Journal
TOXICOLOGY AND APPLIED PHARMACOLOGY
Volume 229, Issue 2, Pages 206-214Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.taap.2008.01.022
Keywords
cadmium; disulfiram; proteasome inhibitor; calpain; apoptosis
Categories
Funding
- NCI NIH HHS [R03 CA112625, R01 CA120009, P30 CA022453, CA112625, CA120009] Funding Source: Medline
Ask authors/readers for more resources
The ubiquitin-proteasome system is involved in various cellular processes, including transcription, apoptosis, and cell cycle. In vitro, in vivo, and clinical studies suggest the potential use of proteasome inhibitors as anticancer drugs. Cadmium (Cd) is a widespread environmental pollutant that has been classified as a human carcinogen. Recent study in our laboratory suggested that the clinically used anti-alcoholism drug disulfiram (DSF) could form a complex with tumor cellular copper, resulting in inhibition of the proteasomal chymotrypsin-like activity and induction of cancer cell apoptosis. In the current study, we report, for the first time, that DSF is able to convert the carcinogen Cd to a proteasome-inhibitor and cancer cell apoptosis inducer. Although the DSF-Cd complex inhibited the chymotrypsin-like activity of a purified 20S proteasome with an IC50 value of 32 mu mol/L, this complex was much more potent in inhibiting the chymotrypsin-like activity of prostate cancer cellular 26S proteasome. Inhibition of cellular proteasome activity by the DSF-Cd complex resulted in the accumulation of ubiquitinated proteins and the natural proteasome substrate p27, which was followed by activation of calpain and induction of apoptosis. Importantly, human breast cancer MCF10DCIS cells were much more sensitive to the DSF-Cd treatment than immortalized but non-tumorigenic human breast MCF-10A cells, demonstrating that the DSF-Cd complex could selectively induce proteasome inhibition and apoptosis inhuman tumor cells. Our work suggests the potential use of DSF for treatment of cells with accumulated levels of carcinogen Cd. (C) 2008 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available