Table 2

STAT3 pathway inhibitors sensitize 2F7 and U266 tumor cells independent of drug efflux

Tumor cells were treated for 1 h with piceatannol, AG490, or verapamil, or combinations there of, as listed. After treatment, cells were incubated with Adriamycin (ADR), as described in “Materials and Methods,” and analyzed by flow cytometric analysis. Numbers are percentage of population displaying auto fluorescence, an indication of intracellular ADR accumulation.

10 min60 min
2F7 Treatment
 Complete medium only1.982.15
 Medium + ADR (1 μg/ml)96.66.8
 Piceatannol (50 μm) + ADR99.07.8
 Verapamil (100 μm) + ADR96.886.2
U266 Treatment
 Complete medium only1.111.35
 Medium + ADR (1 μg/ml)97.357.4
 AG490 (10 μm) + ADR98.545.2
 Verapamil (100 μm) + ADR98.461.2