NSC23925 increases Pgp1 substrates accumulation in SKOV-3<sub>TR</sub>.

<p>Images of SKOV-3<sub>TR</sub> cells incubated with various fluorescent substrates of Pgp1 in the presence (bottom panel) and absence (top panel) of NSC23925. For visualization of effects of NSC23925 on the intracellular retention of rhodamine 123, mitoxantrone, Dioc2, doxorobucin, and calcein AM, 10,000 resistant cells were seeded on to Lab-Tek 8-well chamber slides on the day prior to the assay. SKOV-3<sub>TR</sub> cells were then incubated with either 1 µM rhodamine 123, 10 µM mitoxantrone, 0.1 µM Dioc2, 10 µM doxorubicin or 0.25 µM calcein AM either alone or in the presence of NSC23925 in RPMI 1640 media for one hour at 37°C. Image were acquired a Nikon Eclipse Ti-U fluorescence microscope (Nikon Corp.) equipped with a SPOT RT digital camera (Diagnostic Instruments, Inc., Sterling Heights, MI).</p>