Impact of drug transporters on cellular resistance towards saquinavir and darunavir.

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Konig SK, Herzog M, Theile D, Zembruski N, Haefeli WE, Weiss J

Impact of drug transporters on cellular resistance towards saquinavir and darunavir.

J Antimicrob Chemother. 2010 Nov;65(11):2319-28. doi: 10.1093/jac/dkq324. Epub 2010 Sep 3.

PubMed ID

20817741 [ View in PubMed

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Abstract

OBJECTIVES: Highly active antiretroviral therapy is complicated by drug-drug interactions and the development of viral resistance. Drug interactions involve transporters that may critically affect the pharmacokinetics of many antiretroviral drugs and contribute to the formation of functional sanctuary sites. We therefore investigated the effect of saquinavir and darunavir on drug transporter expression and functional consequences for cellular resistance towards these compounds. METHODS: Induction of transporters was investigated in LS180 cells over a period of 4 weeks by means of RT-PCR, and for some transporters also at the protein and functional levels. Cellular resistance was measured by growth inhibition assays. RESULTS: Incubation with 10 microM darunavir for 1 week significantly increased mRNA expression of P-glycoprotein (P-gp/MDR1/ABCB1) 3.8-fold and of organic anion-transporting polypeptide 2B1 (SLCO2B1) 1.9-fold. In contrast, 10 microM saquinavir significantly increased mRNA expression of P-gp 5.7-fold, multidrug resistance-associated protein 1 (MRP1/ABCC1) 2.3-fold, MRP2/ABCC2 4.5-fold, MRP3/ABCC3 2.0-fold, MRP4/ABCC4 1.8-fold, MRP5/ABCC5 3.8-fold, breast cancer resistance protein (BCRP/ABCG2) 4.1-fold, SLCO1B1 4.6-fold, SLCO2B1 1.8-fold and SLCO3A1 1.8-fold. P-gp induction was also confirmed at the protein and functional levels. Induction by darunavir caused an increase in cellular resistance towards this compound, as measured in growth inhibition assays; however, saquinavir treatment did not cause reduced sensitivity of cells, indicating unchanged intracellular concentration. Hence, induction by darunavir increased drug efflux and might therefore lead to a suboptimal intracellular concentration of darunavir. CONCLUSIONS: The study revealed substantial induction of several drug transporters by saquinavir and darunavir, possibly leading to decreased efficacy of antiretrovirals and drugs used to treat co-morbidity.

DrugBank Data that Cites this Article

Drug Transporters

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