粪便脱落细胞中p53基因突变检测对大肠癌诊断价值的探讨

Evaluation of the diagnostic value of p53 gene mutations detection in the stool exfoliated cell to patients with colorectal carcinoma

目的探讨利用PCR—SSCP分析技术进行粪便脱落细胞中p53基因突变检测用于大肠癌早期筛选诊断的可能性。方法对40例大肠癌患者留取手术切除的癌组织及术前保存的粪便。分别从肿瘤组织及粪便中提取DNA。应用基因扩增．单链多态性分析。溴乙锭（PCR—SSCP—EB）染色方法检测两种标本中p53基因扩增情况及第5、6、7、8外显子突变情况，进行对照分析。结果p53基因特异性扩增产物及5，8外显子突变在肿瘤组织及粪便脱落细胞中广泛存在。肿瘤组织中p53基因突变27例，粪便中24例，其p53突变检出的敏感性为60％，无粪便中检出突变而肿瘤组织未检出者，两种标本中突变检出部分符合率为100％。结论检测粪便脱落细胞中p53基因突变为大肠癌的早期诊断提供了可能性。

Objective To evaluate the possibility of using PCR-SSCP technology detecting mutations of p53 gene in the stool exfoliated cell to screen early stage colorcctal carcinoma. Methods For 40 patients with colorectal carcinoma, surgically resected tumor specimens and stool samples attained before operation were examined for mutations of exons 5 - 8 of p53 gene with the technique of polymerase chain reaction-single strand conformation polymorphism（PCR-SSCP） and ethidinm bromide （EB） staining. Results Both the specific amplified production and mutations of p53 gent occurs frequently in the tumor specimens and stool samples. Of the 40 carcinoma specimens, mutations of p53 gene occurred in 27 cases（67.5%）. In the group of stool samples, the figure was 24. The sensitivity for p53 mutation detection was 60%. Conclusion The detection of p53 mutations in stool samples is expected to serve as a possible way in colorectal carcinoma screening.