RESUMO
Melanoma is a highly metastatic and rapidly progressing cancer, a leading cause of mortality among skin cancers. The melanoma microenvironment, formed from the activity of malignant cells on the extracellular matrix and the recruitment of immune cells, plays an active role in the development of drug resistance and tumor recurrence, which are clinical challenges in cancer treatment. These tumoral metabolic processes are affected by proteins, including Galectin-3 (Gal-3), which is extensively involved in cancer development. Previously, we characterized a partially methylated mannogalactan (MG-Pe) with antimelanoma activities. In vivo models of melanoma were used to observe MG-Pe effects in survival, spontaneous, and experimental metastases and in tissue oxidative stress. Analytical assays for the molecular interaction of MG-Pe and Gal-3 were performed using a quartz crystal microbalance, atomic force microscopy, and contact angle tensiometer. MG-Pe exhibits an additive effect when administered together with the chemotherapeutic agent dacarbazine, leading to increased survival of treated mice, metastases reduction, and the modulation of oxidative stress. MG-Pe binds to galectin-3. Furthermore, MG-Pe antitumor effects were substantially reduced in Gal-3/KO mice. Our results showed that the novel Gal-3 ligand, MG-Pe, has both antitumor and antimetastatic effects, alone or in combination with chemotherapy.
Assuntos
Antineoplásicos , Galectina 3 , Melanoma , Neoplasias Cutâneas , Animais , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Dacarbazina/metabolismo , Dacarbazina/farmacologia , Dacarbazina/uso terapêutico , Galectina 3/metabolismo , Galectina 3/farmacologia , Galectina 3/uso terapêutico , Ligantes , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Camundongos , Recidiva Local de Neoplasia , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/fisiologiaRESUMO
The non-steroidal anti-inflammatory drugs are emerging contaminants in aquatic ecosystems. This study aimed to evaluate toxic effects of some representative drugs of this pharmaceutical group on primary culture of monocytic lineage of Hoplias malabaricus anterior kidney. The effects of diclofenac, acetaminophen and ibuprofen in cell viability, lipopolysaccharide (LPS)-induced NO production and genotoxicity were evaluated. Cytometry analysis CD11b(+) cells showed 71.5% of stem cells, 19.5% of macrophages and 9% of monocytes. Cell viability was lower in the ficoll compared to percoll separation. LPS-induced NO production by these cells was blocked after treatment with dexamethasone and NG-Methyl-L-Arginine (L-NMMA). Exposure of the cells to diclofenac (0.2-200 ng/mL), acetaminophen (0.025-250 ng/mL) ibuprofen (10-1000 ng/mL) reduced basal NO production and inhibited LPS-induced NO production at all concentrations after 24 h of exposure. Genotoxicity occurred at the highest concentration of diclofenac and at the intermediary concentration of acetaminophen. Genotoxicity was also observed by ibuprofen. In summary, the pharmaceuticals influenced NO production and caused DNA damage in monocytic cells suggesting that these drugs can induce immunosuppression and genotoxicity in fish.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Characidae/metabolismo , Animais , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Diclofenaco/farmacologia , Ibuprofeno/farmacologia , Lipopolissacarídeos/farmacologia , Testes de Mutagenicidade , Óxido Nítrico/metabolismoRESUMO
Endothelial cells (ECs) are a source of physiologically important molecules that are synthesized and released to the blood and/or to the subendothelial extracellular matrix such as a heparan sulfate proteoglycan (HSPG) with antithrombotic properties. Previously, we have shown that heparin stimulates the synthesis and modifies the sulfation pattern of this HSPG. Here the molecular mechanisms involved in the up-regulation of HSPG synthesis by heparin in endothelial cells were decoded. The cells were stimulated with heparin and the expression of HSPG and intracellular pathways were evaluated by a combination of methods involving confocal microscopy, flow cytometry, Western blotting analyses, and [(35) S]-sulfate metabolically labeling of the cells. We observed that the up-regulation of HSPG synthesis evoked by heparin is dependent on the interaction of heparin with integrin since RGD peptide abolishes the effect. The activation of integrin leads to tyrosine-phosphorylation of focal adhesion-associated proteins such as FAK, Src, and paxillin. In addition, heparin induces ERK1/2 phosphorylation and inhibitors of Ras and MEK decreased heparin-dependent HSPG synthesis. Moreover, heparin also induced intracellular Ca(2+) release, PLCγ1 (phospholipase Cγ1) and CaMKII (calcium calmodulin kinase II) activation, as well as an increase in nitric oxide (NO) production. Finally, an intracellular Ca(2+) chelator, Ca(2+) signaling inhibitors, and an endothelial NO synthase inhibitor were all able to abolish the effect in heparan sulfate synthesis. In conclusion, the heparin-induced up-regulation of HSPG expression is associated with the phosphorylation of focal adhesion proteins and Ras/Raf/MEK/ERK MAP and Ca(2+) /NO pathways.
Assuntos
Células Endoteliais/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Heparina/metabolismo , Heparitina Sulfato/metabolismo , Integrinas/metabolismo , Animais , Anticoagulantes/metabolismo , Anticoagulantes/farmacologia , Western Blotting , Cálcio/metabolismo , Sinalização do Cálcio , Adesão Celular , Fibronectinas/química , Fibronectinas/metabolismo , Citometria de Fluxo , Heparina/farmacologia , Heparitina Sulfato/genética , Microscopia Confocal , Óxido Nítrico , Fosforilação , Ligação Proteica , Coelhos , Regulação para CimaRESUMO
In recent years, the antitumoral activity of antimicrobial peptides (AMPs) has been the goal of many research studies. Among AMPs, gomesin (Gm) displays antitumor activity by unknown mechanisms. Herein, we studied the cytotoxicity of Gm in the Chinese hamster ovary (CHO) cell line. Furthermore, we investigated the temporal ordering of organelle changes and the dynamics of Ca(2+) signaling during Gm-induced cell death. The results indicated that Gm binds to the plasma membrane and rapidly translocates into the cytoplasm. Moreover, 20 µM Gm increases the cytosolic Ca(2+) and induces membrane permeabilization after 30 min of treatment. Direct Ca(2+) measurements in CHO cells transfected with the genetically encoded D1-cameleon to the endoplasmic reticulum (ER) revealed that Gm induces ER Ca(2+) depletion, which in turn resulted in oscillatory mitochondrial Ca(2+) signal, as measured in cells expressing the genetically encoded probe to the mitochondrial matrix (mit)Pericam. This leads to mitochondria disruption, loss of mitochondrial membrane potential and increased reactive oxygen species prior to membrane permeabilization. Gm-induced membrane permeabilization by a Ca(2+)-dependent pathway involving Gm translocation into the cell, ER Ca(2+) depletion and disruption, mitochondrial Ca(2+) overload and oxidative stress.
Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Animais , Células CHO , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Cricetinae , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
The increase in the number of deaths from infections caused by multidrug-resistant bacteria and cancer diseases highlights the need for new molecules with biological activity. Actinobacteria represent a potential source of new compounds, as these microorganisms have already produced a great diversity of clinically employed antibiotics. Endophytes from unexplored biomes, such as the Pantanal (the largest wetland in the world), can be a source of new molecules. Hymenachne amplexicaulis is among the unexplored native plants of the Pantanal in terms of its endophytic community. This plant is considered a weed in other countries due to its ability to adapt and compete with native plants, and there is evidence to suggest that the endophytic community of H. amplexicaulis plays an important role in this competitiveness. To explore its therapeutic potential, the present study isolated, identified (using partial sequence of the 16S rDNA) and bioprospected H. amplexicaulis endophytic actinobacteria. Ten isolates belonging to the genera Streptomyces, Microbispora, Leifsonia, and Verrucosispora were obtained from root fragments. The susceptibility profile of the isolates to the different classes of antibiotics was evaluated, with 80 % of the isolates showing resistance to the antibiotics Nalidixic Acid, Ampicillin, Chloramphenicol, Oxacillin, and Rifampicin. To assess antibacterial and antitumor activities, methanolic extracts were obtained by fermentation in SG culture medium at 36 °C at 180 rpm for 10 days. The extract produced from the S. albidoflavus CMRP4854 isolate was the only one to show activity against the Gram-negative bacterium Acinetobacter baumanii. Due to the great clinical importance of this pathogen and the difficulty in obtaining active compounds against it, the CMRP4854 isolate should be further investigated for the identification of active compounds and mode of action. We also emphasize the results obtained by the extract of the isolates Streptomyces albidoflavus CMRP4852 and Verrucosispora sp. CMRP4860 that presented antibacterial effect against Methicilin-resistant Staphylococcus aureus (MRSA) (MIC: 1.5 µg/mL and 13 µg/mL, respectively) and Vancomycin-resistant Enterococcus (VRE) (MIC: 40 µg/mL for both extracts). Extracts (200 µg/mL) of these two endophytes also showed selective cytotoxicity action against murine B16-F10 melanoma cells. However, the CMRP4852 extract also affected the density of normal cells. Due to these results, the crude extract of isolate CMRP4860 Verrucosispora sp., which was the only one that presented cytotoxicity and reduced cell density only in tumor cells, was selected for subsequent analysis involving scale-up fermentation of the CMRP4860 resulting in 9 fractions that were tested against both bacteria and tumor cells, with particular fractions showing promise and meriting further investigation. Taken together, the results of this study not only show for the first time that the endophytic community of H. amplexicaulis actinobacteria can produce secondary metabolites that potentially possess important antibacterial and cytotoxic properties, but also reinforce the pressing need to conserve biomes such as the Brazilian Pantanal.
Assuntos
Actinobacteria/química , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Endófitos/química , Poaceae/microbiologia , Actinobacteria/classificação , Actinobacteria/isolamento & purificação , Actinobacteria/metabolismo , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Brasil , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Endófitos/classificação , Endófitos/isolamento & purificação , Endófitos/metabolismo , Enterococcus/efeitos dos fármacos , Enterococcus/crescimento & desenvolvimento , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Camundongos , Áreas AlagadasRESUMO
Advanced melanoma patients that are not included in common genetic classificatory groups lack effective and safe therapeutic options. Chemotherapy and immunotherapy show unsatisfactory results and devastating adverse effects for these called triple wild-type patients. New approaches exploring the intrinsic antitumor properties of gold nanoparticles might reverse this scenario as a safer and more effective alternative. Therefore, we investigated the efficacy and safety of a composite made of gum arabic-functionalized gold nanorods (GA-AuNRs) against triple wild-type melanoma. The natural polymer gum arabic successfully stabilized the nanorods in the biological environment and was essential to improve their biocompatibility. In vivo results obtained from treating triple wild-type melanoma-bearing mice showed that GA-AuNRs remarkably reduced primary tumor growth by 45%. Furthermore, GA-AuNRs induced tumor histological features associated with better prognosis while also reducing superficial lung metastasis depth and the incidence of intrapulmonary metastasis. GA-AuNRs' efficacy comes from their capacity to reduce melanoma cells ability to invade the extracellular matrix and grow into colonies, in addition to a likely immunomodulatory effect induced by gum arabic. Additionally, a broad safety investigation found no evidence of adverse effects after GA-AuNRs treatment. Therefore, this study unprecedentedly reports GA-AuNRs as a potential nanomedicine for advanced triple wild-type melanomas.
Assuntos
Ouro/administração & dosagem , Goma Arábica/química , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Melanoma/tratamento farmacológico , Animais , Células 3T3 BALB , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Ouro/química , Ouro/farmacologia , Humanos , Neoplasias Pulmonares/metabolismo , Melanoma/metabolismo , Nanopartículas Metálicas , Camundongos , Resultado do Tratamento , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Melanoma is the most aggressive form of skin cancer and the most rapidly expanding cancer in terms of worldwide incidence. Chemotherapeutic approaches to treat melanoma have had only marginal success. Previous studies in mice demonstrated that a high diluted complex derived from Calcarea carbonica (M8) stimulated the tumoricidal response of activated lymphocytes against B16F10 melanoma cells in vitro. METHODS: Here we describe the in vitro inhibition of invasion and the in vivo anti-metastatic potential after M8 treatment by inhalation in the B16F10 lung metastasis model. RESULTS: We found that M8 has at least two functions, acting as both an inhibitor of cancer cell adhesion and invasion and as a perlecan expression antagonist, which are strongly correlated with several metastatic, angiogenic and invasive factors in melanoma tumors. CONCLUSION: The findings suggest that this medication is a promising non-toxic therapy candidate by improving the immune response against tumor cells or even induce direct dormancy in malignancies.
Assuntos
Materia Medica/farmacologia , Melanoma Experimental/tratamento farmacológico , Animais , Células da Medula Óssea/patologia , Neoplasias Colorretais/tratamento farmacológico , Células HT29 , Humanos , Imunofenotipagem , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Masculino , Melanoma Experimental/sangue , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
The tumor microenvironment (TME) is composed of multiple infiltrating host cells (e.g., endothelial cells, fibroblasts, lymphocytes, and myeloid cells), extracellular matrix, and various secreted or cell membrane-presented molecules. Group 1 innate lymphoid cells (ILCs), which includes natural killer (NK) cells and ILC1, contribute to protecting the host against cancer and infection. Both subsets are able to quickly produce cytokines such as interferon gamma (IFN-γ), chemokines, and other growth factors in response to activating signals. However, the TME provides many molecules that can prevent the potential effector function of these cells, thereby protecting the tumor. For example, TME-derived tumor growth factor (TGF)-ß and associated members of the superfamily downregulate NK cell cytotoxicity, cytokine secretion, metabolism, proliferation, and induce effector NK cells to upregulate ILC1-like characteristics. In concert, a family of carbohydrate-binding proteins called galectins, which can be produced by different cells composing the TME, can downregulate NK cell function. Matrix metalloproteinase (MMP) and a disintegrin and metalloproteinase (ADAM) are also enzymes that can remodel the extracellular matrix and shred receptors from the tumor cell surface, impairing the activation of NK cells and leading to less effective effector functions. Gaining a better understanding of the characteristics of the TME and its associated factors, such as infiltrating cells and extracellular matrix, could lead to tailoring of new personalized immunotherapy approaches. This review provides an overview of our current knowledge on the impact of the TME and extracellular matrix-associated components on differentiation, impairment, and function of NK cells.
Assuntos
Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Microambiente Tumoral/imunologia , Diferenciação Celular , Quimiocinas/metabolismo , Citocinas/metabolismo , Células Endoteliais/metabolismo , Matriz Extracelular/metabolismo , Galectinas , Glicosaminoglicanos , Humanos , Imunoterapia , Interferon gama/metabolismo , ProteoglicanasRESUMO
Natural killer (NK) cells are innate lymphocytes responsible for the elimination of infected or transformed cells. The activation or inhibition of NK cells is determined by the balance of target cell ligand recognition by stimulatory and inhibitory receptors on their surface. Previous reports have suggested that the glycosaminoglycan heparin is a ligand for the natural cytotoxicity receptors NKp30, NKp44 (human), and NKp46 (both human and mouse). However, the effects of heparin on NK cell homeostasis and function remain unclear. Here, we show that heparin does not enhance NK cell proliferation or killing through NK cell activation. Alternatively, in mice models, heparin promoted NK cell survival in vitro and controlled B16-F10 melanoma metastasis development in vivo. In human NK cells, heparin promisingly increased interferon (IFN)-γ production in synergy with IL-12, although the mechanism remains elusive. Our data showed that heparin is not able to increase NK cell cytotoxicity.
RESUMO
This work describes the development of polysaccharide-coated liposomes to modulate the delivery of epidermal growth factor (EGF), with the aim to produce different EGF release profiles depending on the milieu of infected wounds. For this purpose, cationic liposomes were coated with one layer of sodium alginate (ALG) followed by one layer of chitosan (CHI) using the layer-by-layer (LbL) technique. The coated liposomes exhibited apparent hydrodynamic diameters of 278 ± 36 and 216 ± 96 nm for Lip-ALG and Lip-ALG-CHI, respectively. Thus, it appears that adding the CHI layer compacted the Lip-ALG one. The incorporation efficiency of EGF was a maximum of 55% for liposomes with a polymeric coating. In vitro release experiments showed that Lip-ALG-CHI exhibits a higher release rate constant under acidic pH conditions, resembling those of infected tissue. Using an ex vivo model of EGF release in porcine ear skin, these liposomes were found to accumulate in the epidermis. Thus, coated liposomes could represent a local EGF delivery mechanism to promote healing.
Assuntos
Quitosana , Lipossomos , Alginatos , Animais , Fator de Crescimento Epidérmico , Pele , SuínosRESUMO
Alpha5beta1 integrin from both wild-type CHO cells (CHO-K1) and deficient in proteoglycan biosynthesis (CHO-745) is post-translationally modified by glycosaminoglycan chains. We demonstrated this using [35S]sulfate metabolic labeling of the cells, enzymatic degradation, immunoprecipitation reaction with monoclonal antibody, fluorescence microscopy, and flow cytometry. The alpha5beta1 integrin heterodimer is a hybrid proteoglycan containing both chondroitin and heparan sulfate chains. Xyloside inhibition of sulfate incorporation into alpha5beta1 integrin also supports that integrin is a proteoglycan. Also, cells grown with xyloside adhered on fibronectin with no alteration in alpha5beta1 integrin expression. However, haptotactic motility on fibronectin declined in cells grown with xyloside or chlorate as compared with controls. Thus, alpha5beta1 integrin is a proteoglycan and the glycosaminoglycan chains of the integrin influence cell motility on fibronectin. Similar glycosylation of alpha5beta1 integrin was observed in other normal and malignant cells, suggesting that this modification is conserved and important in the function of this integrin. Therefore, these glycosaminoglycan chains of alpha5beta1 integrin are involved in cellular migration on fibronectin.
Assuntos
Movimento Celular/fisiologia , Fibronectinas/fisiologia , Glicosaminoglicanos/química , Integrina alfa5beta1/química , Animais , Células CHO , Cricetinae , Cricetulus , Eletroforese em Gel de Ágar , Citometria de Fluxo , Imunoprecipitação , Microscopia de FluorescênciaRESUMO
BACKGROUND: Melanoma is the most aggressive form of skin cancer, and the most rapidly expanding cancer in terms of worldwide incidence. Chemotherapeutic approaches to treat melanoma have been uniformly disappointing. A Brazilian complex homeopathic medication (CHM), used as an immune modulator, has been recommended for patients with depressed immune systems. Previous studies in mice have demonstrated that the CHM activates macrophages, induces an increase in the number of leukocytes and improves the murine response against Sarcoma-180. METHODS: Here we studied the interaction of mouse lymph node lymphocytes, co-cultured in vitro with macrophages in the presence or absence of the CHM, with B16F10 melanoma cells. RESULTS: Lymphocytes co-cultured with macrophages in the presence of the CHM had greater anti-melanoma activity, reducing melanoma cell density and increasing the number of lysed tumor cells. There was also a higher proportion of activated (CD25+) lymphocytes with increased viability. Overall, lymphocytes activated by treatment destroyed growing cancer cells more effectively than control lymphocytes. CONCLUSION: Co-culture of macrophages with lymphocytes in the presence of the CHM enhanced the anti-cancer performance of lymphocytes against a very aggressive lineage of melanoma cells. These results suggest that non-toxic therapies using CHMs are a promising alternative approach to the treatment of melanomas. In addition, they are attractive combination-therapy candidates, which may enhance the efficacy of conventional medicines by improving the immune response against tumor cells.
Assuntos
Linfócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Materia Medica/farmacologia , Melanoma/imunologia , Animais , Linhagem Celular Tumoral , Células Cultivadas , Técnicas de Cocultura , Citotoxicidade Imunológica , Linfócitos/imunologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Melanoma/tratamento farmacológico , CamundongosRESUMO
World fisheries and aquaculture production totaled 167â¯millionâ¯tons in 2014. This high fish production generates a lot of waste that could be used as raw material for extraction of substances of pharmacological interest. In this work, we extract and characterize glycosaminoglycans (GAGs) present in the viscera of Nile tilapia (Oreochromis niloticus) and Pacu (Piaractus mesopotamicus), which are among the most vastly produced fishes in inland aquaculture in Brazil. Moreover, the anticoagulant activity of the GAGs fractions was evaluated. GAGs were obtained from total defatted viscera, after proteolysis, precipitation with ethanol, anion exchange chromatography and treatment with chondroitinase. Chondroitin sulfate (CS), dermatan sulfate (DS) and heparan sulfate (HS) were identified by agarose gel electrophoresis and NMR analyses. CS, DS and HS were identified in equivalent fractions obtained from both fishes, and all GAGs fractions showed anticoagulant activity.
Assuntos
Anticoagulantes/isolamento & purificação , Anticoagulantes/farmacologia , Caraciformes/anatomia & histologia , Ciclídeos/anatomia & histologia , Glicosaminoglicanos/isolamento & purificação , Glicosaminoglicanos/farmacologia , Vísceras/química , AnimaisRESUMO
Excitotoxicity has been related to play a crucial role in Parkinson's disease (PD) pathogenesis. Pedunculopontine tegmental nucleus (PPT) represents one of the major sources of glutamatergic afferences to nigrostriatal pathway and putative reciprocal connectivity between these structures may exert a potential influence on rapid eye movement (REM) sleep control. Also, PPT could be overactive in PD, it seems that dopaminergic neurons are under abnormally high levels of glutamate and consequently might be more vulnerable to neurodegeneration. We decided to investigate the neuroprotective effect of riluzole administration, a N-methyl-D-aspartate (NMDA) receptor antagonist, in rats submitted simultaneously to nigrostrial rotenone and 24h of REM sleep deprivation (REMSD). Our findings showed that blocking NMDA glutamatergic receptors in the SNpc, after REMSD challenge, protected the dopaminergic neurons from rotenone lesion. Concerning rotenone-induced hypolocomotion, riluzole reversed this impairment in the control groups. Also, REMSD prevented the occurrence of rotenone-induced motor impairment as a result of dopaminergic supersensitivity. In addition, higher Fluoro Jade C (FJC) staining within the SNpc was associated with decreased cognitive performance observed in rotenone groups. Such effect was counteracted by riluzole suggesting the occurrence of an antiapoptotic effect. Moreover, riluzole did not rescue cognitive impairment impinged by rotenone, REMSD or their combination. These data indicated that reductions of excitotoxicity, by riluzole, partially protected dopamine neurons from neuronal death and appeared to be effective in relieve specific rotenone-induce motor disabilities.
RESUMO
Metastasis is responsible for the majority of deaths among patients with malignant melanoma. Despite recent advances, the majority of current and modern therapies are ineffective and/or financially unfeasible. Thus, in this study, we investigated two lowcost highlydiluted natural complexes (HDNCs) that have been shown to be effective against malignant melanoma in a murine model in vivo. The aim of this study was to determine the mechanisms through which these HDNCs directly affect melanoma cells, either alone or in an artificial tumor microenvironment, suppressing the metastatic phenotype, thus explaining previous in vivo effects. For this purpose, HDNC in vitro treatments of B16F10 melanoma cells, alone or in coculture with Balb/3T3 fibroblasts, were carried out. Molecular biology techniques and standard functional assays were used to assess the changes in molecule expression and in cell behaviors related to the metastatic phenotype. Melanoma progression features were found to be regulated by HDNCs. Molecules related to cell adhesion (Ncadherin, ß1integrin and CD44), and migration, extracellular matrix remodeling and angiogenesis were modulated. The cell migratory, invasive and clonogenic capacities were reduced by the HDNCs. No loss of cell proliferation or viability were observed. On the whole, the findings of this study indicate that HDNCs directly reprogram, molecularly and functionally, melanoma cells in vitro, modulating their metastatic phenotype. Such findings are likely to be responsible for the attenuation of tumor growth and lung colonization previously observed in vivo.
Assuntos
Antígenos CD/metabolismo , Caderinas/metabolismo , Receptores de Hialuronatos/metabolismo , Integrina beta1/metabolismo , Melanoma/metabolismo , Extratos Vegetais/farmacologia , Neoplasias Cutâneas/metabolismo , Animais , Células 3T3 BALB , Adesão Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/tratamento farmacológico , Camundongos , Metástase Neoplásica , Extratos Vegetais/química , Plantas/química , Neoplasias Cutâneas/tratamento farmacológico , Melanoma Maligno CutâneoRESUMO
A fucomannogalactan (FMG-Hm), with a molecular weight of 17.1â¯kDa, obtained from fruiting bodies of Hypsizygus marmoreus exhibited promising in vitro antimelanoma effects. FMG-Hm was not cytotoxic, nor did it alter the cell morphology and proliferation, but was able to inhibit colony-forming ability and cell migration in B16-F10 murine melanoma cells. An analysis of the monosaccharide composition indicated that FMG-Hm was composed of fucose, mannose, and galactose in a ratio of 1.00:1.08:3.17. The FMG-Hm was structurally characterized based on methylation analysis, partial acid hydrolysis, and NMR experiments. The results indicated that FMG-Hm contained a α-(1â6)-linked galactopyranosyl main chain, partially substituted at O-2 by non-reducing ends of α-L-fucopyranose and ß-D-mannopyranose. The predicted structure of the heteropolysaccharide was established as.
Assuntos
Agaricales/metabolismo , Galactanos/química , Galactanos/isolamento & purificação , Galactanos/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Carpóforos/metabolismo , Estrutura Molecular , Peso MolecularRESUMO
In vitro, heparin and antithrombotic drugs specifically stimulate the synthesis of an antithrombotic heparan sulfate proteoglycan (HSPG) produced by endothelial cells. The putative heparin binding site(s) that may be related to this phenomenon were investigated. In the preceding article, using various heparin probes, it was shown that the heparin does not bind to the endothelial cell surface, but only to the extracellular matrix. The present study demonstrated that, when the cells were exposed to heparin at 37 degrees C, the heparin was internalized and with time was localized in lysosomes. However, endocytosis of heparin was not required for the stimulation of HSPG synthesis. The requirement for heparin degradation in the stimulus of HSPG synthesis was also investigated. When the cells were incubated with chloroquine, a lysosomotropic amine that raises the lysosomal pH thus inhibiting enzymatic degradation of internalized compounds, stimulation of HSPG synthesis was still observed. These combined results indicate that neither internalization nor degradation of heparin is required for stimulation of HSPG synthesis, and suggests that its binding to the extracellular matrix could be responsible for this effect.
Assuntos
Endocitose , Células Endoteliais/efeitos dos fármacos , Fibrinolíticos/farmacologia , Heparina/análogos & derivados , Heparina/farmacologia , Lisossomos/efeitos dos fármacos , Proteoglicanas/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Cloroquina/farmacologia , Células Endoteliais/enzimologia , Células Endoteliais/ultraestrutura , Matriz Extracelular/metabolismo , Fibrinolíticos/metabolismo , Heparina/metabolismo , Concentração de Íons de Hidrogênio , Lisossomos/enzimologia , Lisossomos/ultraestrutura , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Microscopia de Vídeo , Ligação Proteica , Coelhos , Fatores de TempoRESUMO
Exposure of endothelial cells to heparin and other antithrombotic drugs specifically stimulates the synthesis of an antithrombotic heparan sulfate (HS). In the present work, biotinylated heparin (BiotHep) was used to characterize the binding site(s) of heparin responsible for the stimulus in HS synthesis on endothelial cells. No differences were observed between biotinylated and non-biotinylated heparin in their ability to increase the synthesis of HS. In kinetic studies the BiotHep showed fast, saturable and specific binding with an apparent K(D) of 83 nM to adherent cells and 44 nM to the extracellular matrix (ECM) in the absence of cells. By confocal and electron microscopy, BiotHep bound only to the ECM, co-localizing with fibronectin. The same pattern of binding to the ECM was observed using heparin conjugated with FITC or Alexa Fluor 488 in the presence or absence of fetal calf serum. However, after degradation of HS, heparin binds to the cell surface, indicating that endogenous HS possibly occupied the heparin binding sites. Analyses by flow cytometry and confocal microscopy of cells with non-associated ECM, showed labeling of the cell surface using syndecan-4 monoclonal antibody as well as wheat germ agglutinin, but no binding of heparin. Furthermore, the stimulation in HS synthesis is not elicited by heparin in the absence of ECM. These results indicate that the stimulus for the synthesis of HS does not require binding of the heparin to the cell surface, and the signaling may be mediated through the ECM.
Assuntos
Células Endoteliais/efeitos dos fármacos , Matriz Extracelular/efeitos dos fármacos , Fibrinolíticos/farmacologia , Heparina/análogos & derivados , Heparina/farmacologia , Proteoglicanas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Sítios de Ligação , Biotinilação , Células COS , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Chlorocebus aethiops , Células Endoteliais/metabolismo , Células Endoteliais/ultraestrutura , Matriz Extracelular/metabolismo , Matriz Extracelular/ultraestrutura , Fibrinolíticos/metabolismo , Citometria de Fluxo , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Heparina/metabolismo , Humanos , Hidrazinas , Cinética , Ligantes , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Ligação Proteica , Coelhos , Regulação para CimaRESUMO
An aqueous extract containing polysaccharides was obtained from the giant mushroom Macrocybe titans, and it was purified by amylase treatment, freeze-thawing process and dialysis. The purified fraction (ESP) was analyzed by HPSEC and GC-MS which showed a homogenous polysaccharide with Mw 14.2â¯×â¯103â¯g/mol composed by galactose and fucose. NMR and methylation analysis of ESP confirmed the presence of a fucogalactan with a (1â¯ââ¯6)-linked α-d-Galp main chain partially substituted at O-2 by non reducing end units of α-l-Fucp residues in the side chain. Its biological activity was evaluated against murine melanoma cells B16-F10. The fucogalactan did not alter the viability, proliferative capacity and morphology of cells. However, this polysaccharide was able to reduce the cell migration in vitro at 40% (100⯵g/mL) and 33% (250⯵g/mL). The results obtained showed that Macrocybe titans fucogalactan is a promising agent capable of altering melanoma cell migration without decrease the cell viability.
Assuntos
Agaricales/química , Movimento Celular/efeitos dos fármacos , Galactanos/farmacologia , Melanoma Experimental/patologia , Melanoma/patologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Galactanos/químicaRESUMO
The fungal genus Fonsecaea comprises etiological agents of human chromoblastomycosis, a chronic implantation skin disease. The current hypothesis is that patients acquire the infection through an injury from plant material. The present study aimed to evaluate a model of infection in plant and animal hosts to understand the parameters of trans-kingdom pathogenicity. Clinical strains of causative agents of chromoblastomycosis (Fonsecaea pedrosoi and Fonsecaea monophora) were compared with a strain of Fonsecaea erecta isolated from a living plant. The clinical strains of F. monophora and F. pedrosoi remained concentrated near the epidermis, whereas F. erecta colonized deeper plant tissues, resembling an endophytic behavior. In an invertebrate infection model with larvae of a beetle, Tenebrio molitor, F. erecta exhibited the lowest survival rates. However, F. pedrosoi produced dark, spherical to ovoidal cells that resembled muriform cells, the invasive form of human chromoblastomycosis confirming the role of muriform cells as a pathogenic adaptation in animal tissues. An immunologic assay in BALB/c mice demonstrated the high virulence of saprobic species in animal models was subsequently controlled via host higher immune response.