P53及Bcl-2蛋白在大肠腺瘤及腺癌中的表达

目的：检测大肠腺瘤及腺癌中Ｐ５３蛋白及Ｂｃｌ－２蛋白的表达，探讨ｐ５３基因、ｂｃｌ－２基因在大肠癌发生发展过程中的作用。方法：应用免疫组织化学ＡＢＣ法检测１０例正常大肠粘膜、３０例大肠腺瘤、１００例大肠腺癌及癌旁粘膜中Ｐ５３蛋白及Ｂｃｌ－２蛋白的表达。结果：大肠腺瘤Ｐ５３、Ｂｃｌ－２蛋白阳性率分别为２６．７％及７６．７％，大肠腺癌Ｐ５３、Ｂｃｌ－２蛋白阳性率分别为４３％及６７％，均显著高于正常粘膜与癌旁粘膜（Ｐ＜０．０１）；随着腺瘤不典型增生程度的加重，Ｐ５３蛋白阳性率显著增高（Ｐ＜０．０１），而Ｂｃｌ－２蛋白表达与腺瘤分级无关；大肠腺癌Ｐ５３蛋白阳性率显著高于腺瘤Ⅰ级不典型增生（Ｐ＜０．０１），与Ⅱ、Ⅲ级不典型增生间差异无统计学意义（Ｐ＞０．０５），分化差的大肠腺癌Ｐ５３蛋白阳性率显著高于分化好的大肠腺癌（Ｐ＜０．０１），而分化差的大肠腺癌Ｂｃｌ－２蛋白阳性率显著低于分化好的大肠腺癌（Ｐ＜０．０５），大肠腺癌Ｐ５３、Ｂｃｌ－２蛋白表达呈负相关（Ｐ＜０．０５）；Ｐ５３蛋白表达患者复发率高、５年生存率低（Ｐ＜０．０５），Ｂｃｌ－２蛋白过度表达的大肠癌患者复发率低、５年生存率高（Ｐ＜０．０５）。结论：ｂｃｌ－２

Expression of P53 and Bcl 2 proteins in colorectal adenoma and adenocarcinoma

Objective: To determine the expression of P53 and Bcl 2 proteins in colorectal adenoma and adenocarcinoma to explore the possible role of p53 and bcl 2 genes in occurrence and development of colorectal carcinoma. Methods: The expression of P53 and Bcl 2 proteins was determined with immunohistochemical ABC method in 10 normal individuals, 30 patients with colorectal adenoma and 100 patients with colorectal adenocarcinoma and the adjacent mucosa. Results: The positive rates of P53 and Bcl 2 proteins were significantly higher in colorectal adenoma and adenocarcinoma than in normal mucosa and adjacent mucosa of adenocarcinoma ( P< 0.01). The expression of P53 was increased with aggravation of dysplasia in adenoma but that of Bcl 2 showed no evidence to relate to the grade of adenoma. In colorectal adenocarcinoma, the expression Bcl 2 protein was inversely correlated to P53 protein accumulation. The recurrence rate and mortality in patients with P53 overexpression were significantly ( P <0.05) and those in patients with Bcl 2 overexpression were significantly ( P <0.05). Conclusion: Bcl 2 gene may play an important role in the early stage of colorectal adenocarcinoma while the mutation of p53 gene participates in the transformation from colorectal adenoma to adenocarcinoma and is associated with the invasion of colorectal adenocarcinoma. The expression of P53 and Bcl 2 proteins can be used to determine the prognosis of colorectal carcinoma. bcl 2 gene might be negatively regulated by mutated p53 gene.