Surface expression of Bcl-2 in chronic lymphocytic leukemia and other B-cell leukemias and lymphomas without a breakpoint t(14;18).
Since its discovery in follicular lymphoma cells at the breakpoint t(14;18), Bcl-2 has been studied extensively in many basic and clinical science settings. Bcl-2 can locate as an integral mitochondrial membrane component, where its primary role is to block apoptosis by maintaining membrane integrity. Here we show that Bcl-2 also can position on the outer cell surface membrane of B cells from patients with chronic lymphocytic leukemia (B-CLL) and certain other leukemias that do not classically possess the chromosomal breakpoint t(14;18). Although low levels of Bcl-2 can be detected on the surface membrane of apparently healthy leukemic and normal B cells, expression of Bcl-2 correlates best with spontaneous or induced apoptosis. Notably, upon induction of apoptosis, B-CLL cells were much more efficient in upregulating surface Bcl-2 than normal B cells. It is not clear if this surface membrane expression is a passive consequence of the apoptotic process or an active attempt by the B cell to abort cell death by stabilizing the plasma membrane.
McCarthy
Brian A
BA
Laboratory of Experimental Immunology, The Feinstein Institute for Medical Research, Manhasset, New York 11030, USA.
Boyle
Erin
E
Wang
Xue Ping
XP
Guzowski
Dorothy
D
Paul
Santanu
S
Catera
Rosa
R
Trott
Joshua
J
Yan
Xiao-jie
XJ
Croce
Carlo M
CM
Damle
Rajendra
R
Yancopoulos
Sophia
S
Messmer
Bradley T
BT
Lesser
Martin
M
Allen
Steven L
SL
Rai
Kanti R
KR
Chiorazzi
Nicholas
N
D017209:Apoptosis; D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D015448:Leukemia, B-Cell / Q000378:metabolism / Q000473:pathology*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism / Q000473:pathology*; D016393:Lymphoma, B-Cell / Q000378:metabolism / Q000473:pathology*; D018613:Microscopy, Confocal; D020411:Oligonucleotide Array Sequence Analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger