中国成人动脉粥样硬化病变中P53抑癌基因的结构突变及与病…

应用ＰＣＲ－ＳＳＣ方法，系统地研究了中国成人动脉粥样硬化（ＡＳ）病变组织中Ｐ５３抑癌基因结构的突变及与病变程度之间的关系。结果：受检的８９例ＡＳ组织中的９例 ＰＣＲ－ＳＳＣＰ的异常，其中６例经测序证实Ｐ５３基因突变的具体内容。在此基础上，应用高特异性的Ｐ５３蛋白单克隆抗体，证实在有Ｐ５３基因突变的ＡＳ组织中也同时有Ｐ５３突变蛋白的异常表达；对动脉管腔狭窄面积、斑声的相对厚度及二乾与Ｐ５３基因突变之     

p53基因突变及p53,APC基因缺失与胃癌关系的研究

为明确ｐ５３基因突变，缺失，ＡＰＣ基因缺失在胃癌发病机制中的作用，应用ＰＣＲ－ＳＳＣＰ方法对抑癌基因ｐ５３第４，５，６，７，８外显子，第６内含子在８７例胃癌及癌前病变中的突变规律以及ＰＣＲ－ＲＦＬＰ方法对ｐ５３基因第４外显子，第６内含子，ＡＰＣ基因在２５对胃癌及癌旁组织的杂合缺失规律进行了探讨，结果发同，ｐ５３突变率在肠化，不典型增生，胃癌分别为３７．５％（３／８），４２．１％（８／１９），５３．     

p53基因突变及p53、APC基因缺失与胃癌关系的研究

为明确ｐ５３基因突变、缺失，ＡＰＣ基因缺失在胃癌发病机制中的作用，应用ＰＣＲ－ＳＳＣＰ方法对抑癌基因ｐ５３第４、５、６、７、８外显子、第６内含子在８７例胃癌及癌前病变中的突变规律以及ＰＣＲ－ＲＦＬＰ方法对ｐ５３基因第４外显子、第６内含子、ＡＰＣ基因在２５对胃癌及癌旁组织中的杂合缺失规律进行了探讨。结果发现，ｐ５３突变率在肠化、不典型增生、胃癌分别为３７．５％ （３／８），４２．１％（８／１９），５３．３％（１６／３０）。正常组织、浅表胃炎未发现ｐ５３突变。肠化、不典型增生、胃癌与正常对照组、浅表胃炎组相比均存在显著差异（Ｐ＜０．０５，Ｐ＜０．０１，Ｐ＜０．０１）。在肠化、不典型增生病变中未发现Ｅｘｏｎ８的突变，而在胃癌组Ｅｘｏｎ８的突变为４例（４／３０），提示Ｅｘｏｎ８的突变主要发生在晚期。在各病变组未发现Ｅｘｏｎ４、Ｉｎｔｒｏｎ６的突变。对Ｅｘｏｎ４、Ｉｎｔｒｏｎ６、ＡＰＣ基因的杂合缺失研究表明，２５对胃癌标本中有１９对Ｅｘｏｎ４杂合子，杂合率为７６．０％，９对有杂合缺失，ＬＯＨ为４７．４％，２３对Ｉｎｔｒｏｎ６杂合子，杂合率为９２．０％，其中２对为杂合缺失，ＬＯＨ为８．７％，１８对ＡＰＣ杂合子（１８／２５     

肝细胞癌抑癌基因p53异常的研究

目的：分析我国重庆地区肝细胞癌ｐ５３基因失活机制及突变谱，方法：采用ＰＣＲ－ＲＦＬＰ，ＰＣＲ－ＳＳＣＰ和ＰＣＲ直接测序技术对来自我国重庆地区２８例肝细胞ｐ５３抑癌基因结构异常进行了分析。结果，６１．５％的肝癌存在的ｐ５３基因的杂合缺失；５０％肝癌伴有ｐ５３基因突变，其突变模式为突变散在于５，６，７和８外显子，其中第７外显子２４９位密码子突变率最高（２１％）；具有突变的肝癌多同时伴有缺失，伴有ｐ５３     

肝细胞癌基因P53异常的研究

目的：分析我国重庆地区肝细胞癌Ｐ５３基因失活机制及突变谱。方法：采用ＰＣＲ—ＲＦＬＰＰＣＲＳＳＣＰ和ＰＣＲ直接测序技术对来自我国重庆地区２８例肝细胞癌Ｐ５３抑癌基因结构异常进行了分析。结果：６１．５１％的肝癌存在ｐ５３的杂合缺失：５０％肝癌伴有ｐ５３基因突变，其突变模式为突普通散在于５６７和８外显子，其中第７外显子２４９们密友情子突弯率最高（２１％）；具有突变的肝癌多同时伴夺缺失。伴有ｐ５３基因结构异常的肝癌均属进展期。结论：我国重庆地区肝癌存在Ｐ５３基因结构异常，Ｐ５３基因结构异常，ｐ５３基因突变模式反映了该地区肝癌发生可能与肝炎病互和黄贡互素两种因素及其相互作用有关；ｐ５３基因结构异常属肝癌晚期事件，可能参加与肝癌的进展过程。     

肝细胞癌抑癌基因p53突变

目的分析重庆地区肝细胞癌ｐ５３基因突变谱．方法住院肝细胞癌患者２０例，皆经病理证实，长期在重庆地区居住，其中早期小肝癌４例，中期６例，晚期１０例．采用ＰＣＲ－ＳＳＣＰ，ＰＣＲ直接测序技术分析ｐ５３基因５，６，７和８外显子突变．结果ｐ５３基因总的突变率为４０％．其中外显子５和６各占１０％，外显子７占２０％，未发现外显子８的突变；测序证实外显子７为第２４９位密码子Ｇ→Ｔ的颠换突变．突变病例多为晚期肿瘤．结论重庆地区肝细胞癌存在明显的ｐ５３基因突变，反映了该地区肝癌与黄曲霉毒素和ＨＢＶ或ＨＣＶ病毒有关     

胃癌P53基因突变的检测及其意义

胃癌ｐ５３基因突变的检测及其意义何向民赵莹刘春荣张学孙开来应用聚合酶链反应－单链构象多态性（ＰＣＲ－ＳＳＣＰ）分析法对３０例胃癌组织及癌旁正常组织进行ｐ５３基因第５－６、第７外显子突变的检测，旨在探索ｐ５３基因突变与胃癌的相互关系。一、材料和方法１．...     

肺鳞癌组织Mdm2蛋白表达p53基因突变相关性研究

目的探讨原发性肺鳞癌与Ｍｄｍ２蛋白表达、ｐ５３基因突变之间的相关性。方法采用ＳＰ免疫组织化学方法和银染聚合酶链式反应单链构象多态性（银染ＰＣＲＳＳＣＰ）方法检测手术切除、经病理证实的４５例原发性肺鳞癌组织及癌旁肺组织中Ｍｄｍ２蛋白表达和ｐ５３基因突变情况。结果免疫组织化学检测的４５例肺鳞癌组织Ｍｄｍ２蛋白阳性率为６２％（２８／４５）,２例癌旁肺组织中Ｍｄｍ２蛋白呈弱阳性表达,免疫组织化学方法结合银染ＰＣＲＳＳＣＰ检测４５例肺癌组织ｐ５３基因突变,阳性率为５１％（２３／４５）,４５例癌旁肺组织未检测到ｐ５３基因突变。（１）肺鳞癌与ｐ５３基因突变有明显相关性（Ｐ＜０．０５）。（２）肺鳞癌与Ｍｄｍ２基因产物过度表达有明显相关性（Ｐ＜０．０５）。（３）Ｍｄｍ２蛋白过度表达与ｐ５３基因突变复合存在和肺鳞癌淋巴转移（６６％,１０／１５）有明显相关性（Ｐ＜０．０５）。结论Ｍｄｍ２蛋白过度表达与ｐ５３基因突变是临床估计患者预后重要的分子生物学指标     

大肠肿瘤癌旁淋巴结p53基因检测的临床意义

目的：探讨癌旁淋巴结ｐ５３基因检测与Ｄｕｋｅｓ Ｂ期大肠肿瘤患者临床预后的关系。材料与方法：３０例Ｄｕｋｅｓ Ｂ期大肠肿瘤患者，取癌灶组织、癌旁淋巴结组织及远切端正常大肠粘膜组织，选用ＰＣＲＳＳＣＰ（聚合酶链反应－单链构像多态性）法行ｐ５３基因第５～８外显子检测，同时进行临床随访。结果：３０例患者中，ｐ５３基因突变率为４３．３％（１３／３０），有癌旁淋巴结ｐ５３基因突变的大肠肿瘤患者局部复发率明显高于未突变者（８０％比１２％，Ｐ＜０．０５）。结论：癌旁淋巴结ｐ５３基因检测将有助于发现病理检查中所不能发现的微转移灶和准确判断预后。     

胃癌癌旁组织中幽门螺杆菌感染及基因改变

应用ＰＣＲ、ＰＣＲ／ＲＦＬＰ对胃癌及癌旁组织中Ｈｐ感染进行了检测，并应用ＰＣＲ／ＲＦＬＰ、ＰＣＲ／ＳＳＣＰ、ＰＣＲ－ＤＮＡ测序探讨了Ｈｐ感染与ｒａｓ基因、ｐ５３基因变化的关系。研究结果发现：２４例胃癌组织Ｈｐ阳性１２例（１２／２４，５０％），２４例癌旁组织Ｈｐ阳性１１例（１１／２４，４８．５％），两者无显著差异，胃癌组基因改变者１７例（１７／２４，７０．８３％），其中Ｈｐ阳性１２例（１２／１７，７０．５９％），７例无基因改变者未发现Ｈｐ感染。癌旁组基因改变者１例，其中Ｈｐ为阴性。２４对胃癌ｐ５３Ｅｘｏｎ４的杂合缺失率为４７．３７％（９／１９）。ｐ５３Ｅｘｏｎ５、６、７、８突变在癌组织中有１１例（１１／２４；４５．８％），癌旁组仅一例，发生Ｈ－ｒａｓ１２位点突变者７例（７／２４，２９．１７％），癌旁组则无突变。胃癌基因改变与Ｈｐ＋相关性比较发现，Ｈｐ感染与基因改变关系密切（Ｐ＜０．０１）。各种基因改变中以ｐ５３改变似与Ｈｐ感染关系更紧密（ｒ＝０．５Ｐ＜０．０５）。结果表明，ｒａｓ基因及ｐ５３基因的协同作用在胃癌的致病机理中显示出重要作用。在癌变过程中，可能Ｈｐ的感染是基因改变进而促进组织恶变的促动因素之一。     

Codon 249 mutations of p53 gene in development of hepatocellular carcinoma

Ｃｏｄｏｎ２４９ｍｕｔａｔｉｏｎｓｏｆｐ５３ｇｅｎｅｉｎｄｅｖｅｌｏｐｍｅｎｔｏｆｈｅｐａｔｏｃｅｌｕｌａｒｃａｒｃｉｎｏｍａＰＥＮＧＸｉａｏＭｏｕ,ＰＥＮＧＷｅｎＷｅｉａｎｄＹＡＯＪｉＬｕＳｕｂｊｅｃｔｈｅａｄｉｎｇｓｌｉｖｅｒｎｅｏｐｌａ...     

Codon 249 mutations of p53 gene in non-neoplastic liver tissues

Ｓｕｂｊｅｃｔｈｅａｄｉｎｇｓｌｉｖｅｒ;ｐ５３ｇｅｎｅ;ｃｏｄｏｎ２４９ｍｕｔａｔｉｏｎ;ｌｉｖｅｒｎｅｏｐｌａｓｍｓ;ｈｅｐａｔｉｔｉｓ,ｖｉｒａｌ;ｌｉｖｅｒｃｉｒｈｏｓｉｓ;ｐｏｌｙｍｅｒａｓｅｃｈａｉｎｒｅａｃｔｉｏｎＡｂｓｔｒａｃｔＡＩＭ...     

粪便中p53与APC突变检测在大肠癌诊断中的意义

目的探讨在大肠癌患者粪便中检测p53、APC基因突变的可行性及其应用前景和意义。方法从36例大肠癌患者、10例大肠腺瘤患者以及30例正常对照者的粪便中分别提取DNA,应用PCR-SSCP法检测粪便中p53、APC基因突变情况。结果36例大肠癌患者粪便中p53及/或APC基因突变检出率为77.78%(19/36),二者突变率分别为52.78%(19/36)和36.11%(13/36);10例大肠腺瘤中p53基因突变检出率为0%,APC为20%;30例正常对照粪便中p53、APC基因突变检出率均为0%。p53的突变随大肠癌分化程度的降低而增高(P<0.05);APC基因突变与大肠癌组织学类型无关(P>0.05)。结论联合检测粪便中p53与APC突变在大肠癌诊断和筛查中有潜在的应用价值。     

An inherited mutation outside the highly conserved DNA-binding domain of the p53 tumor suppressor protein in children and adults with sporadic adrenocortical tumors

Mutations of the p53 tumor suppressor gene are the single most common genetic alterations in human cancers. Recently, a distinct nucleotide substitution was identified in exon 10 of the p53 gene, leading to an Arg337His mutation in 97% of children with adrenocortical tumors from Southern Brazil. In the present study, we investigated the presence of this mutation in a larger series of 55 patients (37 adults and 18 children) with benign and malignant sporadic adrenocortical tumors. None of the patients had family cancer histories that conformed to the criteria for Li-Fraumeni syndrome. Twenty-one asymptomatic close relatives of patients with p53 mutations and 60 normal unrelated individuals were also studied. The missense Arg337His mutation was identified in 19 patients (14 children and 5 adults), and 8 of 11 cases studied had LOH. Among the 19 patients with the Arg337His mutation, only one boy and three adults showed fatal evolution or recurrent metastases. This mutation was also identified in heterozygous state in asymptomatic first-degree relatives of the patients, indicating that Arg337His mutation was inherited in most cases. In contrast, this mutation was not found in 120 alleles of normal unrelated controls. In conclusion, the germ line Arg337His mutation of p53 protein is present at a high frequency (77.7%) in children with benign or malignant sporadic adrenocortical tumors, but it is not restricted to the pediatric group, since 13.5% of adults with adrenocortical tumors also had this mutation. The presence of this mutation was related to unfavorable prognosis in most of the adults, but not in the children with adrenocortical tumors.     

Is p53 gene mutation an indicatior of the biological behaviors of recurrence of hepatocellular carcinoma？

AIM: To evaluate mutant p53 gene in primary hepatocellular carcinoma and to investigate the correlation between it and the recurrence of hepatocellular carcinoma. METHODS: Mutations of p53 gene were examined using anti-human p53 monoclonal antibody and immunohistochemical staining in 79 resected hepatocellular carcinomas. The correlations among variables of p53 positivity and invasiveness, disease free interval and survival were studied. In addition, in those who developed recurrence, the correlation among p53 positivity, clinical features and post-recurrence survival were also studied. RESULTS: Of these 79 cases, 64 (81 %) had p53 mutation. Those patients with mutant p53 positivity had significantly more tumor recurrence (76.6 % vs 40.0 %, P=0.0107). However, the COX proportional hazards model showed that p53 overexpression had only weak correlations with recurrence free interval and survival time (P=0.088 and 0.081), which was probably related to the short duration of follow-up. The invasiveness variables may be predictors of HCC recurrence. On univariate analysis, more patients with mutant p53 positivity had vascular permeation (78.1 vs 40.0 %, P=0.0088, O.R. (odds ratio) =5.3), grade II-IV differentiation (98.4 vs 80.0 %, P=0.0203, O.R. =15.7), no complete capsule (82.8 vs 53.3 %, P=0.0346, O.R. =4.2) and daughter nodules (60.9 vs. 33.3 %, P=0.0527, O.R. =3.1) than patients with negative p53 staining. On multivariate analysis, only vascular permeation and grade of differentiation remained significant (P=0.042 and 0.012). There was no statistically significant correlation between the status of p53 in the primary lesion and the clinical features of recurrent hepatocellular carcinomas examined, including extrahepatic metastasis (P=0.1103) and the number of recurrent tumors (P=1.000) except for disease over more than one segment in the extent of recurrent tumors (P=0.0043). The post-recurrence median survival was lower in patients in whom p53 mutation had been detected in the primary lesion with a weak significance (3.42 months vs 11.0 months, P=0.051). CONCLUSION: Our findings suggest that p53 mutation correlates significantly with invasiveness including vascular permeation, grade of cellular differentiation, incomplete capsule and multinodular lesions. Hepatocellular carcinomas with p53 mutations had more tumor recurrence and p53 mutation may also influence disease recurrence interval and survival time. Hepatocellular carcinomas with p53 mutations recur more extensively with a shorter survival. Therefore, p53 mutation in the primary lesion is useful as an indicator of the biological behavior of recurrent hepatocellular carcinomas.     

Potential role of p53 mutation in chemical hepatocarcinogenesis of rats

AIM: Inactivation of p53 gene is one of the most frequent genetic alterations in carcinogenesis. The mutation status of p53 gene was analyzed, in order to understand the effect of p53 mutation on chemical hepatocarcinogenesis of rats. METHODS: During hepatocarcinogenesis of rats induced by 3‘-methyl-4- dimethylaminoazobenzene (3‘-Me-DAB),prehepatocarcinoma and hepatocarcinoma foci were collected by laser capture microdissection (LCM), and quantitatively analyzed for levels of p53 mRNA by LightCyclerTM real-time RT-PCR and for mutations in p53 gene exons 5-8 by direct sequencing. RESULTS: Samples consisting of 44 precancerous foci and 24 cancerous foci were collected by LCM. A quantitative analysis of p53 mRNA showed that p53 mRNA peaked at an early stage (week 6) in the prehepatocarcinoma lesion, more than ten times that of adjacent normal tissue, and gradually decreased from week 6 to week 24. The expression of p53 mRNA in adjacent normal tissue was significantly lower than that in prehepatocarcinoma. Similar to prehepatocarcinoma,p53 mRNA in cancer was markedly higher than that in adjacent normal tissue at week 12, and was closer to normal at week 24. Direct p53 gene sequencing showed that 35.3%(24/68) (9 precancer, 15 cancer) LCM samples exhibited point mutations, 20.5% of prehepatocarcinoma LCM samples presented missense mutations at exon 6/7 or/and 8, and was markedly lower than 62.5% of hepatocarcinoma ones(P&lt;0.01). Mutation of p53 gene formed the mutant hot spots at 5 codons. Positive immunostaining for p53 protein could be seen in prehepatocarcinoma and hepatocarcinoma foci at 24 weeks. CONCLUSION: p53 gene mutation is present in initial chemical hepatocarcinogenesis, and the mutation of p53 gene induced by 3‘-Me-DAB is an important factor of hepatocarcinogenesis.     

Analysis of K-ras codon 12 mutations and p53 overexpression in colorectal nodule-aggregating tumors

BACKGROUND AND AIMS: Morphologically, colorectal nodule-aggregating tumors are quite different from polypoid-type colorectal tumors that develop via the adenoma-carcinoma sequence. Although polypoid-type colorectal tumors are well known to have a high incidence of K-ras gene mutation and p53 overexpression, colorectal nodule-aggregating tumors have not been examined in terms of genetic changes and clinicopathological features. In the present study, therefore, we analysed the clinicopathological features, genetic changes in K-ras codon 12, and p53 overexpression in colorectal nodule-aggregating tumors. METHODS: A total of 18 colorectal nodule-aggregating tumors were surgically resected and then analysed clinicopathologically. Immunohistochemistry and polymerase chain reaction-single stranded conformational polymorphism were performed to analyse p53 abnormalities in the tumors. K-ras codon 12 mutations were screened out by the polymerase chain reaction-restriction fragment length polymorphism method and analysed by fluorescence direct sequencing. RESULTS: p53 overexpression was observed in six lesions (33%). p53-overexpressing cells were observed in parts of carcinoma or adenoma showing high-grade atypia. Four of the 10 (40%) samples had a p53 gene mutation. Nine of the 18 (50%) samples had a K-ras codon 12 point mutation. In eight cases (89%), the mutations of the K-ras codon 12 were of the same type: GGT (glycine) to GTT (valine). CONCLUSIONS: The colorectal nodule-aggregating tumor has distinctive characteristics showing a morphological phenotype of the superficial-type tumors and genotype of the polypoid tumors in terms of K-ras gene mutation and p53 overexpression.     

UV and skin cancer: specific p53 gene mutation in normal skin as a biologically relevant exposure measurement.

Many human skin tumors contain mutated p53 genes that probably result from UV exposure. To investigate the link between UV exposure and p53 gene mutation, we developed two methods to detect presumptive UV-specific p53 gene mutations in UV-exposed normal skin. The methods are based on mutant allele-specific PCRs and ligase chain reactions and designed to detect CC to TT mutations at codons 245 and 247/248, using 10 micrograms of DNA samples. These specific mutations in the p53 gene have been reported in skin tumors. CC to TT mutations in the p53 gene were detected in cultured human skin cells only after UV irradiation, and the mutation frequency increased with increasing UV dose. Seventeen of 23 samples of normal skin from sun-exposed sites (74%) on Australian skin cancer patients contained CC to TT mutations in one or both of codons 245 and 247/248 of the p53 gene, and only 1 of 20 samples from non-sun-exposed sites (5%) harbored the mutation. None of 15 biopsies of normal skin from non-sun-exposed or intermittently exposed sites on volunteers living in France carried such mutations. Our results suggest that specific p53 gene mutations associated with human skin cancer are induced in normal skin by solar UV radiation. Measurement of these mutations may be useful as a biologically relevant measure of UV exposure in humans and as a possible predictor of risk for skin cancer.     

胃幽门螺杆菌感染与抑癌基因失活的关系

目的探讨胃癌及癌前病变组织中幽门螺杆菌(H.pylori)感染与抑癌基因失活间的相互关系.方法运用DNA-PCR技术检测H.Pylori感染,采用PCR-RFLP,PCR-SSCP,RT-PCR及免疫组化技术分析182例胃癌及癌前病变及正常胃粘膜中抑癌基因APC,MCC,DCC,YNZ22及p53基因的杂合缺失、突变、mRNA及蛋白异常表达.结果胃癌及癌前病变组织中H.pylori的感染率(IM61.7%,Dys 63.3%,GC 42.3%)显著高于正常胃粘膜(17.5%,P＜0.05).但胃癌及癌前病变间H.pylori感染率无显著差别(P＞0.05),胃肠两型胃癌中H.pylori感染率分别为47.1%及42.2%,两者无显著差别(P＞0.05).胃癌及癌前病变组织中存在多种抑癌基因失活.H.pylori感染与癌前病变-肠化生中APC基因异常蛋白表达有关(Hp+43.2%vsHp-13.0%,P＜0.05).胃癌组织H.pylori感染阳性组中APC基因突变(50.0%)及蛋白表达(63.6%)、p53基因蛋白表达率(59.1%)显著高于阴性组(vs16.7%,P＜0.05;vs30.0%,P＜0.01;vs20.0%,P＜0.01).结论幽门螺杆菌感染及多种抑癌基因失活可能与胃癌的发生发展相关,H.pylori感染与APC,p53基因失活可能相关.     

非小细胞肺癌患者呼出气冷凝液中p53基因突变检测的研究

目的 探讨非小细胞肺癌(NSCLC)患者呼出气冷凝液(EBC)中p53基因突变检测的临床意义.方法 采用PCR结合DNA测序法,检测53例NSCLC患者(治疗前)EBC中p53基因第5、6、7、8外显子的突变情况,32名健康体检者EBC标本作为对照.结果 肺癌组(治疗前)EBC标本中扩增到p53基因26例,其中10例检...