p63 protein expression in high risk diffuse large B-cell lymphoma.
BACKGROUND
p63 gene is a p53 homologue that encodes proteins with transactivation, DNA-binding and tetramerisation domains. The isoforms TAp63 and TAp73 transactivate p53 target genes and induce apoptosis, whereas the isoforms DeltaNp63 and DeltaNp73 lack transactivation and might have dominant-negative effects in p53 family members. p63 is expressed in germinal centre lymphocytes and can be related to the development of the lymphoma, but the prognostic significance of its expression in the survival of patients with diffuse large B-cell lymphoma (DLBCL) remains unclear.


OBJECTIVE
To determine whether quantitative immunohistochemical (IHC) analysis of p63 protein expression correlates with CD10 antigen, Bcl-6 antigen and IRF4 antigen expression and to determine whether p63 is a surrogate predictor of overall survival in high-intermediate and high risk DLBCL populations.


METHODS
CD10, Bcl-6 and IRF4 expression were retrospectively evaluated by IHC in 73 samples of high-intermediate and high risk DLBCL and were used to divide the lymphomas into subgroups of germinal centre B-cell-like (GCB) and activate B-cell-like (ABC) DLBCL. Similarly, p63 expression was evaluated by IHC and the results were compared with subgroups of DLBCL origin and with the survival rates for these patients.


RESULTS
p63 was expressed in more than 50% of malignant cells in 11 patients and did not show correlation with subgroups of GCB-like DLBCL or ABC-like DLBCL, but p63(+) patients had better disease-free survival (DFS) than those who were negative (p = 0.01).


CONCLUSIONS
p63(+) high-intermediate and high risk DLBCL patients have a better DFS than negative cases.
Hallack Neto
A E
AE
Haematology Services, Clinical Hospital of São Paulo University, São Paulo, Brazil. abrahallack@uol.com.br
Siqueira
S A C
SA
Dulley
F L
FL
Ruiz
M A
MA
Chamone
D A F
DA
Pereira
J
J
D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D050835:Interferon Regulatory Factors / Q000378:metabolism; D016403:Lymphoma, Large B-Cell, Diffuse / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging; D015260:Neprilysin / Q000378:metabolism; D011379:Prognosis; D051560:Proto-Oncogene Proteins c-bcl-6; D012189:Retrospective Studies; D016019:Survival Analysis; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D055815:Young Adult; D000099218:Interferon Regulatory Factor-4
D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D050835:Interferon Regulatory Factors; D015260:Neprilysin; D051560:Proto-Oncogene Proteins c-bcl-6; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D000099218:Interferon Regulatory Factor-4; C084103:BCL6 protein, human; C115051:TP63 protein, human