大肠肿瘤组织中Caspase-3、Bcl-2的表达及其与细胞凋亡和增殖的关系

目的探讨半胱氨酸天冬氨酸蛋白酶-3（Caspase-3）、B细胞淋巴瘤伯血病基因2（Bcl-2）与大肠肿瘤发生、发展的关系。方法利用链菌素亲生物素-过氧化物酶法和末端脱氧核苷酸转移酶介导的脱氧三磷酸尿苷缺口末端标记法。检测80例大肠组织（腺癌43例、腺瘤27例、正常组织10例）中Caspase-3、Bel-2和增殖细胞核抗原的表达水平及细胞凋亡情况。结果Caspase-3在大肠腺癌和腺瘤中的表达率分别为41．9％和55．6％，明显低于正常组织的80．0％（P〈0．01）；Caspase-3在大肠腺癌中的表达与肿瘤Dukes分期、分化程度有关（P〈0．05）。Bcl-2在大肠腺癌和腺瘤中的表达率分别为76．7％和70．4％，明显高于正常组织的20．0％（P〈0．01）；Bcl-2在大肠腺癌中的表达与分化程度有关（P〈0．01）。凋亡指数与增殖指数呈正相关（r=0.471，P〈0．01），与Caspase-3的表达呈正相关（r=0．634。P〈0．01）。与Bcl-2的表达呈负相关（r=-0．523，P〈0．01）。结论Caspase-3、Bcl-2与大肠肿瘤的细胞凋亡密切相关，参与细胞凋亡的调节机制，在大肠肿瘤恶变的过程中发挥作用，并与恶性程度关系密切，有可能成为大肠癌预后评估的参考指标。

A expression of Caspase-3 and Bcl-2 protein in colorectal tumor and relation of the expression with cell apoptosis and proliferation

Objective To explore the relation of Caspase-3 and Bcl-2 protein with the occurrence and development of colorectal tumor. Methods Eighty cases of colorectal tissue were studied by using immunohistochemistry and TdT-mediated dUTP nick end labeling (TUNEL) method,to examine the expression of Caspase-3,Bcl-2,proliferating cell antigen (PCNA) and the condition of cell apoptosis. Results The positive rate of Caspase-3 in colorectal cancer and benign tumor were 41.9% and 55.6%,which were obviously lower than the expression in normal tissue(80.0%,P<0.01).The expression of Caspase-3 in colorectal cancer was correlated with its differentiation and Dukes stage (P<0.05). The positive rate of Bcl-2 in colorectal cancer and benign tumor were 76.7% and 70.4%,which were significantly higher than the expression in normal tissue(20.0%,P<0.01). The expression of Bcl-2 in colorectal cancer was correlated with its differentiation (P<0.01). Apoptosis index correlated positively with proliferating index (r=0.471,P<0.01) and the expression of Caspase-3(r=0.634,P<0.01),while inversely with the expression of Bcl-2 (r=-0.523,P<0.01). Conclusion There is close relation between the expression of Caspase-3,Bcl-2 protein and cell apoptosis in colorectal tumor.Caspase-3,Bcl-2 may participate in the regulating mechanism of cell apoptosis and have function in changing malignance.The expression of Caspase-3 and Bcl-2 protein have close relation with malignant degree of colorectal cancer and might be reference of estimating theprognosis.