[Study on expression of caspase-3 and bcl-2 proteins and their relations with cell apoptosis and proliferation in non-Hodgkin's lymphoma].
OBJECTIVE
To explore the possible roles of caspase-3 and bcl-2 proteins in the development and progression of non-Hodgkin's lymphoma (NHL) and their relationship.


METHODS
TdT-mediated dUTP nick end labeling (TUNEL) and immunohistochemistry were used to study cell apoptosis and expression of proliferating cell nuclear antigen (PCNA), caspase-3 and bcl-2 in 119 NHL cases.


RESULTS
The caspase-3 and bcl-2 positive rates were 86.6% (103/119) and 53.8% (64/119) respectively. Contrasting expression of these two proteins were found in reactive and malignant lymphoid tissues: In reactive lymphoid follicles, caspases-3 exhibited strong immunoactivity in cells located in germinal centers but not in mantle zone lymphocytes, whereas bcl-2 exhibited strong immunoactivity in mantle zone lymphocytes but not in cells located in germinal centers, and in neoplastic follicles, caspase-3 was negatively or weakly expressed, whereas bcl-2 was often positively expressed. In B cell lymphomas, the high grade group had a higher caspase-3 immunointensity and a lower bcl-2 immunointensity than the low grade group (P < 0.01). Apoptotic index correlated positively with expression of caspase-3 (r = 0.512, P < 0.01) and inversely with expression of bcl-2 (r = -0.436, P < 0.01). In addition, apoptotic index and proliferative index were positively related (r = 0.710, P < 0.01).


CONCLUSIONS
caspase-3 may participate in the regulation mechanism of lymphoma cell apoptosis. The contrasting expression of caspase-3 and bcl-2 is often seen in reactive and malignant lymphoid tissues, and it may indicate a close relationship between these two proteins in the regulation of lymphocyte proliferation kinetics.
Zhang
W
W
Institute of Pathology and Forensic Medicine, Zhejiang University, Hangzhou 310031, China (Email: zhouren@zju.edu.cn)
Zhou
R
R
Chen
P
P
He
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000096:biosynthesis*; D002455:Cell Division; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008221:Lymphoid Tissue / Q000378:metabolism / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*
D019253:Proto-Oncogene Proteins c-bcl-2; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases