Expression Of Apoptosis-associated Protein Dr5and C-FLIP In Different Human Gastric Tissues And Its Significance

Objective Via detecting the expression level of DR5and c-FLIP in gastriccancer(GC) tissues, chronic gastritis（CG）tissues and peficancerous normal gastrictissues, to analyse the role of these two proteins in genesis and development of gastriccancer and to offer a experiment proof for molecular mechanism of tumorigenesis andfind tumor marker in gastric cancer．Methods Expression of DR5and c-FLIP protein in40gastric cancer tissues,22peficancerous gastric tissues and16chronic gastritis tissues were observed byimmunohistochemistry method．Expression difference of these two protein wasdisplayed between dissimilar differentiation degree by SP method. Relativity of DR5and c-FLIP in gastric cancer with different degree of differentiation was carried outby statistic analysis. Protein expression of DR5or c-FLIP was detected in SGC-7901and MGC803cells by immunocytochemistry and Western-blot respectively.Results1. It showed by Immunohistochemistry method that DR5positive expression wasobserved in6case(27.27%) of22peficancerous gastric tissues, and in9case(56.25%)of16Chronic Gastritis(CG) tissues, and in31case(77.5%) of40gastric cancer(GC).Its expression in GC is much higher than that in peficancerous gastric tissues (P<0.01)or CG tissues (P<0.05). Its expression in CG tissue is higher than that inpeficancerous gastric tissues (P<0.05).2. The expression of DR5protein was40%(4/10),54.5%(6/11),78.95%(15/19)in well-, moderately-and poorly-differentiated adenocarcinoma respectively,whichexpression ratio was related to the degree of gastric cancer differentiation. Theexpression of DR5increased when degree of differention degraded(P<0.05).3. In regard to c-FLIP, there were4cases(18.18%) of22normal gastric tissueswhich showed positive expression of c-FLIP, however,34c-FLIP positive expressioncases (85%) of40gastric cancer,which was higher than peficancerous gastric tissues(P<0.01). There were5c-FLIP positive expression cases (31.25%) of16CGtissues, which was higher than peficancerous gastric tissues while slower than GCtissues.4. The expression of c-FLIP was associated with the degree of differentiation.which expression ratio was50%（5/10）,72.73%（8/11）,94.74%（18/19） in well-,moderately-and poorly-differentiated adenocarcinoma respectively. The positiveexpression of c-FLIP rised when degree of gastric cancer differentionreduced(P<0.05).5. The expression of DR5presented positively relativity with c-FLIP. But both ofthem were not associated with age, sex and lymph node metastasis of patients(P>0.05).6. It showed by immunocytochemistry method that DR5or c-FLIP positiveexpression was observed in SGC-7901and MGC803cells. Western-blot displayedthat neither DR5nor c-FLIP expression was difference in SGC-7901cells orMGC803cells.Conclusions1.The DR5expression was higher in gastric cancer tissue than in peficanceroustissue and CG(chronic gastritis)，which expression lifted gradually to follow lowerdifferentiation degree of gastric cancer．2.The c-FLIP is highly expressed in gastric cancer tissue than in peficanceroustissue and CG(chronic gastritis)，and its increasing expression is concerned with poordifferentiation degree of gastric cancer．3. Positive expression between DR5and c-FLIP suggested that they jointlyparticipate in carcinogenesis of gastric cancer.