Immunocytochemical p63 expression discriminates between primary cutaneous follicle centre cell and diffuse large B cell lymphoma-leg type, and is of the TAp63 isoform.
OBJECTIVE
The p63 gene shares structural and functional homologies with the p53 family of transcriptional activators, but differs in exhibiting a consistent expression pattern in normal tissues. Although p63 is rarely mutated in malignancy studies of primary human tumours and cell lines suggest that p63 may promote tumour development. In non-Hodgkin's nodal lymphoma, TAp63 expression in follicular lymphoma (54%) and diffuse large B cell lymphoma (34%) has been described and correlated with the proliferative index. In this study, we analysed a series of primary cutaneous B cell lymphomas for immunohistochemical expression of p63.


RESULTS
Thirty cases of diffuse large B cell lymphoma leg type (pcDLBCLL) and 34 cases of follicle centre cell lymphoma (pcFCCL) were stained using a generic antibody to p63, and a subset of these with an antibody specific for delta-Np63 isoform. The results indicate a significant difference between pcDLBCLL (21 of 30) and pcFCCL (four of 34) in p63 expression (P = 0.000); expression correlated strongly with the proliferation rate as assessed by Ki-67 (P = 0.015). None of the p63((+)) cases tested expressed the delta-Np63 isoform, suggesting that expression is of the TAp63 isoform.


CONCLUSIONS
Functional studies are required to clarify the significance of p63 overexpression in primary cutaneous B cell lymphoma.
St John's Institute of Dermatology, London, UK.
Alistair
A
Robson
St John's Institute of Dermatology, London, UK.
Zena
Z
Shukur
Department of Dermatology, Stanford University, Stanford, CA, USA.
Mina
M
Ally
St John's Institute of Dermatology, London, UK.
Justine
J
Kluk
Division of Health and Social Care Research, Kings College London, London, UK.
Kun
K
Liu
Department of Pathology, UCSF, San Francisco, CA, USA.
Laura
L
Pincus
Department of Dermatology, Boston University Medical Center, Boston, MA, USA.
Debjani
D
Sahni
Department of Pathology, Stanford University, Stanford, CA, USA.
Uma
U
Sundram
Dermatopathology Department, Yale University School of Medicine, New Haven, CT, USA.
Antonio
A
Subtil
Lake Diagnostics Florida, Lake City, FL, USA.
Laszlo
L
Karai
Department of Dermatology, University Hospital Zurich, Zurich, Switzerland.
Werner
W
Kempf
Department of Dermatology, Medical College of Wisconsin, Milwaukee, WI, USA.
Stefan
S
Schieke
Dundee Cancer Centre, Ninewells Hospital and Medical School, Dundee, UK.
Philip
P
Coates
D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008224:Lymphoma, Follicular / Q000175:diagnosis / Q000378:metabolism*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000175:diagnosis / Q000378:metabolism*; D000072417:Protein Domains; D020033:Protein Isoforms; D012878:Skin Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
D014408:Biomarkers, Tumor; D020033:Protein Isoforms; C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins
B cell lymphoma; cutaneous; immunohistochemistry; oncogene; p63