Figure 7.

Efficacy of the combination of either paclitaxel or sabizabulin with lapatinib on cell growth inhibition and wound healing. (A) Lapatinib sensitivity of BT474, SKBR3, AU565 and JIMT HER2+ cell lines was measured by the MTS assay over a range of doses, data enumerated as a percentage of viable cells, and plotted on log (nM) scale, confirming that JIMT cells are lapatinib-resistant. (B,C) The MTS assay was used to determine the effect of pairing lapatinib (Lap) with paclitaxel (left panels) or sabizabulin (right panels) in AU565 (B) or JIMT (C) cells by the isobole method; the effect of the anti-tubulin targeting agent alone at the IC₃₀ dose is shown as a dashed line. (B,C) Data are plotted as the % maximal proliferation on a log scale (M = molar) after normalization to the untreated control as described in the Materials and Methods. Assays in (A–C) are representative of 3 to 4 biological replicates. (D) Wound healing was assayed by measuring wound width over time after drug added using the IncuCyte S3 instrument. JIMT cells were treated with either lapatinib (Lap), sabizabulin or paclitaxel alone, or in combination with 100 nM of lapatinib (n = 8 wells/cell line/treatment). Data are representative of two biological replicate experiments. ** p < 0.01; N.S., not significant.