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A disintegrin and metalloproteinase (ADAMs) are membrane-bound metalloproteases responsible for the ectodomain shedding of various transmembrane proteins and play important roles in multiple relevant biological processes. Their altered expression is involved in several pathological conditions, and in particular ADAM10 or ADAM17 overexpression is found in various forms of cancer. To better understand how they are regulated in the cellular context, it is useful to visualize the specific ADAMs pathway by means of molecular imaging techniques. For this purpose, we synthesized bioactive fluorescent probes suitable for cell imaging and that are able to specifically target ADAM10 or ADAM17. Two previously developed ADAM17- and ADAM10-selective inhibitors were chosen for conjugation, respectively, to a Cy5.5 dye and to Cy5.5 and FITC dyes. Herein we also report the synthesis of a gold-labeled compound as an additional bioimaging probe for ADAM10. The newly synthesized ligands were found to be active in vitro on human recombinant ADAM10 and/or ADAM17, showing IC 50 values in the nanomolar range and a good selectivity over matrix metalloproteinases (MMPs). Finally, these newly developed probes were successfully used for ADAMs staining on different lymphoma cell lines and lymph node mesenchymal stromal cells., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Aldose reductase (ALR2), a NADPH-dependent reductase, is the first and rate-limiting enzyme of the polyol pathway of glucose metabolism and is implicated in the pathogenesis of secondary diabetic complications. In the last decades, this enzyme has been targeted for inhibition but despite the numerous efforts made to identify potent and safe ALR2 inhibitors, many clinical candidates have been a failure. For this reason the research of new ALR2 inhibitors highly effective, selective and with suitable pharmacokinetic properties is still of great interest. In this paper some new N-(aroyl)-N-(arylmethyloxy)alanines have been synthesized and tested for their ability to inhibit ALR2. Some of the synthesized compounds exhibit IC 50 in the low micromolar range and all have proved to be highly selective towards ALR2. The N-(aroyl)-N-(arylmethyloxy)-α-alanines are a promising starting point for the development of new ALR2 selective drugs with the aim of delaying the onset of diabetic complications., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Hodgkin's lymphoma (HL) is the most common malignant lymphoma in young adults in the western world. This disease is characterized by an overexpression of ADAM-10 with increased release of NKG2D ligands, involved in an impaired immune response against tumor cells. We designed and synthesized two new ADAM-10 selective inhibitors, 2 and 3 based on previously published ADAM-17 selective inhibitor 1. The most promising compound was the thiazolidine derivative 3, with nanomolar activity for ADAM-10, high selectivity over ADAM-17 and MMPs and good efficacy in reducing the shedding of NKG2D ligands (MIC-B and ULBP3) in three different HL cell lines at non-toxic doses. Molecular modeling studies were used to drive the design and X-ray crystallography studies were carried out to explain the selectivity of 3 for ADAM-10 over MMPs., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

A disintegrin and metalloprotease (ADAM)17 is a sheddase, capable of releasing the ectodomains of membrane proteins such as growth factors (e.g. Epidermal Growth Factor Receptor ligands), cytokines and their receptors, adhesion and signaling molecules. These activities regulate several physiological and pathological processes including inflammation, tumor growth and metastatic progression. In this review, we will summarize ADAM17 biology and focus on its role in cancer and the possible usage of ADAM17 inhibitors in cancer therapy. Recent achievements in this area include the development of small molecule metalloprotease inhibitors with enhanced specificity for ADAM17, monoclonal antibodies, and synthetic short RNA molecules for gene silencing. These approaches successfully inhibited cancer cell growth and invasiveness or sensitized them to cytotoxic drugs, ionizing radiations or targeted therapies, in preclinical studies. These findings suggest the repositioning of ADAM17 inhibitors, which have yet proven unsuccessful as anti-inflammatory agents, for the development of new anti-cancer therapies, particularly in EGFR ligand-dependent cancers. Future studies should address ADAM17 inhibitors as short-term treatments in combination with different anti-cancer therapies.

Activated leukocyte cell adhesion molecule (ALCAM) is expressed at the surface of epithelial ovarian cancer (EOC) cells and is released in a soluble form (sALCAM) by ADAM-17-mediated shedding. This process is relevant to EOC cell motility and invasiveness, which is reduced by inhibitors of ADAM-17. In addition, ADAM-17 plays a key role in EGFR signaling and thus may represent a useful target in anticancer therapy. Herein we report our hit optimization effort to identify potent and selective ADAM-17 inhibitors, starting with previously identified inhibitor 1. A new series of secondary sulfonamido-based hydroxamates was designed and synthesized. The biological activity of the newly synthesized compounds was tested in vitro on isolated enzymes and human EOC cell lines. The optimization process led to compound 21, which showed an IC50 of 1.9 nM on ADAM-17 with greatly increased selectivity. This compound maintained good inhibitory properties on sALCAM shedding in several in vitro assays.

A set of hydroxamate derivatives of folic acid and methotrexate (MTX) was synthesized and evaluated for the inhibitory activity against histone deacetylase (HDAC) and dihydrofolate reductase (DHFR), two enzymes overexpressed in metastasizing tumors. The synthesized compounds were further screened for their antiproliferative activity in two human cancer cell lines, A549 (non-small cell lung carcinoma) and PC-3 (prostate adenocarcinoma). All derivatives showed significant inhibitory activity against HDACs (micromolar range) while only the MTX derivative was reasonably effective in DHFR inhibition. A docking study provided insight into the binding mode of the most potent inhibitor in the active sites of the enzymes, allowing rationalization of the bioassays. The MTX-based compound could be of interest for testing against metastasizing tumors in an animal model. The studied derivatives represent promising molecular templates for further development of dual activity anti-cancer drugs.

Matrix metalloproteinase 8 (MMP-8) has been reported to have a key role in several pathologic conditions, like heart diseases, osteoarthritis, multiple sclerosis, and various other inflammatory conditions. Therefore, there is a great interest regarding the development of MMP-8 selective inhibitors. In the recent years, immobilized enzyme reactors (IMERs) proved to be an efficient alternative to solution-based assays. Besides the recycling of the enzyme, IMER approach allows a simple way to determine affinity data and thus the ranking of inhibiting potency of the compounds under study, especially when coupled to MS. In this study, the immobilization of MMP-8 was investigated in terms of type of support, kinetic parameters, storage and pH stability. Epoxy activated silica resulted the best matrix for the preparation of an immobilized enzyme reactor (IMER) containing human MMP-8. The IMER was successfully used for the online screening of known MMP-8 inhibitors in zonal chromatography and inhibition experiments., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Activated leukocyte cell adhesion molecule (ALCAM) plays a relevant role in tumor biology and progression. Our previous studies showed that ALCAM is expressed at the surface of epithelial ovarian cancer (EOC) cells and is released in a soluble form by ADAM-17-mediated shedding. This process is relevant to EOC cell motility and invasiveness, which is reduced by nonspecific inhibitors of ADAM-17. For this reason, ADAM-17 may represent a new useful target in anticancer therapy. Herein, we report the synthesis and biological evaluation of new ADAM-17 inhibitors containing an arylsulfonamidic scaffold. Among the new potential inhibitors, two very promising compounds 17 and 18 were discovered, with a nanomolar activity for ADAM-17 isolated enzyme. These compounds proved to be also the most potent in inhibiting soluble ALCAM release in cancer cells, showing a nanomolar activity on A2774 and SKOV3 cell lines.

Matrix metalloproteinases (MMPs) and carbonic anhydrases (CAs) are two classes of zinc enzymes with different roles and catalytic targets, such as the degradation of most of the extracellular matrix (ECM) proteins and the regulation of the CO(2)/HCO(3)(-) equilibrium in the cells, respectively. Both families have isoforms which were proved to be involved in several stages of carcinogenic processes, and so the selective inhibition of these enzymes might be of interest in cancer therapy. We report herein the design, synthesis, and in vitro evaluation of a series of compounds possessing the iminodiacetic acid as the main backbone and two functional groups attached, namely, the hydroxamic acid and the arylsulfonamide (ArSO(2)NH(2)) moieties, to enable the inhibition of MMPs and CAs, respectively. These compounds were demonstrated to strongly inhibit both MMPs and CAs, some of them from the nanomolar to subnanomolar range. Furthermore, a docking study for MMPs was reported for the most promising compound in order to investigate its binding interactions with the different MMPs.

A series of sulfonylated hydroxamates were synthesized and evaluated as dual inhibitors of both human carbonic anhydrases (hCAs) and matrix metalloproteinases (MMPs), two metalloenzyme families involved in carcinogenesis and tumor invasion processes. The new derivatives were tested on three CA isozymes, the cytosolic isozymes I and II, and the transmembrane, tumor-associated isozyme IX, and also on human gelatinases (MMP-2 and MMP-9). Some of the new derivatives proved to be potent and selective inhibitors of CA II, but only compounds 3b and 6b, devoid of the arylsulfonyl moiety, proved to have a better inhibitory activity on hCA IX than on hCA I and II, in the micromolar range.

The ability of Gold software to predict the binding disposition of carbonic anhydrase (CA) inhibitors was evaluated using CA II as a case study. The best procedure was subsequently used for docking almost 300 CA II ligands, and the best poses were used as an alignment tool for the development of a 3D quantitative structure-activity relationship (QSAR) study. Evaluation of the resulting 3D-QSAR model allowed us to indicate the ligand properties and residues important for CA II inhibition. Since CAs are an important target involved in many pathologies such as glaucoma, obesity, and tumors, the results obtained could accurately predict the binding affinity of newly designed CA II inhibitors. Furthermore, it is reasonable that this strategy could be profitably used also for the investigation of other CAs.

A series of new aminopteroyl-based hydroxamate derivatives were synthesized and tested in vitro in cell culture models as potential dual target drugs. These compounds were designed to target two families of enzymes, matrix metalloproteinases (MMP) and a folate enzyme, dihydrofolate reductase (DHFR). These enzymes are the components of two unrelated cellular pathways and they are often over-expressed in metastasizing tumors. In addition to the synthesis and full structural characterization of the hybrid molecules, we describe their inhibitory activities against a series of MMPs (MMP-2, MMP-7, MMP-9, MMP-14) and DHFR, as well as their antiproliferative activity in three cancer cell lines. The new hydroxamate derivatives of MTX proved to be effective inhibitors of MMPs and DHFR in the micromolar and nanomolar range, respectively. Furthermore, they showed strong antiproliferative activity against A549 cells (non-small cell lung carcinoma), and PPC-1 and Tsu-Pr1 prostate cancer cell lines. Therefore, based on the present results, these bi-functional drugs may be good candidates to target specific tumors in animal models due to potential combined effects on two pathways crucial for tumor development.

Starting from the observation that the CbzNH(CH2)2 side chain of the potent MMP-2/MMP-14 inhibitor, benzyl-(3R)-4-(hydroxyamino)-3-[isopropoxy(1,1'-biphenyl-4-yl-sulfonyl)amino]-4-oxobutylcarbamate, (R)-1 lies in a hydrophobic region (S1) exposed to the solvent of the protease active site, we hypothesized that an aminoethylcarboxamido chain structurally related to that of (R)-1 might be an useful tool to bind another linker stretching out from the protein. This would be able to interact either with a enzyme region adjacent to the active site, or with other molecules of matrix metalloproteinases (MMPs), or other proteins of the extracellular matrix (ECM) that may be involved in the enzyme activation. On these basis we describe new dimeric compounds of type 2, twin hydroxamic acids, obtained by the joint of two drug entities of (R)-1 linked in P1 by extendable semirigid linkers. Type 2 compounds are potentially able to undergo more complex inhibitor-enzyme interactions than those occurring with monomeric compounds of type 1, thus influencing positively the potency, selectivity and/or cytotoxicity of the new compounds.

Structural manipulation of the pharmacophoric model of type A selective MMP inhibitors (MMPi), obtained by the insertion of some alkyl substituents R2 possessing an appropriate geometry, steric bulkiness and lipophilicity, is able to improve potency, in the subnanomolar range on MMP-2, and to give a good MMP inhibition on MMP-14 (MT1-MMP) in the designed MMPi of type C, while maintaining a good MMP-1/MMP-2 selectivity profile. The simultaneous inhibition of these two enzymes yields type C compounds, which are potent antiangiogenic agents, able to block a chemoinvasion model on HUVEC cells in the micromolar range.

New N-arylsulfonyl-substituted alkoxyaminoaceto hydroxamic acid derivatives of types 8 and 10 designed as oxa-analogues of known sulfonamide-based MMPi of types 2 and 7 were synthesized and tested for their inhibitory activities on some matrix metalloproteinases. The combination of a biphenylsulfonamide group with oxyamino oxygen in the pharmacophoric central skeleton of sulfonamide-based MMPi obtained in the new sulfonamides 10 seems to be able to give selectivity for MMP-2 over MMP-1. The most potent derivative of this type, 10a, shows similar anti-invasive properties to the analogue reference drug CGS27023A, 2, in an in vitro model of invasion on matrigel, carried out on cellular lines of fibrosarcoma HT1080 (tumoural cells over-expressing MMP-2 and MMP-9).

Abstract: Glioblastoma multiforme is the most commonly diagnosed malignant primary brain tumour in adults. Invasive behaviour is the pathological hallmark of malignant gliomas; consequently, its inhibition has been suggested as a therapeutic strategy. Tumour cell-derived gelatinases (matrix metalloproteinase-2, matrix metalloproteinase-9) can be considered prime factors in glioma invasiveness: their expression correlates with the progression and the degree of malignancy. Thus, broad spectrum matrix metalloproteinase inhibitors (MMP inhibitors) have been included in clinical trials. In the present study, the invasiveness, viability and progression of the human glioma cell line U87MG were investigated following treatment with N-O-isopropyl sulfonamido-based hydroxamates (compounds 1 and 2) as MMP-2 inhibitors used at nanomolar concentration. A standard broad spectrum MMP-inhibitor belonging to the classical tertiary sulfonamido-based hydroxamates family (CGS_27023A) was used too. The compounds 1 and 2 resulted in potent inhibition of cell invasiveness (P<0.0001) without affecting viability. In some clinical trials, the combined therapy of temozolomide (an alkylating agent used in glioma treatment) plus marimastat (a broad spectrum MMP inhibitor) has provided evidence of the importance of MMPs to tumor progression and invasiveness. On this basis, the effect on U87MG cells of a combined treatment with temozolomide, plus each of the two MMP inhibitors at nanomolar concentration, was investigated. The obtained data demonstrated the inhibition of cell invasiveness and viability after treatment. These results can help in developing clinical combined therapy using MMP inhibitors that, at low doses, increase the anticancer efficacy of chemotherapeutic drugs, probably without causing the side effects typical of broad-spectrum MMP inhibitors. [Copyright &y& Elsevier]