p21WAF1基因多态性与胃癌易感性关系

目的:探讨p21WAF1基因缺失与多态性及其意义。方法:采用聚合酶链反应-限制性片断长度多态性(PCR-RFLP)法和链霉菌抗生物素蛋白-过氧化酶(SP)法分别检测胃癌中p21WAF1基因缺失与多态性和p21蛋白表达。结果:PCR扩增显示,30例胃癌和45例非胃癌标本均无p21WAF1第二外显子缺失。PCR-RFLP发现胃癌和正常胃粘膜p21第二外显子多态性分别为26.7%(8/30)和8.9%(4/45),有显著性差异(P<0.05),且8例具多态性胃癌标本中的正常胃粘膜亦具有这种多态性。p21蛋白阳性表达率,胃癌为43.3%(13/30),非胃癌为100%(45/45),两者有显著性差异(P<0.05),具p21WAF1基因多态性胃癌为37.5%(3/8),与无多态性胃癌45.5%(10/22)无相关性(P>0.05)。结论:胃癌中p21WAF1基因无缺失,而存在多态性。p21WAF1基因多态性和p21表达与胃癌发生有关,但两者无相关性。WAF1

Relationship between p21WAF1 gene Polymorphism and Carcinogenesis in Gastric Carcinoma

Objective:To inverstigate the relationship between p21 WAF1 gene polymorphism and carcinogenesis in gastric carcinoma.Methods :Deletion and polymorphism of p21 WAF1 gene in exon2and expression of p21protein were examined by polymerase chain reaction -restriction fragment length polymorphism (PCR-RFLP)analysis and streptavidin-peroxidase conjugated (SP).Results:There was no deletion of p21 WAF1 gene in exon2in30cases of gastric carcinama and45cases of non-gastric carcinama,but polymorphism of p21 WAF1 gene in exon2was found in26.7%(8/30)of gastric carcinoma and8.9%(4/45)0f non-gasstric carcinoma,difference between both was signiticant (P<0.05),and polymorphism of p21 WAF1 gene also was examined in normal gastric mucosa of8cases of gastric carcinoma with polymorphism.The positive expression rates of p21protein were43.3%(13/30)of gastric catcinoma and100%(45/45)of normal gastric mucosa(P<0.05),and the frequency of p21protein positivety of gastric carcinoma with and without polymorphism were37.5%(3/8)and45.5%(10/22)respectively,there was no significant correlation between both of them(P>0.05).Conclusions :There is polymorphism and no deletion of p21 WAF1 gene in gastric carcinoma ,the polymorphism of p21 WAF1 gene and loss of p21protein expression may be involved in gastric carcinogenesis,and there is no significant association between poly-morphism of p21 WAF1 gene and expression of p21protein.