Figure 7.

Poziotinib inhibits the efflux of the ABCG2 and ABCB1 substrates, [³H]-mitoxantrone and [³H]-paclitaxel, respectively, from MDR colon cancer cells. (A) The effect of poziotinib on the efflux of [³H]-mitoxantrone from S1 parental colon cancer cells. (B) The effect of poziotinib on the efflux of [³H]-mitoxantrone from S1-M1-80 colon cancer cells that overexpress the ABCG2 transporter. (C) The effect of poziotinib on the efflux of [³H]-paclitaxel from SW620 parental colon cancer cells. (D) The effect of poziotinib on the efflux of [³H]-paclitaxel from SW620/Ad300 colon cancer cells that overexpress the ABCB1 transporter. Ko143 was used as a positive control for inhibition of the ABCG2 transporter and verapamil was used as a positive control for inhibition of the ABCB1 transporter. Data are expressed as the mean ±SD based on three independent experiments. * p < 0.05 versus the control group.