Dual-action (azurin + gefitinib) combination therapy for lung cancer

The bacterial protein azurin and its derived peptide (p28) have been shown to possess anticancer activities. Up to date, several in vitro and in vivo studies have reported their multi-targeted anticancer properties. Moreover, p28, a cell-penetrating peptide, has completed two US phase I trials with promising results. Prior to this publication, our group at Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico in close collaboration with IPATIMUP, University of Porto, reported the therapeutic effects of azurin in breast cancer cells expressing aberrant levels of P-cadherin. We have also performed a microarray analysis of azurin treated breast cancer cells detecting a decrease in the expression of genes coding for membrane receptors associated to cell signaling. Now in this Cell Cycle paper, Bernardes et al. have evaluated the effects of azurin on A549 lung cancer cells. Our study demonstrates that azurin impairs cell proliferation/invasion by stabilizing the cross talk between integrin beta1 and EGFR. Moreover, in collaboration with Nuno C Santos (IMM, University of Lisbon) we utilized AFM to image cancer cells before and after being exposed to azurin, measuring their morphological and mechanical changes. The azurin treatment revert the biomechanical properties of the cells allowing them to shift to a less invasive phenotype. Finally, we present evidence supporting that azurin, when combined with gefitinib/erlotinib, which target EGFR, enhances the sensitivity of A549 lung cancer cells in response to these drugs. Overall these findings have significant relevance and may pave the way of using azurin to potentiate the anticancer activity of chemotherapeutic drugs.

Authors and Affiliations:

Nuno Bernardes¹, Sofia Abreu¹, Filomena A Carvalho², Fábio Fernandes³, Nuno C Santos², Arsénio M Fialho^1,4,*

¹iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001, Lisbon, Portugal

²Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisbon, Portugal

³Centro de Quimica-Fisica Molecular, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal

⁴Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal

Abstract:

In lung cancer, the Epidermal Growth Factor Receptor (EGFR) is one of the main targets for clinical management of this disease. The effectiveness of therapies toward this receptor has already been linked to the expression of integrin receptor subunit β₁ in NSCLC A549 cells. In this work we demonstrate that azurin, an anticancer therapeutic protein originated from bacterial cells, controls the levels of integrin β₁ and its appropriate membrane localization, impairing the intracellular signaling cascades downstream these receptors and the invasiveness of cells. We show evidences that azurin when combined with gefitinib and erlotinib, tyrosine kinase inhibitors which targets specifically the EGFR, enhances the sensitivity of these lung cancer cells to these molecules. The broad effect of azurin at the cell surface level was examined by Atomic Force Microscopy. The Young 's module (E) shows that the stiffness of A549 lung cancer cells decreased with exposure to azurin and also gefitinib, suggesting that the alterations in the membrane properties may be the basis of the broad anticancer activity of this protein. Overall, these results show that azurin may be relevant as an adjuvant to improve the effects of other anticancer agents already in clinical use, to which patients often develop resistance hampering its full therapeutic response.

Journal: Cell Cycle

Link: http://dx.doi.org/10.1080/15384101.2016.1172147