Ras基因P53基因在食管癌贲门癌的过度表达及相互关系的探讨

目的探讨食管癌、贲门癌的发生与癌基因、抑癌基因的作用及相互关系.方法对60例食管癌、贲门癌进行了病理分析及Ras癌基因蛋白和P53抑癌基因蛋白单克隆抗体免疫组化对比分析.结果P21蛋白总阳性率为90.0%(占36例食管癌86.1%,24例贲门癌95.8%),P53蛋白总阳性率为93.3%(食管癌94.4%,贲门癌91.7%),且2组病例在P21蛋白阳性表达和P53蛋白阳性表达方面均无显著性差异(P＞0.05);同时还发现P21阳性表达在肿瘤分化程度上不具有显著性差异,而P53阳性表达在中、低分化组明显增强,说明P21阳性表达在肿瘤发生发展过程中起着持续作用,而P53阳性表达在肿瘤发展的某一阶段起着重要作用.结论提示食管癌和贲门癌的发生发展在癌基因激活和抑癌基因失活等方面具有相似之处,支持食管癌和贲门癌在肿瘤发生及其它生物学特性方面属同一类肿瘤的观点;P53蛋白的过度表达可作为判断该肿瘤生物学行为的一个敏感可靠的指标;Ras癌基因的激活、P53抑癌基因的突变及失活在食管癌和贲门癌的发生发展中是否具有协同关系尚待进一步研究.

DISCUSS OVEREXPRESSION AND INTEERRELATION OF Ras GENE AND P53 GENE IN ESOPHAGUS CANCER AND CARDIA CANCER

Objective To discuss the relationship between the genesis of esophagus cancer and cardia cancer and the role of oncegene and suppressive genes.Methods Pathology and expression of Ras gene and P 53 gene were analysed in 60 cases of esophagus cancer and cardia cancer using immuohistochemistry method.Results The positive expression rate of P 21 was 90.0% in 60 cases of tumor ( that was 86.1% in 36 cases of esophagus canceramd 95.8% in 24 cases of cardia cancer ),and that of P 53 protein was 93.3% (esophagus cancer 94.4% and cardia cancer 91.7% ).There was no marked difference between the two groups in the positive expression of P 21 and P 53 protein(P>0.05).There was no marked difference between the differentiation degrees of tumor in the positive expression of P 21 protein,but in that of P 53 protein they were more evident in the medinm and low differentiation groups of tumor.It suggested that the role of positive expression of P 21 protein might be persistent in the genesis and development of tumor,and the positive expression of P 53 protein might play an important role in a certain phase of development of tumor.Conclusion The genesis and development of esophagus cancer are kindred with those of cardia cancer in the way of oncegene activation and suppressive genes lose activation.It agrees with the viewpoint that esophagus cancer and cardia cancer belong to the same genus in the genesis and biology actions of tumor.Overexpression of P 53 protein may be regarded as a susceptive and credible index judged by biology actions the tumor.It needs more studiesd to determine whether Ras oncegene activation cooperates with P 53 suppressive genes mutation and loses activation in the genesis and development of esophagus cancer and cardia cancer.