| BackgroundGastric cancer(GC)is the second leading cause of cancer-related deaths worldwide.Most patients are found to be in advanced disease and have lost the opportunity for surgery.Biomarkers,especially those for pre-warning and early detection of GC are of great importance to improve the survival chance of patients,but all of the biomarkers can be non-specific and insensitive in the early diagnosis of GC.In the preliminary study,we have been completed the study on the expression,functions and mechanisms of MG5 in GC.The study was to investigate the expression level and changes of MG5/LAMP2 A in GC tissues,as well as the different expressions of MG5/LAMP2 A in GC cell lines and normal gastric mucosa cells,In order to r study the value of MG5/LAMP2 A in early warning,the prognosis judgement of GC,we compared the expression of MG5/LAMP2 A with that of cytological function and systemic clinicopathological study in patients with GC.MethodsIn this study,100 patients with GC and adjacent tissue microarrays(100 cases)and their complete clinical follow-up data were collected from Tumor Hospital of Tianjin Medical University,Xijing Hospital Affiliated of Air Force Medical University and Ruijin Hospital of Shanghai Jiaotong University from January 2004 to September 2007.Immunohistochemistry(IHC)was used to detect the expression of MG5/LAMP2 A protein in tumor cell.PCR was used to analyze the gene expression of LAMP2 A in order to analyze the transcription level of gastric mucosal cells and different human GC cell lines at the level of nucleotides.The expression levels of protein in tissues,paracancerous tissues and normal gastric mucosa cells were different.The expression of MG5/LAMP2 A was down-regulated by interfering plasmid transfection,and the expression of MG5 in GC cells after down-regulated LAMP2 A gene expression was detected by WB.Human GC cells and original GC cells were tested for cell function to evaluate the differences in biological behavior of GC cells.Results1.IHC and tissue microarray were used to detect the expression of LAMP2 A in GC tissues.There were 59 cases with high expression of LAMP2 A in 100 GC patients,while only 39 cases with positive expression in adjacent tissues.The difference was statistically significant(P = 0.015).2.The expression of MG5/LAMP2 A protein in GES-1 cells was significantly lower than that in GC cell lines(P < 0.05);the expression of MG5/LAMP2 A messenger RNA in GES-1 cells was significantly lower than that in GC cell lines(P <0.05).-The expression of III and AGS(P < 0.05).3.Univariate and Multivariate survival analysis(COX risk regression model)showed that MG5/LAMP2 A protein expression was an independent risk factor for prognosis of patients with GC(P < 0.05).4.The proliferation,invasion,migration and cell viability of the interfered GC cells were significantly decreased by cell cloning,MTT,scratch and Transwell invasion tests,and the difference was statistically significant(P < 0.05).Conclusions1.The expression of MG5/LAMP2 A protein is an independent risk factor for the prognosis of gastric cancer patients.Gastric cancer patients with high expression of MG5/LAMP2 A protein have poor prognosis.2.The transcription and translation of MG5/LAMP2 A gene in gastric cancer tissues are more common in paracancerous tissues.It is believed that the occurrence and progression of gastric cancer are related to the expression of MG5/LAMP2 A.3.MG5/LAMP2 A expression can promote the proliferation,and invasion of gastric cancer cells,and suggest that the expression of MG5/LAMP2 A is associated with the mechanism of biological behavior of gastric cancer. |
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