食管鳞状细胞癌p53基因突变及其蛋白表达

食管鳞癌常伴有ｐ５３基因突变和（或）ｐ５３蛋白积聚。文献报道ｐ５３基因改变与ｐ５３蛋白积聚常出现不一致的现象〔１，２〕。我们应用ＰＣＲＳＳＣＰ及免疫组化方法探讨食管鳞癌ｐ５３基因突变与ｐ５３蛋白表达的关系。１　材料和方法１１　材料　取食管癌新鲜组织３０例，同一标本分为２份，１份按常规方法提取ＤＮＡ，另１份经福尔马林固定，石蜡包埋，连续切片。１２　ＰＣＲＳＳＣＰ〔３〕　ＰＣＲ常规扩增反应后，取１０μｌＰＣＲ产物与等量电泳缓冲液混合，９６℃变性５ｍｉｎ后立即置冰浴，电泳后，凝胶经固定、银染、…     

骨肉瘤p53蛋白过度表达与预后的关系

目的；探讨ｐ５３蛋白过度表达与骨肉瘤临床病理，肿瘤细胞增殖活性及预后的关系。方法：用免疫组化方法检测５０例骨肉瘤标本中ｐ５３蛋白及增殖细胞核抗原（ＰＣＮＡ）的表达。结果５０例骨肉瘤中１６例ｐ５３蛋白阳性（３２％）；ｐ５３蛋白过度表达与骨肉瘤组织学类型，组织学分级及ＰＣＮＡ分级无关，１６例ｐ５３蛋白阳性病你中，１０例在２年内死亡（６２．５％）３４例阴性病例中，１１例在２年内死亡（３２．４％），结论；     

星形细胞肿瘤中MDM2蛋白与突变型p53蛋白的表达及其相关性研究

目的：探讨ｍｄｍ－２基因表达和ｐ５３基因突变在星形细胞肿瘤发生发展中的作用及两者的相关性。方法：采用ＳＡＢＣ免疫组化法对１２０例星形细胞肿瘤进行检测。结果：在分化不良性星形细胞瘤及多形性胶质母细胞瘤中，ＭＤＭ２蛋白的阳性率分别为３０．００％和３５．２９％，突变型ｐ５３蛋白的阳性率分别为３５．００％和４４．１２％，均明显高于高分化星形细胞瘤（４．３５％和６．５２％）；突变型ｐ５３蛋白染色阴性的星形细胞肿瘤中，ＭＤＭ２蛋白阳性率（２６．１５％）明显高于其染色阳性的肿瘤（９．３８％）。结论：ＭＤＭ２蛋白及突变型ｐ５３蛋白在星形细胞肿瘤中的表达均与该肿瘤的分化程度有关；ｍｄｍ－２基因扩增及产物ＭＤＭ２蛋白过度表达，可能是突变型ｐ５３蛋白染色阴性的星形细胞肿瘤发生的分子基础     

星形细胞肿瘤中MDM2蛋白与突变型p53蛋白的表达及其？…

目的：探讨ｍｄｍ－２基因表达和ｐ５３基因突变在星形细胞肿瘤发生发展中的作用及两者的相关性。方法：采用ＳＡＢＣ免疫组化法对１２０例星形细胞肿瘤进行检测。结果：在分化不良性星形细胞瘤及多形性胶质母细胞瘤中，ＭＤＭ２蛋白的阳性率分别为３０．００％和３５．２９％，突变型ｐ５３蛋白的阳性率分别为３５．００％和４４．１２％，均明于高于高分化星形细胞瘤（４．３５％和６．５２％）；突变型ｐ５３蛋白染色阴性的星形细     

膛胱移行细胞癌中c—erbB—2,p53及p16蛋白的表达

目的 探讨膛胱癌组织中ｐ１６、ｃ－ｅｒｂＢ－２和ｐ５３蛋白表达与胱癌病理分级、临床分期和转移的关系。方法 应用免疫组化ＳＰ法对７５例膛胱癌组织中ｐ１６、ｐ５３及ｃ－ｅｒｂＢ－２蛋白表达进行检测。结果 ７５例膛胱癌中ｐ１６、ｐ５３及ｃ－ｅｒｂＢ－２的阳性率分别为４１．３％（３１／７５）、４４．０％（３３／７５）和４０．０％（３０／７５）,ｐ１６和ｃ－ｅｒｂＢ－２蛋白在膛胱癌中的阳性率与肿瘤中的阳性率     

大肠肿瘤中抑凋亡基因bcl－2和p53蛋白产物的表达和意义

用免疫组化方法观察４５例大肠腺瘤和６１例大肠腺癌中ｂｃ１－２和ｐ５３蛋白的表达。结果显示：正常大肠粘膜中ｂｃ１－２和ｐ５３均未见表达，而大肠腺瘤及大肠腺癌阳性率均较正常组织明显增加（Ｐ＜０．０１）．大肠腺瘤中ｂｃ１－２表达位于不典型增生较重区域。大肠腺瘤ｐ５３表达随腺瘤直径增加而增加，其中≥２０ｍｍ组阳性率显著高于＜１０ｍｍ组（ｐ＜０．０５）。ｐ５３蛋白阳性率也随不典型增生程度增加而增高。ｐ５３表达与大肠腺癌分化程度及Ｄｕｋｅｓ分期有关。大肠腺瘤中ｂｃ１－２和ｐ５３蛋白的表达呈负相关。结果表明，ｂｃ１－２蛋白表达对大肠腺瘤的增殖有一定意义，ｐ５３在大肠腺瘤癌变和大肠腺癌进展中起重要作用。     

p-MAPK、cyclinD1和p53蛋白在大肠癌中的表达及其相关性

目的：检测ｐ－ＭＡＰＫ、ｃｙｃｌｉｎＤ１和ｐ５３蛋白在大肠癌中的表达，并探讨其相关性。方法：免疫组织化学Ｓ－Ｐ法。结果：１４０例大肠癌中ｐ－ＭＡＰＫ、ｃｙｃｌｉｎＤ１和ｐ５３蛋白的阳性表达率分别为９２．９％（１３０／１４０）、８７．１％（１２２／１４０）和６６．４％（９３／１４０）；５０例相应癌旁肠粘膜中阳性表达率分别为４．０％（２／５０）、６．０％（３／５０）和２．０％（１／５０）。三者阳性表达     

肝癌组织中N—ras基因突变和p53蛋白表达

目的：研究Ｎ－ｒａｓ和ｐ５３基因与肝癌发生，发展的关系。方法：应用多聚酶链反应－单链构象多态性分析法（ＰＣＲ－ＳＳＣＰ）和免疫组化法，检测２９例肝癌中的Ｎ－ｒａｓ基因突变和ｐ５３蛋白的表达。结果，１３例肝癌ｐ５３蛋白阳性（４４．８％），表明广西地区肝癌中曾普遍存在ｐ５３基因的突变，肝癌及癌旁组织中Ｎ－ｒａｓ基因在第２～３７密码子间的突变率分别为７９．３１％和８０．７７％，２２例有２个以上突变位点（     

肺癌中MTS1/p16和p53基因产物的表达与细胞增殖的关系

目的：研究肺癌中ＭＴＳ１／ｐ１６和ｐ５３基因产物的表达与细胞增殖的关系。方法：应用Ｓ－Ｐ免疫组织化学方法研究６２例肺癌组织中ｐ１６蛋白和ｐ５３蛋白的表达情况，并进行增殖细胞核抗原（ＰＣＮＡ）检测，计算细胞增殖指数（ｐｒｏｌｉｆｅｒａｔｉｏｎｉｎｄｅｘ，ＰＩ）。结果：６２例肺癌组织中ｐ１６蛋白和ｐ５３蛋白阳性率分别为５８．１％和５９．７％。腺癌ｐ１６蛋白的阳性率明显高于小细胞癌（Ｐ＜０．０５）；淋巴结转移阳性组ｐ１６蛋白的表达显著低于阴性组（Ｐ＜０．０５）；ＰＩ分级为Ⅱ级的ｐ１６蛋白表达显著高于Ⅳ级（Ｐ＜０．０５）。不同组织类型肺癌中ｐ５３蛋白的表达未见明显差异，淋巴结转移阳性组ｐ５３蛋白的表达高于阴性组（Ｐ＜０．０１）；不同ＰＩ分级中ｐ５３蛋白的表达，Ⅳ级明显高于Ⅰ级（Ｐ＜０．０５）和Ⅱ级（Ｐ＜０．０５），Ⅲ级明显高于Ⅰ级（Ｐ＜０．０５）和Ⅱ级（Ｐ＜０．０１）。ｐ１６蛋白低表达和ｐ５３蛋白过表达之间未见明显相关。结论：ｐ１６蛋白低表达和ｐ５３蛋白过表达均有促进肺癌细胞增殖的作用，ｐ１６蛋白的表达与肺癌的细胞分化有关，ｐ５３蛋白过表达对肺癌细胞的转移起重要作用。抑癌基因ｐ５３对ＭＴＳ１／ｐ１６基因无明显调控作     

bcl—2,p53蛋白在肺癌中的表达

目的：探讨ｂｃｌ－２和ｐ５３蛋白的异常表达与肺癌临床病理因素之间的关系。方法：应用免疫组化方法检测了术后随访５年以上的１２９例肺癌标本中ｂｃｌ－２、ｐ５３蛋白的表达。结果：ｂｃｌ－２及ｐ５３蛋白在肺癌中的阳性表达率分别为２８．７％和５２．７％，两种蛋白表达间呈显著正相关关系。在不同组织学类型中，两种蛋白阳性表达率间无显著差异。淋巴结癌转移阳性组中ｂｃｌ－２蛋白阳性表达率显著高于淋巴结转移阴性组（Ｐ     

Can p53 staining be used to identify patients with aggressive superficial bladder cancer?

Approximately 10% of patients with superficial bladder cancer (pTa/pT1) recur with life-threatening muscle-invasive disease. Identification of these patients has been a major goal of bladder cancer research. In 1994, it was suggested that p53 immunostaining could identify the cancers that would progress and it was proposed that tumours that stain for p53 should be treated aggressively with radiotherapy or cystectomy. Despite the hundreds of studies published since on the relationship between p53 and progression in superficial bladder cancer, the clinical utility of p53 immunostaining has not been resolved because of limitations concerning the numbers of patients and the length of follow-up. This study set out to overcome these limitations by using tissue from a large multicentre trial that recruited 502 patients with a median follow-up of 10 years. Each of 34 patients that had progressed with >/= pT2 disease or had distant metastases or had died from bladder cancer was compared with one or two matched controls. Sections were stained with a mouse monoclonal antibody to p53, pAb1801. In agreement with many of the earlier studies, p53 immunostaining had prognostic significance. The adjusted hazard ratio for time to progression for the pAb1801-positive versus negative group was 2.5, with 95% confidence intervals of 1.05-5.98 (p = 0.039). The other major risk factor that is associated with progression of superficial bladder cancer is pT1G3 disease. Of the 42 pT1G3 cancers, 14 (33%) progressed. The proportion of cancers with p53 staining that progressed was similar to the proportion of pT1G3 cancers that progressed, but neither the sensitivity nor the specificity of association of p53 staining with progression is sufficient to recommend cystectomy in individual patients.     

鼻咽癌中p53蛋白积聚的生物学特征和临床意义

收集３４７例鼻咽癌组织，全部或部分进行了ＣＭ－１、ｐＡｂ２４０、ｐＡｂ１８０１和ｐＡｂ４２１四种ｐ５３蛋白抗体以及ＰＣＮＡ和Ｋｉ６７抗体的染色。综合分析染色结果并结合组织学特征，临床分期以及预后等资料，得出以下结论：①鼻咽癌中ｐ５３蛋白的积聚率为４４．３％，积聚的ｐ５３蛋白其抗原性不完全一样；②ｐ５３积聚的癌细胞具有增殖活性较强和侵袭性较弱的特点；③ｐ５３蛋白积聚的百分率在无颈淋巴结转移的原发瘤中比有颈淋巴结转移者高；在早期原发瘤中比晚期原发瘤中高；在放疗后存活５年以上者中比放疗后１．５年内死亡者中高。     

人野生型p53 cDNA的克隆、表达和意义

目的：为探讨肿瘤细胞ｗｔ ｐ５３蛋白功能失活机制的研究,检测肿瘤患者血清抗ｐ５３抗体辅助临床诊断提供人ｗｔ ｐ５３蛋白。方法 将人ｗｔ ｐ５３基因ｃＤＮＡ片段插入到大肠杆菌表达载体ｐＱＥ－３０中,得到重组表达质粒ｐＱＥ３０－ｐ５３,用ｐＱＥ３０－ｐ５３重组质粒转化大肠杆菌Ｍ１５细胞,转化菌落经ＰＣＲ扩增和ＢａｍＨⅠ、Ｘｂａ Ｉ酶切证实ｐ５３基因插入。ＩＰＴＧ诱导大肠杆菌表达ｗｔ ｐ５３蛋白,通过Ｎ     

Significance of p53 expression as a prognostic factor in oesophageal squamous cell carcinoma

The tumour suppressor gene product p53 is believed to play an important role in the progression of human malignant tumours through mutation and over-expression. Using a microwave oven heating method, we have detected over-expression of p53 in buffered-formalin fixed, paraffin-embedded sections of oesophageal carcinomas immunohistochemically and examined the relationship between the p53 over-expression and postoperative survival. Employing a monoclonal antibody (pAb1801), nuclear p53 was detected in 56 of 105 (53%) tumour specimens. Homogeneous, heterogeneous, and focal immunostaining patterns were noted. No immunostaining was found in adjacent benign tissues. The results in buffered-formalin fixed sections were similar to those in the frozen sections. The cumulative survival rate of patients with p53 expression was significantly lower than that of the patients without expression (P<0.05), even though there were no significant differences between the clinicopathological features of the two groups. The results indicate that the nuclear accumulation of p53 might be an independent prognostic factor in patients with oesophageal squamous cell carcinomas.     

Variations in immunohistochemical detection of p53 protein overexpression in cervical carcinomas with different antibodies and methods of detection

Immunocytochemical detection of p53 protein products in paraffin sections is possible with a number of antisera, monoclonal and polyclonal. Few corroborative results amongst different laboratories have been published due to variations in the antibodies, the fixation protocols, and the immunocytochemical methods applied. Antigen unmasking methods employing microwaves or proteolytic enzymes add to the disparity in the percentage of positive cases reported. In this study, paraffin sections of 55 cases of cervical carcinoma were immunostained with monoclonal antibodies p53-DO7 and p53-1801 (a) without section pretreatment, (b) with pronase digestion, and (c) with microwave antigen retrieval in citric acid buffer. Specimens fixed in buffered formalin required antigen unmasking to show positive staining. Pronase digestion caused false-negative immunostaining. Microwave pretreatment with p53-DO7 yielded 100 per cent positivity for p53 proteins but only 7/55 cases with more than 50 per cent positive cells. Monoclonal antibody p53-DO7 detected more positive cases than p53-1801. Immunostaining with antibodies to p53 proteins must be interpreted cautiously as variations in fixation, antibodies, and section pretreatment will significantly affect results.     

Expression of epidermal and nerve growth factor receptors in human thymus and thymomas

We have investigated the immunohistochemical expression of p53 protein in 96 cases of non-Hodgkin's lymphoma using a panel of five antibodies. Positive neoplastic cells were found in 30 (31.2%) cases, which could be divided into two groups according to their patterns of reactivity with the different antibodies; i.e. those positive with both polyclonal and monoclonal antibodies, and those which were stained only by monoclonal antibodies PAb1801 and/or PAb240. Positivity was nuclear in all but six cases in which cytoplasmic staining was found. In view of the hypothesis recently raised that p53 protein induces apoptosis we have compared our results with parallel staining for bcl-2 protein since bcl-2 is believed to be important, at least in lymphomas, in suppression of apoptosis. Staining for bcl-2 protein was performed on 83 cases and it was shown that p53-positive cases accounted for 10 out of 17 (59%) of the bcl-2 -negative lymphomas but only for 15 out of the 66 (23%) bcl-2 -positive cases, suggesting a possible relationship between the expression of these two proteins. Thus, our data show that p53 protein is abnormally expressed in a substantial proportion of non-Hodgkin's lymphomas and bears a significant inverse relationship to bcl-2 protein expression. However the molecular basis of this expression remains to be elucidated.     

Apoptosis in dengue virus infected liver cell lines HepG2 and Hep3B

While both in vivo and in vitro evidence has suggested that liver cells undergo apoptosis in response to dengue virus infection, little is known about the mechanism of induction. Given that the p53 tumour suppressor gene is a key mediator of apoptosis, we sought to define the role of this gene in response to dengue virus infection. After infection, a p53 wild type liver cell line (HepG2) showed changes consistent with apoptosis including alterations of cell morphology, cellular detachment and DNA laddering. However, p53 was neither up-regulated, nor showed any evidence of complexing with dengue virus proteins as determined by immunoprecipitation. Infection of a p53 null liver cell line (Hep3B) also produced changes consistent with the induction of apoptosis. While the profile of the cells undergoing apoptosis in each cell line was similar as determined by flow cytometry, the absolute levels were markedly different with up to 90% of Hep3B cells undergoing apoptosis compared to only 20% of HepG2 cells at day 5 post infection. By day 7, all Hep3B infected cells were dead. In contrast, it proved possible to culture dengue virus infected HepG2 cells for 3 months. Viral progeny released from the p53 null cell line were nine-fold higher per attached cell than from the p53 wild type cell line. These results suggest that, while induction of apoptosis in liver cells is mediated by a non-p53 regulated pathway, p53 may play a role in restricting the level of viral progeny to below a critical level at which apoptosis is triggered.     

p53 expression in normal paraffin-embedded tissue using different antibodies and antigen retrieval buffer systems

AIMS: The study was undertaken to demonstrate wild-type p53 in normal paraffin-embedded tissues using two widely used antibodies, DO7 and 1801 and two different antigen retrieval buffer systems. METHODS AND RESULTS: Formalin-fixed paraffin-embedded normal tissue samples were obtained from the archives of the John Radcliffe Hospital, Oxford. Antigen retrieval was performed by microwaving using two different buffer systems: (i) the commercially available Dako target retrieval solution (Cat. no. 1699) (pH 9.8-9.9), (ii) freshly prepared buffer consisting of 0.1 m EDTA with 0.1% Tween pH 6.0, and (iii) freshly prepared buffer consisting of 0.1 m EDTA with 0.1% Tween pH 8.0. Staining was performed with DO7 and 1801 antibodies using the Dako Envision kit (peroxidase/DAB). DO7 antibody elicited strong nuclear staining in the mucosal cells of the small and large intestine, lymphoid cells, decidua, neurones such as Purkinje cells of the cerebellum, glandular epithelial cells and stromal cells of the prostate, cardiac myocytes and bronchial epithelial cells. Cytoplasmic staining was noted in Purkinje cells, glandular epithelium of prostate, exocrine pancreas and renal tubular epithelium. The 1801 antibody did not produce staining in any of these tissues. CONCLUSIONS: Our study demonstrates the presence of p53 in normal paraffin-embedded tissue with nuclear and/or cytoplasmic localization in some instances. In our view, DO7 appears to be better suited for such detection.     

p53对人乳腺癌细胞MCF-7生长及周期相关基因的影响

目的探讨抑癌基因p53对人乳腺癌细胞MCF-7生长以及周期相关基因cyclinD1、cyclinE、CDK2和CDK4表达的影响.方法将正义的p53真核表达载体导人MCF-7细胞,获得稳定表达正义p53的细胞模型,并经PCR和Western blot鉴定.分析了细胞的各种生长特性包括生长曲线、血清依赖、单细胞克隆形成、软琼脂成集落等;利用TdR双阻断法同步化细胞,流式细胞术分析了细胞周期;Western blot检测了其他周期相关基因的表达.结果p53的高表达可以使细胞的生长速度减慢、血清依赖性增加、单细胞克隆成集落能力降低、非锚定依赖性生长能力减弱,S期的进程减缓,一定程度上抑制cyclinD1和CDK2的表达,cyclinE和CDK4的表达未见明显变化.结论抑癌基因p53的表达能够抑制人乳腺癌细胞MCF-7的生长,并可能通过阻抑cyclinD1和CDK2的表达而阻抑细胞周期S期进程,实现其调节功能.