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%,P0.01).The expression of Caspase-3 in colorectal cancer was correlated with its differentiation and Dukes stage (P0.05). 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%,P0.01). The expression of Bcl-2 in colorectal cancer was correlated with its differentiation (P0.01). Apoptosis index correlated positively with proliferating index (r=0.471,P0.01) and the expression of Caspase-3(r=0.634,P0.01),while inversely with the expression of Bcl-2 (r=-0.523,P0.01). 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.