大肠癌的p53基因点突变  

p53 GENE POINT MUTATION IN HUMAN COLORECTAL CARCINOMA

作　　者：徐文怀[1] 杨定成[1] 万远廉[1] 白景香 李通[1] 李勇 王东民 

机构地区：[1]北京医科大学第一临床医学院外科

出　　处：《中华肿瘤杂志》1995年第5期328-331,共4页Chinese Journal of Oncology

摘　　要：作者以改良的ＰＣＲ－ＳＳＣＰ的ＰＣＲ直接测序方法，分析了２２例大肠癌原发灶和１例转移淋巴结组织中ｐ５３基因第七外显子的基因结构变化。发现２７％（６／２２）大肠癌原发灶和检测的１例转移淋巴结中存在ｐ５３基因第七外显子点突变，突变位点分别为２４５、２５１、２５９和２６０密码子。５０％点突变是２４５密码子中碱基Ｇ∶Ｃ向Ａ∶Ｔ转换，其它突变形式是碱基插入和碱基缺失。本研究ｐ５３点突变阳性标本均为结肠癌，其中低分化腺癌突变率高于高、中分化腺癌（Ｐ＝０．０１７８），ＤｕｋｅｓＣ１期突变率高于ＤｕｋｅｓＡ２、Ｂ期（Ｐ＝０．０３６１）。此结果提示，临床检测大肠癌原发灶和转移淋巴结中是否存在ｐ５３基因第七外显子突变，可有助于识别高度恶性的大肠癌和判断大肠癌病员的预后。Abstract We introduced two modified assay systems,PCR-SSCP and PCR-direct sequencing for the i-dentification of structure aberration at p53 exon 7 in 22 colorectal carcinomas and 1 metastaticlymph node.The data indicated that 27.2%(6/22)colorectal carcinomas and one metastaticlymph node were shown to contain the point matations in codons 245,251,259 and 260 of exon7.One half of all the mutations was G:c to A:T transition in codon 245.Other mutation patternswere base insertion.and deletion. All positive point mutations of p53 exon 7 existed in colon carci-nomas in this study.The point mutation in p53 exon 7 was usually associated with poorly differ-entiated primary carcinomas(P=0.0178)and the mutation rate of was higher in Duckes C stageof the disease than in stage Duckes A and B(P=0.0361).Thus p53 exon 7 point mutation in pri-mary colorectal tumors and regional lymph nodes may identity a subgroup of colorectal cancer pa-tients with more aggressive disease and may be as a new tumor markers for assessing the progno-sis of colorectal carcinomas.

关 键 词：大肠肿瘤 P53基因 基因突变 

分 类 号：R735.340.2[医药卫生—肿瘤]