Fig. 4

Inhibition of tumor cell adhesion by the PF-573, 228 inhibitor. a, c Adhesion test. The tumor cells were incubated with 1 μM PF-573, 228 inhibitor or vehicle alone (0.1% DMSO) for 24 h before irradiation with 4 Gy. The fluorescence-labelled tumor cells were placed on a monolayer of primary HUVEC cells and incubated for 4 h. After washing out the non-adherent tumor cells, the adhesion rate was quantified in the fluorescence reader and normalized (100%) to the adhesion of untreated cells (TC and EC). b, d Cell proliferation and determination of the toxic effect of the PF-573, 228 inhibitor (FAK-I) with a MTT viability test. Cells were treated with different concentrations of the inhibitor for 24 h, 48 h and 72 h. The control cells were treated with DMSO (0.1%) alone. Shown are means (n = 3) and standard deviations. Statistics: T-test, *p < 0.05; **p < 0.01; ***p < 0.001. e, f Western blot analysis of the impact of this inhibitor on the phosphorylation of FAK and its downstream target paxillin in U-373 MG cells (e) and MDA-MB-231 cells (f). The samples were isolated 24 h after irradiation with 4 Gy and treatment with 1 μM PF-573, 228