Study On The Significance Of Expression Of Bmi-1 And P16 Gene In Gastric Adenocarinoma

ObjectiveTo investigate the roles of Bmi-1 and p16 genes and proteins in the pathogenesis and progression of gastric adenocarcinoma.MethodsThe protein expression of Bmi-1 and p16 were detected by immunohistochemical P-V method in 78 cases of gastric adenocarcinoma and adjacent gastric mucosa tissues;in 30 cases of gastric adenocarcinoma and adjacent gastric mucosa tissues, mRNA of Bmi-1 and p16 expression detected using Semi-quantitative RT-PCR.The correlation of Bmi-1 and p16 was analyzed.Results1.In the group of gastric adenocarcinoma,the positive rate of Bmi-1 protein was significantly higher than that in the adjacent gastric mucosa tissues (66.7% VS 19.2%,p=0.000);The positive rate of p16 protein was significantly lower than that in the adjacent gastric mucosa tissues(35.9% VS 69.2%, p=0.000).2.The higher relative expression level of Bmi-1 mRNA was found in 30 cases gastric adenocarcinoma,than that of adjacent gastric mucosa tissues (0.285±0.119 VS 0.029±0.118, p=0.000);but lower relative expression level of p16 mRNA was detected than that of adjacent gastric mucosa tissues(0.044±0.016 VS 0.238±0.029, p=0.000). 3.Different expression leves of Bmi-1 and p16 proteins could be observed among different histological grade: histological gradeⅠ-Ⅱ: 43.5%,65.2%,histological gradeⅢ:81.8%,36.4%;At the different clinical stages,the positive of Bmi-1 and p16 proteins were different, clinicalⅠ-Ⅱs tage: 27.1%,77.1% ,clinicalⅢ-Ⅳstage: 83.3%,40%; in metastatic lymph nodes : 88.2%,33.3%, without metastatic lymph nodes: 63%,59.3%;and infiltrating depth of tumor gradeT1: 25%,62.5%, in grade T2T3: 82.9%,48.6%. The expression of p16 protein was unaffected by the depth of cancer invasion (P=0.455),and other groups compares the difference to be remarkable(P<0.05).The expression level of Bmi-1 and p16 mRNA were different at the histological grade, histological gradeⅠ-Ⅱ: 0.142±0.038,0.080±0.010,histological gradeⅢ: 0.343±0.094,0.037±0.011;and at the clinical stageⅠ-Ⅱ:0.262±0.116,0.052±0.015, clinical stageⅢ-Ⅳ: 0.381±0.149,0.024±0.013,and without metastatic lymph nodes : 0.156±0.128,0.073±0.019, in metastatic lymph nodes: 0.295±0.093,0.050±0.011 ; and infiltrating depth of tumor gradeT1: 0.251±0.068,0.112±0.018 , in grade T2T3: 0.313±0.116,0.097±0.526.In the infiltrating depth of tumor grade ,p16 mRNA was no statiatically significant(p =0.136), and other groups compares the difference to be remarkable(P<0.05).4.In the protein and mRNA level, negative correlation could be found between Bmi-1 and p16 (r=-0.507,p=0.000;r=-0.408,p=0.025respectively)Conclusions1.In the protein and mRNA level,overexpression of Bmi-1and lower expression of p16 in gastric adenocarcinoma suggested that Bmi-1 gene activation and p16 gene deactivation might closely ralate with the progress of originating of partial gastric adenocarcinoma.2. Overexpression of Bmi-1and(or) lower expression of p16 might have correlation with the low differentiation ability of gastric adenocarcinoma cell and gradully gain the attacking.