A novel variant of VEGFR2 identified by a pan-cancer screening of recurrent somatic mutations in the catalytic domain of tyrosine kinase receptors enhances tumor growth and metastasis.

In cancer genomics, recurrence of mutations in gene families that share homologous domains has recently emerged as a reliable indicator of functional impact and can be exploited to reveal the pro-oncogenic effect of previously uncharacterized variants. Pan-cancer analyses of mutation hotspots in the catalytic domain of a subset of tyrosine kinase receptors revealed that two infrequent mutations of VEGFR2 (R1051Q and D1052N) recur in analogous proteins and correlate with reduced patient survival. Functional validation showed that both R1051Q and D1052N mutations increase the enzymatic activity of VEGFR2. The expression of VEGFR2R1051Q potentiates the PI3K/Akt signaling axis in cancer cells, increasing their tumorigenic potential in vitro and in vivo. In addition, it confers to cancer cells an increased sensitivity to the VEGFR2-targeted tyrosine kinase inhibitor Linifanib. In the context of an efficacious application of anti-cancer targeted therapies, these findings indicate that the screening for uncharacterized mutations, like VEGFR2R1051Q, may help to predict patient prognosis and drug response, with significant clinical implications.

Natural Histogel-Based Bio-Scaffolds for Sustaining Angiogenesis in Beige Adipose Tissue.

In the treatment of obesity and its related disorders, one of the measures adopted is weight reduction by controlling nutrition and increasing physical activity. A valid alternative to restore the physiological function of the human body could be the increase of energy consumption by inducing the browning of adipose tissue. To this purpose, we tested the ability of Histogel, a natural mixture of glycosaminoglycans isolated from animal Wharton jelly, to sustain the differentiation of adipose derived mesenchymal cells (ADSCs) into brown-like cells expressing UCP-1. Differentiated cells show a higher energy metabolism compared to undifferentiated mesenchymal cells. Furthermore, Histogel acts as a pro-angiogenic matrix, induces endothelial cell proliferation and sprouting in a three-dimensional gel in vitro, and stimulates neovascularization when applied in vivo on top of the chicken embryo chorioallantoic membrane or injected subcutaneously in mice. In addition to the pro-angiogenic activity of Histogel, also the ADSC derived beige cells contribute to activating endothelial cells. These data led us to propose Histogel as a promising scaffold for the modulation of the thermogenic behavior of adipose tissue. Indeed, Histogel simultaneously supports the acquisition of brown tissue markers and activates the vasculature process necessary for the correct function of the thermogenic tissue. Thus, Histogel represents a valid candidate for the development of bioscaffolds to increase the amount of brown adipose tissue in patients with metabolic disorders.

Speeding Up the Identification of Cystic Fibrosis Transmembrane Conductance Regulator-Targeted Drugs: An Approach Based on Bioinformatics Strategies and Surface Plasmon Resonance.

Cystic fibrosis (CF) is mainly caused by the deletion of Phe 508 (ΔF508) in the cystic fibrosis transmembrane conductance regulator (CFTR) protein that is thus withheld in the endoplasmic reticulum and rapidly degraded by the ubiquitin/proteasome system. New drugs able to rescue ΔF508-CFTR trafficking are eagerly awaited. An integrated bioinformatics and surface plasmon resonance (SPR) approach was here applied to investigate the rescue mechanism(s) of a series of CFTR-ligands including VX809, VX770 and some aminoarylthiazole derivatives (AAT). Computational studies tentatively identified a large binding pocket in the ΔF508-CFTR nucleotide binding domain-1 (NBD1) and predicted all the tested compounds to bind to three sub-regions of this main pocket. Noticeably, the known CFTR chaperone keratin-8 (K8) seems to interact with some residues located in one of these sub-pockets, potentially interfering with the binding of some ligands. SPR results corroborated all these computational findings. Moreover, for all the considered ligands, a statistically significant correlation was determined between their binding capability to ΔF508-NBD1 measured by SPR and the pockets availability measured by computational studies. Taken together, these results demonstrate a strong agreement between the in silico prediction and the SPR-generated binding data, suggesting a path to speed up the identification of new drugs for the treatment of cystic fibrosis.

Oversulfated heparins with low anticoagulant activity are strong and fast inhibitors of hepcidin expression in vitro and in vivo.

Hepcidin is a peptide hormone that controls systemic iron availability and is upregulated by iron and inflammation. Heparins have been shown to be efficient hepcidin inhibitors both in vitro and in vivo, even when their anticoagulant activity has been abolished by chemical reactions of oxidation/reduction (glycol-split). We analyzed a modified heparin type, characterized by a high, almost saturated, sulfation degree and low molecular weight. It inhibited hepcidin expression in hepatic HepG2 cells, and when used in mice, it readily suppressed liver hepcidin mRNA and serum hepcidin, with a significant decrease of spleen iron. This occurred also in inflammation-model, LPS-treated animals, and after heparin chronic 10-day treatments. The heparin had low/absent anticoagulant activity, as tested for factor-Xa and -IIA, APTT and anti Xa. It reduced triglyceride levels in the mice. This heparin acts faster and is more potent than the glycol split-heparins, probably because of its smaller molecular weight and higher sulfation degree. This modified heparin has potential applications for the treatment of diseases with high hepcidin levels.