The copper influx transporter human copper transport protein 1 regulates the uptake of cisplatin in human ovarian carcinoma cells.

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Holzer AK, Samimi G, Katano K, Naerdemann W, Lin X, Safaei R, Howell SB

The copper influx transporter human copper transport protein 1 regulates the uptake of cisplatin in human ovarian carcinoma cells.

Mol Pharmacol. 2004 Oct;66(4):817-23. Epub 2004 Jun 30.

PubMed ID

15229296 [ View in PubMed

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Abstract

Cells selected for resistance to cisplatin are often cross-resistant to copper and vice versa, and the major copper influx transporter copper transport protein 1 (CTR1) has been shown to regulate the uptake of cisplatin, carboplatin, and oxaliplatin in yeast. To further define the role of hCTR1 in human tumor cells, the ovarian carcinoma cell line A2780 was molecularly engineered to increase expression of hCTR1 by a factor of 20-fold. Enhanced expression of hCTR1 in the A2780/hCTR1 cells was associated with a 6.5-fold increase in basal steady-state copper content and a 13.7-fold increase in initial copper influx, demonstrating that the exogenously expressed hCTR1 was functional in altering copper homeostasis. The A2780/hCTR1 cells accumulated 46% more platinum after a 1-h exposure to 2 microM cisplatin, and 55% more after a 24 h exposure, than the control A2780/empty vector cells. The initial uptake of cisplatin was 81% higher in the A2780/hCTR1 cells when measured at 5 min. Thus, increased expression of hCTR1 had a substantially larger effect on the cellular pharmacology of copper than cisplatin. Interestingly, the increased uptake of copper and cisplatin was accompanied by only a marginal increase in sensitivity to the cytotoxic effect of copper and cisplatin, and there was no increase in the extent of cisplatin-DNA adduct formation. Thus, although increased expression of hCTR1 mediates greater cellular accumulation of copper and cisplatin, hCTR1 delivers these compounds into intracellular compartments from which they do not have ready access to their key cytotoxic targets.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Cisplatin	Arylamine N-acetyltransferase	Protein	Mycobacterium tuberculosis	Unknown	Inhibitor	Details

Drug Transporters

Drug	Transporter	Kind	Organism	Pharmacological Action	Actions
Cisplatin	High affinity copper uptake protein 1	Protein	Humans	Unknown	Substrate	Details