PRDM1/BLIMP-1 expression in multiple B and T-cell lymphoma.
OBJECTIVE
The positive regulatory domain I (PRDM1) protein or BLIMP-1, belonging to the PRDM gene family of transcriptional repressors, is a key regulator of terminal differentiation in B-lymphocytes and is critical for plasma cell differentiation.


METHODS
Here we document the expression of PRDM1 in normal and neoplastic lymphoid cells, through the use of a monoclonal antibody that recognizes the molecule in paraffin-embedded tissue sections. A large series of B and T-cell lymphomas (679 cases) was studied, using tissue microarrays.


RESULTS
Multiple myeloma, plasmacytoma and lymphoplasmacytic lymphoma cases (n=19) were positive. Plasmablastic lymphoma, oral mucosa-type (n=15), were also found to be positive. PRDM1 protein was expressed in some cases of B-cell neoplasia, i.e. chronic lymphocytic leukemia/small lymphocytic lymphoma (15%), diffuse large B-cell lymphoma (43%), classical Hodgkin's lymphoma (41%) and also in T-cell lymphoma (23%).


CONCLUSIONS
Most B-neoplastic cells showing plasmablastic differentiation were PRDM1-positive. Unexpectedly, a subset of diffuse large B-cell lymphoma expressed PRDM1, lacked detectable plasmablastic or immunoblastic changes and displayed more aggressive behavior, with a shorter failure-free survival. In contrast to normal B-cells, diffuse large B-cell lymphoma cases with increased PRDM1 expression co-expressed BCL-6 and MUM1/IRF4, confirming that PRDM1 expression in these tumors is insufficient to drive the full genetic program associated with plasmacytic differentiation.
Garcia
José-Francisco
JF
Monoclonal Antibodies Unit, Biotechnology Program, Spanish National Cancer Centre (CNIO), Madrid, Spain. jgarcia@cnio.es
Roncador
Giovanna
G
García
Juan-Fernando
JF
Sánz
Ana-Isabel
AI
Maestre
Lorena
L
Lucas
Elena
E
Montes-Moreno
Santiago
S
Fernandez Victoria
Rebeca
R
Martinez-Torrecuadrara
Jorge L
JL
Marafioti
Teresa
T
Mason
David Y
DY
Piris
Miguel A
MA
D002454:Cell Differentiation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000473:pathology*; D046228:Microarray Analysis; D010950:Plasma Cells / Q000166:cytology; D000074462:Positive Regulatory Domain I-Binding Factor 1; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
D012097:Repressor Proteins; D014157:Transcription Factors; C087042:PRDM1 protein, human; D000074462:Positive Regulatory Domain I-Binding Factor 1