Table 4.

Sensitization of MRP1-Expressing PC-3^rVCR²⁰ Cells to Vincristine by Saq, Saq-NO, or MK571 (MRP1 Inhibitor).

	IC50* Vincristine	Fold Sensitization†
Vincristine	33.10 ± 4.07
Vincristine + MK571 10 µM	12.54 ± 1.88‡	3.7
Vincristine + saq 5 µM	4.28 ± 0.61‡	7.7
Vincristine + saq 2.5 µM	8.76 ± 1.19‡	3.8
Vincristine + saq-NO 5 µM	2.73 ± 0.42‡,§	12.1
Vincristine + saq-NO 2.5 µM	4.51 ± 0.73‡,§	7.3

Values are mean ± SD from three independent experiments.

^*Concentration that decreases cell viability by 50%.

^†IC₅₀ vincristine/IC₅₀ vincristine + saq, saq-NO, or MK571.

^‡P < .05 relative to vincristine alone.

^§P < .05 relative to vincristine + corresponding saq concentration.