Presence of the bcl‐2 protein and apoptosis in non‐hodgkin lymphomas with diffuse growth pattern

Abstract

In an attempt to further clarify the role of the apoptosis-counteracting protein bcl-2, non-Hodgkin lymphomas (NHL, n = 170) were examined immunohistochemically, across the boundaries of histologic classification, for the presence of this oncoprotein, in comparison with apoptotic indices (AI) and percentages of Ki-67+ cells (growth fraction). The results of this retrospective study revealed a highly significant inverse relationship ("mirror image") between the proportion of bcl-2+ cells and the AI per case. Both these parameters, although variable, clearly distinguished low- from high-grade-malignancy lymphomas according to the Kiel classification. Cluster analysis detected 2 separate groups of high-grade NHL, one with rather high AI and low percentages of bcl-2+ cells, comprising most anaplastic large-cell lymphomas, the other group with reverse characteristics. We found no correlation between the percentage of bcl-2+ cells per case and overall survival.

High-Grade Malignant Non-Hodgkin’s Lymphomas Differ from Low-Grade Lymphomasin the Extent of Apoptosis andTheir Expression of bcl-2, mcl-1,bax and p53

“…Our results are in line with previous studies showing a lower extent of apoptosis in follicular than in large-cell or diffuse lymphomas, or between low-and high-grade nonHodgkin's lymphomas [32][33][34]. In one of these studies, an inverse association between bcl-2 and the extent of apoptosis could be seen, which is in keeping with our results [34].…”

Histopathological Evaluation of Apoptosis in Cancer

“…[95][96][97][98] This correlates nicely with the occurrence of antiapoptotic bcl-2, which is overexpressed in low-grade follicular lymphomas due to a translocation that takes the bcl-2 locus to a highly active chromosomal environment. 58 In fact, there is an inverse association between the immunohistochemical expression of bcl-2 and the apoptotic index.…”

“…58 In fact, there is an inverse association between the immunohistochemical expression of bcl-2 and the apoptotic index. 95,98 Also, other members of the bcl-2 group, such as the apoptosispromoting bax and apoptosis-inhibiting mcl-1, are expressed in lymphomas. 98,99 They are also seen in ReedSternberg cells of Hodgkin's disease.…”

CD34+ Cord Blood Cell-Transplanted Rag2−/− γc−/− Mice as a Model for Epstein-Barr Virus Infection

“…20 A large panel of antibodies (Table 2), recognizing formalin-resistant epitopes of various antigens, was used in conjunction with the streptavidin-biotin method to visualize antibody binding. 21 Double staining for LMP1 and EBNA2 as well as for EBNA2 and both CD20 and CD27 were also performed on consecutive sections as previously described.…”