胃癌中p16基因表达、缺失及突变的检测

Expression,Mutation,and Deletion of p16 Gene in Gastric Carcinoma

目的:研究p16基因表达与胃癌发生发展、侵袭、转移的关系及p16基因外显子2缺失、突变在胃癌发生中的地位。方法:运用链霉菌抗生物素蛋白-过氧化酶SP免疫组织化学方法检测胃癌及癌前病变组织中p16蛋白的表达;采用聚合酶链反应PCR、聚合酶链反应-单链构象多态性PCRSSCP分析方法检测胃癌中p16基因外显子2的缺失、突变。结果:1p16蛋白表达阳性率:①正常胃粘膜96.25%77/80,不典型增生92.00%45/50,胃癌47.54%58/122,胃癌组中p16蛋白表达低于正常胃粘膜及不典型增生(P<0.05);②粘液腺癌10.00%,1/10低于低分化腺癌51.22%,21/41、未分化癌57.69%,15/26和印戒细胞癌62.50%,10/16(P<0.05);③30例原发癌和淋巴结转移癌配对标本中p16蛋白表达阳性率:原发癌46.67%(14/30),淋巴结转移癌16.67%5/30,淋巴结转移癌低于原发癌P<0.05;2p16基因缺失与突变分析:25例胃癌中检测出缺失5例但未发现突变。结论:①p16蛋白表达缺失与胃癌的发生、组织学类型及淋巴结转移有关。②p16基因外显子2缺失可能与胃癌发生有关而p16基因突变可能与胃癌发生无关。

Objective:This study was designed to investiga te the relationship between p16protein expression and gastric carcinogenesis,depth of in vasion,lymph node metastasis,and e valuate the role of deletion and muta tion of p16gene in exon 2in gastric carcinoma.Methods :p16protein expression in gastric ca rcinoma and precancerous lesion was examined by streptavidin-peroxidase conjugated(S-P)method;The deletion and mutation of p16gene were examined respectively by polymerase chain reaction(PCR)and polymerase chain reaction single-strand conformation polymorphis m analysis(PCR-SSCP)in gastric carcinoma.Results:①The positive rates of p16protein exp ression were 96.25%(77/80)in normal gastric mucosa,92.00%(45/50)in dysplastic gastric mucosa,and 47.54%(58/122)in gastric carcinoma.The positive rate of p16protein expr ession in gastric carcinoma was sign ificantly lower than that in normal gastric mucosa and in dysplastic gastric mucosa(P<0.05).②The positive rate of p16protein expr ession in mucoid carcinoma (10.00%,1/10)was significantly lower than that of poorly differentiated carcinoma (51.22%,21/41),undifferentiated carcinoma (57.69%,15/26),and signet ring cell carcinoma (62.50%,10/16)(P<0.05).③The positive rates of p16protein in30cases paired primary and lymph nod e metastatic gastric carcinoma were 46.67%(14/30)in primary gastric carcinoma,16.67%(5/30)in lymph node metastatic gastric carcinoma.The positive rate of lymp h node metastatic carcinoma was sign ificantly lower than that of primary carcinoma (P<0.05).④Evaluation of mutation and deletion of p16gene:There was no mutation of p16gene in ex on 2,but there were 5cases displayed deletio n of p16gene in exon 2in the 25primary gastric carcinoma.Conclusions :①The expression loss of p16protein is related to carcinogenesis,histopathological subtypes,and lymph metasta sis of gastric carcinoma.②The mutation of p16gene in exon 2may n ot be involved in gastric carcinogen esis.But the deletion of p16gene in exon 2might be involved in gastric carcinogenesis.