No Influence of bcl-2, p53, and p21 waf1 Protein Expression on the Outcome of Pediatric Hodgkin Lymphomas

Abstract

In Argentina, lymphomas account for 13.6% of all pediatric tumors and 47% of them are Hodgkin lymphoma. Previous studies of lymphoma series have reported the expression of apoptotic and cell cycle proteins. Our aim was to study these markers in our pediatric patients and correlate them with their outcome. Immunohistochemical staining with monoclonal antibodies anti-p53, bcl-2, p21waf1, and mdm2 were performed on formalin fixed paraffin-embedded Hodgkin lymphoma lymph node biopsies from 54 pediatric patients. The analyzed oncogenes p53, bcl-2, p21waf1, and mdm2 exhibited 81%, 44%, 76%, and 90% positive staining, respectively. The most prevalent p53/p21waf1 expression pattern was p53+/p21waf1+, in 57% of cases, whereas concerning p53/mdm2 expression pattern p53+/mdm2+ was observed in 61% of cases. We failed to .nd any statistically signi.cant correlation between oncogene expression and patient’s survival. It seems that p53 plays an important role in lymphomagenesis in our studied population, because it is overexpressed in 81% of Hodgkin lymphoma cases and in more than 50% of cases, it might be able to activate its cellular e.ectors. Bcl-2 staining observed in 44% of our cases could represent a failure in bcl-2 down-regulation that leads to a rescue event in defective germinal center B-cells, that allows them to develop into Reed-Sternberg and Hodgkin cells.