Calzolari A, Chiarelli I, Bianchi S, Messerini L, Gallo O, Porfirio B, Mattiuz P L
Institute of Anatomic Pathology, Florence University School of Medicine, Italy.
Am J Clin Pathol. 1997 Jan;107(1):7-11. doi: 10.1093/ajcp/107.1.7.
The purpose of this study was to correlate p53 gene alterations and their expression in 85 head and neck squamous cell carcinomas. Genomic p53 was amplified with the polymerase chain reaction (PCR) from formalin-fixed, paraffin-embedded tissues. Exons 5 through 8 were screened for mutations by means of non-isotopic single-strand conformation polymorphism (SSCP) analysis. p53 expression was detected by means of immunohistochemistry (IHC) with the p53 monoclonal antibody DO-7. Twenty-three lesions (27%) showed both SSCP variants and DO-7 immunostaining, whereas 37 (44%) demonstrated both SSCP normal patterns and negative staining. Twenty-five lesions (29%) were discordant, including 12 IHC-positive (14%) and 13 SSCP-positive (15%) lesions. However, discordant IHC-negative, SSCP-positive lesions could have been easily interpreted after sequencing of the abnormal samples. Had these been screened with IHC only, all nonsense or frameshift p53 mutations would have been missed. IHC-positive, SSCP-negative lesions were interpreted in light of current models of p53 immunodetection. Had these been screened with SSCP or sequencing only, a sizeable number of tumors expressing p53 protein abnormalities would have been undetected. Therefore, simultaneous use of both methods increases the number of p53 abnormalities detected, and is warranted.
本研究的目的是关联85例头颈部鳞状细胞癌中p53基因改变及其表达情况。采用聚合酶链反应（PCR）从福尔马林固定、石蜡包埋组织中扩增基因组p53。通过非同位素单链构象多态性（SSCP）分析筛选第5至8外显子的突变。用p53单克隆抗体DO-7通过免疫组织化学（IHC）检测p53表达。23个病灶（27%）显示既有SSCP变异又有DO-7免疫染色，而37个（44%）显示既有SSCP正常模式又有阴性染色。25个病灶（29%）不一致，包括12个IHC阳性（14%）和13个SSCP阳性（15%）病灶。然而，对异常样本进行测序后，IHC阴性、SSCP阳性的不一致病灶很容易解释。如果仅用IHC进行筛查，所有无义或移码p53突变都会被漏检。根据当前p53免疫检测模型解释IHC阳性、SSCP阴性病灶。如果仅用SSCP或测序进行筛查，相当数量表达p53蛋白异常的肿瘤将无法被检测到。因此，同时使用这两种方法可增加检测到的p53异常数量，这是有必要的。
