Modulation of the Cellular Pharmacology of Cisplatin and Its Analogs by the Copper Exporters ATP7A and ATP7B
The copper efflux transporters ATP7A and ATP7B sequester intracellular copper into the vesicular secretory pathway for export from the cell. The influence of these transporters on the pharmacodynamics of cisplatin, carboplatin, and oxaliplatin was investigated using human Menkes' disease fibrob...
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Published in | Molecular pharmacology Vol. 66; no. 1; pp. 25 - 32 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Pharmacology and Experimental Therapeutics
01.07.2004
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Subjects | |
Online Access | Get full text |
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Summary: | The copper efflux transporters ATP7A and ATP7B sequester intracellular copper into the vesicular secretory pathway for export
from the cell. The influence of these transporters on the pharmacodynamics of cisplatin, carboplatin, and oxaliplatin was
investigated using human Menkes' disease fibroblasts (Me32a) that do not express either transporter and sublines molecularly
engineered to express either ATP7A (MeMNK) or ATP7B (MeWND). Cellular copper levels were significantly higher in the Me32a
cells than in the MeMNK and MeWND sublines. These transporter-proficient sublines were resistant to the cytotoxic effect of
copper, cisplatin, and carboplatin but were hypersensitive to oxaliplatin. Whole-cell accumulation of platinum after a 24-h
exposure was significantly increased in the MeMNK and MeWND cells for all three platinum drugs, but this was accompanied by
an increase in the amount of platinum reaching the DNA only for oxaliplatin. Vesicles isolated from MeMNK cells contained
more platinum after exposure to cisplatin and carboplatin, whereas the platinum content of vesicles from MeWND cells was increased
after exposure to all three drugs. Although copper triggered relocalization of ATP7A from the perinuclear region to more peripheral
locations, the platinum drugs did not. These results demonstrate that both ATP7A and ATP7B modulate the pharmacodynamics of
all three clinically used platinum drugs. The data are consistent with the hypothesis that these copper exporters sequester
the platinum drugs into subcellular compartments, limiting their cytotoxicity, similar to their effect on copper. However,
in this model system, although copper is readily exported after vesicular sequestration, the platinum drugs are not. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0026-895X 1521-0111 |
DOI: | 10.1124/mol.66.1.25 |