Objective   To study the expression of P115 and MIF in gastric tissue and cells

and its significance in occurrence and progression of gastric cancer.    Methods   Protein and mRNA expressions of P115 and MIF in normal gastric mucosa

gastric cancer tissue

normal gastric epithelial cell line GES-1

and differentiated gastric carcinoma cell lines (MKN-28 and BGC-823) were detected by S-P

RT-PCR and Western blot analysis

respectively.    Results    The positive expression rate of P115 and MIF was significantly higher in gastric cancer tissue

than in normal gastric mucosa (73.3% and 80% vs 40% and 46.7%，P0.01). The expression of P115 was positively correlated with the expression of MIF （r=0.433

P=0.017）. The  protein and mRNA expression levels of p115 and MIF were significantly higher in gastric cancer tissue than in normal gastric mucosa（P0.01 ). Immunocytochemistry

Western blot and RT-PCR analysis showed that the protein and mRNA expression levels of P115 and MIF were higher in gastric cancer cell lines (MKN-28 and BGC-823) than in normal gastric epithelial cell line GES-1（P0.01 ). The expression levels of P115 and MIF was higher in poorly-differentiated cell line than in well-differentiated cell line（P0.05）.    Conclusion   Over-expression of P115 and MIF may play a synergetic role in the pathogenesis of gastric cancer. The mechanism underlying the interaction between P115 and MIF may be a potential target for the molecular mechanism of gastric cancer occurrence and progression.