Chen Y H, Dong J P, Zhang S J
Department of Pathology, First Military Medical University, Guangzhou.
Zhonghua Bing Li Xue Za Zhi. 1994 Dec;23(6):327-9.
Non-isotopic PCR-SSCP method was used to detect point mutation of p53 gene in paraffin-embedded breast cancers. The abnormal shifting of the single-stranded DNA (ssDNA) was identified in 14 out of 60 cases. The point mutations of four cases were found in exons 5-6, three in exon 7 and seven in exon 8. The mutant p53 protein was detected by immunohistochemistry. The positive nuclear staining was observed in 13 cases, among which 11 cases showed abnormal shifting of ssDNA in SSCP analysis. The point mutations of the other two cases might occur in the regions which were not examined in this study. The point mutations of p53 were found in 5 cases in the absence of detectable protein. This probably resulted from the reduction or loss of antigenicity of p53 in some of the routinely processed tissues. Our results indicate that detection of point mutations of p53 gene by PCR-SSCP method is more accurate and reliable than that by immunohistochemistry and non-isotopic PCR-SSCP is especially useful in the screening of point mutations during handling a large number of samples.
采用非同位素聚合酶链反应-单链构象多态性（PCR-SSCP）方法检测石蜡包埋乳腺癌组织中p53基因的点突变。60例病例中有14例检测到单链DNA（ssDNA）异常迁移。4例点突变位于外显子5-6，3例位于外显子7，7例位于外显子8。采用免疫组织化学方法检测突变型p53蛋白。13例观察到细胞核阳性染色，其中11例在SSCP分析中显示ssDNA异常迁移。另外2例的点突变可能发生在本研究未检测的区域。5例未检测到可检测蛋白的病例中发现了p53基因的点突变。这可能是由于一些常规处理组织中p53抗原性降低或丧失所致。我们的结果表明，PCR-SSCP方法检测p53基因点突变比免疫组织化学方法更准确可靠，非同位素PCR-SSCP在大量样本检测中对筛选点突变特别有用。
