P~(53)突变产物在睑板腺癌中的增强表达及其意义

我们采用免疫组化S－P法，对17例石蜡包埋睑板腺癌及癌旁组织标本的P53突变蛋白表达进行了检测。结果：17例癌组织有12例表达阳性，阳性率71％。其中分化型7例，6例呈阳性（86％）表达。在一组原发灶及淋巴结转移癌配对标本中，同一病人之两个部位P(53)突变蛋白表达差异无明显意义。癌旁（睑缘）组织17例中5例上皮有异常增生，且同时伴有P(53)突变蛋白呈强阳性表达。以上结果提示：抑癌基因P53的突变在睑板腺癌的发生中是一个比较常见的基因改变，且在分化型癌的发生中表现明显；P(53)基因异常发生在肿瘤转移之前且在淋巴道转移中可能起重要作用；P(53)突变蛋白在癌旁上皮异型增生组织中的过度表达具有十分重要的意义。     

人原发性肝癌P53基因缺失和突变

在多种人体肿瘤组织中P53基因有缺失,P53基因作为一个抗癌基因,能在体外抑制肿瘤细胞的生长。肿瘤组织中P53基因缺失或发生突变,丧失了抗癌基因的活性,某些突变体还具有协同转化活性。本文分析了12例肝癌及其相应癌旁正常组织P53基因的存在状态,发现3例(25％)P53基因有缺失,3例P53基因有突变。这一结果提示P53基因为人肝癌抗癌基因,它的缺失或突变与肝癌的发生或演进有关。     

p53基因突变在人恶性肿瘤发生中的分子病理学意义

p53抑癌基因突变或丢失是人类恶性肿瘤最常见的基因异常变化.该基因249密码子点突变常伴有P53蛋白在细胞核内聚积.用抗P53蛋白免疫组化染色有助于了解肿瘤组织内p53基因异常变化情况,为探索肿瘤基因治疗提供依据.我们对人707例癌组织(原发性肝癌104例,胆囊癌76例,胃腺癌79例,宫内膜腺癌36例;喉鳞癌50例,口腔鳞癌50例,食管鳞癌58例,恶性黑色素瘤46例,脑胶质细胞瘤     

视网膜母细胞瘤组织中Survivin、P53的表达及其意义

目的 探讨视网膜母细胞瘤组织中survivin、P53表达的变化及其临床价值.方法 采用免疫组化S-P法检测100例视网膜母细胞瘤和30例正常视网膜组织中survivin、P53的表达水平,并分析两者与视网膜母细胞瘤临床病理参数的关系.结果 视网膜母细胞瘤组织中survivin的阳性率为63.0％ (63/100),高于正常视网膜组织的0.0％ (0/30) (P ＜0.05);视网膜母细胞瘤组织中P53的阳性率为51.0％ (51/100),高于正常视网膜组织的3.3％ (1/30) (P ＜0.05).视网膜母细胞瘤组织中survivin、P53的表达均与患者的分化程度、临床分期有关(P＜0.05).视网膜母细胞瘤组织中survivin、P53的表达呈正相关关系(r=0.575,P＜0.05).结论 视网膜母细胞瘤组织中存在survivin、P53的异常表达,且两者可能参与了肿瘤的浸润、转移等疾病进展过程.     

胃癌组织中P53蛋白的异常表达

目的 探讨突变型P53基因产物在胃癌中异常表达的意义。方法 应用免疫组织化学方法研究P53基因在98例胃痛中的表达。结果 98例胃癌标本中,P53表达阳性率为59.2％,与组织学类型无关,不同浸润深度胃癌与P53异常表达有关(P<0.05),肿瘤直径大于5cm者P53阳性率明显高于直径小于5cm者,在淋巴结转移组和无转移组间P53阳性程度有显著差异。结论 P53异常表达是胃癌重要标志之一。     

非小细胞肺癌FHIT基因蛋白表达缺失及与突变型p53表达相关性

[目的]了解非小细胞肺癌组织(NSCLC)中脆性组氨酸三联体(FHIT)基因蛋白(Fhit)表达缺失及其与突变型p53基因蛋白(p53)表达的相关性.[方法]应用免疫组织化学方法了解NSCLC组织中Fhit及p53的表达.[结果]62.2%(56/90)的NSCLC组织显示Fhit表达缺失,同时48.9%(44/90)有突变型p53表达;两者的异常表达在非鳞组中明显相关(P＜0.001),而在鳞癌组中无相关性(P=0.079);另外,两者的异常表达在非吸烟组中明显相关(P=0.006),而在吸烟组中无相关性(P=0.113).[结论]Fhit表达缺失和突变型p53表达是NSCLC中常见事件;而且两者在non-SqCC和非吸烟的肺癌者中有明显的相关性.     

bc1-2、P53和c-erb-B2基因在前列腺癌中的表达

 探讨癌基因在前列腺癌发生发展中意义,应用免疫组化S－P(过氧化物酶—链霉卵白素)法对50例前列腺癌组织中bcl－2、P53和c－erb－B2的表达产物进行检测。结果bcl－2、P53和c－erb－B2的表达率为42％、48％和44％,bcl－2、P53和c－erb－B2的表达与肿瘤的分级、分期皆相关。66％肿瘤有癌基因表达异常,26％的肿瘤同时有多个癌基因表达异常,多个癌基因表达异常与分级、分期相关,bcl－2的表达与P53的表达呈负相关:(γ＝-0.51,P<0.05)。结论:上述癌基因参与了前列腺癌发生发展过程,肿瘤多个基因分析比单个分析更有价值。     

卵巢癌和乳腺癌P53、P21、P16和Rb基因表达水平的研究

目的 :研究肿瘤组织癌相关基因P53、Rb、P16、和P21表达水平的临床意义。 方法:用流式细胞仪(FCM)检测30例卵巢癌和乳腺癌瘤体中心灶P53、Rb、P16、和P21异常表达的阳性细胞百分率。 结果: 卵巢癌和乳腺癌的P53、Rb、P16、和P21基因蛋白表达水平及异常表达率均无明显差异(P>0.05)。30例肿瘤的4种基因异常表达率分别为 :P5340 % ;Rb53.3 % ;P2166.7 %和P1653.3 %。96.7 %(29/30)的肿瘤存在至少一种以上癌相关基因的异常表达。异常表达两个以上癌相关基因的患者较易出现临床转移。 结论:联合检测实体肿瘤P53、Rb、P16、和P21基因蛋白表达水平并综合分析这些指标 ,有助于识别肿瘤不同的生物学特性和准确判断患者预后     

EBV相关胃癌与P53基因异常的研究

[目的]探讨EBV感染和p53基因异常在胃癌发生发展中的病因学作用.[方法]应用免疫组化技术检测13例EBV相关胃癌(EBV associated gastric carcinoma,EBVaGC),45例临床指标与之匹配的EBV阴性胃癌(EBV negative gastric carcinoma,EBVnGC)以及58例相应癌旁组织中p53蛋白的表达;PCR-SSCP银染技术检测p53基因exon 5～8突变情况.[结果]①胃癌组p53蛋白阳性率为86.2%(50/58),而相应癌旁组织均为阴性,胃癌组p53蛋白的阳性率明显高于癌旁组织组,两组间有极显著性差异(P=0.0000).②EBVnGC p53蛋白阳性率为86.7%(39/45),过表达率为57.8%(26/45);EBVaGC p53蛋白阳性率为84.6%(11/13),过表达率仅为15.4%(2/13).两组间p53蛋白的阳性检出率无明显差异(P=0.7912),但EBVaGC组p53蛋白过表达率明显低于EBVnGC组,两组间有显著性差异(P=0.0085).③2例EBVnGC检测到p53基因突变,突变均位于exon 5,13例EBVaGC和58例相应癌旁组织均未检测到p53基因突变.[结论]p53基因异常与胃癌的发生密切相关,EBVaGC组织中存在p53蛋白的表达和过表达,但p53蛋白的异常累积可能并非p53基因突变所致.     

102. 人1 673例恶性肿瘤764例良性病变中P53基因异常改变的免疫组化研究

目的：抑癌基因P53的突变、被降解或丢失在人类多种恶性肿瘤病的发生发展中具有重要作用。研究这种变化的规律及其调控环节，可为肿瘤病的有效防治提供可靠的分子病理学依据。方法：对人1 673例不同恶性肿瘤及764例不同良性病变分别进行单克隆抗P53蛋白免疫组化检测（LSAB法）。结果：恶性肿瘤组织P53蛋白阳性率56.1%(939／1 673)，良性病变7.85%（60／764），两者有极显著差异（P＜0．001）；在恶性肿瘤中，鳞癌阳性率62．9％（387／615）、腺癌55.9%(320/572)其他恶性瘤(包括颅内原发肿瘤，黑色素瘤，骨肉瘤、生殖细胞瘤等)47.7％(232／486）均分别高于相应组织的良性病变，相差极显著(P＜0．001）；恶性肿瘤中，以睾丸恶性生殖细胞瘤的阳性率81．0％(47／58）最高，而恶性程度很高的颅内髓母细胞瘤最低，仅3．9％（2／51）；良性病变以喉鳞状上皮乳头状瘤、结肠腺瘤或及不典型增生病变阳性率较高，可达16％。但良性瘤变中P53蛋白阳性细胞的染色强度与细胞密度明显低于恶性肿瘤。值得注意的是正常睾丸的曲细精管内的不同发育阶段的生精细胞，其阳性率高达40％（6／15）。虽然阳性细胞数稀少也应重视。结论：①P53基因突变或其他异常改变在人细胞恶性转化与肿瘤形成中具有重要作用；②不同类型肿瘤P53蛋白变化的差异，反映了多种不同癌基因或及抑癌基因在肿瘤发生过程的不同作用。髓母细胞瘤等恶性肿瘤的发生、发展可能是P53基因以外的基因异常调控的结果；③应用免疫组化染色可检测细胞原位的基因或其调控分子异常改变；对肿瘤的理论研究、临床应用都是很有用处。     

1364例恶性肿瘤p53蛋白表达的检测及其临床病理学意义

目的：探讨p53基因异常表达在人癌发生过程的病理生物学作用和临床病理学意义。方法：对人体1364例不同类型恶性肿瘤（其中615例鳞癌，382例腺癌及367例其它恶性肿瘤）及相应良性病变组织进行p53蛋白表达的免疫组化（LASB法）检测。结果：恶性肿瘤组织p53蛋白表达的阳性检出率56．7％（773／1364）明显高于良性病变组织6．7％ （42／628）（P＜0．001）。结论：p53基因的异常表达（基因突变或／及蛋白积累）是人体多种恶性肿瘤病的普遍现象，可能是人癌发生发展过程中关键的变化之一。免疫组化检测p53蛋白过度表达可以作为区别良恶性病变有参考价值的指标之一。     

Human p53 knock-in (hupki) mice do not differ in liver tumor response from their counterparts with murine p53

Mouse models are important tools in toxicologic research. Differences between species in pathways contributing to tumor development, however, raise the question in how far mouse models are valid for human risk assessment. One striking difference relates to the frequency of spontaneous liver cancer which is high in certain mouse strains but rather low in humans. Similarly, mutation frequencies in cancer genes are characteristically different, i.e. P53 mutations are frequent in human but very rare in murine liver tumors, whereas Ras genes are often mutated in mouse liver tumors but hardly ever in human liver cancers. Since P53 has been shown to control oncogenic RAS in human cells, we hypothesized that this function of the tumor suppressor could differ in mouse hepatocytes. To test this hypothesis, we used hupki (human p53 knock-in) mice which carry a partly humanized P53 sequence (P53KI). In this study, we report the results of the first hepatocarcinogenesis experiment with this strain of mice. Mice of the genotypes P53KI/KI, P53WT/KI and P53WT/WT were treated with N-nitrosodiethylamine at 2 weeks of age and killed 35 weeks later. The frequency of liver tumors and glucose-6-phosphatase-altered liver lesions was almost identical in all three P53 genotypes and approximately 40-50% of liver tumors showed activating mutations in codon 61 of the Ha-Ras gene independent of genotype. Moreover, only very few P53-positive lesions were observed but without nuclear localization of the protein, suggesting the absence of P53 mutations. These data suggest that the hupki allele behaves like its murine ortholog in mouse hepatocarcinogenesis.     

O(6)-Methylguanine-DNA methyltransferase promoter hypermethylation shifts the p53 mutational spectrum in non-small cell lung cancer.

The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) removes mutagenic adducts from the O6 position of guanine, thereby protecting the genome against G to A transition mutations. MGMT is inactivated by promoter hypermethylation in many human cancers and has been associated with G to A mutations in K-ras in colorectal cancer. We hypothesized that MGMT promoter hypermethylation would be associated with an increase in G to A transitions in the p53 gene in non-small cell lung cancer (NSCLC). p53 mutations were detected by both dideoxy sequencing and p53 GeneChip analysis in 92 patients with primary NSCLC. Methylation of the promoter region of the MGMT gene was determined using methylation-specific PCR and was present in 27 of 92 (29%) tumors. Hypermethylation of the MGMT promoter was more common in adenocarcinoma than in other histological types of NSCLC and was also more common in poorly differentiated tumors. MGMT promoter hypermethylation was present significantly more often in tumors with a G to A mutation in p53 (9 of 14; 64%) than in tumors with other types of p53 mutations (11 of 41; 27%; P = 0.02) or in tumors with wild-type p53 (7 of 37; 18%; P = 0.006). MGMT promoter hypermethylation was also strongly associated with G to A transitions at CpG sites. Inactivation of the MGMT gene by promoter hypermethylation alters the pattern of p53 mutation in NSCLC.     

Inhibitory effect of Survivin promoter-regulated oncolytic adenovirus carrying P53 gene against gallbladder cancer

Gene therapy has become an important strategy for treatment of malignancies, but problems remains concerning the low gene transferring efficiency, poor transgene expression and limited targeting specific tumors, which have greatly hampered the clinical application of tumor gene therapy. Gallbladder cancer is characterized by rapid progress, poor prognosis, and aberrantly high expression of Survivin. In the present study, we used a human tumor-specific Survivin promoter-regulated oncolytic adenovirus vector carrying P53 gene, whose anti-cancer effect has been widely confirmed, to construct a wide spectrum, specific, safe, effective gene-viral therapy system, AdSurp-P53. Examining expression of enhanced green fluorecent protein (EGFP), E1A and the target gene P53 in the oncolytic adenovirus system validated that Survivin promoter-regulated oncolytic adenovirus had high proliferation activity and high P53 expression in Survivin-positive gallbladder cancer cells. Our in vitro cytotoxicity experiment demonstrated that AdSurp-P53 possessed a stronger cytotoxic effect against gallbladder cancer cells and hepatic cancer cells. The survival rate of EH-GB1 cells was lower than 40% after infection of AdSurp-P53 at multiplicity of infection (MOI) = 1 pfu/cell, while the rate was higher than 90% after infection of Ad-P53 at the same MOI, demonstrating that AdSurp-P53 has a potent cytotoxicity against EH-GB1 cells. The tumor growth was greatly inhibited in nude mice bearing EH-GB1 xenografts when the total dose of AdSurp-P53 was 1 × 10⁹ pfu, and terminal dUTP nick end-labeling (TUNEL) revealed that the apoptotic rate of cancer cells was (33.4 ± 8.4)%. This oncolytic adenovirus system overcomes the long-standing shortcomings of gene therapy: poor transgene expression and targeting of only specific tumors, with its therapeutic effect better than the traditional Ad-P53 therapy regimen already on market; our system might be used for patients with advanced gallbladder cancer and other cancers, who are not sensitive to chemotherapy, radiotherapy, or who lost their chance for surgical treatment.     

Increased p53 mutation frequency during tumor progression--results from a breast cancer cohort.

The mutational patterns of the p53 gene for exons 4-9 were analyzed in 30 recurring tumors compared with the p53 status of the corresponding 30 primary breast cancers. The prevalence of p53 mutations was higher, although not statistically significant (P = 0.07), in the evaluable recurring tumors compared with the corresponding primaries, 12 of 29 (41%) versus 7 of 30 (23%). Twenty-one of the patients had unchanged p53 mutation status in the recurring compared with the primary tumors, whereas 8 had an altered mutational status or pattern in the sequential tumor. These findings indicate that p53 mutations may be an important factor for tumor progression in human breast cancer.     

Prognostic value and clinicopathologic correlation of p53 gene mutations and nuclear DNA content in human lung cancer: A prospective study

The aim of this prospective study was to determine whether use of a combination of biomarkers, p53 and nuclear DNA content, led to improved prognosis and Clinicopathologic correlation in human non-small cell lung cancer. Nineteen patients undergoing curative resection of primary non-small cell lung cancer were evaluated. Resected tumors were studied by polymerase chain reaction/single strand conformation polymorphism analysis (p53 gene mutations), flow cytometry (nuclear DNA content and cell cycle analysis), and immunohistochemically (p53 oncoprotein). Histologically normal lung was used as an internal control for each patient. Minimum postoperative follow-up was 4 years. p53 gene mutations (5/19 tumors; 26%), tumor ploidy (5/19 diploid), patterns of immunoreactivity, or combination of biomarkers did not appear to correlate with clinicopathologic findings or clinical outcome. Two of three patients with associated second primary malignancies, had squamous cell diploid tumors with p53 gene mutations. We conclude that p53 gene mutations and tumor ploidy may represent different biologic markers for human nonsmall cell lung cancer. Although trends in improved predictive accuracy were not seen when both markers were incorporated into the tumor analysis, flow cytometry and molecular analysis of the p53 gene may identify patients at increased risk of the development of a second primary maligmancy. © 1994 Wiley-Liss, Inc.     

Zinc deficiency potentiates induction and progression of lingual and esophageal tumors in p53-deficient mice

Upper aerodigestive tract (UADT) cancer, including oral and esophageal cancer, is an important cause of cancer deaths worldwide. Patients with UADT cancer are frequently zinc deficient (ZD) and show a loss of function of the pivotal tumor suppressor gene p53. The present study examined whether zinc deficiency in collaboration with p53 insufficiency (p53+/-) promotes lingual and esophageal tumorigenesis in mice exposed to low doses of the carcinogen 4-nitroquinoline 1-oxide. In wild-type mice, ZD significantly increased the incidence of lingual and esophageal tumors from 0% in zinc sufficient (ZS) ZS:p53+/+ mice to approximately 40%. On the p53+/- background, ZD:p53+/- mice had significantly greater tumor incidence and multiplicity than ZS:p53+/- and ZD:p53+/+ mice, with a high frequency of progression to malignancy. Sixty-nine and 31% of ZD:p53+/- lingual and esophageal tumors, respectively, were squamous cell carcinoma versus 19 and 0% of ZS:p53+/- tumors (tongue, P = 0.003; esophagus, P = 0.005). Immunohistochemical analysis revealed that the increased cellular proliferation observed in preneoplastic lingual and esophageal lesions, as well as invasive carcinomas, was accompanied by overexpression of cytokeratin 14, cyclooxygenase-2 and metallothionein. In summary, a new UADT cancer model is developed in ZD:p53+/- mouse that recapitulates aspects of the human cancer and provides opportunities to probe the genetic changes intrinsic to UADT carcinogenesis and to test strategies for prevention and reversal of this deadly cancer.     

Promoter hypermethylation of the death-associated protein kinase gene in breast cancer is associated with the invasive lobular subtype

Expression of death-associated protein (DAP) kinase, a proapoptotic serine/threonine protein kinase, is frequently lost in human tumors. In a study of 134 primary breast cancer specimens hypermethylation of the DAP kinase gene was found in 13% of cases. A highly significant difference (P < 0.001) of DAP kinase inactivation was observed between invasive lobular cancer (n = 19) and invasive ductal cancer (n = 85; 53% versus 9%, respectively). Hypermethylation correlated with loss of RNA expression, estrogen receptor positivity (P < 0.01), and the absence of p53 overexpression (P < 0.01). In contrast to invasive lobular cancer, the in situ-growing precursor lesion lacked epigenetic modification of the DAP kinase promotor by aberrant methylation indicating a potential role in tumor progression. Unlike the DAP kinase gene, hypermethylation of the cyclin D2 and RASSF1A genes did not correlate with a particular histological subtype or to invasiveness [corrected]. We conclude that different histological subtypes of breast cancer may not only differ concerning specific chromosomal abnormalities and DNA mutations but also with regard to epigenetic inactivation patterns.     

14-3-3σ expression is associated with poor pathological complete response to neoadjuvant chemotherapy in human breast cancers

14-3-3σ is a tumor suppressor gene induced by p53 in response to DNA damage and reportedly associated with resistance to chemotherapy. The aim of this study was to investigate whether 14-3-3σ expression is also associated with resistance to neoadjuvant chemotherapy consisting of paclitaxel followed by 5-FU/epirubicin/cyclophosphamide (P-FEC) in human breast cancer patients. A total of 123 primary breast cancer patients treated with neoadjuvant chemotherapy (P-FEC) were included in this study. Immunohistochemistry of 14-3-3σ and p53 as well as direct sequencing of TP53 were performed using the tumor biopsy samples obtained prior to neoadjuvant chemotherapy. Thirty-eight of the tumors (31%) were positive for 14-3-3σ. There was no significant association between 14-3-3σ expression and TP53 mutation or p53 expression. However, 14-3-3σ expression showed a significantly (P=0.009) negative association with pathological complete response (pCR) to P-FEC, and multivariate analysis demonstrated that only 14-3-3σ (P=0.015) and estrogen receptor (P=0.021) were significantly and independently associated with pCR. The combination of 14-3-3σ expression and TP53 mutation status had an additive negative effect on pCR, i.e., pCR rates were 45.5% for 14-3-3σ negative/TP53 mutant tumors, 24.6% for 14-3-3σ negative/TP53 wild tumors, 23.1% for 14-3-3σ positive/TP53 mutant tumors, and 0% for 14-3-3σ positive/TP53 wild tumors. These results demonstrate that 14-3-3σ expression is significantly associated with resistance to P-FEC and this association is independent of other biological markers. The combination of 14-3-3σ expression and TP53 mutation status has an additively negative effect on the response to P-FEC.     

The p53 codon 72 proline allele is associated with p53 gene mutations in non-small cell lung cancer.

The p53 gene plays a critical role in cell cycle control, the initiation of apoptosis, and in DNA repair. An Arg/Pro polymorphism at codon 72 of the p53 gene alters the ability of the p53 protein to induce apoptosis, influences the behavior of mutant p53, decreases DNA repair capacity, and may be linked with an increased risk of lung cancer. To further define the role of the p53 codon 72 polymorphism on DNA repair, lung cancer risk, and mutant p53 function, we examined the effect of this polymorphism on mutation of the p53 gene and patient survival in non-small cell lung cancer (NSCLC). Tumor and nonneoplastic (lung or lymphocyte) samples were collected from 182 patients with NSCLC. p53 mutations were detected by direct sequencing and/or the Gene Chip p53 assay in 93 of 182 (51%) tumors. p53 codon 72 polymorphisms were identified by PCR/RFLP analysis. p53 mutations were significantly (P = 0.01) associated with the number of codon 72 Pro alleles: Pro/Pro homozygotes, 17 of 26 (65%); Arg/Pro heterozygotes, 45 of 79 (57%); and Arg/Arg homozygotes, 31 of 77 (40%). The number of codon 72 Pro alleles was independently associated with p53 mutations (odds ratio, 1.97; 95% confidence interval, 1.14-3.40; P = 0.01) in a multiple logistic regression model. The codon 72 polymorphism did not influence patient survival in either the entire patient group or among patients with p53 mutant tumors. In summary, the p53 Pro allele is associated with an increased frequency of p53 mutations in NSCLC.