Mateo M S, Saez A I, Sanchez-Beato M, Garcia P, Sanchez-Verde L, Martinez J C, Orradre J L, Piris M A
Department of Pathology, Hospital Virgen de la Salud, Toledo, Spain.
J Clin Pathol. 1997 Aug;50(8):645-53. doi: 10.1136/jcp.50.8.645.
To determine the expression of p21WAF1/CIP1 in relation to the expression of Ki67 and p53 in various normal adult and fetal tissues, and to investigate its distribution throughout the cell cycle.
The expression of p21WAF1/CIP1 in relation to Ki67 and p53 was analysed in adult and fetal tissues using immunohistochemical techniques. Heat induced epitope retrieval techniques were used to characterise the presence of p21WAF1/CIP1 in different tissues, as well as to detect its distribution throughout the cell cycle. In addition, flow cytometry and western blotting were used to test whether the level of p21WAF1/CIP1 expression varied at different phases of the cell cycle in phytohaemagglutinin (PHA) stimulated lymphocytes.
p21WAF1/CIP1 expression varied from one tissue to another, and it was restricted mainly to the squamous and glandular epithelium, where it appeared in association with p53. Human tissues in which p21WAF1/CIP1 was found showed a mutually exclusive topographical sequential expression between p21WAF1/CIP1 and Ki67. This was confirmed by double labelling studies, which showed that p21WAF1/CIP1 positive cells were in the G0 phase. Unlike these findings of a decline in p21WAF1/CIP1 expression after the G0 phase, PHA stimulated lymphocytes showed a level of p21WAF1/CIP1 expression that rose as the cell progressed through the cell cycle.
The analysis of p21WAF1/CIP1 expression in relation to the status of p53 should take into account the existence of variable p21WAF1/CIP1 expression in different tissues. This could provide an explanation for the varying frequency of p53 mutations in tumours of different cellular origin. In tissues characterised by regular p21WAF1/CIP1 expression, it appears in a pattern that is consistent with the proposed role of this inhibitor of cyclin dependent kinases in cell cycle arrest-that of inducing cell differentiation. The conflicting results of in vivo and in vitro studies could support the hypothesis that microenvironmental conditions may influence the location of p21WAF1/CIP1 in different phases of the cell cycle.
确定p21WAF1/CIP1在各种正常成人及胎儿组织中的表达与Ki67和p53表达的关系，并研究其在整个细胞周期中的分布。
采用免疫组织化学技术分析成人及胎儿组织中p21WAF1/CIP1与Ki67和p53的表达关系。利用热诱导抗原修复技术来鉴定不同组织中p21WAF1/CIP1的存在情况，以及检测其在整个细胞周期中的分布。此外，使用流式细胞术和蛋白质印迹法检测在植物血凝素（PHA）刺激的淋巴细胞中，p21WAF1/CIP1表达水平在细胞周期不同阶段是否有所变化。
p21WAF1/CIP1的表达因组织而异，主要局限于鳞状上皮和腺上皮，且其表达与p53相关。发现p21WAF1/CIP1的人体组织中，p21WAF1/CIP1与Ki67之间呈现相互排斥的拓扑顺序表达。双重标记研究证实了这一点，该研究表明p21WAF1/CIP1阳性细胞处于G0期。与G0期后p21WAF1/CIP1表达下降的这些发现不同，PHA刺激的淋巴细胞中，p21WAF1/CIP1的表达水平随着细胞在细胞周期中的进展而升高。
分析p21WAF1/CIP1表达与p53状态的关系时，应考虑到不同组织中p21WAF1/CIP1表达存在差异。这可以解释不同细胞起源的肿瘤中p53突变频率的差异。在以p21WAF1/CIP1有规律表达为特征的组织中，其表达模式与这种细胞周期蛋白依赖性激酶抑制剂在细胞周期阻滞中的假定作用一致，即诱导细胞分化。体内和体外研究结果相互矛盾，这可能支持微环境条件可能影响p21WAF1/CIP1在细胞周期不同阶段定位的假说。
