Expression And Correlationship Of Apoptosis-inducing Factor(AIF) And Mutant P53(mp53) Protein In Gastric Cancer And Gastric Precancerous Lesions

Background Gastric carcinoma is one of most outstanding malignant tumor in the world. There are multiple factors and many procedures participate in the stomach tumorigenesis, including disregulation of proliferation-apoptosis mechanism. Apoptosis-inducing factor (AIF) is one of novel difunctional protein in organism, one of its function is inducing caspase-independed apoptosis, the other is acting as a redox in mitochondria of normal cells and colon cancer cells. Many evidence is still required to identify which function of AIF maybe executing in the development of gastric tumor. p53 gene is called "guardian of the genome", for its function in cell cycle arresting and inducing apoptosis. In the progression of most somatic tumor, there are isolocus deletion and/or spot mutation taken place in the gene, making it lost its tumor-suppressing function. Expressions of mutant p53(mp53) are researched in several preceding experiments, however, their research consequences are quite different, further validating is needed.Objective To investigate the expression diffenrences of AIF and mp53 protein among gastric carcinoma (GC), non-invasive high grade neoplasia (HGN), non-invasive low grade neoplasia (LGN), intenal metaplasia (IM) and chronic atrophic gastritis (CAG), and to identify the relationship between AIF and mutant p53 expression in gastric precancer-carcinoma sequence.Methods Expression of AIF and mp53 were assessed by immunohistochemistry staining in 40 cases formalin-fixed and paraffin embedded gastric cacer tissues and adjacent mucosa, incluing 19 intestinal type GC,11 diffuse type GC and 10 mixed type GC,18 HGN,27 LGN,33 IM,35 CAG. Results Expession of AIF and mp53 are found in all the groups. The tissue scores of AIF and mp53 in gastric cancer and precarcinoma tissues were significantly higher than those in the normal glands of CAG (P< 0.01), but no significant differences in tissue score of mp53 were detected between IM and CAG (P> 0.05). AIF expression in GC and HGN were higher than its expression in LGN and IM (P< 0.05) and tissue scores of mp53 in GC, HGN, LGN were significant higher than those in IM (P< 0.01). None of the clinicopathological characteristics, including age, gender, histological subtypes, the depth of invasions, metastasis, was associated with the scores of AIF and mp53 in gastric cancer (P> 0.05). Expression of mp53 had no prominent correlation with the AIF expression in every group (P> 0.05).Conclusions The upregulation of AIF and mutant p53 expression were early events in gastric carcinogenesis. AIF maybe act as a oxidoreductase in those processions, but more further immediate evidences are needed to identify our hypothesis. Expression of mp53 had no prominent correlation with the AIF expression in gastric tumorigenesis.