Tariquidar methanesulfonate, hydrate

Cell experiment:

Cells (EMT6 AR1.0 8×102/well; A2780 5×103/well; 2780AD 6×103/well) are seeded into 96-well plates. After ~4 h, varying concentrations of Tariquidar are added, and cells are incubated for an additional 4 days (EMT6 AR1.0) or 6 days (2780AD) before quantification of cell growth and calculation of IC10 values (concentration resulting in 10% inhibition of cell growth)[2].

Animal experiment:

Mice[2] MC26 tumor slurry is implanted s.c. in BALB/c mice (day 0). The animals are then randomized, 24 h later, into groups of 15-18 and treated once with various regimens. Tariquidar methanesulfonate or vehicle is administered either i.v. via a lateral tail vein or p.o. with Doxorubicin (5 mg/kg) or vehicle i.v. The modulator is administered either i.v. at 2-4 mg/kg (10 mL/kg) at the same time as Doxorubicin or p.o. at 2-8 mg/kg (10 mL/kg) 1 h before the Cytotoxic drug. GG918 is administered p.o. 1 h before doxorubicin. All of the animals are weighed twice weekly. The animals are killed by cervical dislocation on day 14, and the tumors are excised and weighed. The data are analyzed by Student’s t test. Rat[2] Male CD rats (3 animals per time point) are dosed i.v. with paclitaxel alone [15 min infusion at 10 mg/kg in Tween 80:ethanol:5% dextrose (5:10:85% v/v/v)] or in combination with Tariquidar methanesulfonate (10 mg/kg). Tariquidar methanesulfonate is administered as a bolus (i.v.) dose 15 min before infusion of Paclitaxel. Blood samples are collected by cardiac puncture using heparinized syringes at various times between 0.083 and 48 h and are centrifuged to prepare plasma, which is stored at −20°C until analysis. Paclitaxel concentration in plasma samples is measured by a LC-MS/MS assay.

References:

[1]. Martin C, et al. The molecular interaction of the high affinity reversal agent XR9576 with P-glycoprotein. Br J Pharmacol, 1999, 128(2), 403-411.
[2]. Mistry P, et al. In vitro and in vivo reversal of P-glycoprotein-mediated multidrug resistance by a novel potent modulator, XR9576. Cancer Res, 2001, 61(2), 749-758.
[3]. Vraka C, et al. A new method measuring the interaction of radiotracers with the human P-glycoprotein (P-gp) transporter. Nucl Med Biol. 2018 Feb 14;60:29-36.