The Expressions Of RACK1 In Gastric Cancer Tissue And To Discuss The Mechanism Of RACK1 On Growth And Proliferation Of Gastric Cancer Cells

ObjectiveStudy on Receptor ofactivated CKinase 1(Rack1)and the relationship between its occurrence and development in gastric cancer.To explore the effect and mechanism of Rack1 overexpression on the growth and proliferation of gastric cancer cells,which pay the experimental foundation for the new therapeutic target of gastric cancer.Methods1.Immunohistochemical SP method was used to detect the expression of Rack1 andβ-catenin protein in 70 human gastric carcinomas and 30 gastric carcinoma(distance from tumor edge≥10 cm)and surrounding tissues and analyze the expression of Rack1 in gastric cancer tissue and its relationship with clinical pathological features.2.To express the Rack1 DNA by using the Gene transfection technology and observe the effect of Rack1 gene increase on growth and proliferation of gastric cancer cell line HGC27 in vitro.The transfection experiment can be divided into untreated group,empty carrier transfection group and Rack1 transfection group.The cell proliferation was detected of MTT method,RT-PCR and blot Western methods were used to determine the expression of Rack1 and Wee1 gene m RNA and protein in each group of cells.3.Coimmuneprecipitation Immune confirmed the existence of interaction between Rack1 and Wee1 in gastric cancer cells.Through Indirect immunofluorescence test,observing if there is A total of positioning in Rack1 and Wee1 in HGC27 gastric cancer cells.Results1.Compared to the gastric surrounding tissues,the expression of Rack1 in gastric cancer decreases apparently(p<0.05),and it was related with TNM stage,tumor differentiation,and lymphatic metastasis.2.The loss ofβ-catenin in membrane was related with TNM stage,tumor differentiation,and lymphatic metastasis.Furthemore,the expression of Rack1 and the loss ofβ-catenin in membrane have a negative correlation3.The m RNA in Rack1 HGC27 in gastric cancer cell and protein levels were low significantly,overexpression of Rack1 gene expression inhibition of gastric cancer cell line HGC27 proliferation of Wee1 protein.4.Co-immunoprecipitation confirmed that Rack1 and Wee1 interact each other in the gastric cancer cells,and immunofluorescence proved Rack1 and Wee1 in the cytoplasm of HGC27 gastric cancer cell.Conclusions1.The abnormal expression of Rack1 in gastric cancer tissue may be involved in the occurrence and development of gastric cancer.This study suggests that low expression of Rack1 may be a poorly important indicator of the prognosis.2.Overexpression of Rack1 inhibits the growth and proliferation of poorly differentiated HGC27 gastric cancer cell line.The mechanism may be related to the interactions of RACK1 and Wee1.