p21WAF1/CIP1基因上游主要转录调控序列区及其相关功能

p21蛋白作为周期依赖性蛋白激酶抑制因子,调节细胞周期的进程,参与细胞生长、增殖、分化、衰老等多种活动.p21/WAF1/CIP1基因上游启动子中含有多个转录调控序列,包括p53,Sp1,Ap2,VDR及RAR,STAT,C/EBPα,β,E2A,MyoD和E2F等转录因子的顺式结合元件.在细胞的生长、分化,凋亡,衰老及疾病的发生发展中,这些转录因子通过与p21上游相应调控区相互作用,调节p21基因的表达.     

抑癌基因CIP1／WAF1及其产物的研究现状

抑癌基因的研究近年来已超过了致癌基因的研究而成为当今肿瘤探索的一个主流并已取得了突破性的进展。随着对ｐ５３基因及其产物作用机制研究的进一步深入，人们又发现ｐ５３只是诱导了ＣＩＰ１／ＷＡＦ１基因的转录间接地起到抑制细胞生长的作用。本文就ＣＩＰ１／ＷＡＦ１基因及其产物的一般性状及生物学功能的研究现状作一叙述。     

前列腺癌p21CIP1/WAF1、Rb及PCNA的表达及意义

目的研究p21^CIP1/WAF1、Rb及PCNA在人前列腺癌标本中的表达及三者相关性,阐述它们与前列腺癌病理分级及临床分期的关系。方法收集36例确诊前列腺癌石蜡包埋存档标本作为研究对象,采用免疫组化SABC法对其p21^CIP1/WAF1、Rb及PCNA进行检测,并应用图象分析仪判定,统计学处理,对前列腺癌的病理分级及临床分期进行了对比分析及相关性研究。结果p21^CIP1/WAF1、Rb及PCNA的免疫组化阳性染色为棕黄色和／或棕褐色,定位于细胞浆或细胞核。所得数据均经统计学处理。在不同病理分级、临床分期之间差异均有显著性,同时还发现PCNA与p21^CIP1/WAF1及Rb之间存在显著负相关性。但未发现p21^CIP1/WAF1、与Rb有显著相关性。结论p21^CIP1/WAF1、Rb表达与前列腺癌组织的病理分级、临床分期呈负相关性,在发病机制中可能涉及到p21^CIP1/WAF1、Rb和PCNA凋节通路的异常。同时,作为一种检测方法,可用于判定前列腺癌恶性程度及进程的有价值的指标,对诊治康复也可提供有意义的帮助。     

胃癌组织cyclinE和p21~(WAF1/CIP1)蛋白表达的意义

目的 :探讨cyclinE和p2 1WAF1/CIP1蛋白在胃癌发生发展中的作用及其表达的意义。方法 :采用免疫组化S P法检测正常胃黏膜、萎缩性胃炎伴肠上皮化生、萎缩性胃炎伴不典型增生各 2 0例和 78例胃腺癌组织中cyclinE和 p2 1WAF1/CIP1蛋白表达。结果 :cyclinE蛋白阳性表达在胃癌组高于正常胃黏膜、萎缩性胃炎伴肠上皮化生组 ,而 p2 1WAF1/CIP1蛋白表达则相反 ,差异均有显著性 (P <0 0 5 ) ;cyclinE、p2 1WAF1/CIP1蛋白表达与胃癌细胞分化程度相关 (P <0 0 5 ) ;有肝转移的胃癌组cyclinE阳性表达率高于无肝转移组 (P <0 0 5 ) ;有淋巴结转移组 p2 1WAF1/CIP1蛋白表达率低于无淋巴结转移组 (P <0 0 5 )。结论 :cyclinE蛋白高表达与 p2 1WAF1/CIP1蛋白失表达可能参与胃癌的发生发展过程 ,检测cyclinE和p2 1WAF1/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     

p21^WAF1／CIP1与乳腺癌

p21WAF1/CIP1是目前认为最广泛的激酶抑制蛋白,对多种cyclin-CDK复合物具有抑制作用,可抑制乳腺肿瘤细胞的发生发展.它在乳腺癌中的高表达对乳腺癌的内分泌治疗和判断其预后具有重要意义.     

转录因子Ets-1与妊娠期高血压疾病的相关研究进展

妊娠期高血压疾病（hypertensive disorders complicating pregnancy）是妊娠期特有的疾病,包括妊娠期高血压、子痫前期、子痫、慢性高血压并发子痫前期以及慢性高血压。本病以妊娠20周后高血压、蛋白尿、水肿为特征,并伴有全身多脏器的损害;严重患者可以出现抽搐、昏迷、脑出血、心力衰竭、胎盘早剥和弥漫性血管内凝血,甚至死亡。该病严重影响母婴健康,是孕产妇和围生儿发病及死亡的主要原因之一^[1]。     

人脑神经胶质瘤中p16、p21~(WAF1/CIP1)蛋白表达的研究

目的　探讨 p16、p2 1WAF1/CIP1两种抑癌基因与人脑神经胶质瘤恶性程度的关系。方法　采用SABC免疫组织化学方法对 6 4例人脑胶质瘤组织及 8例正常脑组织标本中p16和 p2 1WAF1/CIP1表达情况进行检测 ,并进行相关分析。结果　①p16和 p2 1WAF1/CIP1阳性表达率在人脑胶质瘤中分别为 4 5 .3%和 6 4 .1%与正常脑组织中的表达情况差异显著 (P <0 0 5 ) ;②p16蛋白和 p2 1WAF1/CIP1蛋白阳性表达率均随着胶质瘤的恶性程度的增高而降低 ,差异显著 (P <0 0 1) ,且呈负相关关系 ;③p16蛋白和 p2 1WAF1/CIP1蛋白可协同表达 ,且在正常脑组织和脑胶质瘤各分级中 p16蛋白和 p2 1WAF1/CIP1蛋白协同表达率差异显著 (P <0 0 5 ) ,并呈负相关关系。结论　p16与p2 1WAF1/CIP1蛋白的阳性表达率及协同表达率可在一定程度上反映胶质瘤细胞的恶性程度 ,可作为判断其恶性程度的有效指标     

PSA启动子介导的TAT-p21WAF1/CIP1融合蛋白在前列腺癌细胞中的特异表达及活性初探*

目的：设计并构建含有前列腺组织特异性抗原（PSA）启动子的TAT-p21WAF1/CIP1融合蛋白真核表达载体（pPSA-TAT-p21），使由TAT蛋白转导结构域（TAT）介导的抑癌基因蛋白p21WAF1/CIP1(p21)能够在前列腺癌细胞中实现特异性的跨膜转运，增强p21对前列腺癌的抑制作用。方法：利用PCR技术构建含有PSA启动子、TAT蛋白转导序列和p21读码框架的真核表达载体pPSA-TAT-p21，并进行酶切、测序鉴定。脂质体法在前列腺癌LNCaP细胞和大肠癌HT-29细胞中转染上述表达载体及对照质粒后进行反转录PCR（RT-PCR），检测p21的mRNA以及蛋白在不同细胞中的表达情况。MTT法检测转染pPSA-TAT-p21后LNCaP细胞的增殖情况。结果：成功构建pPSA-TAT-p21真核表达载体。RT－PCR和Western blotting结果显示PSA-TAT-p21在前列腺癌细胞中有明显表达，在大肠癌细胞中基本不表达，呈现特异性的表达，而由CMV启动子介导的p21（pCMV-21）对照组在两个细胞株中均有表达。细胞增殖实验结果显示，含有TAT蛋白转导结构域的PSA-TAT-p21的融合蛋白对前列腺癌细胞增殖的抑制作用明显高于不含TAT的PSA-p21蛋白。 结论：pPSA-TAT-p21能够在前列腺癌细胞中特异性地高效表达，为前列腺癌基因的靶向治疗提供了实验依据。     

肝细胞癌p53基因与p21WAF1／CIP1基因的相关性分析

近年来，癌基因、抑癌基因在肿瘤发生发展中的作用日益受到人们的关注，不少学者进行了ｐ５３基因与肝细胞肝癌（ＨＣＣ）发生的相关性研究。有作者报道，野生型ｐ５３基因抑制细胞增殖的功能是通过ｐ２１ＷＡＦ１／ＣＩＰ１基因介导的〔１〕。本文检测７２例ＨＣＣ组织中...     

转录调节因子Ets-1在大鼠血管平滑肌细胞增殖与凋亡中的作用

目的： 研究转录调节因子Ets-1对大鼠血管平滑肌细胞增殖与凋亡的影响及其可能的机制。 方法： 用定量细胞DNA片段的方法观察大鼠血管平滑肌细胞增殖与凋亡。用Western印迹法检测磷酸化视网膜母细胞瘤（RB-P）蛋白表达。 结果： Ets-1抑制大鼠血管平滑肌细胞凋亡。反义P21WAF1/CIP1能够阻断Ets-1的抗凋亡作用，并抑制Ets-1诱导的平滑肌细胞增殖。Ets-1能够上调RB-P蛋白表达，反义P21WAF1/CIP1可以阻断Ets-1诱导的RB-P蛋白表达。 结论： 在大鼠血管平滑肌细胞中，Ets-1通过P21WAF1/CIP1旁路发挥抑制凋亡和促进增殖作用。     

p21WAF1/CIP1 expression in colorectal carcinoma correlates with advanced disease stage and p53 mutations

Defects in the mechanisms controlling the cell cycle are crucial in cell transformation and/or tumour progression. p21^WAF1/CIP1 is an inhibitor of cyclin-dependent kinases, induced by p53-dependent and p53-independent pathways, which can block progression through the cell cycle. p21^WAF1/CIP1 expression has been investigated immunohistochemically in a series of 191 patients with colorectal cancer of known p53 status. The purpose of the study was two-fold: to assess the relationship between p21^WAF1/CIP1 immunoreactivity and p53 alterations, and to evaluate the prognostic significance of p21^WAF1/CIP1 expression. In 96 carcinomas (51 per cent), p21^WAF1/CIP1 was expressed in over 10 per cent of tumour cells, whereas in 26, p21^WAF1/CIP1 was detected in under 10 per cent of neoplastic cells; 69 tumours lacked p21^WAF1/CIP1 expression. Immunoreactivity was more frequent in tumours of the right colon (p < 0·003) and was inversely correlated with tumour stage (p < 0·03), p53 gene mutations (p < 0·0007), p53 protein accumulation (p < 0·019), and Bcl-2 expression (p < 0·0005). In univariate analysis, down-regulation of p21^WAF1/CIP1 expression was associated with poor overall (p = 0·0022) and disease-free survival (p = 0·0009). Multivariate analysis, however, did not confirm any independent prognostic significance of p21^WAF1/CIP1 expression. The results indicate that p21^WAF1/CIP1 is associated with abnormal accumulation of p53 protein and the occurrence of p53 gene mutations in colorectal cancer and that lack of p21^WAF1/CIP1 expression is correlated with reduced patient survival in univariate analysis. These data underline the crucial pathogenetic role of the p53–p21^WAF1/CIP1 pathway in carcinomas of the large bowel. Copyright © 1999 John Wiley & Sons, Ltd.     

DNA damage and p21WAF1/CIP1/SDI1 in experimental injury of the rat adrenal cortex and trauma-associated damage of the human adrenal cortex

In vivo models are needed to study the reactions of tissues to DNA damage, such as the induction of the cyclin-dependent kinase inhibitor p21, indicating potential repair of the damage, versus apoptosis, indicating the elimination of the damaged cells. Damage to DNA occurs in tissues during shock, sepsis, and other critical medical conditions. Previous studies have found evidence of damage to the cortex of adrenal glands from organ donors who had undergone severe trauma prior to death. The present experiment studied rats under experimental interventions of clinical relevance to patients with conditions that put them at risk for damage to the adrenal glands. These interventions comprised ischaemia and reperfusion injury, sepsis following caecal ligation and puncture, acute pancreatitis, and administration of chemical agents (zymosan and acrylonitrile). All the interventions caused an increase in p21 mRNA as assessed by northern blotting and in situ hybridization. Increased nuclear p21 protein was shown by immunohistochemistry. All the interventions caused damage to DNA, as shown by labelling of available 3′ termini of single-strand breaks with terminal transferase. The number of cells undergoing apoptosis, visualized by ligation of a hairpin oligonucleotide probe to double-strand breaks in DNA, was much lower. In rat adrenal glands, apoptotic cells were infrequent under all the conditions studied. They were more abundant in human organ donor adrenal glands that were previously shown to have extensive DNA damage accompanied by induction of p21. The similarity of the effects of a wide variety of surgical interventions and chemical agents suggest a common pathophysiological mechanism which is not specific to the initiating injury. Experimental injury of the rat adrenal cortex provides a model for investigating the role of organ DNA damage and of mediators of the response to DNA damage, such as p21. Copyright © 1999 John Wiley & Sons, Ltd.     

EXPRESSION OF CYCLIN-DEPENDENT KINASE INHIBITOR p21WAF1/CIP1 IN NON-NEOPLASTIC MUCOSA AND NEOPLASIA OF THE STOMACH: RELATIONSHIP WITH p53 STATUS AND PROLIFERATIVE ACTIVITY

The expression of the p53-inducible cyclin-dependent kinase inhibitor p21^WAF1/CIP1 in non-neoplastic mucosa, adenoma, and adenocarcinoma of the stomach was examined immunohistochemically and its relationship with p53 expression and proliferative activity was analysed. In normal gastric mucosa as well as in intestinal metaplasia the epithelial cells at the surface which showed no proliferative activity expressed p21whereas the cells in the deep area of the glands expressing Ki-67 did not. In the neoplastic lesions, the expression of p21^WAF1/CIP1 was detected in 78 per cent (112/144) of the adenomas and 76 per cent (262/343) of the adenocarcinomas. The incidence of p21^WAF1/CIP1 expression did not differ among histological types of gastric carcinoma. The strong expression of p21^WAF1/CIP1 was more frequently observed in carcinomas invading into submucosa or in cases of stages 2, 3, and 4 than in carcinomas limited to the mucosa or in stage 1 cases. The incidence of strongly positive cases was higher in carcinomas with lymph node metastasis than in those without metastasis. There was no apparent correlation between the expression of p21^WAF1/CIP1 and the abnormal accumulation of p53 or with proliferative activity measured by Ki-67 expression. These findings overall suggest that p21^WAF1/CIP1 might be associated with the senescence of non-neoplastic gastric epithelial cells; that a p53-independent pathway might be substantially involved in the induction of p21^WAF1/CIP1 in gastric neoplasia; and that the proliferative activity of gastric cancer might not be solely dependent on control of the cell cycle by p21^WAF1/CIP1.