Kyritsis A P, Xu R, Bondy M L, Levin V A, Bruner J M
Department of Neuro-Oncology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
Mol Carcinog. 1996 Jan;15(1):1-4. doi: 10.1002/(SICI)1098-2744(199601)15:1<1::AID-MC1>3.0.CO;2-O.
This study examines the relationship between p53 immunostaining and direct sequencing of polymerase chain reaction (PCR) products in 61 gliomas. Glioma tissues obtained from patients at surgery were analyzed immunohistochemically with the monoclonal antibody PAb1801 to detect p53 protein abnormalities. Amplified p53 cDNA from these samples was analyzed by direct sequencing. Four grades of p53 immunostaining were evaluated: grade 0 = no labeling, grade 1 = less than 5% labeled cells, grade 2 = 5-30% labeled cells, and grade 3 = more than 30% labeled cells. Twenty-six of 36 glioblastomas, 14 of 23 anaplastic gliomas, and none of two low-grade gliomas had positive p53 immunoreactivity. Direct sequencing of PCR-amplified p53 cDNA revealed that 10 glioblastomas, 11 anaplastic gliomas, and no low-grade gliomas had mutations. Comparison of p53 immunostaining and sequencing data revealed that among all the gliomas, mutations were found in three of 21 with p53 grade 0, one of 16 with p53 grade 1, seven of nine with p53 grade 2, and 10 of 15 with p53 grade 3. These results indicate a good correlation between the p53 immunostaining and sequencing data when the percentage of abnormal cells within the tumor was greater than 5% (p53 grades 2 and 3). However, the correlation was poor when the percentage of abnormal cells was less than 5% (p53 grade 1) because of the limited sensitivity of sequencing techniques. Thus, p53 immunostaining may be more accurate in detecting p53 alterations when the percentage of abnormal cells is small; however, in rare cases, p53 immunostaining may fail to detect mutations confirmed by sequencing.
本研究检测了61例神经胶质瘤中p53免疫染色与聚合酶链反应（PCR）产物直接测序之间的关系。手术中获取的神经胶质瘤组织用单克隆抗体PAb1801进行免疫组织化学分析，以检测p53蛋白异常。对这些样本中扩增的p53 cDNA进行直接测序。评估了四级p53免疫染色：0级 = 无标记，1级 = 标记细胞少于5%，2级 = 标记细胞为5%-30%，3级 = 标记细胞超过30%。36例胶质母细胞瘤中有26例、23例间变性神经胶质瘤中有14例，而2例低级别神经胶质瘤均无p53免疫反应阳性。PCR扩增的p53 cDNA直接测序显示，10例胶质母细胞瘤、11例间变性神经胶质瘤有突变，低级别神经胶质瘤无突变。p53免疫染色与测序数据比较显示，在所有神经胶质瘤中，p53 0级的21例中有3例、p53 1级的16例中有1例、p53 2级的9例中有7例、p53 ۳级的15例中有10例发现有突变。这些结果表明，当肿瘤内异常细胞百分比大于5%（p53 2级和3级）时，p53免疫染色与测序数据具有良好的相关性。然而，当异常细胞百分比小于5%（p53 1级）时，由于测序技术敏感性有限，相关性较差。因此，当异常细胞百分比小时，p53免疫染色在检测p53改变方面可能更准确；然而，在少数情况下，p53免疫染色可能无法检测到测序证实的突变。
