Screening And Validation Of Lymph Node Metastasis Related Genes Of Gastric Adenocarcinoma Based On Bioinformatics Analysis

Background and Purpose:Lymph node metastasis is one of the important factors that affects the prognosis of gastric cancer.So far,there is no accurate and reliable judgement of preoperative lymph node metastasis in patients with gastric adenocarcinoma.We apply the bioinformatics analysis to screen and validate lymph node metastasis related genes of gastric adenocarcinoma.Methods: In our study,collect the microarray data of 186 cases of gastric adenocarcinoma and 33 cases of normal gastric tissue from TCGA database.Lymph node metastasis related genes were screened by SAM mathods and were analyzed by DAVID function annotation,GO and KEGG pathway analysis.Selected genes were validate by qRT-PCR and western-blot in 30 pairs samples.The expression of MDM4 and MDM2 were detected in 336 cases of gastric adenocarcinoma tissue and 33 cases of normal gastric tissue.The comparison of clinical and pathological characteristics were analysis between tumor patients.Results: Bioinformatics analysis showed MDM4 associated with lymph node metastasis of gastric adenocarcinoma,MDM2 do not related with lymph node metastasis of gastric adenocarcinoma,but associated with the occurrence of gastric adenocarcinoma.The results of qRT-PCR and western blot show m RNA and protein expression of MDM4 is higher in positive lymph node metastasis of gastric adenocarcinoma tissue than normal gastric tissue,but not in without lymph node metastasis of gastric adenocarcinoma tissue.The expression of MDM2 is higher in gastric adenocarcinoma tissue than normal gastric tissue,but is not related with lymph node metastasis.In our further study,the expression of MDM4 and MDM2 were detected in 336 cases of gastric adenocarcinoma and 33 cases of normal gastric paraffin embedded tissue.Results show the expression of MDM4 and MDM2 in cancer tissues were higher than in normal tissues,and MDM4 associated with lymph node metastasis,MDM2 is associated with the prognosis of gastric adenocarcinoma.Conclusions: Screening of lymph node metastasis related genes of gastric adenocarcinoma based on bioinformatics analysis is reliable.The expression of MDM4 and MDM2 in gastric adenocarcinoma were higher than normal gastric tissue.MDM4 expression associated with the lymph node metastasis of gastric adenocarcinoma,MDM2 expression is associated with the prognosis of gastric adenocarcinoma.