Figure 1.
An anti-EGFR antibody decreases viability of lung cancer cell lines expressing L858R-EGFR but it does not affect cells expressing the E746_A750 deletion mutant (Del19) or T790M-EGFR
(A) H3255 cells (2 × 104; L858R), along with 11-18 (5 × 103; L858R), PC9 (3 × 103; Del19), PC9ER (3 × 103; Del19 and T790M), and H1975 cells (5 × 103; L858R and T790M), were seeded in 96-well plates and treated for 72 h with cetuximab, trastuzumab (anti-HER2), or the combination of antibodies (2XmAbs) at 5, 10, or 20 μg/mL. Cell viability was assessed using the MTT assay. Data are presented as means ± SEM of three biological replicates.
(B) The indicated NSCLC cell lines (H3255, 2 × 104 cells; 11-18, 5 × 103; PC9 and PC9ER, each at 3 × 103) were seeded in 96-well plates and later treated for 72 h with the indicated anti-EGFR antibodies (each at 10 μg/mL). Cell viability was assessed using the MTT assay. Results are presented as means + SEM of three biological replicates. Significance was assessed using one-way ANOVA followed by Dunnett’s multiple comparisons test. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001; ns, not significant.
(C) H3255, 11-18 and PC9 cells were treated for 48 h with cetuximab (Cetux., 10 μg/mL), trastuzumab (Trast., 10 μg/mL), or 2XmAbs (cetuximab + trastuzumab, each at 5 μg/mL). Protein extracts were resolved, blotted and probed with antibodies specific to the indicated apoptosis and cell-cycle markers, including an antibody specific to the cleaved form of caspase-3 (Cl.Casp.3). Vinculin and GAPDH were used as gel loading controls. See also Figures S1 and S2.