Extracellular matrix proteins as circulating biomarkers for the diagnosis of non-small cell lung cancer patients

The extracellular matrix (ECM) is composed of a dynamic network of macromolecules which assemble into three-dimensional structures functioning as ligands for cellular integrins or acting as a scaffold for soluble cytokines and growth factors (1). Whereas the role of ECM in the regulation of physiological tissue development and homeostasis has been already characterized, the study of the involvement of the ECM in cancer progression is a subject of growing interest. Abnormal changes in the amount and composition of the ECM, consisting in increased deposition and altered organization of ECM proteins or in enhanced post-translational modifications, are commonly observed in cancer. Altered ECM proteins can promote cell survival and proliferation, and can support cell migration and invasion. Moreover, ECM proteins can also induce tumor-associated inflammation and angiogenesis, thus contributing to cancer progression (1). As a consequence of deregulated ECM remodeling in cancer, an increased number of protein-specific fragments deriving from ECM turnover are released into blood. Such molecules can be potentially used as circulating biomarkers useful for clinical diagnosis and monitoring of cancer patients (2)