食管鳞癌组织中p21蛋白的表达及意义

Expression and significance of p21 in esophageal squamous cell carcinoma

为探讨ｐ２１基因在食管癌发生中的意义，采用ＬＳＡＢ免疫组化染色法，对４３例食管癌手术标本的ｐ２１蛋白进行标记。结果发现：从正常鳞状上皮→癌旁不典型增生→鳞癌组织，ｐ２１的阳性表达率呈逐渐下降趋势，而且鳞癌组织中ｐ２１阳性表达率与正常鳞状上皮中ｐ２１的阳性表达率的差异有显著性（Ｐ＜０００１）；同时，随着癌分化程度的下降，ｐ２１蛋白阳性表达率呈现下降趋势，低分化者阳性率显著低于中等分化及高分化者（Ｐ＜００５）。另外，还观察到正常上皮中表层细胞的ｐ２１蛋白表达率较高。结论：ｐ２１蛋白表达的变化是食管癌发生中的早期事件，可能与癌的进展密切相关。

In order to study the role of p21 gene in the carcinogesis of esophageal cancer, p21 of the specimens from 43 cases of esophageal squamous cell carcinomas were studied with immunohistochemical LSAB method. The results are as follows: with the change from the normal epithelium to dysplasia and to squamous cancer tissue, the number of p21 positive cells decreased gradually and there was a significant difference between the cancer tissue and normal epithelium ( P <0.001); meanwhile, the positive rate of p21 protein in cancers of grade Ⅰ, Ⅱ and Ⅲ decreased gradually. The cancer of grade I showed a significantly low expression of p21 protein than cancer of grade Ⅱ and Ⅲ ( P <0.05), but there was a high positive expression rate of p21 in the surficial cells of normal epithelia. The findings suggest that the alteration of p21 gene is an early event in the carcinogenes of esophageal cancer and may be closely related to the progress of the cancer. In addition, p21 gene provides a negative control regulation for normal cell cycle.