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Background gliomas are the most common nervous system tumors, can be derived from a variety of neuroectodermal mesenchymal cells, and even parenchymal cells, incidence, and were more common in malignant, difficult to eradicate traditional surgery, often with its recurrent malignancy constantly increased, leading to a large number of patients maimed, killed, great harm. Radiotherapy, chemotherapy efficacy is far from satisfactory. As the tumor is deepening the concept of genetic diseases, gene therapy developed new techniques to overcome this kind of tumor diseases brought hope. NDRG2 (N-myc downstream regulated gene 2) gene was my mentor Professor Deng Yanchun first discovered in 1999 in the new normal brain tissue and glioma differentially expressed genes in the low expression or no expression of the latter, while In the former high expression. Series of studies showed that the gene is also a variety of low malignant tissue expression, whereas in the corresponding normal tissues with high expression. NDRG2 recombinant proteins on tumor cell lines to intervene or malignant cell line transfected with the gene and found that the malignant phenotype of these cells decreased significantly. Therefore, the tumor suppressor gene as a candidate gene, and its role in the mechanism of tumor suppressor series of studies in order to develop their clinical value. NDRG2 play function may be expressed by its protein product in different signal transduction pathways play different roles achieved. PI3K-AKT pathway in the development and progression of glioma often abnormal activation promote its further evolution to malignancy. Study abroad in the insulin signaling pathway, we found NDRG2 AKT substrate is, by its regulation of phosphorylation. Since NDRG2 widely expressed in various tissues, suggesting that it may play multiple and important functions, these functions can also be played by different or the same signal transduction pathways involved. Therefore, in order to initially explore glioma NDRG2 protein kinase AKT relationship, we designed the following experiment. Experimental methods: 1. Collect clinical glioma resection specimens in 24 cases, according to WHO histological grade of Ⅱ, Ⅲ, Ⅳ grade of eight cases, cryogenic freezing preservation. Total protein were extracted, BCA determined concentration. Cultured glioma cell lines U87 and U251, application concentration of 10uM of PI3K inhibitor LY294002 treated cells 1 hour, inhibition of endogenous PI3K activity, protein extraction method with the former. (2) using a semi-quantitative protein Western-blotting method for determination of total protein content in the same NDRG2 protein, AKT2 protein, 332 serine phosphorylation of NDRG2 protein (P-NDRG2-SER332), 348 threonine phosphorylated protein NDRG2 (P-NDRG2-THR348), 474 AKT2 serine phosphorylated protein (P-AKT2-SER474) content of different pathological levels of statistical analysis of the specimens and the various protein content in between. 3 in the U87 and U251 glioma cell lines, the still determined using Western-blotting of these proteins in the application of LY294002 inhibited PI3K-AKT pathway changes before and after phosphorylation and analyzed. The experimental results 1. Western-blot detected in Ⅱ, Ⅲ, Ⅳ grade glioma specimens, with pathological grades of glioma increased, NDRG2 protein expression decreased, the difference between the level of statistical significance, P lt; 0.05. AKT2 protein in each sample were expressed glioma, 474 AKT2 serine phosphorylated protein (P-AKT2-SER474) in 58% of glioma specimens expression; 332 serine phosphorylation of NDRG2 protein (P- NDRG2-SER332) and 348 NDRG2 threonine phosphorylated protein (P-NDRG2-THR348) in Ⅱ, Ⅲ, Ⅳ grade glioma specimens of varying concentrations were Ⅲ grade gliomas in the highest expression level . 2 in most high expression of P-AKT2-SER474 samples, P-NDRG2-SER332 and P-NDRG2-THR348 low or no expression; contrary, in the low or no expression of P-AKT2-SER474 samples, P -NDRG2-SER332 and P-NDRG2-THR348 highly expressed. 3 in the cell lines U87 and U251, NDRG2 protein phosphorylation amount PI3K inhibition were decreased. P-NDRG2-SER332 protein and P-NDRG2-THR348 protein expression in both cell lines after PI3K inhibition of phosphorylation were decreased. In cell lines U87 and U251, AKT2 protein was expressed, P-AKT2-SER474 protein expression in U87 cells, inhibition decreased; while in U251 cells after the inhibition of either no expression. Conclusion 1. NDRG2 protein levels in different pathological differentially expressed in gliomas, with pathological grade increased, the levels decreased significantly (P lt; 0.05), to support its tumor suppressor genes. 2 in glioma, NDRG2 phosphorylation is not dependent on phosphorylation of AKT2 and AKT2 protein phosphorylation, and there may be competition. 3. NDRG2 is one of PI3K downstream signaling molecules, in addition to AKT2, there are other PI3K downstream kinase molecule can be phosphorylated NDRG2.
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