Rifampicin enhances anti-cancer drug accumulation and activity in multidrug-resistant cells.

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Fardel O, Lecureur V, Loyer P, Guillouzo A

Rifampicin enhances anti-cancer drug accumulation and activity in multidrug-resistant cells.

Biochem Pharmacol. 1995 May 11;49(9):1255-60.

PubMed ID

7763306 [ View in PubMed

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Abstract

Rifampicin, a semi-synthetic antibiotic used in the treatment of tuberculosis and belonging to the chemical class of rifamycins, was examined for its effect on anti-cancer drug accumulation and activity in multidrug resistant cells overexpressing P-glycoprotein (P-gp). Rifampicin was shown to strongly enhance vinblastine accumulation in both rat hepatoma RHC1 and human leukemia K562 R7 multidrug resistant cells, but had no effect in rat SDVI drug-sensitive liver cells. By contrast, two other rifamycins, rifamycins B and SV, had no or only minor effect on vinblastine accumulation in RHC1 cells. Efflux experiments revealed that rifampicin was able, like the well-known chemosensitizer agent verapamil, to decrease export of vinblastine out of resistant cells. Rifampicin, when used at a concentration close to plasma concentrations achievable in humans (25 microM), was able to increase sensitivity of RHC1 cells to both vinblastine and doxorubicin. Rifampicin was also demonstrated to inhibit P-gp radiolabeling by the photoactivable P-gp ligand azidopine, thereby suggesting that the antituberculosis compound can interfere directly with P-gp drug binding sites. These results thus indicate that rifampicin was able to down-modulate P-gp-associated resistance through inhibition of P-gp function.

DrugBank Data that Cites this Article

Drug Transporters

Drug	Transporter	Kind	Organism	Pharmacological Action	Actions
Rifampicin	P-glycoprotein 1	Protein	Humans	Unknown	Inducer	Details