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. 2016 Mar 10;11(3):e0150567. doi: 10.1371/journal.pone.0150567

Fig 2. Erlotinib cytotoxicity is synergistically enhanced by the FAK inhibitor PF-228.

Fig 2

(A) Cells were treated with PF-228 and erlotinib for 48 hours and assayed for cell viability using MTT assay. Data indicates the mean ± SEM for cell viability presented as a percentage of control DMSO-treated cells (100% viable) from two independently performed experiments. (B) Fraction affected/Combination index (CI) plots indicating the synergistic cytotoxicity of erlotinib and PF-228. CIs < 1 are considered synergistic, CIs > 1 are considered antagonistic, and CIs = 1 are considered additive. (C) FAK inhibition reduces cell viability in human lung tumor tissue but not normal lung tissue ex vivo. Tissues from five unselected patients were treated for 48 hours with vehicle control (DMSO), erlotinib (10 μM), PF-271 (5 μM), or the combination of erlotinib and PF-271. Cell viability was assessed for both tumor tissue and normal tissue by alamarBlue from three wells per condition with each well containing three 2 mm x 1 mm tissue pieces. Fluorescence was normalized to baseline fluorescence readings for each well taken prior to drug treatment. Experimentation was performed independently on each patient sample Mean fluorescence is indicated for each condition as a horizontal line and statistically significant differences were determined by ANOVA and indicated as P values above the comparison.