cells was detected by MTT. The results showed that the cell growth was significantly inhibited after Ars2interference. Then we did the Brdu labeling experiment to detect the cell proliferation ability, the results showed that the Brdu labeled positive cells were significantly decreased compared with the control group, the cell proliferation ability was decreased after the intervention of Ars2. These results showed that Ars2 has important effects on the proliferation and growth of glioblastoma cells.2. Effect of Ars2 on the cloning of human glioblastoma cells and the ability of tumor formation in vivoTo detect the effect of Ars2 on the growth of glioblastoma cells in SCID mice. The experimental results showed that the growth rate of mice subcutaneous tumor after Ars2 down-regulation was significantly slower than that of the control group, and the tumor volume was significantly decreased. In the cell clone formation experiment, the number of clones that interfere with the formation of Ars2 cells decreased. From the above results, we can draw the conclusion that Ars2 plays a key role in the occurrence and development of glioblastoma.3. The effect of Ars2 on the cell cycle of glioblastomaCell proliferation and cell cycle are closely related. The results showed that the G1 phase of cells increased significantly, and the period of S decreased of Ars2 down-regulation by flow cytometry. Subsequently, we detected the cell cycle proteins, Compared with the control group, the expression of CDK2 and cyclin E2 after the intervention of Ars2 decreased. In the cell cycle progression, cyclin E2 and cyclin dependent kinase CDK2 complex is a key kinase complex from G1 phase to S phase, which has a crucial role in the cell cycle from G1 phase to S phase. CDK2 and cyclin E2 protein expression is reduced, the cell can not enter the S phase which DNA synthesis phase. These results indicate that the main block of the cells in the G1 phase of Ars2 down-regulation.4. A preliminary study on the mechanism of Ars2 on the proliferation and growth of glioblastoma cellsWe performed a gene chip analysis in neuroblastoma cells, and found that the effect of interference Ars2 on MAPK signaling pathway was relatively large. In recent years, many researches have been made on the MAPK signaling pathway. It is found that the MAPK signaling pathway is involved in the occurrence, metastasis, invasion, and regulation of cell growth and so on. So we suspect that whether Ars2 play an important role in the proliferation and growth of glioblastoma cells by MAPK signaling pathwayplays. Then we detected the MAPK signaling pathway related protein, PAK2, MEK, ERK, the results show that the protein expression of these proteins are reduced after the knockdown of Ars2. Therefore, we speculated that Ars2 is through the MAPK signaling pathway to influence the proliferation of glioblastoma cell growth, clone, tumorigenicity.