【摘要】 目的　研究 p16基因的突变及蛋白表达异常在人胰腺癌发生及侵润转移中的作用。方法应用 PCR、PCR- SSCP、DNA测序及免疫组织化学技术 ,对 35例人胰腺癌的 p16基因第 2外显子进行了检测 ,研究 p16基因的突变及蛋白表达情况。结果　 12例在 p16基因第 2外显子部分存在至少 5 2 2 bp的纯合缺失。 7例存在 2个点突变 (突变位点均相同 ) :其一为第 12 6密码子碱基 GTC→ AAT的错义突变 ,氨基酸由缬氨酸 (Val)变成了天冬酰胺 (Asn) ;另一为第 12 7密码子 GCA- GCG的同义突变。缺失及突变共占5 4.3% (19/ 35 )。P16蛋白三维结构模拟提示 ,Val12 6 Asn对蛋白空间结构有一定影响 ,从而影响 P16蛋白的功能。 12例缺失标本呈现 P16蛋白表达阴性 ,9例标本 (其中 7例点突变 )出现 P16蛋白表达下降 ,共占6 0 % (2 1/ 35 )。结论　p16基因的突变及蛋白表达异常 ,与人胰腺癌的发生、侵润转移及临床分期有明显的相关性 ,且有助于判断胰腺癌的恶性程度和患者的预后更多还原

【Abstract】 Objective To directly investigate the effect of genetic alteration(homozygous deletion and point mutation) and expression of p16 gene on pancreatic carcinomas. Methods Thirty five cases were analyzed for genetic alteration and expression of p16 gene by polymerase chain reaction(PCR), single strand conformation polymorphism(SSCP), DNA sequencing and immunohistochemical method. Results The analysis of pancreatic carcinoma for p16 gene revealed alteration in 19 of 35 cases, among which 12 pancreatic carcinomas had 522 bp homozygous deletion at least and 7 cases had two point mutations at the same site. One of them is 126th codon GTC→AAT (Val126Asn); the other is 127th codon GCA→GCG (A127A). The 3D (three dimensional)structure of P16 protein determined by computer techniques according to PDB indicated that Val126Asn influenced the space structure of P16 protein and affected the function of P16 protein. Twelve cases revealed no P16 protein and 9 cases showed low level expression of P16 protein. Conclusion The alteration of p16 gene and abnormal expression of P16 protein are significantly correlated with the biological behavior and clinical staging of pancreatic carcinoma and may hence be helpful to prognostication.更多还原