Abstract
Human monocytic leukemia U937 cells undergo apoptosis when cells are treated with the anticancer drug etoposide. To study the mechanism of drug-induced apoptosis, we used an in vitro apoptosis system with cytosol from etoposide-treated U937 cells. The cytosol from apoptotic U937 cells showed activity to induce morphologic changes and oligonucleosomal DNA fragmentation in isolated nuclei in vitro; both are typical features of apoptosis. We generated monoclonal antibodies to the proteins in the etoposide-treated U937 cytosol. We found that a 50 kDa protein, recognized by SN-1 monoclonal antibody, appeared in the cytosol of U937 cells, in accordance with its cell-free apoptosis activity. Z-Asp, an inhibitor of interleukin-1β converting enzyme (ICE) family proteases, inhibited the appearance of the 50 kDa protein and the emergence of the cell-free apoptosis activity in the etoposide-treated U937 cytosol. These results indicate that the 50 kDa protein is produced by the activation of ICE family protease during apoptosis and suggest some roles of the protein in the development of apoptosis.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Naito, M., Shiina, K., Mashima, T. et al. Induction of in vitro nuclear apoptosis activity coincides with the production of 50 kDa cytosolic protein. Cell Death Differ 4, 617–622 (1997). https://doi.org/10.1038/sj.cdd.4400287
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/sj.cdd.4400287
Keywords
This article is cited by
-
Anti-proliferative properties of ethyl acetate extract of Phellinus linteus grown on ginseng (Panax ginseng) on HT-29 human colon carcinoma cells through inducing apoptosis
Food Science and Biotechnology (2012)
-
Could 99mTc-glucarate be used to evaluate tumour necrosis?
European Journal of Nuclear Medicine and Molecular Imaging (2008)