Figure 1.

A) Azurin alters adhesion of A549 lung cancer cells to some extracellular matrix (ECM) components. Azurin treatment (50 µM and 100 µM, 48h) caused a reduction in the percentage of adhesion of cells to laminin-332, fibronectin and collagen type-I and IV (adhesion time = 20 min; * p < 0.05). B) A single treatment with azurin at 100 µM for 48h (same conditions as for adhesion assays) reduces protein expression of integrin subunit β₁ under normal plastic conditions (black bars), or a matrix formed by collagen type-I (white bars) in A549 lung cancer cells. In contrary, these cells exhibit higher levels of E-cadherin under the same conditions. In the right panel, results are presented as the ratio of band intensity of target protein between azurin treated samples and control samples, both normalized to their respective actin band intensity (* p < 0.05). C) Immunofluorescence staining of integrin β₁ (green, upper panel) and E-cadherin (green, lower panel) under the same treatment conditions (nuclei – DAPI, blue). Treatment with azurin alters the normal membrane staining of this transmembrane protein causing a delocalozation to a diffuse pattern in the interior of cells; D) Co-immunoprecipitation of ubiquitin and integrin β₁. An antibody to this integrin was incubated with total cell lysates and used to precipitate it from both control and azurin treated total cell lysates. Proteins were separated in SDS-Page gels transferred to membranes which were probed with anti-ubiquitin antibody. A band corresponding to ubiquitin was detected at the molecular weight correspondent to integrin β₁.