The Expression Of ARID1A In Human Gliomas And The Mechanism On Its Biological Behavior

Part I The expression of ARID1 A in normal brain tissues and gliomatissuesObjective: In this study, we aimed to detect the expression of ARID1 A in normal brain tissues and glioma tissues in human and to analyze its correlation with clinicopathological features.Methods: RT-PCR and Western blot were used to detecte the expression of ARID1 A in human brain glioma tissues and normal brain tissues. In addition, we examined whether ARID1 A expression levels have relations with age, sex, KPS score, WHO grades or recurrence.Results: We found that ARID1 A m RNA and protein levels were both significantly lower in gliomas tissues than those in normal brain tissues(P < 0.001), and ARID1 A m RNA and protein levels were decreased with the advancement of WHO grades I-IV. Part II Correlation and clinical significance of expression of ARID1 A inserum of glioma patientsObjective: We aimed to investigate the correlation and clinical significance of ARID1 A in serum of glioma patients.Methods: High performance liquid chromatography was performed in blood samples of 83 patients and 46 healthy controls, then clinical significance(pathological grading, age and KPS score) and prognosis of ARID1 A were analyzed in the same population. Besides, the relationship between ARID1 A expression levels and pathological grading, age or KPS score was analyzed at the same time, respectively.Results: We found that the concentration of ARID1 A in serum of glioma patients was significantly lower than that in the healthy controls(P < 0.001). Moreover, the ARID1 A expression was closely related to pathological grading, age and KPS score(P < 0.05), while no relationship was found between ARID1 A expression and gender, preoperative epilepsy, or tumor range(P > 0.05). Besides, the overall survival time of patients with high ARID1 A expression was significantly longer than those with low ARID1 A expression according to Kaplan-Meier analysis(P = 0.005). Cox regression analysis illustrated that ARID1 A expression was a potential factor for prognosis of glioma patients and it might be an independent biomarker(P = 0.002, HR = 4.992, 95% CI = 1.831-13.611). Part III The impact on glioma biological characteristics by regulation ofARID1A expressionObjective: To explore the effect and mechanism of ARID1 A gene expression on the invasion and metastasis of glioma cells in vivo and in vitro experiments.Methods: ARID1A(RNAi2801) stable low expression cell line was established by chronic virus transfection, while ARID1A(WV0081) over-expression cell line was stably transfected by plasmid. The expression levels of ARID1 A were determined by q RT-PCR and Western blot, respectively. The migration, invasion and proliferation abilities in glioma cells and normal brain cell lines were detected by transwell and MTT experiments. What’s more, the apoptosis of cells was detected by flow cytometry. In addition, the U251 cells were inoculated in nude mice to construct the tumor model. The gross tumor volumes were measured dynamically. The expression of p53 and C-myc were performed by q RT-PCR and Western blot.Results: We established down-regulated expressed and over-expressed cell lines. After the changes of ARID1 A expression, the migration, invasion, proliferation and apoptosis abilities of glioma cells were changed significantly in vitro. Over-expression of ARID1 A can significantly increase p53 expression and remarkably decrease C-myc expression, while the expression of p53 decreased significantly and the expression of C-myc increased remarkably with low expression of ARID1 A. The role of ARID1 A gene in the tumor suppressor gene was described. In vivo, the tumor mass in the low expression group was higher than the high expression group.Conclusions:1 ARID1 A may play an important role in the development of glioma.2 The down-regulation of ARID1 A can be a promising marker in predicting the prognosis of glioma patients.3 We conclude that up/down of ARID1 A expression in glioma cells can decrease/increase the invasion and metastasis of glioma. Overexpression of ARID1 A can increase the expression of p53 and decrease the expression of C-myc, while low expression of ARID1 A decreased the expression of p53 and increased the expression of C-myc.