| Absract:Objective:This study through detected the distribution and expression level of AQP-4 in meningiomas and normal brain tissue,to explore the correlation between the expression of AQP-4 in meningioma and the clinicopathologic classification of meningioma, and explore its relationship the peritumoral edema and the mechanism. Method:46 cases of meningiomas tissues specimenes and 20 cases of non-tumor tissues were subjected to immunohistochemical staining (SP) for AQP-4. The meningiomas tissues were obtained from 46 patients undergoing meningiomas resection at the Department of Surgery, the Affiliated Hospital of Luzhou Medical College. No patient had received Steroids therapy before surgery. Detailed clinicopathological parameters including age, sex, degree of meningiomas and degree of PTBE are as following. There were 16 males and 30 females. Their ages ranged from 19 to 75. All the specimens were dealt with formalin fixation, paraffin imbedding and section-cutting. After deparaffinage and hydration, we rinsed the sections with distilled water and soaked them in phosphate buffer saline. Then they were subjected to an antigen retrieval procedure by heating. Endogenous peroxidase activity was blocked using 3% H2O2 solution and nonspecific binding sites were blocked by incubating with goat serum. The slides were incubated with appropriate primary antibody (Rabbit anti-AQP-4 Polyclonal Antibody). Wait 2 hours and then wash them with PBS. The second antibody with biotin labeling were dropped to the slides and incubated. Wait 15 minutes and then wash them with PBS. After that, the slides were incubated with S-A/HRP for 25 minutes and then washed with PBS. Immunologic reaction was developed using DAB. The slides were counterstained with hematoxylin, mounted and then observed through microscope. Consider the cells whose cytoplasm or nucleus had brownish yellow matter as positive cells. The AQP-4 positive signal was localized in both cytoplasm and nucleus, but predominantly in nucleus. They were divided into 4 levels according to proportion of positive cells and colour depth of each slice. Experimental group on the preoperative imaging data to determine the extent of peritumoral edema and to compare the corresponding degree of peritumoral edema in meningiomas AQP-4 expression; Experimental group to collect different clinicopathol ogical AQP-4 expression level in the data, the use of statistical data obtained from the SPSS software. Results:There were no expression of AQP-4 protein in the parenchymal, in addition to microvascular foot processes of astrocytes surrounding membrane region in the normal brain tissue of control group. In experimental group, the positive expression of AQP-4 were 26 cases (56.5%), that means appeared mass granules with brown or buffy. Among the total:the expression of weakly positive (+), positive (++), strongly positive (+++) were 16 cases (34.7%),6 cases (13.1%),4 cases (8.7.5%) respectively. There were statistical significance in the differences (P<0.001)between the experimental groups and control groups to the expression of AQP-4.The expression of AQP-4 concerned with pathological grade of meningioma, there were 10 cases express AQP-4 in 24 cases which were gradeâ… of meningiomas, the expression was 41.7%, there were 9 cases express AQP-4 in 14 cases which were gradeâ…¡of meningiomas, the expression was 64.3%.The expression of AQP-4 was 7 cases in 8 cases gradeâ…¢of meningiomas, the rate of expression was 87.5%. The expression of AQP-4 in high-level meningiomas was higher than the low-level meningiomas, and there were statistical significance in the differences(X2=35.41, P<0.05).The expression of AQP-4 concerned with meningioma which were different severity of brain edema (0,â… ,â…¡,â…¢grade) and there were statistical significance in the differences (X2=28.93, P<0.001).Combined in this study we can see that the expression of AQP-4 levels increased with PTBE trend. Conclusion:1.The expression of AQP-4 in meningioma higher than in normal brain tissue, and mainly in the nucleus of meningioma cells. The expression of AQP-4 increased more significantly following the histological grade increased of tumor. This suggests that:The expression of AQP-4 is reflected in the indicators of tumor cell proliferation which relate to clinical pathology of meningiomas intimately, and may be associated with the growth and differentiation of tumor cell.2. The high expression of AQP-4 was positively correlated with the severity of meningioma peritumoral edema, which indicated that AQP-4 involved in- formation of meningiomas and peritumoral edema.Therefor,AQP-4 played an important effect on deteriorating clinical symptoms of meningioma patient and pathogenetic condition after operation.3. Vasogenic brain edema as well as cellular brain edema is involved in the formation of peritumoral brain edema in meningioma.4. The expression and control mechanism of AQP-4 in meningiomas need further study. Exploring whether or not use the inhibitor, activator or control the regulation mechanism of AQP-4 to balance the secretion and absorption of fluid, which will become the direction of treatment to cerebral edema. |
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