P21~(ras)、P16在大肠癌中的表达及临床意义

目的探讨癌基因P21~(ras)及抑癌基因P16与大肠癌的关系。方法应用免疫组化SP法分析、研究了P21~(ras)蛋白、P16蛋白在80例大肠癌、20例大肠腺瘤及20例正常大肠组织中的表达。结果①P21~(ras)在前二者中的阳性表达率分别为70.1％(57/80)和65％(13/20),明显高于在正常组织中的30％(6/20),其比较具有显著性差异(x~2=17.66、P<0.005;x~2=5.23、P<0.05);P16在大肠癌中的阳性表达率为36.3％(29/80)低于在腺瘤及正常组织中的65％(13/20)和75％(15/20),其比较亦具有显著性差异。②P21~(ras)、P16的阳性表达率在大肠癌患者的年龄、性别及肿瘤大小方面无显著性差异,而与肿瘤的临床Dukes分期(x~2=6.20、P<0.025;x~2=6.25、P<0.05)、有无淋巴结转移及术后5a生存率密切相关。③P21~(ras)在不同的大肠癌组织病理类型中,其表达率无显著性差异;P16的阳性表达率随着肿瘤浸润深度的增加有下降趋势,但无统计学意义。④在80例大肠癌患者中,P21~(ras)阳性而P16阴性者比率高于其他三者,而且这类大肠癌患者的术后5a生存率下降。结论大肠癌的发生、发展,是由包括癌基因、抑癌基因在内的多种因素作用的结果;在临床工作中联合检测P21~(ras)及P16蛋白在大肠癌中的表达水平,对我们估计患者的病情、推测其预后有指导性意义。

Expression of P21~(ras) P16 protein in colorectal carcinoma and its clinical implication

AIM To study the relationship between oncogene and TSG and colorectal carcinoma by P21~(ras) protein and P16 protein. METHODS By means of immunohistochemistry, the expression of gene product was conducted. Eighty cases of colorectal carcinoma, 20 adenoma and 20 normal tissues were studied by the method of immunohist ochemical S-P. RESULTS The positive expression rate of P21~(ras) was 70% (57/80), 65% (13/20) and 30% (6/20) respectively, the former two were higher than the latter, with statistical significance (x~2=17.66, p<0.005 and x~2=5.23, p<0. 05). P16 protein positive rate of 36% (29/80) in colorectal carcinoma was markedly lower than 65% (13/20) in adenoma and 75% (15/20) in normal tissues (x~2=9.75, p <0.01 and x~2=5.42, p<0.025). Neither P21~(ras) nor P16 protein expression was correlated with the patient age, sex and size of the tumor. On the contrary, it was significantly associated with the Duke's stage (x~2=6.20, p<0.025 and x~2=6.25, p<0.05, lymph node metastasis (x~2=8.06, p<0.005 and x~2=5.44, p<0.025) and postoperative survival rate. There was no significant correlation between P21~(ras) protein expression and histologic type of the tumor. The deeper the carcinoma invaded, the higher the positive rate of P16 protein expression, but the difference was not significant. There is an inverse effect between P21~(ras) gene and P16 gene. The shortest survival rate was found in the patients with colorectal carcinoma having positive P21~(ras) protein and negative P16 gene (p<0.01), and the proportion of these patients was higher than the others. CONCLUSIONS P21~(ras) and P16 gene varied in the formation and development process of colorectal carcinoma, it may be a useful means to predict the severity and the prognosis in patients with colorectal carcinoma by detecting the expression of P21 protein and P16 protein.