Structure-Activity Study of the Peptides P5U and Urantide by the Development of Analogues Containing Uncoded Amino Acids at Position 9.

Previous modifications of the peptide sequence of human urotensin-II (U-II) led to the identification of two well-known ligands: P5U and urantide. These derivatives are considered to be the most representative agonist and antagonist, respectively, at the human urotensin receptor (UT). Optimization of P5U and urantide was carried out to stabilize specific conformations that may suggest new elements for discriminating agonist versus antagonist activity.

Enhanced Ca(2+) response and stimulation of prostaglandin release by the bradykinin B2 receptor in human retinal pigment epithelial cells primed with proinflammatory cytokines.

Kallikrein, kininogen and kinin receptors are present in human ocular tissues including the retinal pigment epithelium (RPE), suggesting a possible role of bradykinin (BK) in physiological and/or pathological conditions. To test this hypothesis, kinin receptors expression and function was investigated for the first time in human fetal RPE cells, a model close to native RPE, in both control conditions and after treatment with proinflammatory cytokines. Results showed that BK evoked intracellular Ca(2+) transients in human RPE cells by activating the kinin B2 receptor.

Benzofused hydroxamic acids: useful fragments for the preparation of histone deacetylase inhibitors. Part 2: 7-fluorobenzothiophenes and benzofurans.

In the search for a new class of histone deacetylase inhibitors, we prepared a series of very simple benzofused hydroxamic acids to find an anchoring fragment of minimal molecular weight: they showed very good ligand efficiencies. Following these findings, classical fragment growing work was performed to increase binding energy and selective cytotoxicity. In the second phase of the work, information from the SARs of the benzothiophene series and data available in literature, we explored the in vitro pharmacological properties of the 6-substituted-7-fluoro-benzothiophene hydroxamates and the 5-susbtituted-benzofuran hydroxamates.

Lead optimization of P5U and urantide: discovery of novel potent ligands at the urotensin-II receptor.

We have optimized 1 (P5U) and urantide, two important ligands at the h-UT receptor, designing several analogues by the exchange of the Tyr9 residue with different unnatural aromatic amino acids. This study allowed us to discover novel ligands with improved activity. In particular, the replacement of the Tyr9 residue by (pCN)Phe or (pNO2)Phe within the urantide sequence led to compounds 13 (UPG-83) and 15 (UPG-95), respectively, which showed pure antagonist activity toward UT receptor in a rat aorta bioassay.

Antagonist profile of ibodutant at the tachykinin NK(2) receptor in guinea pig isolated bronchi.

In this study we have characterized the pharmacological profile of the non-peptide tachykinin NK(2) receptor antagonist ibodutant (MEN15596) in guinea pig isolated main bronchi contractility. The antagonist potency of ibodutant was evaluated using the selective NK(2) receptor agonist [βAla8]NKA(4-10)-mediated contractions of guinea pig isolated main bronchi. In this assay ibodutant (30, 100 and 300 nM) induced a concentration-dependent rightward shift of the [βAla8]NKA(4-10) concentration-response curves without affecting the maximal contractile effect.

Antagonism of bradykinin B2 receptor prevents inflammatory responses in human endothelial cells by quenching the NF-kB pathway activation.

Background: Bradykinin (BK) induces angiogenesis by promoting vessel permeability, growth and remodeling. This study aimed to demonstrate that the B2R antagonist, fasitibant, inhibits the BK pro-angiogenic effects.

Methodology: We assesed the ability of fasibitant to antagonize the BK stimulation of cultured human cells (HUVEC) and circulating pro-angiogenic cells (PACs), in producing cell permeability (paracellular flux), migration and pseocapillary formation.

MicroRNA-130b promotes tumor development and is associated with poor prognosis in colorectal cancer.

MicroRNA-130b (miR-130b) is involved in several biologic processes; its role in colorectal tumorigenesis has not been addressed so far. Herein, we demonstrate that miR-130b up-regulation exhibits clinical relevance as it is linked to advanced colorectal cancers (CRCs), poor patients' prognosis, and molecular features of enhanced epithelial-mesenchymal transition (EMT) and angiogenesis. miR-130b high-expressing cells develop large, dedifferentiated, and vascularized tumors in mouse xenografts, features that are reverted by intratumor injection of a specific antisense RNA.

Comparison between oral and intra-articular antinociceptive effect of dexketoprofen and tramadol combination in monosodium iodoacetate-induced osteoarthritis in rats.

Dexketoprofen and tramadol, alone or in combination, were evaluated after oral or intra-articular administration on knee osteoarthritis nociception induced by intra-articular (i.ar.) monosodium iodoacetate (MIA, 1 mg/25 µl) in the rat right knee while the left knee received saline (25 µl).

Characterization of a novel proinflammatory effect mediated by BK and the kinin B₂ receptor in human preadipocytes.

Obesity and adipose tissue contribute to local and systemic inflammation. However the role of the inflammatory mediator bradykinin (BK) in this context is not known. We therefore evaluated the effect of BK on adipokines secretion in human preadipocytes during the course of differentiation and characterized the receptors involved.

Benzofused hydroxamic acids: useful fragments for the preparation of histone deacetylase inhibitors. Part 1: hit identification.

In the search for a new class of histone deacetylase inhibitors, we prepared a series of simple benzofused hydroxamic acids to find an anchoring fragment of minimal molecular weight. These initial hits, all belonging to the benzothiophene class, showed very good ligand efficiencies. Following these findings, a classical fragment growing approach was performed to increase binding affinity and cytotoxicity.

New insight into the binding mode of peptides at urotensin-II receptor by Trp-constrained analogues of P5U and urantide.

Urotensin II (U-II) is a disulfide bridged peptide hormone identified as the ligand of a G-protein-coupled receptor. Human U-II (H-Glu-Thr-Pro-Asp-c[Cys-Phe-Trp-Lys-Tyr-Cys]-Val-OH) has been described as the most potent vasoconstrictor compound identified to date. We have recently identified both a superagonist of human U-II termed P5U (H-Asp-c[Pen-Phe-Trp-Lys-Tyr-Cys]-Val-OH) and the compound termed urantide (H-Asp-c[Pen-Phe-D-Trp-Orn-Tyr-Cys]-Val-OH), which is the most potent UT receptor peptide antagonist described to date.

Abagovomab as maintenance therapy in patients with epithelial ovarian cancer: a phase III trial of the AGO OVAR, COGI, GINECO, and GEICO--the MIMOSA study.

Purpose: To determine whether abagovomab maintenance therapy prolongs recurrence-free (RFS) and overall survival (OS) in patients with ovarian cancer in first clinical remission.

Patients And Methods: Patients with International Federation of Gynecology and Obstetrics stage III to IV ovarian cancer in complete clinical remission after primary surgery and platinum- and taxane-based chemotherapy were randomly assigned at a ratio of 2:1 in a phase III, double-blind, placebo-controlled, multicenter study. Abagovomab 2 mg or placebo was administered as 1-mL suspension once every 2 weeks for 6 weeks (induction phase) and then once every 4 weeks (maintenance phase) until recurrence or up to 21 months after random assignment of the last patient.

OC125, M11 and OV197 epitopes are not uniformly distributed in the tandem-repeat region of CA125 and require the entire SEA domain.

The human cancer antigen 125 (CA125) is over-expressed in epithelial ovarian cancer cells and it plays a role in the pathogenesis of ovarian cancer. This protein presents a repeat region containing up to sixty tandem repeat units. The anti-CA125 monoclonal antibodies have been previously classified into three groups: two major families, the OC125-like antibodies and M11-like antibodies, and a third group, the OV197-like antibodies.

Characterization of ibodutant at NK(2) receptor in human colon.

We have characterized the pharmacological profile of the nonpeptide tachykinin NK2 receptor antagonist ibodutant (MEN15596) through radioligand binding and contractility assays in the human colon smooth muscle. The antagonist affinity of ibodutant was evaluated through concentration-dependent inhibition curves at the [(125)I]NKA specific binding by using membranes prepared from human colon smooth muscle. In this assay the affinity of ibodutant (pKi 9.

Set-up of a new series of HDAC inhibitors: the 5,11-dihydrodibenzo[b,e]azepin-6-ones as privileged structures.

We report here the strategy used in our research group to find a new class of histone deacetylase (HDAC) inhibitors. A series of 5,11-dihydrodibenzo[b,e]azepine-6-ones alkylated on the amide nitrogen with an alkyl chain bearing an hydroxamic acids moiety at the end, has been designed (based upon the general motif for HDAC inhibitors), synthesized and tested. This allowed us to identify a new series of submicromolar HDAC inhibitors, which showed antiproliferative activity on HCT-116 colon carcinoma cells.

SAHA/Vorinostat induces the expression of the CD137 receptor/ligand system and enhances apoptosis mediated by soluble CD137 receptor in a human breast cancer cell line.

HDAC inhibitors (HDACis) represent a class of anticancer agents including suberoylanilide hydroxamic acid (SAHA, Vorinostat), which has shown a strong antitumor effect, both in vitro and in vivo. Induction of apoptotic genes is an important pathway of SAHA cytotoxic mechanism of action and it has been largely described that SAHA induces sensitization of cell death receptor-resistant breast cancer cells to apoptosis. In this study, we investigated the activation of some apoptotic genes which could be responsible for the in vivo antitumor potency of SAHA in a model of human breast cancer.

Design and synthesis of novel sulfonamide-containing bradykinin hB(2) receptor antagonists. Synthesis and structure-relationships of α,α-tetrahydropyranylglycine.

A series of α,α-cycloalkylglycine sulfonamide compounds of general formula 1 has previously been identified by our group as selective human B(2)(hB(2)) receptor antagonists. Here we report the in vitro and in vivo BK antagonist activity of a further evolution of the series, consisting in compounds of the general formula 2, containing either an alkyl piperazine or a 4-alkyl piperidine ring bearing various positively charged groups (R'). These studies unexpectedly revealed quite a flat nanomolar/subnanomolar SAR for the binding affinity, while differences were seen in the in vitro functional activities.

Fasitibant chloride, a kinin B₂ receptor antagonist, and dexamethasone interact to inhibit carrageenan-induced inflammatory arthritis in rats.

Background And Purpose: Bradykinin, through the kinin B₂ receptor, is involved in inflammatory processes related to arthropathies. B₂ receptor antagonists inhibited carrageenan-induced arthritis in rats in synergy with anti-inflammatory steroids. The mechanism(s) underlying this drug interaction was investigated.

4-N-Hydroxy-4-[1-(sulfonyl)piperidin-4-yl]-butyramides as HDAC inhibitors.

A series of N-substituted 4-alkylpiperidine hydroxamic acids, corresponding to the basic structure of histone deacetylase (HDAC) inhibitors (zinc binding moiety-linker-capping group) has been previously reported by our group. Linker length and aromatic capping group connection were systematically varied to find the optimal geometric parameters. A new series of submicromolar inhibitors was thus identified, which showed antiproliferative activity on HCT-116 colon carcinoma cells.

Alkyl piperidine and piperazine hydroxamic acids as HDAC inhibitors.

We report here the strategy used in our research group to find a new class of histone deacetylase (HDAC) inhibitors. A series of N-substituted 4-alkylpiperazine and 4-alkylpiperidine hydroxamic acids, corresponding to the basic structure of HDAC inhibitors (zinc binding moiety-linker-capping group) has been designed, prepared, and tested for HDAC inhibition. Linker length and aromatic capping group connection were systematically varied to find the optimal geometric parameters.

Maintenance therapy in ovarian cancer: Molecular basis and therapeutic approach.

Ovarian cancer has the highest mortality rate among gynaecological tumours despite the fact that the majority of patients with advanced disease achieve complete remission after first-line surgery and chemotherapy. Unfortunately, disease recurrence occurs in the majority of patients and second-line treatments are not curative. Clearly, the persistence of dormant and drug-resistant cells after front-line treatments results in the inability to cure the disease.

hNK2 receptor antagonists. The use of intramolecular hydrogen bonding to increase solubility and membrane permeability.

Starting from in-house capped tripeptide libraries, we have developed two series of compounds as potent antagonists of the hNK(2) receptor with a reduced peptide character. These two series maintained a crucial amide bond, which could not be methylated or substituted with classical isostere without a dramatic loss in binding affinity, very likely due conformational changes. We report here the planning, synthesis and evaluation of molecules belonging to the selected chemical series, which contain a strategically placed hydrogen bond acceptor.

Antiproliferative and differentiating activities of a novel series of histone deacetylase inhibitors.

Histone deacetylases are promising molecular targets for the development of antitumor agents. A novel series of histone deacetylase inhibitors of the hydroxamic acid type were synthesized for structure-activity studies. Thirteen tricyclic dibenzo-diazepine, -oxazepine, and -thiazepine analogues were studied and shown to induce variable degrees of histone H3/H4 and tubulin acetylation in a cellular model of myeloid leukemia sensitive to all-trans retinoic acid (ATRA).

Induction of a less aggressive phenotype in human colon carcinoma HCT116 cells by chronic exposure to HDAC inhibitor SAHA.

Histone deacetylase inhibitors (HDACis) are anticancer molecules that epigenetically modulate cell functions. Chronic exposure of HCT116 colon cancer cells to SAHA has been investigated for a better understanding of resistance mechanisms but, surprisingly, a less aggressive tumor phenotype both in vitro and in vivo was obtained after exposure to increasing concentrations of SAHA. Indeed, HCT116/SAHA cells when injected into nude mice showed a reduced engraftment and growth with respect to HCT116 cells.

Differences between zofenopril and ramipril, two ACE inhibitors, on cough induced by citric acid in guinea pigs: role of bradykinin and PGE2.

Dry and persistent cough is one of the commonest side effects experienced by patients treated with angiotensin-converting enzyme (ACE) inhibitors for the therapy of hypertension and congestive heart failure. The present study investigated the effect of zofenopril and ramipril on cough induced by citric acid in guinea pig and the involvement of bradykinin (BK) and prostaglandin E2 (PGE2) in mediating the responses of these drugs. Zofenopril (10 mg/kg) or ramipril (3-10 mg/kg), which is threefold more potent than zofenopril, on a mg basis, in lowering blood pressure, was orally administered daily in drinking water for 2 weeks.