Helland A, Holm R, Kristensen G, Kaern J, Karlsen F, Trope C, Nesland J M, Børresen A L
Department of Genetics, Norwegian Radium Hospital, Oslo.
J Pathol. 1993 Oct;171(2):105-14. doi: 10.1002/path.1711710207.
Primary cervical carcinomas from 92 patients were investigated for genetic alterations in the tumour suppressor gene TP53. Studies of allelic imbalance (AI) were performed by Southern blot analysis and by using two PCR (polymerase chain reaction) polymorphisms within the TP53 gene. AI in the tumour was observed in 22 per cent (11 of 52 informative patients) and was significantly associated with recurrence both in a univariate (P = 0.013) and in a multivariate (P = 0.045) analysis. The DNA samples were subjected to mutation analysis of four of the conserved domains in the TP53 gene, using PCR followed by constant denaturant gel electrophoresis (CDGE). Mutations were observed in 2 of 92 tumours (2 per cent), of which one was a silent mutation and the other a frameshift. Overexpression of the p53 protein was found by immunostaining of sections from formalin-fixed, paraffin-embedded material in 55 per cent (51/92) of the tumours. In 88 per cent (45/51) of these, overexpression was present in less than 5 per cent of the tumour cells. Overexpression was significantly associated with relapse-free survival only in a univariate analysis (P = 0.045). AI of the TP53 locus did not correlate with p53 expression or mutation. The important gene on 17p, responsible for the shorter disease-free survival for patients with AI of TP53, may therefore be another gene closely linked to TP53. In addition, the 92 tumour samples were tested for the presence of human papillomavirus (HPV) types 16 and 18. Fifty-four per cent (50/92) of the samples were positive for HPV 16 using in situ hybridization, and 93 per cent (86/92) using the PCR technique. The numbers for HPV 18 were 15 per cent (14/92) and 23 per cent (21/92), respectively. Twenty-one per cent (19/92) were positive for both HPV 16 and HPV 18, while 4 per cent (4/92) were negative for both HPV 16 and 18. The tumour with the frameshift TP53 mutation was HPV 16-positive, and the four samples negative for HPV 16 and 18 did not contain TP53 mutations within the conserved domains but had elevated p53 protein expression.
对92例原发性宫颈癌患者的肿瘤抑制基因TP53的基因改变进行了研究。通过Southern印迹分析以及利用TP53基因内的两种聚合酶链反应（PCR）多态性进行等位基因不平衡（AI）研究。在22%（52例信息充分的患者中的11例）的肿瘤中观察到AI，在单变量分析（P = 0.013）和多变量分析（P = 0.045）中，AI均与复发显著相关。对DNA样本进行TP53基因四个保守结构域的突变分析，采用PCR然后进行恒定变性剂凝胶电泳（CDGE）。在92个肿瘤中的2个（2%）观察到突变，其中一个是沉默突变，另一个是移码突变。通过对福尔马林固定、石蜡包埋材料切片进行免疫染色，发现55%（51/92）的肿瘤中有p53蛋白过表达。在这些肿瘤中，88%（45/51）的肿瘤细胞中过表达率低于5%。仅在单变量分析中，过表达与无复发生存显著相关（P = 0.045）。TP53基因座的AI与p53表达或突变无关。因此，对于TP53基因座AI的患者，导致无病生存期较短的17p上的重要基因可能是另一个与TP53紧密连锁的基因。此外，对92个肿瘤样本检测了人乳头瘤病毒（HPV）16型和18型的存在情况。采用原位杂交时，54%（50/92）的样本HPV 16呈阳性，采用PCR技术时为93%（86/92）。HPV 18型的相应比例分别为15%（14/92）和23%（21/92）。21%（19/92）的样本HPV 16和HPV 18均为阳性，而4%（4/92）的样本HPV 16和18均为阴性。发生移码TP53突变的肿瘤HPV 16呈阳性，4个HPV 16和18均为阴性的样本在保守结构域内未检测到TP53突变，但p53蛋白表达升高。
