Monden T, Morimoto H, Nakanishi H, Fukunaga M, Shimano T, Mori T
Int J Oncol. 1992 Dec;1(7):773-8.
This paper reports on a comparative immunohistochemical study of p53 and proliferating-cell nuclear antigen (PCNA) performed on microwave (MW)-fixed paraffin sections of 24 colorectal carcinomas and 68 adenomas in order to investigate the relationship between p53 expression and proliferative activity. Nuclear p53 was detected in 12 cases out of 24 carcinomas and eight out of 68 adenomas were found to focally express p53. Examination of PCNA expression in the adjacent sections of carcinomas revealed that the incidence of PCNA expression was not affected by p53, and both p53-positive and p53-negative carcinomas exhibited a high level of PCNA expression that reached more than 75% of the cancer cells. In the colorectal adenomas, the incidence of PCNA expression averaged about 30% although highly heterogenous distribution of PCNA-positive cells in the section was observed. When we examined eight adenomas positive for p53, the incidence of PCNA expression in the p53-positive glands of each adenoma was significantly higher (52.1%) than that in the neighboring glands without p53 expression (36.5%) (p<0.05). The results indicate that the abnormal expression of p53 in colorectal adenomas may reflect a failure in the control of cell proliferation. Furthermore, lack of the association of p53 expression with proliferative activity in colorectal carcinomas implies that several gene alterations together with p53 may be responsible for the complete loss of the regulatory mechanism for cell proliferation.
本文报道了一项对24例结直肠癌和68例腺瘤的微波（MW）固定石蜡切片进行的p53和增殖细胞核抗原（PCNA）的比较免疫组织化学研究，以探讨p53表达与增殖活性之间的关系。24例癌中有12例检测到细胞核p53，68例腺瘤中有8例发现局灶性表达p53。对癌旁切片中PCNA表达的检查显示，PCNA表达的发生率不受p53影响，p53阳性和p53阴性的癌均表现出高水平的PCNA表达，达到癌细胞的75%以上。在结直肠腺瘤中，PCNA表达的发生率平均约为30%，尽管在切片中观察到PCNA阳性细胞的分布高度不均一。当我们检查8例p53阳性的腺瘤时，每个腺瘤中p53阳性腺体中PCNA表达的发生率（52.1%）明显高于相邻无p53表达的腺体（36.5%）（p<0.05）。结果表明，结直肠腺瘤中p53的异常表达可能反映了细胞增殖控制的失败。此外，结直肠癌中p53表达与增殖活性缺乏关联意味着，除p53外的几种基因改变可能共同导致细胞增殖调节机制的完全丧失。
