BCL-6 expression in reactive lymphoid tissue and in B-cell non-Hodgkin's lymphomas.
Chromosomal abnormalities involving 3q27 have recently been associated with diffuse large B-cell lymphomas and, less frequently, with follicular lymphomas. Molecular studies have led to the identification of the BCL-6/LAZ-3 gene, located at 3q27 and coding for a putative zinc-finger protein that might act as a transcriptional regulator during cell differentiation and development. Rearrangement of BCL-6 results in truncation of the gene in its 5' portion, leaving the protein intact; a resultant deregulation of its expression has been hypothesized. In order to test this hypothesis, the expression of BCL-6 protein was investigated in human reactive lymphoid tissue and compared with a group of non-Hodgkin's lymphomas (NHLs) with or without 3q27 anomalies and/or BCL-6 gene rearrangement. BCL-6 protein is consistently expressed in reactive lymphoid tissues, where it is restricted to the follicle centre. The protein is also widely expressed in NHL: all follicular lymphomas tested showed a pattern of expression similar to the reactive B follicle, independently of the presence of BCL-6 gene rearrangement and/or 3q27 anomalies. In the diffuse large B-cell lymphomas, there was more variation in BCL-6 expression, but a correlation with 3q27 anomalies and/or BCL-6 rearrangement was not found. Deregulation of the BCL-6 gene did not result in an aberrant tissue expression as detected by immunohistochemistry.
Pittaluga
S
S
Department of Pathology, K.U. Leuven, Belgium.
Ayoubi
T A
TA
Wlodarska
I
I
Stul
M
M
Cassiman
J J
JJ
Mecucci
C
C
Van Den Berghe
H
H
Van De Ven
W J
WJ
De Wolf-Peeters
C
C
D000918:Antibody Specificity; D015153:Blotting, Western; D002869:Chromosome Aberrations; D002893:Chromosomes, Human, Pair 3; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry; D008221:Lymphoid Tissue / Q000378:metabolism*; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors