大肠肿瘤p53蛋白过表达对原位Th1／Th2平衡的影响

目的：评价p53蛋白过表面对大肠腺瘤和大肠癌局部辅助T细胞（Th1/Th2)平均的影响，进而探讨大肠癌发生的免疫学机制，方法：研究对象包括大肠腺瘤30例，大肠癌38例，癌旁正常粘膜68例作为对照组。石蜡切片以免疫组化法检测p53蛋白表达，采用酶联免疫吸附试验（ELISA）检测肠组织培养上清液中4种细胞因子（IL－2，IL－4，IL－10，IFN－r)水平。结果：p53蛋白表达阳性组培养上清液的IL－2，IFN－r水平显著低于阴性组和对照组（P＜0．01），而IL－10则高于阴性组及对照组（P＜0．05），各组IL－4水平未显示差异（P＞0．05），结论：p53蛋白表达引起原位Th1/Th2平衡失调，表现为由Th1向Th2漂移，初步推断：p53基因失活在大肠癌发生的免疫学机制中可能具有重要作用。

Effects of p53 overexpression on the balance of helper T cell 1 with helper T cell 2 in colorectal tumors

Purpose:To evaluate the effects of p53 overexpression on the balance of in situ T helper cell 1 with T helper cell 2 in colorectal adenomas and carcinomas, with further study of the immunological mechanism of p53 overexpression stimulating colorectal cancer formation.Methods:Endoscopic colorectal mucosal biopsies were taken from 68 patients with colorectal tumors,including adenomas(n=30) and carcinomas(n=38),and their normal mucosas served as control(NS,n=68).Paraffin sections were examined immunohistochemically for p53 protein overexpression and four cytocine(IL-2,IL-4,IL-10,IFN-r) levels were detected by enzyme linked immunosorbent assay(ELISA) with the culture supernatants of colorectal tissue.Results:IL-2 and IFN-r levels in culture supernants of the positive group were significantly lower (P<0.01),in contrast,IL-10 levels were significantly higher (P<0.05) than those of the negative group,but there was no difference of IL-4 levels among all groups(P>0.05).Conclusions:p53 overexpression induced inbalance of in situ Th1 with Th2 levels,shown as a drift from Th1 toTh2.p53 gene inactivation may play an critical role in immunological mechanism of colorectal carcinoma carcinogenesis.