Members of the T2 extracellular ribonucleases family have long been reported as stress response proteins, often involved in host defence, in many different taxonomic groups. In particular, the human RNASET2 protein (hRNASET2) has been reported as an extracellular tumor suppressor protein, endowed with the ability to act as an "alarmin" signalling molecule following its expression and secretion in the tumor microenvironment by cancer cells and the subsequent recruitment and activation of cells belonging to the host innate immune system. Many in vitro and in vivo assays have been recently reported in support of the oncosuppressive role of hRNASET2: most of them relied on genetically engineered cell lines and the use of recombinant proteins from non-mammalian sources.
View Article and Find Full Text PDFHuman RNASET2 acts as a powerful oncosuppressor protein in in vivo xenograft-based murine models of human cancer. Secretion of RNASET2 in the tumor microenvironment seems involved in tumor suppression, following recruitment of M1-polarized macrophages. Here, we report a murine -based syngeneic in vivo assay.
View Article and Find Full Text PDFRecent studies demonstrated that allograft inflammatory factor-1 (AIF-1) and RNASET2 act as chemoattractants for macrophages and modulate the inflammatory processes in both vertebrates and invertebrates. The expression of these proteins significantly increases after bacterial infection; however, the mechanisms by which they regulate the innate immune response are still poorly defined. Here, we evaluate the effect of bacterial lipopolysaccharide injection on the expression pattern of these genes and the interrelation between them during innate immune response in the medicinal leech, an invertebrate model with a simple anatomy and a marked similarity with vertebrates in inflammatory processes.
View Article and Find Full Text PDFMacrophages represent key inflammatory cellular effectors of the innate immune response. Despite being widely acknowledged as professional phagocytes, the functional roles played by these cells have been progressively widened over the years to encompass regulation of the adaptive immune system, stimulation or suppression of cancer cell growth and tissue remodeling. These diverse functional features have led to the concept of "macrophage plasticity", i.
View Article and Find Full Text PDFRibonuclease T2 (RNASET2) is a pleiotropic and polyfunctional protein, which exerts several different activities in neoplastic cells since the early steps of tumor development. Besides having an antitumorigenic activity, RNASET2 inhibits both bFGF-induced and VEGF-induced angiogenesis and has a role as a stress-response, alarmin-like, protein. In this study, we investigated RNASET2 expression in well-differentiated and poorly differentiated neuroendocrine neoplasms of the lung (Lu-NENs), which are known to show clear-cut differences in morphology, biology and clinical behavior.
View Article and Find Full Text PDFRibonucleases (RNases) are hydrolytic enzymes endowed with the ability to either process or degrade ribonucleic acids. Among the many biological functions assigned to RNases, a growing attention has been recently devoted to the control of cancer growth, in the attempt to bring novel therapeutic approaches to clinical oncology. Indeed, several enzymes belonging to different ribonuclease families have been reported in the last decade to display a marked oncosuppressive activity in a wide range of experimental models.
View Article and Find Full Text PDFAs widely recognized, tumor growth entails a close and complex cross-talk among cancer cells and the surrounding tumor microenvironment. We recently described the human RNASET2 gene as one key player of such microenvironmental cross-talk. Indeed, the protein encoded by this gene is an extracellular RNase which is able to control cancer growth in a non-cell autonomous mode by inducing a sustained recruitment of immune-competent cells belonging to the monocyte/macrophage lineage within a growing tumor mass.
View Article and Find Full Text PDFRibonucleases form a large family of enzymes involved in RNA metabolism and are endowed with a broad range of biological functions. Among the different RNase proteins described in the last decades, those belonging to the Rh/T2/S subfamily show the highest degree of evolutionary conservation, suggesting the occurrence of a key critical ancestral role for this protein family. We have recently defined the human RNASET2 gene as a novel member of a group of oncosuppressors called "tumor antagonizing genes," whose activity in the control of cancer growth is carried out mainly in vivo.
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