Subcellular localization of the bcl-2 protein in malignant and normal lymphoid cells.
The bcl-2 oncogene is expressed in lymphoid and myeloid cells as well as in neurons and several types of epithelial cells and inhibits programmed cell death (apoptosis). Deregulation by the t(14;18) translocation in lymphoid malignancies induces inappropriate cell survival and serves as one of the steps toward a fully malignant behavior. Using pre- and postembedding immunoelectron microscopy in normal and neoplastic lymphocytes, we demonstrate bcl-2 immunoreactivity to the mitochondrial outer circumference and the nuclear envelope and to a lesser degree to the cell membrane. Mitochondrial staining was patchy, reminiscent of mitochondrial contact zones. Additionally, there was a suggestion of association with nuclear pores. In these regions, transmembrane transport is mediated. This may suggest that bcl-2 exerts its function in this process.
de Jong
D
D
Laboratory of Pathology, University of Leiden, The Netherlands.
Prins
F A
FA
Mason
D Y
DY
Reed
J C
JC
van Ommen
G B
GB
Kluin
P M
PM
D015100:3,3'-Diaminobenzidine / Q000032:analysis; D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D006801:Humans; D007425:Intracellular Membranes / Q000737:chemistry; D015451:Leukemia, Lymphocytic, Chronic, B-Cell; D008214:Lymphocytes / Q000737:chemistry*; D008928:Mitochondria / Q000737:chemistry; D009685:Nuclear Envelope / Q000737:chemistry; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D019253:Proto-Oncogene Proteins c-bcl-2; D014178:Translocation, Genetic
D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D015100:3,3'-Diaminobenzidine