Investigation of the expression and localisation of Caspase-3 in high grade Non-Hodgkin's Lymphoma

Although B cell Diffuse Large Cell Lymphoma (DLCL) can respond with chemotherapy and radiotherapy, a large number of patients are still resistant to treatment. The caspase family of enzymes are crucial components of the apoptotic cell death process, and are believed to be important in the pathogenesis and treatment of lymphoid malignancies. It was hoped that the investigation of the expression and localisation of Caspase-3 in high grade Non-Hodgkin's Lymphoma (NHLs) would provide information with respect to the progression and treatment of DLCL.;The pattern of proCaspase-3 expression was studied using immunohistochemistry with a commercial antibody in 54 cases of DLCL. The patterns of expression of the active p17 fragment of Caspase-3 was also examined using immunohistochemistry in both reactive lymph nodes and DLCL cases. Tumour cells displayed both a diffuse cytosolic and a punctate cytosolic staining for proCaspase-3 and survival curves indicated that tumour cells with a diffuse cytosolic expression of Caspase-3 correlated with a poor prognosis. In addition, a punctate expression was associated with complete response to treatment. Cases with a small percentage of lymphoma cells expressing Caspase-3 also tended to show poor survival. Levels of Caspase-3 mRNA were not significant, although a weak trend was observed similar to the immunohistochemical analysis. Furthermore, a survival curve indicated that a high TUNEL positivity was associated with a poor survival probability. In the reactive lymph node tissue the immunopositivity pattern of the p17 fragment of Caspase-3 mirrored that of the TUNEL staining in that apoptotic cells and the occasional tingeable body macrophage were staining.