Cell delivery of Met docking site peptides inhibit angiogenesis and vascular tumor growth.

Angiogenesis is a very complex biological process that drives the formation of new blood vessels starting from pre-existing one. In adulthood, it occurs both in physiological and pathological processes. Pathological angiogenesis is involved in several diseases, including cancer. In the last decade, the concept of anti-angiogenic therapy has been developed as a strategy to treat cancer inducing the inhibition of new vessels that provide sustenance to the tumor. Recently, Met receptor and its ligand HGF (Hepatocyte Growth Factor) has been proposed as target for the anti-angiogenic therapy. HGF and its receptor Met are responsible for a wide variety of cellular responses, both physiologically during embryo development and tissue homeostasis, and pathologically, particularly during tumor growth and dissemination. In cancer, Met can act as an oncogene on tumor cells, as well as a pro-angiogenic factor activating endothelial cells and inducing new vessel formation. Molecules interfering with Met activity could be valuable agents for anti-cancer treatment simultaneously inhibiting oncogenesis and angiogenesis. The aim of this study has been the identification of peptides able to interfere with HGF-induced angiogenesis. We synthesized three different peptides containing the Met docking site fused to the internalization sequences of Antennapedia homeodomain or of Tat transactivation domain which were used to deliver peptides into living cells. In vitro we treated human endothelial cells with peptides and we quantified proliferation. We then evaluated the ability of peptides to interfere with HGF-induced migration, invasion and morphogenesis of endothelial cells. By western blotting analysis we investigated whether these peptides affect Met activation and downstream signalling. In vivo we performed matrigel sponge assay and Kaposi\u2019s sarcoma xenograft to test the peptides efficacy on angiogenesis and tumor growth. We observed that in endothelial cells internalized peptides inhibited ligand-dependent cell proliferation, motility, invasiveness and morphogenesis in vitro, to an even greater extent and with much less toxicity than the Met inhibitor PHA-665752, which correlated with interference of HGF-dependent downstream signalling, as shown by reduction in ERK1/2 activation (Cantelmo et al.). In vivo, the peptides inhibited HGF-induced angiogenesis in the matrigel sponge assay and impaired xenograft tumor growth and vascularization in Kaposi\u2019s sarcoma (Cantelmo et al.). These data show that interference with the Met receptor intracellular sequence impairs HGF-induced angiogenesis, suggesting the use of antidocking site compounds as a therapeutic strategy to counteract angiogenesis in cancer as well as in other diseases

Impairment of angiogenesis by fatty acid synthase inhibition Involves mTOR malonylation

The role of fatty acid synthesis in endothelial cells (ECs) remains incompletely characterized. We report that fatty acid synthase knockdown (FASNKD) in ECs impedes vessel sprouting by reducing proliferation. Endothelial loss of FASN impaired angiogenesis in vivo, while FASN blockade reduced pathological ocular neovascularization, at >10-fold lower doses than used for anti-cancer treatment. Impaired angiogenesis was not due to energy stress, redox imbalance, or palmitate depletion. Rather, FASNKD elevated malonyl-CoA levels, causing malonylation (a post-translational modification) of mTOR at lysine 1218 (K1218). mTOR K-1218 malonylation impaired mTOR complex 1 (mTORC1) kinase activity, thereby reducing phosphorylation of downstream targets (p70S6K/4EBP1). Silencing acetyl-CoA carboxylase 1 (an enzyme producing malonyl-CoA) normalized malonyl-CoA levels and reactivated mTOR in FASNKD ECs. Mutagenesis unveiled the importance of mTOR K1218 malonylation for angiogenesis. This study unveils a novel role of FASN in metabolite signaling that contributes to explaining the anti-angiogenic effect of FASN blockade

Cell delivery of Met docking site peptides inhibit angiogenesis and vascular tumor growth.

Angiogenesis is a very complex biological process that drives the formation of new blood vessels starting from pre-existing one. In adulthood, it occurs both in physiological and pathological processes. Pathological angiogenesis is involved in several diseases, including cancer. In the last decade, the concept of anti-angiogenic therapy has been developed as a strategy to treat cancer inducing the inhibition of new vessels that provide sustenance to the tumor. Recently, Met receptor and its ligand HGF (Hepatocyte Growth Factor) has been proposed as target for the anti-angiogenic therapy. HGF and its receptor Met are responsible for a wide variety of cellular responses, both physiologically during embryo development and tissue homeostasis, and pathologically, particularly during tumor growth and dissemination. In cancer, Met can act as an oncogene on tumor cells, as well as a pro-angiogenic factor activating endothelial cells and inducing new vessel formation. Molecules interfering with Met activity could be valuable agents for anti-cancer treatment simultaneously inhibiting oncogenesis and angiogenesis. The aim of this study has been the identification of peptides able to interfere with HGF-induced angiogenesis. We synthesized three different peptides containing the Met docking site fused to the internalization sequences of Antennapedia homeodomain or of Tat transactivation domain which were used to deliver peptides into living cells. In vitro we treated human endothelial cells with peptides and we quantified proliferation. We then evaluated the ability of peptides to interfere with HGF-induced migration, invasion and morphogenesis of endothelial cells. By western blotting analysis we investigated whether these peptides affect Met activation and downstream signalling. In vivo we performed matrigel sponge assay and Kaposi’s sarcoma xenograft to test the peptides efficacy on angiogenesis and tumor growth. We observed that in endothelial cells internalized peptides inhibited ligand-dependent cell proliferation, motility, invasiveness and morphogenesis in vitro, to an even greater extent and with much less toxicity than the Met inhibitor PHA-665752, which correlated with interference of HGF-dependent downstream signalling, as shown by reduction in ERK1/2 activation (Cantelmo et al.). In vivo, the peptides inhibited HGF-induced angiogenesis in the matrigel sponge assay and impaired xenograft tumor growth and vascularization in Kaposi’s sarcoma (Cantelmo et al.). These data show that interference with the Met receptor intracellular sequence impairs HGF-induced angiogenesis, suggesting the use of antidocking site compounds as a therapeutic strategy to counteract angiogenesis in cancer as well as in other diseases

Endothelial Metabolism Driving Angiogenesis: Emerging Concepts and Principles

Angiogenesis has been traditionally studied by focusing on growth factors and other proangiogenic signals, but endothelial cell (EC) metabolism has not received much attention. Nonetheless, glycolysis, one of the major metabolic pathways that converts glucose to pyruvate, is required for the phenotypic switch from quiescent to angiogenic ECs. During vessel sprouting, the glycolytic activator PFKFB3 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3) promotes vessel branching by rendering ECs more competitive to reach the tip of the vessel sprout, whereas fatty acid oxidation selectively regulates proliferation of endothelial stalk cells. These studies show that metabolic pathways in ECs regulate vessel sprouting, more importantly than anticipated. This review discusses the recently discovered role of glycolysis and fatty acid oxidation in vessel sprouting. We also highlight how metabolites can influence EC behavior as signaling molecules by modulating posttranslational modification.status: publishe

Synthetic analogs of xanthohumol for use in the prevention and​/or treatment of tumors

The present invention relates to novel synthetic analogs I [wherein: R1 and R2 are independently selected from the group consisting of H, Me, straight or branched C2-​10-​alkyl, straight or branched C2-​10-​alkenyl or -​alkadienyl, C4-​6-​cycloalkyl, C4-​6-​cycloalkenyl or -​alkadienyl, alkoxyalkyl, (un)​substituted benzyl; n is an integer ranging from I to 5;]​. [A is a mono- or bicyclic aryl, or an (non)​arom. heterocycle ring selected from the group consisting of pyrrole, pyrrolidine, 3-​pyrroline, 2H-​pyrrole, 2-​pyrroline, indole, isoindole, 3H-​indole, indolizine, indoline, carbazole, furan, benzofuran, isobenzofuran, 2H-​pyran, 4H-​pyran, benzo[b]​thiophene, thiophene, pyridine, piperidine, 4H-​quinolizine, isoquinoline, quinoline, tetrahydroquinoline, 1,​8-​naphthyridine, acridine, oxazole, isoxazole, benzoxazole, benzothiazole, isothiazole, thiazole, imidazole, 2-​imidazole, imidazolidine, tetrazole, 1,​2,​3-​triazole, 1,​2,​4-​triazole, 1,​2,​3-​oxadiazole, benzimidazole, purine, 1,​4-​dioxane, 1,​3-​dioxolane, 1,​3-​dithiane, 1,​4-​dithiane, 1,​3,​5-​trithiane, morpholine, thiomorpholine, phenothiazine, pyrazole, 2-​pyrazoline, pyrazolidine, quinazoline, cinnoline, pyrimidine, pyrazine, pteridine, phthalazine, 1,​2,​4-​triazine, 1,​3,​5-​triazine, pyridazine, piperazine, quinoxaline, phenazine, lH-​indazole;]​. [Wherein the substituents on ring A, independently from each other, are selected from the group consisting of H, O-​alkyl, OCH3, Cl, F, Br, iodo, NO2, NH2, NHCH3, NH-​alkyl, NHCOCH3, NHCO-​alkyl, NHSO2CH3, NHSO2-​alkyl, SO2CH3, SO2-​alkyl, SO2NH2, SO2NHCH2, SO2NH-​alkyl, SO2NHCOCH3, SO2NHCO-​alkyl, CO2H, CONHCH3, CONH-​alkyl, CO2CH3, CO2-​alkyl, CONHSO2CH3, CONHSO2-​alkyl, alkyl being as defined above for R1 and R2; wherein at least one of the substituents on the A ring is H;]​. [Provided that the compd. of general formula I is not: (E)​-​3-​phenyl-​1-​(2,​4,​6-​trimethoxy-​3-​(3-​methylbut-​2-​enyl)​phenyl)​prop-​2-​en-​1-​one or (E)​-​3-​phenyl-​1-​(2-​hydroxy-​4,​6-​dimethoxy-​3-​(3-​methylbut-​2-​enyl)​phenyl)​prop-​2-​en-​1-​one;] and tautomers, pharmaceutically acceptable salts and pro-​drugs thereof, of xanthohumol (II) and the use thereof. Thus, (E)​-​1-​[2,​4-​dihydroxy-​6-​methoxy-​3-​(3-​methylbut-​2-​enyl)​prenyl]​-​3-​(4-​fluorophenyl)​prop-​2-​en-​1-​one (III) was prepd. from 2',​4',​6'-​trihydroxyacetophenone monohydrate (IV·H2O) via regioselective O-​protection with MOM-​Cl in CH2Cl2 contg. DIPEA; O-​etherification with 3-​methyl-​2-​buten-​1-​ol in THF contg. PPh3 and DEAD;. Claisen rearrangement of the prenyl ether in N,​N-​dimethylaniline; O-​methylation with Me2SO4 in acetone contg. K2CO3; aldol condensation with 4-​FC6H4CHO in MeOH contg. aq. NaOH; and, demethoxymethylation with HCl in MeOH. The antitumor activity of III was detd. [significant inhibition of HUVEC cell growth at concn. of 20 μM after only 24 h; at the concn. of 10 μM it was proved able to reduce cell proliferation after 72 and 96 h treatment]​

Diacylglycerol kinases are essential for hepatocyte growth factor-dependent proliferation and motility of Kaposi's sarcoma cells.

Hepatocyte growth factor (HGF) is involved in the pathogenesis of Kaposi's sarcoma (KS), the most frequent neoplasia in patients with AIDS, characterized by proliferating spindle cells, infiltrating inflammatory cells, angiogenesis, edema, and invasiveness. In vitro, this factor sustains the biological behavior of KS derived cells, after activation of its receptor and the downstream MAPK and AKT signals. In other cell types, namely endothelial and epithelial cells, movement, proliferation, and survival stimulated by HGF and other growth factors and cytokines depend on diacylglycerol kinases (DGK). In an effort to identify new intracellular transducers operative in KS cells, which could represent therapeutic targets, we investigated the role of DGK in KS cell movement and proliferation by treating cells with the DGK pharmacological inhibitor R59949. We report that R59949 strongly inhibits HGF-induced KS motility, proliferation, and anchorage-independent growth with only a partial effect on cell adhesion and spreading. R59949 does not affect cell survival, HGF receptor activation, or the classical MAPK and AKT signalling pathways. Furthermore, we carried out an siRNA screen to characterize the DGK isoforms involved in KS motility and anchorage independent growth. Our data indicate a strong involvement of DGK-δ in KS motility and of DGK-ι in anchorage-independent growth. These results indicate that DGK inhibition is sufficient to impair in vitro KS cell proliferation and movement and suggest that selected DGK represent new pharmacological targets to interfere with the malignant properties of KS, independently from the well-known RAS/MAPK and PI3K/AKT pathways

The Proangiogenic Phenotype of Natural Killer Cells in Patients with Non-Small Cell Lung Cancer

The tumor microenvironment can polarize innate immune cells to a proangiogenic phenotype. Decidual natural killer (dNK) cells show an angiogenic phenotype, yet the role for NK innate lymphoid cells in tumor angiogenesis remains to be defined. We investigated NK cells from patients with surgically resected non-small cell lung cancer (NSCLC) and controls using flow cytometric and functional analyses. The CD56+CD16- NK subset in NSCLC patients, which represents the predominant NK subset in tumors and a minor subset in adjacent lung and peripheral blood, was associated with vascular endothelial growth factor (VEGF), placental growth factor (PIGF), and interleukin-8 (IL-8)/CXCL8 production. Peripheral blood CD56+CD16- NK cells from patients with the squamous cell carcinoma (SCC) subtype showed higher VEGF and PlGF production compared to those from patients with adenocarcinoma (AdC) and controls. Higher IL-8 production was found for both SCC and AdC compared to controls. Supernatants derived from NSCLC CD56+CD16- NK cells induced endothelial cell chemotaxis and formation of capillary-like structures in vitro, particularly evident in SCC patients and absent from controls. Finally, exposure to transforming growth factor-β1 (TGFβ1), a cytokine associated with dNK polarization, upregulated VEGF and PlGF in peripheral blood CD56+CD16- NK cells from healthy subjects. Our data suggest that NK cells in NSCLC act as proangiogenic cells, particularly evident for SCC and in part mediated by TGFβ1

Incomplete and transitory decrease of glycolysis: A new paradigm for anti-angiogenic therapy?

During vessel sprouting, a migratory endothelial tip cell guides the sprout, while proliferating stalk cells elongate the branch. Tip and stalk cell phenotypes are not genetically predetermined fates, but are dynamically interchangeable to ensure that the fittest endothelial cell (EC) leads the vessel sprout. ECs increase glycolysis when forming new blood vessels. Genetic deficiency of the glycolytic activator PFKFB3 in ECs reduces vascular sprouting by impairing migration of tip cells and proliferation of stalk cells. PFKFB3-driven glycolysis promotes the tip cell phenotype during vessel sprouting, since PFKFB3 overexpression overrules the pro-stalk activity of Notch signaling. Furthermore, PFKFB3-deficient ECs cannot compete with wild-type neighbors to form new blood vessels in chimeric mosaic mice. In addition, pharmacological PFKFB3 blockade reduces pathological angiogenesis with modest systemic effects, likely because it decreases glycolysis only partially and transiently.status: publishe