Study Of The Expression And Role Of RGS16 In Glioma And Its Relationship With P53

Background: Being charactered as highly invasion, frequent recurrence and poor prognosis, gliomas are the most frequent tumor (about 40% of brain tumor) in human brain. And the tumorgenesis of glioma is a very complicated muti-steped course and a lot of gene alteration involved in it. Our former study showed RGS16 might promote the progression of cell cycle of rat glioma C6 cell. Regulators of G-protein signaling (RGS) proteins are a new family which has been learned in recent years. Family members are defined by a shared RGS domain, which markedly stimulates the GTPase activity of Ga subunits leading to their negative regulation of G-protein signals and plays an important role in cell growth and differentiation, cell motility, and intracellular trafficking. Among the members of RGS family, only RGS 16 can be induced by wide type p53 gene. Overexpression of RGS16 can inhibit G protein-coupled mitogenic signal transduction and activation of the mitogen-activated protein kinase (MAPK) signaling cascade. Thus, deep study of the expression and role of RGS16 in glioma and its relationship with protein 53 is of great significance to clarify the cause of glioma and is helpfulto the prevention and treatment of it.Objectives: To detect the expression of RGS 16 in human glioma and its relationship with p53 in vivo and vitro level; to construct C6-RGS16 glioma cell model which showed a stable expression of RGS 16 to observe the effect of RGS16 gene on C6 cell in its biology behavior, and thus provide a tentative theoretical basis for gene therapy for glioma.Methods: (1) Immunohistochemistry SABC method was used to exam the expression of RGS16 and P53 in 42 cases of human gliomas and the results were statically analyzed. (2) After C6 cells were transfected with pEGFP-C3-wt p53 or treated by epirubicin (400ng/ml) respectively for Oh, 4h, 8h, 16h, 26h, 32h and 52h, the cells were fixed respectively and the expression of P53 and RGS16 protein was detected by immunocytochemistry. (3) Acquired the RGS16 gene fragment from pBKS-RGS16 by Sma VXho I and inserted it to pIRES2-EGFP and thus constructed plasmid pIRES2-EGFP-RGS16 successfully. Respectively transfected pIRES2-EGFP-RGS16 and pIRES2-EGFP to C6 cell and selected the cell model C6-RGS16 and C6-GFP by geneticin, which showed a stable expression of RGS16 and pIRES2-EGFP respectively. Observe the effect of RGS16 gene on C6 cell in cell cycle, proliferation and the capability of cell clone formation by flow cytometry, cell growth curve and clonogenic assay in plant.Results: (1) In 42 gliomas, 37 cases (88.10%) expressed RGS16 in the glioma cells, and in 10 adjacent noncancerous brain tissues, 8 cases expressed RGS16 in neurons, but not in gliocytes. The difference between the normal tissue and the glioma was observed (P<0.05). The expression of P53 in the adjacent brain tissues and gliomas were 0 and 15 respectively, and the difference was observed (P<0.05). However, the expression of RGS16 and P53 was not realated to the different tumor type and pathologic grades...