The Expression Of P53 And Mdm2 In Simple Intestinal Metaplasia (SIM) And Atypical Intestinal Metaplasia (AIM) And Their Relationship To Gastric Adenocarcinoma

Objective:To investigate the expressions of p53 and mdm2 in intestinal metaplasia and gastric adenocarcinoma and explore their relationships.Methods:Biopsies from 58 cases of intestinal metaplasia(IM) were stained with HE and classified into SIM and AIM according to morphology changes of the epithelial cells. The same IM cases were identified typeⅠ, typeⅡand typeⅢIM based on different mucus substances.58 gastric IM and 30 gastric adenocarcinoma specimens were stained for p53 and mdm2 by Envision immunohistochemical technique. SPSS 13.0 for Windows was utilized for statistical analysis.Results:1. The positive expression of p53 was observed in SIM 25.81%(8/31), AIM 51.85% (14/27) and gastric carcinomas 56.67%(17/30) respectively. The expression of p53 in gastric carcinomas and AIM were higher than in SIM (χ2=6.0030, P<0.05) while no significant difference between AIM and gastric carcinomas (χ2=0.1328,P>0.05).2. The positive expression rates of mdm2 were observed in SIM 19.35%(6/31), AIM 51.85%(14/27) and gastric carcinomas 53.33%(16/30) respectively. The expression of mdm2 in gastric carcinomas and AIM were significantly higher than in SIM (χ2=7.6337, P<0.05) while no significant difference between AIM and gastric carcinomas (χ2=0.0125, P>0.05)Conclusions:1. p53 and mdm2 may take part in the transformation from IM to gastric carcinoma. The over-expression of p53 protein may play an important role in gastric intestinal meteplasia especially in AIM as well as early stage of gastric carcinoma. mdm2 may have a possible role in regulating the expression of p53 protein in IM.2. The detection of p53 and mdm2 proteins is a good help for researching AIM, and AIM may be involved as a preneoplastic lesion and therefore be an effective indicator in the clinical follow-up of gastric carcinoma patients.