Altered sensitivity to retinoid-induced apoptosis associated with changes in the subcellular distribution of Bcl-2
Abstract
In the acute promyelocytic leukemia cell line NB4, Bcl-2 downregulation occurred as a late event of retinoid-induced differentiation. In the maturation-resistant NB4-R1 subclone, retinoids failed to downregulate Bcl-2 even in the situation of apoptosis massively induced by pan-agonists and RXR-selective agonists. We observed that NB4 and NB4-R1 cells differed with respect to the intracellular localization of Bcl-2 which showed a perinuclear localization in NB4-R1 cells, while Bax was broadly expressed in the cytoplasm and to only a minor extent in the perinuclear area. Therefore, the distinct intracellular localization of Bcl-2 and Bax was in general nonoverlapping. Bcl-2 remained massively expressed until cell disruption. Bax was not significantly upregulated in cells committed to death. However, Bax localization changed from a diffuse pattern to concentrate in few specific cytoplasmic area at a stage preceding the formation of apoptotic bodies. A human Bcl-2 transgene was transiently overexpressed in NB4-R1 cells which showed increased resistance to apoptosis induced by retinoids. Stably transfected clones of NB4-R1 cells showed an increased expression of Bcl-2 and a marked resistance to apoptosis. Interestingly, the overexpr...Continue Reading
References
The proto-oncogene bcl-2 can selectively rescue neurotrophic factor-dependent neurons from apoptosis
Citations
Related Concepts
Related Feeds
BCL-2 Family Proteins
BLC-2 family proteins are a group that share the same homologous BH domain. They play many different roles including pro-survival signals, mitochondria-mediated apoptosis and removal or damaged cells. They are often regulated by phosphorylation, affecting their catalytic activity. Here is the latest research on BCL-2 family proteins.
Apoptosis
Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis