Induction of p53 and p21/WAF1/CIP1 expression by nitric oxide and their association with apoptosis in human cancer cells

In this study, human and rat cancer cells were used to investigate the expression of p53 and p21/WAF1/CIP1 and their association with apoptosis after exposure to nitric oxide (NO). It was found that NO induced nuclear accumulation of p53 protein in a dose- and time-dependent manner. The level of p53 protein was elevated by about fivefold compared with that of mock-treated cells 48 h after exposure to 300 ppm NO. The induction of p53 by NO was found by pulse-chase analysis to be mainly regulated by post-translational modification. The correlation between p53 status and apoptosis induced by NO in human cancer cells was also investigated in this study. We found that apoptosis was easily induced in cells containing wild-type p53 (COLO 205 and Hep G2) after exposure to NO. The p21/WAF1/CIP1 protein was induced by NO in cells containing wild-type p53 (Hep G2) but not in cells without p53 (Hep 3B) or with mutated p53 (HT-29). Our results indicate that wild-type p53 and p21/WAF1/CIP1 expression was elevated in human cancer cells by exposure to NO and suggest that this may eventually promote apoptosis. © 1996 Wiley-Liss, Inc.     

Reduced p21(WAF1/CIP1) protein expression is predominantly related to altered p53 in hepatocellular carcinomas

To investigate the relationship between the expression of p21(WAF1/CIP1) protein and p53 status and the possible role of the two proteins in hepatocellular carcinomas (HCCs), we examined the expression of p21(WAF1/CIP1) and p53 immunohistochemically in 81 tumours from 65 patients with hepatocellular carcinoma. p21(WAF1/CIP1) protein was absent from 59 of 81 tumours (72.8%), and altered p53 expression was found in 43 (53.1%). p21(WAF1/CIP1) expression was significantly associated with p53 status (P = 0.0008); 38 of 59 tumours lacking p21(WAF1/CIP1) protein were accompanied by altered p53 expression. Further analyses showed that p21(WAF1/CIP1) expression was inversely correlated with p53 expression in hepatitis C virus (HCV)-related HCCs, but not in HBV-related hepatocellular carcinomas and hepatocellular carcinomas without viral infection. All 11 tumours with intrahepatic metastasis showed altered p21(WAF1/CIP1) or p53 expression. In contrast, no intrahepatic metastasis was found in any of the 17 tumours without abnormal expression of either of the two proteins. These results suggest that: (1) different modes of p21(WAF1/CIP1) regulation are involved in HCCs differing in their hepatitis viral infection status, and p21(WAF1/CIP1) expression appears to be predominantly related to altered p53 in HCV-related HCCs; (2) disruption of the p53-p21(WAF1/CIP1) cell-cycle-regulating pathway may contribute to malignant progression of HCC.     

细胞周期蛋白D1和p21WAF1/CIP1在喉癌癌变过程中表达及其意义

目的研究喉癌变过程中细胞周期蛋白(cyclin)D1和p21WAF1/CIP1表达及其临床病理学意义.方法用免疫组化检测20例正常黏膜、40例不典型增生病变和60例喉癌组织中cyclinD1和p21WAF1/CIP1的表达.结果①cyclin D1和p21WAF1/CIP1阳性表达定位于细胞核.②在喉癌癌变过程中,喉正常黏膜、不典型增生病变和喉癌中cyclin D1阳性表达率分别为5.0%(1/20),30,0%(12/40),53.3%(32/60)(P＜0.001);p21WAF1/CIP1阳性表达率分别为95.0%(19/20),75.0%(30/40)和63.3%(38/60)(P＜0.05).③p21WAF1/CIP1在高、中和低分化的喉癌中阳性表达率分别为76.2%(16/21),65.5%(19/29)和30.0%(3/10)(P＜0.05);p21WAF1/CIP1阳性表达与肿瘤细胞的分化有关.④cyclin D1和p21WAF1/CIP1阳性表达显著相关.结论①喉癌癌变过程中cyclin D1阳性表达率呈逐渐升高的趋势,而p21WAF1/CIP1阳性表达率呈呈逐渐降低的趋势.②cyclin D1异常表达是喉癌发生中早期分子事件.③p21WAF1/CIP1表达与喉癌细胞分化程度有关.④cyclin D1和p21WAF1/CIP1阳性表达显著相关.     

硒对乳腺癌细胞株p21^WAF1/CIP1启动子的调控作用

目的:研究硒对p21的转录调控及其调控位点.方法:通过向转染了重组质粒pGL3- p21p的乳腺癌细胞株MCF7先后加入不同的p21因子启动子的负调节因子和乳酸硒,对比分析荧光素酶表达活性,以确定硒对p21的转录调控及调控位点,并验证硒对癌细胞的生长的负调控作用.结果:perifosine、depsipeptide、apicidin、butyrate与硒共同诱导荧光素酶,酶活性表达无显著差异;而C-Myc与醋酸硒先后诱导酶活性表达差异显著.结论:硒对癌细胞具有诱导凋亡的作用,转录调节位点在p21启动子的sp1结合位点.     

Prognostic Significance of p53 and p21WAF1/CIP1 Immunoreactivity and Tumor Micronecrosis for Recurrence of Meningiomas

Recurrence is an important factor for prognosis of meningioma patients, this also occurring with some lesions diagnosed histopathologically as benign. To analyze their relationships with clinicopathological factors, p53 and p21^WAF1/CIP1 immunoreactivity, 80 meningiomas were classified into four groups with regard to the World Health Organization (WHO) histological classification and recurrence: 40 cases of Group I (typical type)-NR (no recurrence); five cases of Group I-R (recurrence); 20 cases of Group II (atypical or anaplastic type)-NR and 15 cases of Group II-R.Micronecrosis was detected in 25% of Group II-NR and 73.3% of Group II-R (P=0.007, odds ratio (OR) =8.25, 95% confidence interval (CI) =1.79–38.01). Patients receiving radiation therapy had a lower risk of recurrence (P=0.041, OR =0.20, 95% CI =0.05–0.85). Immunoreactivity for p53 protein was positive in 22% of Group I and 54% or Group II (P=0.005), and in 80% of Group I-R and 15% of Group I-NR (P=0.006, OR = 22.7, 95% CI = 2.15–239.4). p21^WAF1/CIP1 protein was detected in 22% of Group I and 48% of Group II (P=0.017), but with no link to recurrence. Multivariate analysis also showed p53 immunoreactivity in Group I (benign lesions) and micronecrosis in Group II (atypical/anaplastic meningiomas) to be strong prognostic factors for recurrence (P<0.05). These results indicate that p53 immunoreactivity and micronecrosis can help predicting recurrence of meningiomas.     

p21WAF1/CIP1和p53蛋白表达在胃癌发生发展过程中的研究

目的研究p21WAF1/CIP1和p53蛋白在胃癌发生发展过程中的作用及表达的临床病理意义.方法采用免疫组化SP法对正常胃粘膜、萎缩性胃炎伴肠上皮化生、萎缩性胃炎伴不典型增生组织各20例和78例胃癌组织标本进行p21WAF1/CIP1和p53蛋白检测.结果胃癌组织中p53蛋白阳性表达率高于正常胃粘膜、萎缩性胃炎伴肠上皮化生和不典型增生组(P＜0.05),而p21WAF1/CIP1蛋白阳性表达低于正常胃粘膜、萎缩性胃炎伴肠上皮化生组(P＜0.01)p21WAF1/CIP1、p53蛋白表达与胃癌的分化程度相关(P＜0.05);有淋巴结转移组p21WAF1/CIP1蛋白表达率低于无淋巴结转移组(P＜0.05),而有淋巴结转移组p53蛋白表达率高于无淋巴结转移组(P＜0.05);p53蛋白表达与胃癌浸润深度有关.结论p53蛋白高表达与p21WAF1/CIP1蛋白失表达可能参与胃癌的发生发展过程;检测p53和p21WAF1/CIP1蛋白作为反映胃癌病理学特点的参考指标可能有一定意义;p21WAF1/CIP1蛋白表达在胃癌可能存在非p53诱导表达途径.     

胃肠道类癌中生长抑素和p21^WAF1/CIP1蛋白表达的意义

目的探讨生长抑素和p21WAF1/CIP1蛋白阳性表达与胃肠道类癌的组织分化、浸润和转移的关系.方法采用免疫组化S-P法对36例胃肠道类癌组织生长抑素和p21WAF1/CIP1蛋白的表达进行检测.结果 36例类癌组织中,生长抑素和p21WAF1/CIP1蛋白较多表达于高分化类癌组(P＜0.05),随着肿瘤的浸润和淋巴结转移,生长抑素阳性表达率显著降低(P＜0.01),p21WAF1/CIP1阳性表达差异有显著性(P＜0.05).结论生长抑素和p21WAF1/CIP1低表达在类癌的组织分化和发展中起着重要作用,可用于临床对患者进行预后判断.     

WAF1/CIP1 protein expression in human breast tumors

WAF1/CIP1 is a cyclin-dependent kinase inhibitor which isdirectly induced by p53 and negatively controls cellproliferation. To test the hypothesis that increased levelsof WAF1 would be associated with a lowerS-phase fraction and better prognosis, WAF1 protein wasassessed by immunohistochemistry (IHC) in 115 node-negative humanbreast tumors, and results were correlated with establishedprognostic factors and clinical outcome. Nuclear staining wasobserved in malignant cells in 43% of tumors.In most (90%) of the positive tumors, theproportion of cells staining for WAF1 was low(< 10%). WAF1 was not detected in thecytoplasm, or in non-malignant epithelium. Contrary to expectations,the accumulation of p53 protein, a surrogate markerof p53 inactivation, was weakly but positively associatedwith WAF1 expression (p=0.05). Surprisingly, therewas no significant correlation with S-phase fraction, ERor PgR status, tumor size, age, ploidy, nucleargrade, or survival.Conclusion: WAF1 expression is found inthe nuclei of a small fraction of cellsin human breast tumors. WAF1 status is notsignificantly associated with cell proliferation, other established prognosticfactors, or clinical outcome.     

人脑胶质瘤组织中p21WAF1/CIP1表达及临床意义

[目的]探讨人脑胶质瘤组织中p21WAF1/CIP1基因蛋白表达水平与人脑胶质瘤恶性程度的关系。[方法]随机选取的Ⅰ￣Ⅳ人脑胶质瘤标本48例,正常外伤脑组织10例为对照。应用免疫组化技术(SP法)检测p21WAF1/CIP1基因蛋白在人脑胶质瘤中的表达水平。[结果]p21WAF1/CIP1基因蛋白在正常脑组织中均为阴性表达,而在胶质细胞瘤组织中表达增高,阳性率为70%￣78%,在Ⅰ～Ⅳ级胶质瘤组织中表达数值分别为2.11±0.10,1.44±0.56,1.0±0.12及0.89±0.32,表达水平随胶质瘤恶性程度的升高呈下降趋势,在高分化与低分化肿瘤之间存在显著性差异(P<0.05)。[结论]p21WAF1/CIP1可能参与胶质瘤的发生和发展,并可作为评估胶质瘤细胞瘤恶性程度以及预后的手段之一。     

胃癌中p21WAF1/CIP1、细胞周期素D1、p53表达的相关性

目的　探讨p2 1WAF1/CIP1、细胞周期素D1(cyclinD1)、p5 3在胃癌中表达之间的相关性。 方法　应用原位杂交技术检测p2 1WAF1/CIP1mRNA、细胞周期素D1mRNA及免疫组化技术检测p5 3蛋白在胃癌中的表达。结果　p2 1WAF1/CIP1mRNA在癌组织及癌旁正常粘膜中阳性表达率各为 93.15 % (6 8/73)及76 .71% (5 6 /73) ,二者相比具有显著差异 (P <0 .0 5 )。CyclinD1mRNA在癌组织及癌旁正常粘膜中阳性表达率各为 5 4 .79% (40 /73)及 30 .16 % (2 2 /73) ,二者具有显著差异 (P <0 .0 5 )。p5 3蛋白在胃癌中的阳性表达率为 32 .87% (2 4 /73) ,p5 3过表达者 ,其 p2 1WAF1/CIP1mRNA表达较p5 3阴性者为低 ,二者存在显著差异 (P <0 .0 5 )。p2 1WAF1/CIP1表达与细胞周期素D1表达呈负相关。结论　p2 1WAF1/CIP1、CyclinD1、p5 3的异常表达及它们之间可能存在的相互作用 ,对于胃癌的发生发展具有重要意义。     

p53 missense but not truncation mutations are associated with low levels of p21(CIP1/WAF1) mRNA expression in primary human sarcomas

Many growth-suppressing signals converge to control the levels of the CDK inhibitor p21(CIP1/WAF1). Some human cancers exhibit low levels of expression of p21(CIP1/WAF1) and mutations in p53 have been implicated in this down-regulation. To evaluate whether the presence of p53 mutations was related to the in vivo expression of p21(CIP1/WAF1) mRNA in sarcomas we measured the p21(CIP1/WAF1) mRNA levels for a group of 71 primary bone and soft tissue tumours with known p53 status. As expected, most tumours with p53 mutations expressed low levels of p21(CIP1/WAF1)mRNA. However, we identified a group of tumours with p53 gene mutations that exhibited normal or higher levels of p21(CIP1/WAF1) mRNA. The p53 mutations in the latter group were not the common missense mutations in exons 4-9, but were predominantly nonsense mutations predicted to result in truncation of the p53 protein. The results of this study suggest that different types of p53 mutations can have different effects on the expression of downstream genes such as p21(CIP1/WAF1) in human sarcomas.     

p21^WAF1／CIP1在原发性肺癌中的表达

目的：探讨p21^WAF1/CIP1在肺癌中的生物学功能,方法：用免疫组化法检测62例肺癌和14例正常肺组织石蜡切片p21^WAF1/CIP1的染色强度。结果：1．p21^WAF1/CIP1定位于细胞核或细胞浆。2．小细胞肺癌是与非小细胞肺中核p21^WAF1/CIP1表达存在显著性差异（P＜0．005）,浆p21^WAF1/CIP1则不存在显著性差异（P＜0．005）。核与浆p21^WAF1/CIP1表达的对比在高,低分化肺癌中具有显著性差异P＜0．05）。结论：肺癌细胞p21^WAF1/CIP1的生物学功能可能依其定位、量表达的高低及组织学类型的不同而存在差异。     

p21~(WAF1/CIP1)在乳腺癌中的表达及意义

目的　探讨p2 1WAF1/CIP1蛋白在乳腺癌中表达的临床意义。方法　运用免疫组化SP法半定量检测p2 1蛋白在癌旁正常乳腺组织、乳腺癌组织中的表达。结果　p2 1蛋白表达位于细胞核 ,呈棕黄色。在 2 0例癌旁正常乳腺组织中 ,无p2 1蛋白表达。在 69例乳腺癌组织中有 3 0例p2 1蛋白阳性表达。在乳腺癌组织中 ,随组织学分级升高 ,p2 1阳性率下降 (P <0 0 5 ) ,随临床分期升高 ,p2 1阳性率下降 (P <0 0 5 )。有淋巴结转移组p2 1阳性率低于无淋巴结转移组 (P <0 0 5 )。p2 1蛋白阳性表达者术后 5年无瘤生存率高于p2 1蛋白阴性者术后 5年无瘤生存率 (P <0 0 5 )。结论　p2 1蛋白可用来评估乳腺癌细胞分化情况及转移潜能 ,可判断乳腺癌患者预后。     

Differential targeting of the cyclin-dependent kinase inhibitor,p21CIP1/WAF1, by chelators with anti-proliferative activity in a range of tumor cell-types

Chelators such as 2-hydroxy-1-napthylaldehyde isonicotinoyl hydrazone (311) and di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT) target tumor cell iron pools and inhibit proliferation. These agents also modulate multiple targets, one of which is the cyclin-dependent kinase inhibitor, p21. Hence, this investigation examined the mechanism of action of these compounds in targeting p21. All the chelators up-regulated p21 mRNA in the five tumor cell-types assessed. In contrast, examining their effect on total p21 protein levels, these agents induced either: (1) down-regulation in MCF-7 cells; (2) up-regulation in SK-MEL-28 and CFPAC-1 cells; or (3) had no effect in LNCaP and SK-N-MC cells. The nuclear localization of p21 was also differentially affected by the ligands depending upon the cell-type, with it being decreased in MCF-7 cells, but increased in SK-MEL-28 and CFPAC-1 cells. Further studies assessing the mechanisms responsible for these effects demonstrated that p21 expression was not correlated with p53 status, suggesting a p53-independent mechanism. Considering this, we examined proteins that modulate p21 independently of p53, namely NDRG1, MDM2 and ΔNp63. These studies demonstrated that a dominant negative MDM2 isoform (p75^MDM2) closely resembled p21 expression in response to chelation in three cell lines. These data suggest MDM2 may be involved in the regulation of p21 by chelators.     

p53和p21WAF1/CIP1基因在上皮性卵巢癌中的表达及临床意义

目的探讨联合检测p53和p21蛋白表达与上皮性卵巢癌预后的关系.方法 108例上皮性卵巢癌标本用于研究,每个标本同时用免疫组化的方法检测p53和p21蛋白表达.结果 p53(－)和p53( )患者的5年生存率分别为60.47%和29.43%,差异有显著性(P=0.0228).p21(－)和p21( )患者的5年生存率分别为31.58%和47.14%,差异有显著性(P=0.0246).p53(－)而p21( )患者的预后明显优于其他患者(P=0.0013).多因素分析显示p53、p21蛋白联合表达状态是判断上皮性卵巢癌预后的独立因子. 53蛋白表达与p21蛋白表达呈负相关(P=0.0003).结论联合检测p53、p21蛋白表达在判断上皮性卵巢癌预后上的意义优于单纯检测p53或p21蛋白表达,对临床有指导意义.     

人乳腺癌细胞株WAF1/CIP1/p21基因的表达及其与细胞生物学特性的关系

目的研究人乳腺癌细胞株ＷＡＦ１／ＣＩＰ１基因的ＤＮＡ状况、ｍＲＮＡ和蛋白的表达水平及其意义。方法应用细胞培养、分子生物学Ｓｏｕｔｈｅｒｎｂｌｏｔ和Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交以及免疫组化染色等技术，检测人乳腺癌表达野生型ｐ５３（ｗｔｐ５３）的ＭＣＦ７细胞和表达突变型ｐ５３（ｍｔｐ５３）的ＭＤＡＭＢ２３１细胞中ＷＡＦ１／ＣＩＰ１基因ＤＮＡ状况、ｍＲＮＡ和蛋白质的表达水平，研究其与ｍｄｍ２、ｐ５３蛋白的表达和细胞生物学特性的关系。结果比较ＭＣＦ７细胞与ＭＤＡＭＢ２３１细胞：（１）两者ＷＡＦ１／ＣＩＰ１基因ＤＮＡ状况无明显差异，前者ｍＲＮＡ和蛋白质的表达水平明显高于后者（Ｐ＜０．０５）；（２）两者ｐ５３蛋白的性质和分布不同，前者ｍｄｍ２蛋白的表达水平明显高于后者（Ｐ＜０．０５）；（３）前者生物学特性好于后者。结论人乳腺癌细胞株ＷＡＦ１／ＣＩＰ１基因ｍＲＮＡ和蛋白质的表达水平与ｐ５３基因表型和细胞生物学特性有关。