膀胱癌组织中K－ras基因点突变及其基因产物P21的表达研究

为在分子生物学水平探讨膀胱癌的发生发展以及恶性程度的判别和预后评价的指标，作者应用聚合酶链反应（ＰＣＲ）结合单链构象多态性分析（ＳＳＣＰ）和免疫组织化学方法，研究了５４例膀胱癌组织和５例正常膀胱组织的Ｋ－ｒａｓ基因第１２位密码子点突变和其产物Ｐ２１的表达情况。结果表明：５４例膀胱癌组织中，仅有４例Ｋ－ｒａｓ基因第１２位密码子点突变和３４例Ｐ２１蛋白阳性表达，并且浅表性肿瘤Ｐ２１阳性表达率明显低于浸润性肿瘤。提示Ｋ－ｒａｓ基因点突变在膀胱癌中发生率较低，Ｐ２１蛋白的过量表达主要是膀胱癌晚期表现，它可能与Ｈ－ｒａｓ和Ｎ－ｒａｓ基因突变有关。为肿瘤病因学研究和临床研究提供了有用的资料。

POINT MUTATION AND PROTEIN EXPRESSION OF K-ras GENE IN HUMAN BLADDER CANCER

Using polymerase chain reaction(PCR) and single strand conformation polymorphism analysis(SSCP)and immunohistochemical method,we examined the mutation at codon l2 of K-ras gene and expression of P21 protein in 54 cases of bladder cancer and the bladder tissue of 5 normals.The results revealed that point P21 reaction was found in only 4 cases,and P21 protein expression in spherical tumors was lower than that in invasive tumors.These results suggest there be a relatively low incidence at codon 12 of K-ras gene mutation in bladder cancer,and the over expression P21 positive may be a late event and be related to the mutation of H-ras or N-ras gene.