Fig 1: EGFR phosphorylation patterns and drug inhibition are altered by surface roughness in MDA-MB-468. (A) hEGFR phosphorylation micrographs of TNBC cells cultured for 5 days in reduced serum (2% FBS) on surfaces with roughness of Ra = 1.5 µm, TCP surface as a standard control or TCP surface supplemented with 10 ng/mL EGF as a positive control. The array includes 17 phospho-proteins of the pan EGFR, ErbB-2, ErbB-3, ErbB-4 receptors (identified in Supplementary Figure S6). Blots with increased expression are identified and numbered in red. (B–E) Quantification of the phosphorylation of pan EGFR, ErbB-2, ErbB-3, ErbB-4 and their corresponding phospho-proteins, depicted as the normalized intensity relative to assay positive controls. (F) EGFR inhibition-response curve of MDA-MB-468 cells cultured on surfaces with roughness Ra = 1.5 µm compared to TCP control. Error bars depict the mean ± SEM of 2-3 independent experiments with n = 2-3 samples. T-test with Mann-Whitney non-parametric test. Asterisk (*) represent p-values < 0.05, (**) p-values < 0.01, (***) p-values < 0.001 and (****) p-values < 0.0001, (#) p-values<0.1.