人前列腺癌组织中p53基因突变和p21表达缺失

目的 :探讨人前列腺癌组织中p53基因的突变和p2 1WAF1/CIP1　　　蛋白表达的缺失。方法 :采用p53基因突变的PCR SSCP分析及DNA测序测定 2 0例患者前列腺癌标本 ,同时检测p2 1WAF1/CIP1　　　　蛋白的表达。结果 :在 2 0个前列腺癌标本中 ,4例发现有p53基因的点突变 ( 2 0 % ) ,这 4例标本的前列腺癌细胞中均伴有p2 1WAF1/CIP1　　　　蛋白的表达缺失。结论 :人前列腺癌的发生和p53基因的突变有关 ,而这些p53基因异常可导致p2 1WAF1/CIP1　　　　蛋白的表达缺失。     

人前列腺癌组织中p53基因突变和p21表达缺失

目的：探讨人前列腺癌组织中p53基因的突变和p21^WAF1/CIP1蛋白表达的缺失。方法：采用p53基因突变的PCR－SSCP分析及DNA测序测定20例患者前列腺癌标本,同时检测p21^WAF1/CIP1蛋白的表达。结果：在20个前列腺癌标本中,4例发现有p53基因的点突变（20％）,这4例标本的前列腺癌细胞中均伴有p21^WAF1/CIP1蛋白的表达缺失。结论：人前列腺癌的发生和p53基因的突变有关,而这些p53基因异常可导致p21^WAF1/CIP1蛋白的表达缺失。     

前列腺癌和癌前病变细胞中p 53和Bcl-2表达的差异

目的 :研究比较p 5 3和Bcl- 2蛋白在人前列腺癌 (PCa)和癌前病变—高分级的前列腺上皮内瘤 (PIN)细胞中的表达 ,探讨PCa的分子机制。方法 :采用免疫组织化学分析 ,检测 2 3例人PCa标本和 12例高分级PIN细胞中p 5 3和Bcl - 2蛋白的表达。结果 :在 2 3例PCa标本中p 5 3和Bcl- 2蛋白的表达分别有 6例 (2 6 1% )和 5例 (2 1 7% ) ,而 12例高分级PIN标本中均有Bcl- 2的蛋白表达而无p 5 3蛋白的表达。结论 :Bcl- 2的蛋白过表达和PIN的形成有关 ,是PCa形成的早期事件 ;而p 5 3基因突变与PCa的发生有关 ,并可能是较晚期事件。     

原发性肝细胞癌组织中p53和p21WAF/CIP1及MDM2蛋白的表达及其临床意义

目的探讨p53、p21WAF/CIP1及MDM2蛋白在原发性肝细胞癌(hepatocellular carcinoma, HCC)组织中的表达及其临床病理意义.方法选取115例HCC及其相应的癌旁肝组织构建组织芯片,应用免疫组织化学方法检测p53、p21WAF/CIP1及MDM2蛋白的表达,采用统计学分析它们的表达及其与临床病理参数之间的关系.结果p53、p21WAF/CIP1及MDM2在HCC组织中的阳性表达率分别为83.5%(96/115)、36.5%(42/115)和48.7%(56/115),同癌旁组织相比,p53、p21WAF/CIP1及MDM2的表达均明显增高,P＜0.05.两两相关分析比较, p53表达分别与p21WAF/CIP1和MDM2表达有关;p53、p21WAF/CIP1及MDM2的阳性表达率与患者性别、年龄、肿瘤大小、肿瘤数量、HBsAg、病理分级、血清AFP浓度和患者生存时间均无关,P均＞0.05.结论p53、p21WAF/CIP1及MDM2在HCC组织中呈增高表达并具有一定的相关性,提示它们可能在HCC的发生发展中发挥重要的作用.     

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。     

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.     

p21~(WAF1/CIP1)在甲状腺癌组织的表达及临床意义

[目的]探讨 p21WAF1/CIP1与 p53基因在甲状腺癌中的表达与病理类型和分化程度的关系。[方法]应用免疫组化技术检测甲状腺癌组织中的抑癌基因 p21WAF1/CIP1及 p53基因的表达。统计学采用 χ2 检验。[结果]甲状腺腺瘤(TT) ,甲状腺乳头状癌(PTC)、滤泡状癌(FTC)、未分化癌(UDC)组织 p21蛋白阳性率分别为66 7%、62 5 %、58 3 %、50 0% ,各组之间无显著差别(P>0 05) ;高分化癌(WDC)、低分化癌(PDC)、UDC组织p21蛋白阳性率分别为67 7 %、46 2 %、50 0 % ,各组之间无显著差别(P>0 05) ;PTC、FTC、UDC组织 p53蛋白阳性率分别为31 3%、25 0 %、64 3 % ,UDC与PTC、FTC之间存在显著差别(P<0 05) ;WDC、PDC、UDC组织 p53蛋白阳性率分别为16 1 %、61 5 %、64 3 % ,WDC的阳性率明显低于PDC、UDC(P<0 05) ;p53蛋白阳性的癌组织 p21蛋白阳性率为40 9%(9/22) ,p53蛋白阴性的癌组织 p21蛋白阳性率为69 4%(25/36) ,两者之间存在显者差异(P<0 05)。[结论]甲状腺癌中 p21WAF1/CIP1的表达与其病理类型和分化程度无关 ,而 p53基因的表达与甲状腺癌病理类型和分化程度有关 ,p21WAF1/CIP1作为一新的抑癌基因 ,其表达相当程度上依赖于 p53蛋白。     

膀胱移行细胞癌p21WAF1／CIP1mRNA及蛋白的表达

目的 研究p21WAF1／CIP1基因在膀胱移行细胞癌中的表达及意义。方法 采用原位杂交及免疫组化技术检测56例膀胱移行细胞癌标本和10例正常膀胱黏膜组织p21WAF1/CIP1mRNA及蛋白的表达。结果 p21mRNA和p21蛋白在膀胱移行细胞癌中的阳性表达率分别为51．8％（29／56）,35．7％（20／56）;在正常膀胱黏膜中的阳性表达率均为10％（1／10）。它们在低分化,浸润性肿瘤的表达明显低于高分化,浅表性肿瘤（P＜0．05）。结论 p21WAF1／CIP1的表达同膀胱移位细胞癌的恶性程度呈负相关,它的低表达是膀胱移行细胞癌发生、发展中的晚期分子事件。综合运用原位分子杂交和免疫组化技术可以客观、准确地评价基因的功能动态。     

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。     

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.     

Endogenous p21WAF1/CIP1 status predicts the response of human tumor cells to wild-type p53 and p21WAF1/CIP1 overexpression

Expression of exogenous wild-type (wt) p53 protein can suppress the growth and/or induce apoptosis in different tumor cells. The effect of exogenous p21(WAF1/CIP1) expression is more controversial: while it can induce apoptosis in some cells, it can protect against p53-mediated apoptosis in others. We used adenoviral vectors to introduce p53 and p21(WAF1/CIP1) genes into human tumor cell lines with different p53 and/or p21(WAF1/CIP1) status. The cell growth inhibition and the induction of apoptosis were measured. Overexpression of wt p53 induced more efficient growth inhibition and apoptosis in SW 620 (mutant p53) and HeLa (inactivated p53 protein) than in MCF-7 (wt p53) and CaCo-2 cell line, which was the most resistant to p53 overexpression despite the p53 mutation. Unlike HeLa and SW 620 cells, the basal p21 protein level was readily detected in CaCo-2 and MCF-7 cells. Overexpression of p21(WAF1/CIP1) gene induced somewhat less pronounced growth inhibition of all cell lines tested, but it also induced apoptosis in HeLa and SW 620 cells. These results suggest that the basal, but not the inducible, levels of p21(WAF1/CIP1) protein in tumor cells could protect from p53-mediated apoptosis. On the other hand, overexpression of p21(WAF1/CIP1) gene itself can induce apoptosis in cells with no basal p21(WAF1/CIP1) protein level. Possible mechanisms of the differential response to these genes are discussed.     

A cyclin-dependent kinase inhibitor (p21(WAF1/CIP1)) affects thymidine incorporation in human liver cancer cells

p21(WAF1/CIP1) is a universal cyclin-dependent kinase inhibitor. To investigate the role of p21(WAF1/CIP1) in proliferation of human liver cancer cells, we examined the expression of p53, p21(WAF1/CIP1), cdk2 and cdk4 expression in two human liver cancer cell lines (HepG2 and PLC/PRF/5 cells). The effects of p21(WAF1/CIP1) on [(3)H]thymidine incorporation and cdks were also examined in these cells. HepG2 cells expressed all these proteins with lower level of cdk4. PLC/PRF/5 cells expressed the other proteins except p21(WAF1/CIP1). Transfection of p21(WAF1/CIP1) gene inhibited [(3)H]thymidine incorporation of both cells with different extent. Although the transfection of p21(WAF1/CIP1) did not affect cdk2 and cdk4 expression, it did reduce cdk2 kinase activity by 20%. These results suggest that: (a) p21(WAF1/CIP1) involved in DNA synthesis of human liver cancer cells; (b) p21(WAF1/CIP1) could be a target gene for the treatment of human hepatocellular carcinoma.     

人乳腺癌细胞株WAF1／GIP1／p21基因的表达及其与细胞生物学特性的关系

OBJECTIVE: To study the WAF1/CIP1 gene DNA status, mRNA and protein expressions in human breast cancer cell line and its significance. METHODS: Using cell culture, molecular biological techniques such as Southern blot, Northern blot and immunocytochemical methods, the WAF1/CIP1 gene DNA status, mRNA and protein expression levels in MCF-7 expressing wild type p53(wtp53) and MDA-MB-231 expressing mutant p53 (mtp53) human breast cancer cell lines were detected respectively. The p53 and mdm-2 protein expression levels and cytobiological features of the 2 cell lines were compared and correlated to their WAF1/CIP1 gene expression levels. RESULTS: (1) There was no difference in WAF1/CIP1 gene DNA status in the two breast cancer cell lines. Neither of them showed gene amplificatian or deletion. However, the WAF1/CIP1 mRNA and p21WAF1/CIP1 protein expression levels of MCF-7 cells were higer than those of MDA-MB-231 cells (P < 0.05). (2) The character and cellular distribution of p53 protein in the two cell lines were clearly different. The expression level of mdm-2 proteion was significantly higher in MCE-7 than in MDA-MB-231 cells (P < 0.05). (3) Compered to the other breast cancer cell line, MCF-7 cells were better differentiated, grew more slowly and adhered more closely with each other. CONCLUSION: The WAF1/CIP1 gene expression at mRNA and protein levels is associated with p53 phenotype and some cytobiological features of human breast cancer.     

Altered p21(WAF1/CIP1) expression is associated with poor prognosis in extrahepatic bile duct carcinoma

This study was designed to determine the clinical implications of p21(WAF1/CIP1) expression and the relationship between p21(WAF1/CIP1) expression and p53 status in extrahepatic bile duct carcinoma (EBDC). Low p21(WAF1/CIP1) expression was immunohistochemically detected in 23 (67.6%) of 34 EBDCs, moderate in six (17.7%), and high in five (14.7%). Kaplan-Meier curves showed that low and high p21(WAF1/CIP1) expressions were significantly associated with shortened disease-free survival (low vs. moderate, P=0.02; high vs. moderate, P=0.01). There was no correlation between p21(WAF1/CIP1) and p53 expression. These findings suggest that altered p21(WAF1/CIP1) expression exerts an adverse influence on the prognosis of EBDC.     

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.     

Association of increased radiocurability of murine carcinomas with low constitutive expression of p21(WAF1/CIP1) protein

PURPOSE: The study investigated whether basal, constitutive levels of p21(WAF1/CIP1) protein in murine carcinomas are related to in vivo tumor radioresponse. The study is based on recent observations demonstrating that in vitro cancer cell lines are resistant to cytotoxic drugs when they express high basal levels of p21(WAF1/CIP1) protein, and that the loss of the p21 gene in the HCT116 human colorectal cancer cell line results in increased radioresponse of xenografts derived from that cell line. METHODS AND MATERIALS: Protein levels of p21(WAF1/CIP1), p53, bax, and bcl-2 were determined in 8 carcinomas (3 mammary carcinomas designated MCa-4, MCa-29, and MCa-35, 2 squamous cell carcinomas designated SCC-IV and SCC-VII, ovarian adenocarcinoma OCa-I, hepatocarcinoma HCa-I, and adenosquamous carcinoma ACa-SG) syngeneic to C3Hf/Kam mice using Western blot analysis. The tumors, growing in the right hind legs of mice, were 8 mm in diameter at the time of analysis. These tumors greatly differ in their radioresponse, assessed by TCD50 assay, and in their susceptibility to radiation-induced apoptosis. RESULTS: Protein levels of these oncogenes varied among tumors, with p21(WAF1/CIP1) showing the greatest variation: its mean densitometric value ranged from 1 to 19. Bcl-2 levels also showed broad variation in densitometric values, from 1 to 10. In comparison, bax and p53 (7 of 8 tumors contained wild-type p53) varied much less among different tumor types; their variation was within a 5-fold range, and the level of p53 was similar in 6 of 8 tumors. Tumor radioresponse correlated significantly (R = 0.77, p = 0.02) only with the magnitude of p21(WAF1/CIP1)expression: tumors with high levels of p21(WAF1/CIP1)were less radiocurable than those with lower levels. Tumor radiocurability showed a significant positive correlation (p = 0.02) with the extent of radiation-induced apoptosis, indicating that tumors that responded to radiation with higher percentages of apoptosis were more curable by radiation. Despite a strong trend to correlation, (p = 0.15), p21(WAF1/CIP1) expression did not correlate significantly with radiation-induced apoptosis, which suggested that p21(WAF1/CIP1) influenced tumor radioresponse by mechanisms beyond that of apoptosis induction. CONCLUSION: Our findings showed that murine tumors exhibit wide variation in constitutive levels of p21(WAF1/CIP1) which had a significant relationship with tumor radioresponse: tumors with high levels of p21(WAF1/CIP1) were less radiocurable than those with lower levels. These findings support the concept that p21(WAF1/CIP1) is a major determinant of tumor radioresponse in vivo, and may have important clinical implications. The pretreatment assessment of p21(WAF1/CIP1) protein could serve as a useful predictor of radiotherapy outcome and may assist in selecting an effective treatment modality.