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5-Hydroxy-L-tryptophan (5-HTP) is a serotonin pathway metabolite of L-tryptophan in the brain. In the knowledge that the biological properties of some compounds can be modified upon metal complexation, a new solid metal complex, [Cu(5-hydroxytryptophan) 2 ].H 2 O (Cu5HTP), has been synthesized and characterized to analyze the modification of some biological properties. The conformational investigations (optimized in gas phase at B3LYP/6-311G** theory level) suggest the coexistence of two conformers of Cu5HTP with cis- and trans- arrangements of the amino acids in the equatorial plane. The trans- Cu5HTP1 complex is the most stable conformer. The complexation led to an enhancement of the antioxidant properties of the ligand. The metal complex also improved the anticancer behavior of the ligand (tested in cancer cell lines derived from human lung (A549), cervix (HeLa) and colon (HCT-116)). It did not show toxicity against either the non-malignant human lung fibroblast (MRC-5) cell line or Artemia salina and did not behave as mutagenic agent (Ames test). Cellular reactive oxygen species production may be one of the possible mechanisms of action. Besides, the metal complex exerted neuroprotective action on cortical neurons from embryonic 18 days rats exposed to glutamate. Fil: Martínez Medina, Juan José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Chaco Austral; Argentina Fil: Naso, Luciana Gissella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Pérez, Ana Laura. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Rizzi, Alberto Claudio. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Okulik, Nora Beatriz. Universidad Nacional del Chaco Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Valcarcel, María. Innoprot Sl; España Fil: Salado, Clarisa. Innoprot Sl; España Fil: Ferrer, Evelina Gloria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Williams, Patricia Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina

We present a versatile and scalable method for the preparation of microfluidic channels with incorporated nano patterns. Since our approach is highly industrial driven, all used methods and materials are available in common micro-fabrication environment and are available in large quantities, respectively. In comparison to other fabrication methods capable of realizing multi-level patterns, we combine nanoimprint lithography with standard photolithography, and thereby overcome the problems of limited pattern dimensions as well as fabrication time, pathing the way for a new class of microfluidic devices.

The UV-nanoimprint lithography(UV-NIL) fabrication of a novel network of micron-sized channels, forming an open channel microfluidic system is described. Details about the complete manufacturing process, from mastering to fabrication in small batches and in high throughput with up to 1200 micro titer plates per hour is presented. Deep insight into the evaluation of a suitable UV-curable material, mr-UVCur26SF is given, presenting cytotoxic evaluation, cell compatibility tests and finally a neuronal assay. The results indicate how the given pattern, in combination with the resist, paves the way to faster, cheaper, and more reliable drug screening. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement NO. 646260. The research was also partially supported by NextGenMicrofluidics project under HORIZON2020 with grant agreement no 862092.

Nomad Technology (Innoprot [Innovative Technologies in Biological Systems], Derio, Spain), a novel tool for multiplexing high-throughput cell-based G protein-coupled receptor (GPCR) assays, is described in this work. This new technology comprises a family of fluorescent biosensors called Nomad Biosensors that allow for the measurement of responses mediated by G proteins through their interactions with second-messenger transduction proteins. GPCRs are one of the largest protein families of receptors in eukaryotes, and their signaling mediates important physiological processes within cells. Thus, GPCRs are associated with a wide variety of diseases, and considered major targets in therapeutic research. Nomad constitutes a novel tool for unraveling the mechanism of GPCR signal transduction by simultaneously tracing different pathways. GPCR activation changes the structural folding of the biosensor and promotes its vesicularization, as well as an increase in the fluorescence intensity. Based on this technology, the MPXNomad cellular model was developed to discriminate between the Ca2+-mediated pathway and the cyclic adenosine monophosphate (cAMP)-mediated pathway. To validate this model, endothelin receptor B (ETBR) was coexpressed into the MPXNomad cell line and assessed with a specific agonist, an antagonist, and a chemical library of compounds. Nomad Technology optimizes the identification of novel GPCR ligands and enables the testing of large numbers of compounds.

Chemotherapy using metal coordination compounds for cancer treatment is the work of the ongoing research.Continuing our research on the improvement of the anticancer activity of natural flavonoids by metal complexation,a coordination compound of the natural antioxidant flavone luteolin (lut) and the oxidovanadium(IV) cationhas been synthesized and characterized. Using different physicochemical measurements some structural aspects of [VO(lut)(H2O)2]Na·3H2O (VOlut) were determined. The metal coordinated to two cis-deprotonated oxygen atoms (ArO−) of the ligand and two H2O molecules. Magnetic measurements in solid state indicatedthe presence of an effective exchange pathway between adjacent vanadiumions. VOlut improved the antioxidant capacity of luteolin only against hydroxyl radical. The antitumoral effects were evaluated on MDAMB231 breastcancer and A549 lung cancer cell lines. VOlut exhibited higher viability inhibition (IC50=17 μM) than the ligand on MDAMB231 cells but they have the same behavior on A549 cells (ca. IC50=60 μM). At least oxidative stressprocesses were active during cancer cell-killing. When metals chelated through the carbonyl group and one adjacent OH group of the flavonoid an effective improvement of the biological properties has been observed. In VOlut the different coordination may be the cause of the small improvement of some of the tested properties of the flavonoid. Luteolin and VOlut could be distributed and transported in vivo. Luteolin interacted in the microenvironment of the tryptophan group of the serum binding protein, BSA, by means of electrostatic forces and its complex bind the protein by H bonding and van derWaals interactions. Fil: Naso, Luciana Gissella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Lezama, Luis. Universidad del País Vasco; España. Parque científico y Tecnológico de Bizkaia; España Fil: Valcarcel, María. Parque científico y Tecnológico de Bizkaia; España Fil: Salado, Clarisa. Parque científico y Tecnológico de Bizkaia; España Fil: Villacé, Patricia. Parque científico y Tecnológico de Bizkaia; España Fil: Kortazar, Danel. Parque científico y Tecnológico de Bizkaia; España Fil: Ferrer, Evelina Gloria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Williams, Patricia Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina

Purpose To assess the effect of somatostatin (SST) on the permeability of human retinal pigment epithelial cells. Methods We conducted two experiments, exposing cells from human-fetal retinal pigment epithelium (hfRPE) cultures to vascular endothelial growth factor (VEGF), with or without SST pretreatment, in one, and to hypoxic conditions, again with or without SST pretreatment, in the other. The paracellular permeability of hfRPE was assessed by measuring transepithelial electrical resistance (TER) and fluorescein isothiocyanate-sodium (FITC-sodium) flux. Immunochemistry analysis was used to assess the expression of occludin and Zonula occludens-1(ZO-1). Results Both VEGF and hypoxia increased permeability of the hfRPE, as measured by TER and tracer flux, and decreased occludin and ZO-1staining, as measured by immunochemistry. Pretreatment of cultures with SST partially counteracted these effects. Conclusions Somatostatin may play a role in the regulation of permeability across retinal pigment epithelium. It may act as an anti-permeability factor in the retina through the enhancement of tight junction function.

The anticancer and antimetastatic behavior of the flavonoid luteolin and its oxidovanadium(IV) complex [VO(lut)(H2O)2]Na.3H2O (VOlut) has been investigated. Considering that the complex displayed strong anticancer activity on MDAMB231 human breast cancer cell line we herein determined through in vitro assays that the complex would probably reduce breast cancer cell metastasis in a higher extent than the natural antioxidant. In the CT26 colon cancer cell line a stronger anticancer effect has also been determined for the complex (IC50 0.9 μM) and in addition it did not exert toxic effects on normal colon epithelial cells at concentrations up to 10 µM. Working with a murine model of highly aggressive, orthotopic colon cancer model (CT26 cancer cell lines) it has been determined that the complex might prevent metastatic dissemination of the colon cancer cells to the liver. The flavonoid luteolin also exerted anticancer effects (at a low degree, IC50 5.9 μM) on CT26 cell line and produced a 24% reduction of colon cancer liver metastasis. Fil: Naso, Luciana Gissella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Badiola, Iker. Universidad del País Vasco; España Fil: Marquez Clavijo, Joana. Universidad del País Vasco; España Fil: Valcarcel, María. Parque científico y Tecnológico de Bizkaia; España Fil: Salado, Clarisa. Parque científico y Tecnológico de Bizkaia; España Fil: Ferrer, Evelina Gloria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Williams, Patricia Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina

Parkinson disease (PD) is a prevalent neurodegenerative disease characterized by selective degeneration of dopaminergic neurons in the substantia nigra, causing tremor and motor impairment. Parkin protein, whose mutants are the cause of Parkinson disease type 2 (PARK2), has been mechanistically linked to the regulation of apoptosis and the turnover of damaged mitochondria. Several studies have implicated aberrant mitochondria as a key contributor to the development of PD. In the attempt to discover new drugs, high-content cell-based assays are becoming more important to mimic the nature of biological processes and their diversifications in diseases and will be essential for lead identification and the optimization of therapeutic candidates. We have developed a novel fluorescence cell-based assay for high-content screening to find compounds that can promote the mitochondrial localization of Parkin without severe mitochondrial damage induction. In this work, this model was used to screen a library of 1280 compounds. After the screening campaign, the positive compounds were chosen for further testing, based on the strength of the initial response and lack of cytotoxicity. These results indicated that this Parkin cell-based assay is a robust (Z' > 0.5) and valid strategy to test potential candidates for preclinical studies.

The natural antioxidant flavonoid diosmin, found in citric fruits, showed low antioxidant properties among other flavonoids due to its structural characteristics and low cytotoxicity against lung (A549) and breast (T47D, SKBR3 and MDAMB231) cancer cell lines. The anticancer behavior has been improved by the metal complex generated with the flavonoid and the oxidovanadium(IV) ion. This new complex, [VO(dios)(OH)3]Na5·6H2O (VOdios), has been synthesized and characterized both in solid and solution states. The interaction of the metal ion through the sugar moiety of diosmin precluded the improvement of the antioxidant effects. However, the cell-killing effects tested in human lung A549 and breast T47D, SKBR3 and MDAMB231 cancer cell lines, were enhanced by complexation. The anti-proliferative effects on the human lung cancer cell line were accompanied by cellular ROS generation and an increase in cytoplasm condensation. The breast cancer cell lines did not produce caspase3/7 activation, mitochondrial potential reduction and ROS generation. Therefore, a non-apoptotic form of cell death in a caspase- and oxidative stress-independent manner has been proposed. The protein binding ability has been monitored by the quenching of tryptophan emission in the presence of the compounds using bovine serum albumin (BSA) as a model protein. Both compounds could be distributed and transported in vivo and the complex displayed stronger binding affinity and higher contributions to the hydrogen bond and van der Waals forces. Fil: Naso, Luciana Gissella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Martinez, Valeria Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Lezama, Luis. Universidad del País Vasco; España. Parque científico y Tecnológico de Bizkaia; España Fil: Salado, Clarisa. Parque científico y Tecnológico de Bizkaia; España Fil: Valcarcel, María. Parque científico y Tecnológico de Bizkaia; España Fil: Ferrer, Evelina Gloria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Williams, Patricia Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina

Parkinson?s disease (PD) involves the generation of dopaminergic (DA) neurons in the substantia nigra, causing tremor and motor impairment. Defects in PARK2 protein are the cause of Parkinson?s disease type 2 (PARK2), also known as early-onset parkinsonism with diurnal fluctuation (EPDF) or autosomal recessive juvenile Parkinson?s disease (PDJ). In mouse model, Parkin is critical for removing dysfunctional mitochondria via autophagy. The absence of Parkin does not affect turnover under normal conditions. However, during stress conditions, Parkin helps to remove damaged mitochondria by autophagy. Innoprot has developed a novel fluorescence cell-based assay for High Content Screening to screen compounds that can promote Parkin2 mithocondrial localization without mitochondrial stress induction. In this work, we used this model to screen a library of 1200 compounds. After the screening campaign, the positive compounds were chosen for further testing, based on the strength of the initial response and the lack of cytotoxicity. Our results indicate that Parkin2 cell-based assay is a valid strategy for drug screening.

Solid lipid nanoparticles (SLN) composed of long-chain fatty acids (palmitic acid, stearic acid or arachidic acid), Epikuron 200 (purified phosphatidylcholine), and bile salts (cholate, taurocholate or taurodeoxycholate) have been prepared by dilution of a microemulsion. A total of five different systems were prepared, and characterized by photon correlation spectroscopy, transmission electron microscopy, differential scanning calorimetry, and infrared spectroscopy. The SLN formulation showing optimal properties (lowest size and polydispersity index and highest zeta potential) was obtained with stearic acid and taurodeoxycholate as cosurfactant. This formulation was loaded with Calendula officinalis extract, a natural compound used on ophthalmic formulations given its anti-inflammatory, emollient, and wound repairing activity. Calendula-loaded SLN preparations were characterized in order to determine loading capacity and entrapment efficiency. In vitro cytotoxicity and wound healing efficacy of Calendula-loaded SLN compared to that of a free plant extract were evaluated on a conjunctival epithelium cell line WKD. Our results suggest that this SLN formulation is a safe and solvent-free Calendula extract delivery system which could provide a controlled therapeutic alternative for reducing disease-related symptoms and improving epithelium repair in ocular surface.

A new chlorogenate oxidovanadium complex (Na[VO(chlorog)(H 2O)3].4H2O) was synthesized by using Schlenk methodology in the course of a reaction at inert atmosphere in which deprotonated chlorogenic acid ligand binds to oxidovanadium(IV) in a reaction experiment controlled via EPR technique and based in a species distribution diagram. The compound was characterized by FTIR, EPR, UV-visible and diffuse reflectance spectroscopies and thermogravimetric, differential thermal and elemental analyses. The ligand and the complex were tested for their antioxidant effects on DPPH (1,1-diphenyl-2-picrylhydrazyl radical), ABTS+ (radical cation of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), O2-, OH and ROO radicals and their cytotoxic activity on different cancer cell lines (SKBR3, T47D and MDAMB231) and primary human mammary epithelial cells. The complex behaved as good antioxidant agent with strongest inhibitory effects on O2-, OH and ROO radicals and exhibited selective cytotoxicity against SKBR3 cancer cell line. Albumin interaction experiments denoted high affinity toward the complex and its calculated binding constant was indicative of a strong binding to the protein. Based on this study, it is hypothesized that Na[VO(chlorog)(H 2O)3].4H2O would be a promising candidate for further evaluation as an antioxidant and anticancer agent. Fil: Naso, Luciana Gissella. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentina Fil: Valcarcel, María. Innoprot Sl; Fil: Roura-Ferrer, Meritxell. Innoprot Sl; Fil: Kortazar, Danel. Innoprot Sl; Fil: Salado, Clarisa. Innoprot Sl; Fil: Lezama, Luis Raul. Universidad del País Vasco; España Fil: Rojo, Teofilo. Universidad del País Vasco; España Fil: Gonzalez Baro, Ana Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentina Fil: Williams, Patricia Ana María. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentina Fil: Ferrer, Evelina Gloria. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentina

The structure–activity relationships of the natural flavonoids quercetin, chrysin and silibinin have revealed that they meet the key structural requirements for killing tumor cells. When the structures of these three flavonoids are modified by complexation using the oxovanadium(IV) cation their cytotoxic properties in human breast cancer cell lines are enhanced. Breast epithelial cells are used to determine the selectivity of these compounds. The mechanisms of action of the flavonoids and the oxovanadium(IV) cation in the MDA-MB231 cell line seem to be different to the apoptotic mechanisms of cell death exerted by the oxovanadium(IV) complexes. These results showed the mechanisms of the antitumoral effect of these complexes, making them promising compounds for cancer treatment. Fil: Naso, Luciana Gissella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Varcarcel, Maria. Innoprot SL; España Fil: Villace, Patricia. Innoprot SL; España Fil: Roura Ferrer, Meritxell. Innoprot SL; España Fil: Salado, Clarisa. Innoprot SL; España Fil: Ferrer, Evelina Gloria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Williams, Patricia Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina

The mechanism of intrasinusoidal arrest of circulating cancer cells, which is a critical step in liver metastasis, appears to be facilitated by tumor-derived proinflammatory factors that increase sinusoidal cell adhesion receptors for cancer cells. However, how this prometastatic microenvironment is up-regulated remains unknown. Using intrasplenically injected B16 melanoma (B16M) cells, we show that the expression of vascular cell adhesion molecule-1 (VCAM-1) significantly increased in hepatic sinusoidal endothelium (HSE) cells over physiologic baseline within the first 24 hours of metastatic cancer cell infiltration in the liver. This correlated with increased in vitro adhesion of B16M cells to HSE cells isolated from B16M cell-injected mice. In vivo VCAM-1 blockade with specific antibodies before B16M cell injection decreased sinusoidal retention of luciferase-transfected B16M cells by 85%, and metastasis development by 75%, indicating that VCAM-1 expression on tumor-activated HSE cells had a prometastatic contribution. Because VCAM-1 expression is oxidative stress-inducible, recombinant catalase was in vivo administered, resulting in a complete abrogation of both VCAM-1 expression and B16M cell adhesion increases in HSE cells isolated from B16M cell-injected mice. Catalase also abrogated the proadhesive response of HSE cells to B16M-conditioned medium (B16M-CM) in vitro, although this did not affect the concomitant release of major proinflammatory cytokines by HSE cells. HSE cells treated with B16M-CM released interleukin (IL)-18 via tumor necrosis factor-alpha (TNF-alpha)-dependent IL-1beta in vitro. In turn, H(2)O(2) production from B16M-CM-treated HSE cells was regulated by IL-18. Thus, liver-infiltrating B16M cells activated their adhesion to HSE through a sequential process involving TNF-alpha-dependent IL-1beta, which induced IL-18 to up-regulate VCAM-1 via H(2)O(2). The pivotal position of H(2)O(2) was further supported by the fact that incubation of HSE cells with nontoxic concentrations of H(2)O(2) directly enhanced VCAM-1-dependent B16M cell adhesion in vitro without proinflammatory cytokine mediation, which emphasizes the key role of oxidative stress in the pathogenesis of liver inflammation and metastasis.

It is known that flavonoids possess, among others, antioxidant and antitumoral properties that depend on their molecular structure. The central objective if this study was to investigate the potential antioxidant and antiproliferative properties of the flavonol morin and its new oxovanadium(IV) complex (VOmor) that was synthesized in order to modify the morin chemical structure. Two osteoblast (UMR106 and MC3T3E1), two breast tumor (T47D and SKBR3) and breast epithelial cell lines in culture were used for the antitumoral determinations. Additionally, a comparative study of their antioxidant capacities using different radicals (DPPH, ABTS+, OH, O2−, ROO) was performed. Selected mechanisms of action were studied using the breast cancer cell lines. Results obtained show that morin and its complex behaved as good antioxidant agents for some of the radicals and that the complexation improved the behavior with respect to OH and O2− radicals being morin more effective as ROO scavenger. A considerable variation in sensitivity was observed in the breast cancer cells but non-specificity was found for the treatment of osteosarcoma. Moreover, the compounds did not affect the normal proliferation of the breast epithelial mammal cells. The mechanistic studies demonstrated that the complex did not generate reactive oxygen species in the cells (confirming the in vitro studies) and did not produce any damage of DNA. The plasmatic membrane was observed to be damaged only in the SKBR3 cell line. In contrast, the perturbation of the mitochondrial membrane potential and the activation of caspase 3/7 for the breast tumor cells revealed an apoptotic cell death process. All these results collectively suggested that VOmor complex could serve as promising pharmacologically active substance against breast cancer treatment. Fil: Naso, Luciana Gissella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Lezama, Luis Raul. Universidad del País Vasco; España Fil: Rojo, Teófilo. Universidad del País Vasco; España Fil: Etcheverry, Susana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina. Universidad Nacional de la Plata. Facultad de Cs.exactas. Departamento de Cs.biológicas. Cátedra Bioquímica Patologica; Argentina Fil: Valcarcel, Maria. Innoprot SL; España Fil: Roura, Meritxell. Innoprot SL; España Fil: Salado, Clarisa. Innoprot SL; España Fil: Ferrer, Evelina Gloria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina Fil: Williams, Patricia Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina

Background Human melanoma frequently colonizes bone marrow (BM) since its earliest stage of systemic dissemination, prior to clinical metastasis occurrence. However, how melanoma cell adhesion and proliferation mechanisms are regulated within bone marrow stromal cell (BMSC) microenvironment remain unclear. Consistent with the prometastatic role of inflammatory and angiogenic factors, several studies have reported elevated levels of cyclooxygenase-2 (COX-2) in melanoma although its pathogenic role in bone marrow melanoma metastasis is unknown. Methods Herein we analyzed the effect of cyclooxygenase-2 (COX-2) inhibitor celecoxib in a model of generalized BM dissemination of left cardiac ventricle-injected B16 melanoma (B16M) cells into healthy and bacterial endotoxin lipopolysaccharide (LPS)-pretreated mice to induce inflammation. In addition, B16M and human A375 melanoma (A375M) cells were exposed to conditioned media from basal and LPS-treated primary cultured murine and human BMSCs, and the contribution of COX-2 to the adhesion and proliferation of melanoma cells was also studied. Results Mice given one single intravenous injection of LPS 6 hour prior to cancer cells significantly increased B16M metastasis in BM compared to untreated mice; however, administration of oral celecoxib reduced BM metastasis incidence and volume in healthy mice, and almost completely abrogated LPS-dependent melanoma metastases. In vitro, untreated and LPS-treated murine and human BMSC-conditioned medium (CM) increased VCAM-1-dependent BMSC adherence and proliferation of B16M and A375M cells, respectively, as compared to basal medium-treated melanoma cells. Addition of celecoxib to both B16M and A375M cells abolished adhesion and proliferation increments induced by BMSC-CM. TNFα and VEGF secretion increased in the supernatant of LPS-treated BMSCs; however, anti-VEGF neutralizing antibodies added to B16M and A375M cells prior to LPS-treated BMSC-CM resulted in a complete abrogation of both adhesion- and proliferation-stimulating effect of BMSC on melanoma cells. Conversely, recombinant VEGF increased adherence to BMSC and proliferation of both B16M and A375M cells, compared to basal medium-treated cells, while addition of celecoxib neutralized VEGF effects on melanoma. Recombinant TNFα induced B16M production of VEGF via COX-2-dependent mechanism. Moreover, exogenous PGE2 also increased B16M cell adhesion to immobilized recombinant VCAM-1. Conclusions We demonstrate the contribution of VEGF-induced tumor COX-2 to the regulation of adhesion- and proliferation-stimulating effects of TNFα, from endotoxin-activated bone marrow stromal cells, on VLA-4-expressing melanoma cells. These data suggest COX-2 neutralization as a potential anti-metastatic therapy in melanoma patients at high risk of systemic and bone dissemination due to intercurrent infectious and inflammatory diseases.

Background Implantation and growth of metastatic cancer cells at distant organs is promoted by inflammation-dependent mechanisms. A hepatic melanoma metastasis model where a majority of metastases are generated via interleukin-18-dependent mechanisms was used to test whether anti-inflammatory properties of resveratrol can interfere with mechanisms of metastasis. Methods Two experimental treatment schedules were used: 1) Mice received one daily oral dose of 1 mg/kg resveratrol after cancer cell injection and the metastasis number and volume were determined on day 12. 2) Mice received one daily oral dose of 1 mg/kg resveratrol along the 5 days prior to the injection of cancer cells and both interleukin-18 (IL-18) concentration in the hepatic blood and microvascular retention of luciferase-transfected B16M cells were determined on the 18th hour. In vitro, primary cultured hepatic sinusoidal endothelial cells were treated with B16M-conditioned medium to mimic their in vivo activation by tumor-derived factors and the effect of resveratrol on IL-18 secretion, on vascular cell adhesion molecule-1 (VCAM-1) expression and on tumor cell adhesion were studied. The effect of resveratrol on melanoma cell activation by IL-18 was also studied. Results Resveratrol remarkably inhibited hepatic retention and metastatic growth of melanoma cells by 50% and 75%, respectively. The mechanism involved IL-18 blockade at three levels: First, resveratrol prevented IL-18 augmentation in the blood of melanoma cell-infiltrated livers. Second, resveratrol inhibited IL-18-dependent expression of VCAM-1 by tumor-activated hepatic sinusoidal endothelium, preventing melanoma cell adhesion to the microvasculature. Third, resveratrol inhibited adhesion- and proliferation-stimulating effects of IL-18 on metastatic melanoma cells through hydrogen peroxide-dependent nuclear factor-kappaB translocation blockade on these cells. Conclusions These results demonstrate multiple sites for therapeutic intervention using resveratrol within the prometastatic microenvironment generated by tumor-induced hepatic IL-18, and suggest a remarkable effect of resveratrol in the prevention of inflammation-dependent melanoma metastasis in the liver.

Hepatic stellate cells are perisinusoidal fibroblasts that transdifferentiate into myofibroblasts in response to paracrine factors released from cancer cells and cancer-activated endothelial cells. Tumor-associated myofibroblasts exhibit contractility, proliferation, production of extracellular matrix molecules and metalloproteases. They secrete soluble factors inducing proinflammatory and immune suppressant effects. Myofibroblasts are present in avascular micrometastasis prior to endothelial cell recruitment, and act as supporting stroma for tumor neoangiogenesis. In replacement-type cancer growth, the reticular arrangement of tumor-associated myofibroblasts provides a sinusoidal-type angiogenic pattern. In pushing-type cancer growth, fibrous tract-forming myofibroblasts support a portal-type angiogenic pattern. Additionally, tumor-activated myofibroblasts support cancer development via paracrine release of tumor invasion and proliferation-stimulating factors. In summary, this information suggests that the ability of cancer cells to activate hepatic stellate cells and to collaborate with myofibroblasts along the metastatic process may represent a key phenotypic property of liver-colonizing cancer cells. On the other hand, experimental anti-tumor and anti-angiogenic agents have inhibited intrametastatic recruitment and proangiogenic activities of hepatic myofibroblasts, suggesting that targeting tumorigenic effects of these cells may contribute to hepatic metastasis inhibition.

Interleukin-18 (IL-18, interferon [IFN]-gamma-inducing factor) is a proinflammatory cytokine converted to a biologically active molecule by interleukin (IL)-1beta converting enzyme (caspase-1). A wide range of normal and cancer cell types can produce and respond to IL-18 through a specific receptor (IL-18R) belonging to the toll-like receptor family. The activity of IL-18 is regulated by IL-18-binding protein (IL-18bp), a secreted protein possessing the ability to neutralize IL-18 and whose blood level is affected by renal function and is induced by IFNgamma. IL-18 plays a central role in inflammation and immune response, contributing to the pathogenesis and pathophysiology of infectious and inflammatory diseases. Because immune-stimulating effects of IL-18 have antineoplastic properties, IL-18 has been proposed as a novel adjuvant therapy against cancer. However, IL-18 increases in the blood of the majority of cancer patients and has been associated with disease progression and, in some cancer types, with metastatic recurrence risk and poor clinical outcome and survival. Under experimental conditions, cancer cells can also escape immune recognition, increase their adherence to the microvascular wall and even induce production of angiogenic and tumor growth-stimulating factors via IL-18-dependent mechanism. This is particularly visible in melanoma cells. Thus, the role of IL-18 in cancer progression and metastasis remains controversial. This review examines the clinical correlations and biological effects of IL-18 during cancer development and highlights recent experimental insights into prometastatic and proangiogenic effects of IL-18 and the use of IL-18bp against cancer progression.

We investigated effects of endostatin (ES) in the prometastatic microenvironment of inflammation occurring during the microvascular phase of cancer cell infiltration in the liver. We used a model of intrasplenic injection of B16 melanoma (B16M) cells leading to hepatic metastasis through vascular cell adhesion molecule-(VCAM-1)-mediated capillary arrest of cancer cells via interleukin-18 (IL-18)-dependent mechanism. We show that administration of 50 mg/kg recombinant human (rh) ES 30 min before B16M, plus repetition of same dose for 3 additional days decreased metastasis number by 60%. A single dose of rhES before B16M injection reduced hepatic microvascular retention of luciferase-transfected B16M by 40% and inhibited hepatic production of tumor necrosis factor α (TNF-α) and IL-18 and VCAM-1 expression by hepatic sinusoidal endothelia (HSE). Consistent with these data, rhES inhibited VCAM-1-dependent B16M cell adhesion to primary cultured HSE receiving B16M conditioned medium, and it abolished the HSE cell production of TNF-α and IL-18 induced by tumor-derived vascular endothelial cell growth factor (VEGF). rhES abrogated recombinant murine VEGF-induced tyrosine phosphorylation of KDR/flk-1 receptor in HSE cells, preventing the proinflammatory action of tumor-derived VEGF on HSE. rhES also abolished hepatic production of TNF-α, microvascular retention of luciferase-transfected B16M, and adhesion of B16M cells to isolated HSE cells, all of them induced in mice given 5 μg/kg recombinant murine VEGF for 18 h. This capillary inflammation-deactivating capability constitutes a nonantiangiogenic antitumoral action of endostatin that decreases cancer cell arrest within liver microvasculature and prevents metastases promoted by proinflammatory cytokines induced by VEGF.

Myofibroblasts infiltrate malignant liver tumors, although their pathogenic implications are unclear. Immunohistochemical detection of alpha-smooth muscle actin, glial fibrillary acidic protein (GFAP), and CD31 and CD34 expression was used to analyze the contribution of myofibroblasts to angiogenesis in hepatic metastasis produced by intrasplenically-injected B16 melanoma (B16M). Because activated hepatic stellate cells (HSCs) are oxygen-sensing myofibroblasts producing vascular endothelial growth factor (VEGF), the effect of B16M and human A375 melanoma supernatants on VEGF production by immortalized rat HSC line T6 and primary cultured human HSCs also was studied under an hypoxic atmosphere mimicking a tumor microenvironment. Myofibroblast infiltration preceded endothelium recruitment in avascular micrometastasis and generated specific stroma for sinusoidal-type and portal-type angiogeneses. Thereafter, myofibroblasts and endothelial cells colocalized within both angiogenic patterns and their numerical densities correlated with metastasis development. Myofibroblasts often were GFAP-positive, suggesting an HSC origin. Melanoma supernatants stimulated VEGF messenger RNA and protein synthesis by HSCs. These effects were potentiated by hypoxia. VEGF up-regulation was accompanied by increased expression of cyclooxygenase type 2 (COX-2) and PGE2 synthesis. HSC production of VEGF decreased under COX-2 inhibition, whereas it was increased by exogenous PGE2. The high VEGF expression in HSCs induced by melanoma factors and hypoxia resulted in mitogenic, antiapoptotic, and motogenic stimulation of both murine hepatic sinusoidal endothelium and human umbilical vein endothelium. In conclusion, temporal and positional relationships evolve between myofibroblast and endothelium recruitment during metastasis development. Mechanistically, hypoxic induction of VEGF in tumor-activated HSCs may create a proangiogenic microenvironment, facilitating endothelial cell recruitment and survival during hepatic metastasis transition from an avascular to a vascular stage.

We studied the role of endogenous interleukin (IL)-18 in hepatic metastasis by blocking this cytokine using the naturally occurring IL-18 binding protein (IL-18BP). A single i.p. dose of IL-18BP given 30 min before intrasplenic injection of murine B16 melanoma (B16M) cells reduced the number of hepatic metastatic foci by 75% and metastatic volume by 80%. Same treatment reduced the intrahepatic retention of luciferase-transfected B16M by 50% and abolished VCAM-1 up-regulation in the hepatic microvasculature, as assessed by reverse transcription-PCR, Western blot, and immunohistochemistry. Twelve hours after IL-18BP, hepatic sinusoidal endothelium (HSE) cells were isolated, and adhesion of B16M cells to these cultured HSE cells was reduced to the level of vehicle-treated mice. IL-18BP treatment of mice with established micrometastases resulted in a 25% decrease in metastasis number and 40% decrease in metastasis volume, suggesting inhibition of endogenous growth factors. Indeed, the addition of IL-18BP to normal HSE abolished the release of melanoma cell growth factor(s) induced by B16M. IL-18 promoted the in vitro growth of B16M and human melanoma cells, which was IL-1 dependent. These data demonstrate a significant role of endogenous IL-18 on hepatic metastasis by up-regulating melanoma cell adhesion to HSE cells and tumor growth, implicating a possible antimetastatic benefit of neutralizing IL-18.