大肠癌患者粪便p53基因检测及其临床意义

目的: 研究大肠癌患者p53基因突变及蛋白表达之间关系,并探讨从粪便中检测p53基因突变在大肠癌早期诊断中的临床意义。方法: 采用聚合酶链反应单链构象多态性分析(PCR-SSCP)法,检测大肠癌患者癌组织和粪便标本中p53基因第5~8外显子突变情况;同时运用免疫组化法分析癌组织中p53表达情况。结果: 34例大肠癌患者癌组织标本中,p53基因第5~8外显子突变及蛋白表达阳性率分别为52.9%和55.9%,正常黏膜未见p53表达(P<0.01)。p53表达与基因突变呈正相关关系(P<0.05)。p53表达阳性率与肿瘤组织大小有关,肿瘤≤ 5cm者阳性率高于>5 cm者(P<0.05),但与其它临床病理因素无关。12例癌组织中有p53基因突变的患者其粪便中基因突变阳性率为41.7%,正常人未检测出突变。结论: p53基因突变是参与和影响p53表达和生物学功能的主要因素;大肠癌患者粪便中可检测出p53基因突变,粪便中p53基因检测可成为一种新的肿瘤标志物用于大肠癌的诊断及高危人群的筛检普查。

Detection of p53 gene in stool of patients with colorectal cancer and its clinical significance

Objective:To study the relationship between p53 gene mutation and the protein expression,and their roles in the early diagnosis and clinical significances in colorectal cancer.Methods:Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP),the mutations in exon 58 of p53 gene were examined in the tumor tissues and stool of 34 patients and 10 healthy controls.At the same time,using immunohistochemistry(IHC)(S-Pmethods),p53 protein expression were examined in the tumor tissues and normal mucosa.Results:The mutation of exon 58 and protein expression of p53 gene in the tissues were found in 18 of 34(52.9%) cases and 19 of 34(55.9%) cases,respectively,no mutation and protein expression were positive in normal mucosa(P<(0.01)).Of 12 patients who were positive for p53 gene mutation in tumor tissue,5(41.7%) had evidence of alterations in the p53 gene within the stool.The positive rates of p53 protein expression was correlates with the mutation of exon 58.The expression of p53 protein was correlated with tumor size(P<0.05),but not correlates to other cliniopathological factors.Conclusions:Our data indicate that gene mutation of p53 is one of the main factors which participate and affect the protein expression.p53 gene mutation can be detected within the stools.Detection of p53 gene in stool may provide new ways for the early diagnosis and census of high risk population in colorectal cancers.