Microarray analysis of breast cancer cell lines with different levels of P-cadherin expression treated with the anti-cancer bacterial protein azurin

We performed a microarray analysis to compare the expression profile of azurin treated and untreated with different P-cadherin expression levels. We also compared the differentially expressed genes regulated by P-cadherin overexpression. Both cell lines presented an up-regulation of apoptosis mediated by p53 protein, endocytosis and vesicle-mediated transport. Conversely, invasive MCF-7/AZ.Pcad cells treated with azurin presented a decreased expression of genes associated with cell surface receptors and signal transduction, as well as genes associated with biological adhesion and migration. Azurin is a bacterial protein from Pseudomonas aeruginosa which exerts an inhibitory activity in cancer cells. In P-cadherin-overexpressing models, a bad prognosis marker in breast cancer increasing invasion and other malignant features, azurin decreases the invasion of cancer cells. We performed a microarray analysis to compare the expression profile of azurin treated cells with different P-cadherin expression levels. Azurin up-regulated apoptosis mediated by p53 protein, endocytosis and vesicle-mediated transport. In the contrary, in invasive MCF-7/AZ.Pcad cells, azurin decreased the expression of genes associated with cell surface receptors and signal transduction, as well as biological adhesion. Further, azurin decreased adhesion of cells to proteins from the Extracellular matrix (ECM) and altered protein expression of integrins α6, β4 and β1 and interfered with the ability of these cells to form mammospheres. Altogether, our results further enlighten the anti-cancer effects mediated by azurin in P-cadherin overexpression breast cancer models. Cells were exposed to azurin (100uM) for 48h, after which total RNA was extracted. Control cells were exposed during the same time to PBS buffer solution. Three independent samples for each condition were used treated with different azurin production batches.