口腔颊癌p16INK4/CDKN2基因的纯合子缺失与点突变  

Study of p16INK4/CDKN2 Gene Homozygous Deletions and Point Mutation in Squamous Cell Carcinoma of Buccal Mucosa

作　　者：董玉英[1] 王洁[2] 董福生[1] 王旭[2] 张英怀[3] 郭立华[3] 

机构地区：[1]河北医科大学口腔医院口腔颌面外科,河北石家庄050017 [2]河北医科大学口腔医院口腔病理室,河北石家庄050017 [3]河北医科大学第二医院口腔颌面外科,河北石家庄050017

出　　处：《华西口腔医学杂志》2006年第4期362-365,共4页West China Journal of Stomatology

基　　金：河北省科学技术研究与发展指导计划课题资助项目(052761998)

摘　　要：目的探讨p16基因纯合子缺失和点突变与颊癌发生、发展的关系。方法采用聚合酶链反应(PCR)、DNA单链构象多态性(SSCP)分析和DNA测序技术研究30例颊癌及10例颊黏膜白斑p16基因纯合子缺失和点突变的情况,并应用免疫组化检测基因改变组织中P16蛋白质的表达。结果颊白斑和正常颊黏膜无p16基因的纯合子缺失和点突变。在30例颊癌标本中,7例标本p16纯合子缺失,纯合子缺失率是23.3%(7/30);5例颊癌出现点突变,均发生在第2外显子上,点突变率为16.7%(5/30)。经DNA直接测序,发现5例点突变均为错义突变,其中3例突变位点相同,均在第99密码子上由GAT突变为AAT,由门冬酰胺取代门冬氨酸;对纯合子缺失和点突变的12例颊癌组织进行P16蛋白的检测,发现11例标本P16蛋白表达缺失,1例点突变标本表达正常。结论p16基因纯合子缺失和点突变是颊癌基因失活的主要形式,与颊癌的发生、发展密切相关。Objective To explore the correlation between homozygous deletions and mutation of p16 gene and the carcinogenesis and progression of squamons cell carcinoma of buccal mucosa. Methods Thirty buccal cancers, 10 leukoplakias and 8 buccal mucosas were involved. DNA was extracted from the tissues. PCR was used to analyses homozygous deletion of p16 gene. PCR-SSCP-DNA sequencing was performed to detect the point mutation of p16 gene. Immunohistochemical techniques were used to detect the expression of P16 protein. Results Gene deletions and point mutations were not found in leukoplakia and normal buccal mucosa. Gene deletions were found in 7 samples out of 30 cases of squamous cell carcinoma of buccal mucosa（23.3%）, while point mutations were found in 5 samples out of 30 cases of squamous cell carcinoma of buccal mucosa（16.7%）. Sequencing analysis showed that 5 eases point mutations were missense mutations, occurred on exon 2. Three eases occurred in the same point, codon 99 （GAT→AAT）. The result of immunohistochemical stains showed that 11 out of 12 cases gene inactivation did not expressed P16 protein. Conclusion Homozygous deletion and point mutation of p16 were the main pattern of gene inactivation in squamous cell carcinoma of buccal mucosa. There was a closely correlation between p16 gene inactivation and the carcinogenesis of squamous cell carcinoma of buccal mucosa.

关 键 词：颊黏膜 鳞状细胞癌 P16基因 纯合子缺失 点突变 

分 类 号：R739.8[医药卫生—肿瘤]