摘要
AIMS To study bcl-2 and P53 protein expression and inhibition of apoptosis during colorectal tumorigenesis. METHODS Expression of bcl -2 and p53 in 45 colorectal ade- nomas and 61 colorectal carcinomas was detected by immunohis- tochemical staining. RESULTS The bcl-2 and P53 protein expression was uniformly negative in normal mucosa,whereas bcl-2 and p53 positive rates were significantly higher in adenoma and carcinoma than in nor- reals(P<0.01 ).The area with strong bcl-2 expression was of- ten the area with severely dysplasia.In colorectal adenoma,ex- pression of p53 increased with the increasing size and dysplasia, in adenomas≥20 mm being higher than adenomas<10 mm(77, 8% vs 35.0%,P<0.05).p53 was relevant to differentiation and Duke's staging.A significant inverse correlation was found between bcl-2 and p53 in immunostaining in the adenomas,but not in the carcinomas.Furthermore,carcinomas with a high per- centage of bcl-2 positive cells were significantly more likely to have low rates of apoptosis. CONCLUSIONS These results suggest that bcl-2 gene appears to be an early event in colorectal tumorigenesis that can inhibit apoptosis,p53 expression plays an important role in the develop- ment and malignant change of colorectal adenoma,bcl-2 and p53 may be used as a good marker relating to cell apoptosis.
目的探讨 bcl-2和 P53蛋白在大肠肿瘤中的表达及与细胞凋亡关系。方法用免疫组化方法观察了45例大肠腺瘤和61例大肠癌中 bcl-2和 P53蛋白的表达。结果正常大肠粘膜中 bcl-2和 p53均未见表达,而大肠腺瘤及大肠癌阳性率均较正常明显增加(P<0.01)。大肠腺瘤 p53表达随腺瘤大小增加而增加,其中≥20 mm 组阳性率(77.8%)显著高于<10 mm 组(35.0%,P<0.05)。P53蛋白阳性率也随不典型增生程度增加而增高。p53表达与大肠癌分化程度及 Duke 分期有关。大肠癌细胞凋亡指数与 bcl-2阳性表达呈负相关。大肠腺瘤中 bcl-2和 P53蛋白的表达也呈负相关。结论 bcl-2蛋白表达对大肠癌前病变.腺瘤的增殖有一定意义,p53在大肠腺瘤癌变和大肠癌进展中起重要作用,它们是参与细胞凋亡的良好指标。
