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Spatial confinement and temporal regulation of signaling by nitric oxide (NO) and reactive oxygen species (ROS) occurs in cancer cells. Signaling mediated by NO and ROS was investigated in two sub clones of the murine melanoma B16F10-Nex2 cell line, Nex10C and Nex8H treated or not with bradykinin (BK). The sub clone Nex10C, similar to primary site cells, has a low capacity for colonizing the lungs, whereas the sub clone Nex8H, similar to metastatic cells, corresponds to a highly invasive melanoma. BK-treated Nex10C cells exhibited a transient increase in NO and an inhibition in basal O2- levels. Inhibition of endogenous NO production by l-NAME resulted in detectable levels of O2-. l-NAME promoted Rac1 activation and enhanced Rac1-PI3K association. l-NAME in the absence of BK resulted in Nex10C cell migration and invasion, suggesting that NO is a negative regulator of O2- mediated cell migration and cell invasion. BK-treated Nex8H cells sustained endogenous NO production through the activation of NOS3. NO activated Rac1 and promoted Rac1-PI3K association. NO stimulated cell migration and cell invasion through a signaling axis involving Ras, Rac1 and PI3K. In conclusion, a role for O2- and NO as positive regulators of Rac1-PI3K signaling associated with cell migration and cell invasion is proposed respectively for Nex10C and Nex8H murine melanoma cells.
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Bradicinina , Melanoma , Camundongos , Animais , Bradicinina/farmacologia , Bradicinina/metabolismo , Superóxidos , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Movimento CelularRESUMO
Paracoccidioidomycosis (PCM), caused by Paracoccidioides species, is the main cause of death due to systemic mycoses in Brazil and other Latin American countries. Therapeutic options for PCM and other systemic mycoses are limited and time-consuming, and there are high rates of noncompliance, relapses, toxic side effects, and sequelae. Previous work has shown that the cyclopalladated 7a compound is effective in treating several kinds of cancer and parasitic Chagas disease without significant toxicity in animals. Here we show that cyclopalladated 7a inhibited the in vitro growth of Paracoccidioides lutzii Pb01 and P. brasiliensis isolates Pb18 (highly virulent), Pb2, Pb3, and Pb4 (less virulent) in a dose-response manner. Pb18 was the most resistant. Opportunistic Candida albicans and Cryptococcus neoformans were also sensitive. BALB/c mice showed significantly lighter lung fungal burdens when treated twice a day for 20 days with a low cyclopalladated 7a dose of 30 µg/ml/day for 30 days after intratracheal infection with Pb18. Electron microscopy images suggested that apoptosis- and autophagy-like mechanisms are involved in the fungal killing mechanism of cyclopalladated 7a. Pb18 yeast cells incubated with the 7a compound showed remarkable chromatin condensation, DNA degradation, superoxide anion production, and increased metacaspase activity suggestive of apoptosis. Autophagy-related killing mechanisms were suggested by increased autophagic vacuole numbers and acidification, as indicated by an increase in LysoTracker and monodansylcadaverine (MDC) staining in cyclopalladated 7a-treated Pb18 yeast cells. Considering that cyclopalladated 7a is highly tolerated in vivo and affects yeast fungal growth through general apoptosis- and autophagy-like mechanisms, it is a novel promising drug for the treatment of PCM and other mycoses.
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Antifúngicos/farmacologia , Compostos Organometálicos/farmacologia , Paládio/farmacologia , Paracoccidioides/efeitos dos fármacos , Paracoccidioidomicose/tratamento farmacológico , Animais , Antifúngicos/síntese química , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Cadaverina/análogos & derivados , Cadaverina/biossíntese , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Caspases/genética , Caspases/metabolismo , Cromatina/efeitos dos fármacos , Cromatina/patologia , Cromatina/ultraestrutura , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/crescimento & desenvolvimento , Fragmentação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Expressão Gênica , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Compostos Organometálicos/síntese química , Paládio/química , Paracoccidioides/genética , Paracoccidioides/crescimento & desenvolvimento , Paracoccidioides/ultraestrutura , Paracoccidioidomicose/microbiologia , Paracoccidioidomicose/patologia , Superóxidos/metabolismo , Vacúolos/efeitos dos fármacos , Vacúolos/patologia , Vacúolos/ultraestruturaRESUMO
BACKGROUND: Onychomycosis is a fungal nail infection of difficult treatment due to the fungal survival capacity and reduced number of effective therapies. The present study aimed to isolate fungal agents that cause onychomycosis in immunocompetent patients and evaluate how LASER treatments affect the growth and ultrastructure of isolates. METHODS: In total, 21 patients with positive direct microscopic examination (DME) for onychomycosis had nail samples collected for cultivation and phenotypic identification of microorganisms. From these patients, 12 underwent LASER treatment, divided in Group 1 (n = 5) treated with Nd: YAG 1,064 nm, and Group 2 (n = 7) treated with Nd: YAG 1,064 nm + Er: YAG 2,940 nm + topical isoconazole. Transmission Electron Microscopy (TEM) was performed to evaluate ultrastructural changes after treatment. RESULTS: DME, cultivation, and phenotypic identification showed that the most identified fungus was Trichophyton rubrum spp. After LASER therapy, sample cultivation showed alterations in the fungal morphology with reduction of hyphae, conidia, and reproductive structures. Alterations in fungal cell wall structure, cytoplasm density, and organelles were observed by TEM. CONCLUSION: LASER irradiation causes changes in the fungal cells, especially in the number of hyphae and the presence of conidia. In addition, it affects fungal growth and reproduction capacity, which interferes with their infection ability and virulence.
Assuntos
Terapia a Laser , Lasers de Estado Sólido , Onicomicose , Humanos , Onicomicose/microbiologia , Resultado do Tratamento , Unhas/microbiologia , Lasers de Estado Sólido/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêuticoRESUMO
Complementarity-determining regions (CDRs) from monoclonal antibodies tested as synthetic peptides display anti-infective and antitumor activities, independent of the specificity of the native antibody. Previously, we have shown that the synthetic peptide C7H2, based on the heavy chain CDR 2 from monoclonal antibody C7, a mAb directed to a mannoprotein of Candida albicans, significantly reduced B16F10 melanoma growth and lung colony formation by triggering tumor apoptosis. The mechanism, however, by which C7H2 induced apoptosis in tumor cells remained unknown. Here, we demonstrate that C7H2 interacts with components of the tumor cells cytoskeleton, being rapidly internalized after binding to the tumor cell surface. Mass spectrometry analysis and in vitro validation revealed that ß-actin is the receptor of C7H2 in the tumor cells. C7H2 induces ß-actin polymerization and F-actin stabilization, linked with abundant generation of superoxide anions and apoptosis. Major phenotypes following peptide binding were chromatin condensation, DNA fragmentation, annexin V binding, lamin disruption, caspase 8 and 3 activation, and organelle alterations. Finally, we evaluated the cytotoxic efficacy of C7H2 in a panel of human tumor cell lines. All tumor cell lines studied were equally susceptible to C7H2 in vitro. The C7H2 amide without further derivatization significantly reduced lung metastasis of mice endovenously challenged with B16F10-Nex2 melanoma cells. No significant cytotoxicity was observed toward nontumorigenic cell lines on short incubation in vitro or in naïve mice injected with a high dose of the peptide. We believe that C7H2 is a promising peptide to be developed as an anticancer drug.
Assuntos
Actinas/imunologia , Anticorpos Monoclonais Murinos/farmacologia , Anticorpos Antineoplásicos/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cadeias Pesadas de Imunoglobulinas/farmacologia , Região Variável de Imunoglobulina/farmacologia , Melanoma/prevenção & controle , Proteínas de Neoplasias/imunologia , Animais , Anticorpos Monoclonais Murinos/imunologia , Antineoplásicos/imunologia , Candida albicans/imunologia , Caspase 3/imunologia , Caspase 8/imunologia , Linhagem Celular Tumoral , Fragmentação do DNA/efeitos dos fármacos , DNA de Neoplasias/imunologia , Proteínas Fúngicas/imunologia , Humanos , Cadeias Pesadas de Imunoglobulinas/imunologia , Região Variável de Imunoglobulina/imunologia , Masculino , Melanoma/imunologia , Melanoma/patologia , Glicoproteínas de Membrana/imunologia , Camundongos , Metástase NeoplásicaRESUMO
Luiz Rodolpho Travassos, a Brazilian scientist recognized in several areas of research, began his studies in the field of oncology in the late 1970s when he took a sabbatical at the Memorial Sloan Kettering Cancer Center, NY, USA. At that time, the discovery and characterization of human melanoma glycoprotein antigens yielded important publications. This experience allowed 16 years later, and Dr. Travassos founded UNONEX, significantly contributing with discoveries in the area of oncology and training of researchers. This review will address all the contributions of team of researchers who, together with Dr. Travassos, collaborated with investigations into molecules and processes that lead to the development of melanoma.
Assuntos
Melanoma , Humanos , Brasil , BiologiaRESUMO
Malignant melanoma is the main cause of death in patients with skin cancer. Overexpression of Proteolipid protein 2 (PLP2) increased tumor metastasis and the knockdown of PLP2 inhibited the growth and metastasis of melanoma cells. In the present work, we studied the antitumor activity of peptide Rb4 derived from protein PLP2. In vitro, Rb4 induced F-actin polymerization, prevented F-actin depolymerization and increased the ER-derived cytosolic calcium. Such effects were associated with necrosis of murine melanoma B16F10-Nex2 cells and with inhibition of the viability of human cancer cell lines. Loss of plasma membrane integrity, dilation of mitochondria, cytoplasm vacuolation and absence of chromatin condensation characterized tumor cell necrosis. Cleavage of PARP-1 and inhibition of RIP1 expression were also observed. In vivo, peptide Rb4 reduced the lung metastasis of tumor cells and delayed the subcutaneous melanoma growth in a syngeneic model. Rb4 induced the expression of two DAMPs molecules, HMGB1 and calreticulin, in B16F10-Nex2. Our results suggest that peptide Rb4 acts directly on tumor cells inducing the expression of DAMPs, which trigger the immunoprotective effect in vivo against melanoma cells. We suggest that peptide Rb4 is a promising compound to be developed as an anticancer drug.
Assuntos
Morte Celular/genética , Expressão Gênica/genética , Expressão Gênica/fisiologia , Proteínas com Domínio MARVEL/genética , Proteínas com Domínio MARVEL/farmacologia , Melanoma/genética , Melanoma/patologia , Poli(ADP-Ribose) Polimerase-1/fisiologia , Proteolipídeos/genética , Proteolipídeos/farmacologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Animais , Antineoplásicos , Calreticulina/genética , Calreticulina/metabolismo , Linhagem Celular Tumoral , Expressão Gênica/efeitos dos fármacos , Proteína HMGB1/genética , Proteína HMGB1/metabolismo , Humanos , Proteínas com Domínio MARVEL/metabolismo , Proteínas com Domínio MARVEL/fisiologia , Camundongos , Necrose , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Peptídeos , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Proteolipídeos/metabolismo , Proteolipídeos/fisiologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
The functionalization of nanoparticles with therapeutic peptides has been pointed out as a promising strategy to improve the applications of these molecules in the field of health sciences. Peptides are highly bioactive but face several limitations such as low bioavailability due to the difficulty of overcoming the physiological barriers in the body and their degradation by enzymes. In this work, gold nanoparticles (AuNPs) were co-functionalized with two therapeutic peptides simultaneously. The peptides from the complementary determining region of monoclonal antibodies, composed of the amino acid sequences YISCYNGATSYNQKFK (C7H2) and RASQSVSSYLA (HuAL1) were chosen for having exhibited antitumor and antimicrobial activity before. The peptides-conjugated AuNPs were characterized regarding size, morphology, and metal concentration by using TEM, dynamic light scattering, and ICP-OES techniques. Then, peptides-conjugated AuNPs were evaluated regarding the antimicrobial activity against E. coli, P. aeruginosa, and C. albicans. The antitumoral activity was evaluated in vitro by cell viability assays with metastatic melanoma cell line (B16F10-Nex2) and the cytotoxicity was evaluated against human foreskin fibroblast (Hs68) cell line. Finally, in vivo assays were performed by using a syngeneic animal model of metastatic melanoma. Our findings have highlighted the potential application of the dual-peptide AuNPs in order to enhance the antitumor and antimicrobial activity of peptides.
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Malignant melanoma is one the most aggressive types of cancer and its incidence has gradually increased in the last years, accounting for about 75% of skin cancer deaths. This poor prognosis results from the tumor resistance to conventional drugs mainly by deregulation of apoptotic pathways. The aim of this work was to investigate the cell death mechanism induced by α-pinene and its therapeutic application. Our results demonstrated that α-pinene was able to induce apoptosis evidenced by early disruption of the mitochondrial potential, production of reactive oxygen species, increase in caspase-3 activity, heterochromatin aggregation, DNA fragmentation and exposure of phosphatidyl serine on the cell surface. Most importantly, this molecule was very effective in the treatment of experimental metastatic melanoma reducing the number of lung tumor nodules. This is the first report on the apoptotic and antimetastatic activity of isolated α-pinene.
Assuntos
Anacardiaceae/química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Melanoma Experimental/prevenção & controle , Melanoma Experimental/secundário , Monoterpenos/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Animais , Monoterpenos Bicíclicos , Linhagem Celular Tumoral , Neoplasias Pulmonares/prevenção & controle , Neoplasias Pulmonares/secundário , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Cutâneas/patologiaRESUMO
The development of resistance against photodamage triggered by photodynamic therapy (PDT) is ascribed mainly to the cellular redox defenses and repair. If the tumor tissue is not promptly eliminated by the first few PDT sessions, PDT-resistance can be favored, challenging the efficacy of the treatment. Although the mechanism of PDT resistance is still unclear, in vitro assays have evidenced that it can be developed through the PARP damage-repair signaling pathway. Therefore, inhibition of poly(adenosine diphosphate (ADP)-ribose) polymerase (PARP) has the potential to increase PDT efficacy. This work reports on the synthesis of a controlled release system of a photosensitizer, methylene blue (MB) and a PARP-inhibitor, the veliparib. MB and veliparib were co-encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (VMB-NPs). A colloidal stable aqueous suspension of nanoparticles was obtained. The average hydrodynamic diameter was 90 nm and a narrow size distribution was obtained, with a polydispersity index (PDI) of 0.08. The release kinetics of MB and veliparib from VMB-NPs showed an initial burst of 8.7% and 58.3% release of the total amounts of MB and veliparib respectively, in the first 6 h, and a delayed release of up to 11.3% and 70%, in 19 days, for MB and veliparib, respectively. The VMB-NPs showed no cytotoxicity in the dark but the viability of B16F10-Nex2 cells decreased by 36% when the cells were irradiated (102 J/cm2, 660 nm) and treated with VMB-NPs containing 1.0 µM of MB and 8.3 µM of veliparib. Considering the increased photoactivity even at low MB and veliparib concentrations and the absence of cytotoxicity in dark, the co-encapsulation of MB and veliparib was shown to be a promising strategy to improve the PDT efficacy.
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Commensal yeast from the genus Candida is part of the healthy human microbiota. In some cases, Candida spp. dysbiosis can result in candidiasis, the symptoms of which may vary from mild localized rashes to severe disseminated infections. The most prevalent treatments against candidiasis involve fluconazole, itraconazole, miconazole, and caspofungin. Moreover, amphotericin B associated with prolonged azole administration is utilized to control severe cases. Currently, numerous guidelines recommend echinocandins to treat invasive candidiasis. However, resistance to these antifungal drugs has increased dramatically over recent years. Considering this situation, new therapeutic alternatives should be studied to control candidiasis, which has become a major medical concern. Limonene belongs to the group of terpene molecules, known for their pharmacological properties. In this study, we evaluated in vitro the limonene concentration capable of inhibiting the growth of yeast from the genus Candida susceptible or resistant to antifungal drugs and its capacity to induce fungal damage. In addition, intravaginal fungal infection assays using a murine model infected by Candida albicans were carried out and the fungal burden, histopathology, and scanning electron microscopy were evaluated. All of our results suggest that limonene may play a protective role against the infection process by yeast from the genus Candida.
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BACKGROUND: BRN2 transcription factor is associated with the development of malignant melanoma. The cytotoxic activities and cell death mechanism against B16F10-Nex2 cells were determined with synthetic peptide R18H derived from the POU domain of the BRN2 transcription factor. OBJECTIVE: To determine the cell death mechanisms and in vivo activity of peptide R18H derived from the POU domain of the BRN2 transcription factor against B16F10-Nex2 cells. METHODS: Cell viability was determined by the MTT method. C57Bl/6 mice were challenged with B16F10-Nex2 cells and treated with R18H. To identify the type of cell death, we used TUNEL assay, Annexin V and PI, Hoechst, DHE, and determination of caspase activation and cytochrome c release. Transmission electron microscopy was performed to verify morphological alterations after peptide treatment. RESULTS: Peptide R18H displayed antitumor activity in the first hours of treatment and the EC50% was calculated for 2 and 24h, being 0.76 ± 0.045 mM and 0.559 ± 0.053 mM, respectively. After 24h apoptosis was evident, based on DNA degradation, chromatin condensation, increase of superoxide anion production, phosphatidylserine translocation, activation of caspases 3 and 8, and release of extracellular cytochrome c in B16F10-Nex2 cells. The peptide cytotoxic activity was not affected by necroptosis inhibitors and treated cells did not release LDH in the extracellular medium. Moreover, in vivo antitumor activity was observed following treatment with peptide R18H. CONCLUSION: Peptide R18H from BRN2 transcription factor induced apoptosis in B16F10-Nex2 and displayed antitumor activity in vivo.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas de Homeodomínio/química , Melanoma/tratamento farmacológico , Melanoma/patologia , Fatores do Domínio POU/química , Peptídeos/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Melanoma/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Estrutura Molecular , Peptídeos/síntese química , Peptídeos/química , Relação Estrutura-AtividadeRESUMO
The present work aims at investigating the mechanism of action of the Rb9 peptide, which contains the VHCDR 3 sequence of anti-sodium-dependent phosphate transport protein 2B (NaPi2B) monoclonal antibody RebMab200 and displayed antitumor properties. Short peptides corresponding to the hypervariable complementarity-determining regions (CDRs) of immunoglobulins have been associated with antimicrobial, antiviral, immunomodulatory and antitumor activities regardless of the specificity of the antibody. We have shown that the CDR derived peptide Rb9 induced substrate hyperadherence, inhibition of cell migration and matrix invasion in melanoma and other tumor cell lines. Rb9 also inhibited metastasis of murine melanoma in a syngeneic mouse model. We found that Rb9 binds to and interferes with Hsp90 chaperone activity causing attenuation of FAK-Src signaling and downregulation of active Rac1 in B16F10-Nex2 melanoma cells. The peptide also bound to an adhesion G-protein coupled receptor, triggering a concentration-dependent synthesis of cAMP and activation of PKA and VASP signaling as well as IP-3 dependent Ca2+ release. Hsp90 is highly expressed on the cell surface of melanoma cells, and synthetic agents that target Hsp90 are promising cancer therapeutic drugs. Based on their remarkable antitumor effects, the CDR-H3-derived peptides from RebMab200, and particularly the highly soluble and stable Rb9, are novel candidates to be further studied as potential antitumor drugs, selectively acting on cancer cell motility and invasion.
Assuntos
Regiões Determinantes de Complementaridade/genética , Proteínas de Choque Térmico HSP90/genética , Melanoma Experimental/tratamento farmacológico , Peptídeos/genética , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Adesão Celular/genética , Adesão Celular/imunologia , Movimento Celular/genética , Regiões Determinantes de Complementaridade/imunologia , Proteínas de Choque Térmico HSP90/imunologia , Região Variável de Imunoglobulina/genética , Região Variável de Imunoglobulina/imunologia , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Camundongos , Invasividade Neoplásica/genética , Neuropeptídeos/genética , Peptídeos/administração & dosagem , Peptídeos/imunologia , Receptores Acoplados a Proteínas G/genética , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIb/genética , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIb/imunologia , Proteínas rac1 de Ligação ao GTP/genéticaRESUMO
A phosphorylated peptide, named K40H, derived from the constant region of IgMs was detected in human serum by liquid chromatography coupled to high-resolution mass spectrometry. Synthetic K40H proved to exert a potent in vitro activity against fungal pathogens, and to inhibit HIV-1 replication in vitro and ex vivo. It also showed a therapeutic effect against an experimental infection by Candida albicans in the invertebrate model Galleria mellonella. K40H represents the proof of concept of the innate role that naturally occurring antibody fragments may exert against infectious agents, shedding a new light upon the posthumous role of antibodies and opening a new scenario on the multifaceted functionality of humoral immunity.
Assuntos
Candida albicans/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Fragmentos Fc das Imunoglobulinas/sangue , Imunoglobulina M/química , Anti-Infecciosos/sangue , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Cromatografia Líquida , Humanos , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/farmacologia , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Fosforilação , Replicação Viral/efeitos dos fármacosRESUMO
Antibody-derived peptides modulate functions of the immune system and are a source of anti-infective and antitumor substances. Recent studies have shown that they comprise amino acid sequences of immunoglobulin complementarity-determining regions, but also fragments of constant regions. VH CDR3 of murine mAb AC-1001 displays antimetastatic activities using B16F10-Nex2 murine melanoma cells in a syngeneic model. The peptide was cytotoxic in vitro in murine and human melanoma cells inducing reactive oxygen species (ROS) and apoptosis by the intrinsic pathway. Signs of autophagy were also suggested by the increased expression of LC3/LC3II and Beclin 1 and by ultrastructural evidence. AC-1001 H3 bound to both G- and F-actin and inhibited tumor cell migration. These results are important evidence of the antitumor activity of Ig CDR-derived peptides.
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BACKGROUND: Pyrostegia venusta (Ker. Gawl.) Miers (Bignoniacea) is a medicinal plant from the Brazilian Cerrado used to treat leucoderma and common diseases of the respiratory system. OBJECTIVE: To investigate the antitumor activity of P.venusta extracts against melanoma. MATERIALS AND METHODS: The cytotoxic activity and tumor induced cell death of heptane extract (HE) from P. venusta flowers was evaluated against murine melanoma B16F10-Nex2 cells in vitro and in a syngeneic model in vivo. RESULTS: We found that HE induced apoptosis in melanoma cells by disruption of the mitochondrial membrane potential, induction of reactive oxygen species and late apoptosis evidenced by plasma membrane blebbing, cell shrinkage, chromatin condensation and DNA fragmentation, exposure of phosphatidylserine on the cell surface and activation of caspase-2,-3,-8,-9. HE was also protective against singeneyc subcutaneous melanoma HE compounds were also able to induce cell cycle arrest at G2/M phases on tumor cells. On fractionation of HE in silica gel we isolated a cytotoxic fraction that contained a mixture of saturated hydrocarbons identified by (1)H NMR and GC-MS analyses. Predominant species were octacosane (C28H58-36%) and triacontane (C30H62-13%), which individually showed significant cytotoxic activity against murine melanoma B16F10-Nex2 cells in vitro and a very promising antitumor protection against subcutaneous melanoma in vivo. CONCLUSION: The results suggest that the components of the heptane extract, mainly octasane and triacontane, which showed antitumor properties in experimental melanoma upon regional administration, might also be therapeutic in human cancer, such as in the mostly epidermal and slowly invasive melanomas, such as acral lentiginous melanoma, as an adjuvant treatment to surgical excision.
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OBJECTIVE: Available chemotherapy presents poor control over the development of metastatic melanoma. FTY720 is a compound already approved by the Food and Drug Administration for the treatment of patients with multiple sclerosis. It has also been observed that FTY720 inhibits tumor growth in vivo (experimental models) and in vitro (animal and human tumor cells). The aim of this study was to evaluate the effects of FTY720 on a metastatic melanoma model and in tumor cell lines. METHODS: We analyzed FTY720 efficacy in vivo in a syngeneic murine metastatic melanoma model, in which we injected tumor cells intravenously into C57BL/6 mice and then treated the mice orally with the compound for 7 days. We also treated mice and human tumor cell lines with FTY720 in vitro, and cell viability and death pathways were analyzed. RESULTS: FTY720 treatment limited metastatic melanoma growth in vivo and promoted a dose-dependent decrease in the viability of murine and human tumor cells in vitro. Melanoma cells treated with FTY720 exhibited characteristics of programmed cell death, reactive oxygen species generation, and increased ß-catenin expression. In addition, FTY720 treatment resulted in an immunomodulatory effect in vivo by decreasing the percentage of Foxp3+ cells, without interfering with CD8+ T cells or lymphocyte-producing interferon-gamma. CONCLUSION: Further studies are needed using FTY720 as a monotherapy or in combined therapy, as different types of cancer cells would require a variety of signaling pathways to be extinguished.
Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Imunossupressores/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Melanoma Experimental/tratamento farmacológico , Propilenoglicóis/uso terapêutico , Esfingosina/análogos & derivados , Animais , Western Blotting , Caspase 3/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Cloridrato de Fingolimode , Citometria de Fluxo , Humanos , Neoplasias Pulmonares/secundário , Masculino , Melanoma Experimental/patologia , Melanoma Experimental/secundário , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão , Espécies Reativas de Oxigênio , Esfingosina/uso terapêutico , Fatores de TempoRESUMO
BACKGROUND: Malignant melanoma is a deadly type of metastatic skin cancer with increased incidence over the past 30 years. Despite the advanced knowledge on the biology, immunobiology and molecular genetics of melanoma, the alternatives of treatment are limited with poor prognosis. On clinical trials, natural products and among them redox-active quinones have been tested in the attempt to control the growth of cancer cells. Recently, we isolated jacaranone from Pentacalia desiderabilis, a benzoquinone derivative that showed a broad antitumor activity and protective anti-melanoma effect in a syngeneic model. The purified substance is active at micromolar concentrations, is not hemolytic, and is not toxic in naïve mice. METHODOLOGY/PRINCIPAL FINDINGS: The jacaranone antitumor activity was shown against several human cancer cell lines in vitro. Moreover, the induction of apoptosis in murine melanoma cells and jacaranone antitumor activity in vivo, in a melanoma experimental model, were also shown. Jacaranone renders antiproliferative and proapoptotic responses in tumor cells, by acting on Akt and p38 MAPK signaling pathways through generation of reactive oxygen species (ROS). The free radical scavenger N-acetyl-cysteine (NAC) was able to completely suppress cell death induced by jacaranone as it blocked Akt downregulation, p38 MAPK activation as well as upregulation of proapoptotic Bax. Notably, treatment of melanoma growing subcutaneously in mice with jacaranone significantly extended the mean survival times in a dose-dependent manner. CONCLUSIONS/SIGNIFICANCE: The results provide evidence for the mechanisms of action of jacaranone and emphasize the potential use of this quinone for the treatment of melanoma.
Assuntos
Antineoplásicos/farmacologia , Asteraceae/química , Benzoquinonas/farmacologia , Melanoma/tratamento farmacológico , Fitoterapia/métodos , Extratos Vegetais/farmacologia , Transdução de Sinais/efeitos dos fármacos , Acetilcisteína , Animais , Anexina A5 , Antineoplásicos/análise , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Benzoquinonas/análise , Benzoquinonas/uso terapêutico , Western Blotting , Linhagem Celular Tumoral , Cromatina/metabolismo , Colorimetria , Regulação para Baixo , Humanos , Marcação In Situ das Extremidades Cortadas , Técnicas In Vitro , Masculino , Potencial da Membrana Mitocondrial , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão , Ressonância Magnética Nuclear Biomolecular , Propídio , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxidos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Synthetic peptides with sequences identical to fragments of the constant region of different classes (IgG, IgM, IgA) of antibodies (Fc-peptides) exerted a fungicidal activity in vitro against pathogenic yeasts, such as Candida albicans, Candida glabrata, Cryptococcus neoformans, and Malassezia furfur, including caspofungin and triazole resistant strains. Alanine-substituted derivatives of fungicidal Fc-peptides, tested to evaluate the critical role of each residue, displayed unaltered, increased or decreased candidacidal activity in vitro. An Fc-peptide, included in all human IgGs, displayed a therapeutic effect against experimental mucosal and systemic candidiasis in mouse models. It is intriguing to hypothesize that some Fc-peptides may influence the antifungal immune response and constitute the basis for devising new antifungal agents.
Assuntos
Anticorpos/química , Antifúngicos/farmacologia , Peptídeos/farmacologia , Animais , Anticorpos/metabolismo , Antifúngicos/química , Antifúngicos/uso terapêutico , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Caspofungina , Cryptococcus neoformans/efeitos dos fármacos , Modelos Animais de Doenças , Farmacorresistência Fúngica/efeitos dos fármacos , Equinocandinas/farmacologia , Eritrócitos/efeitos dos fármacos , Feminino , Hemólise , Humanos , Imunoglobulina A/química , Imunoglobulina A/metabolismo , Regiões Constantes de Imunoglobulina , Imunoglobulina G/química , Imunoglobulina G/metabolismo , Imunoglobulina M/química , Imunoglobulina M/metabolismo , Lipopeptídeos , Malassezia/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Peptídeos/química , Peptídeos/uso terapêutico , Triazóis/farmacologiaRESUMO
Limonene is a monoterpene that has antitumoral, antibiotic and antiprotozoal activity. In this study we demonstrate the activity of limonene against Leishmania species in vitro and in vivo. Limonene killed Leishmania amazonensis promastigotes and amastigotes with 50% inhibitory concentrations of 252.0+/-49.0 and 147.0+/-46.0 microM, respectively. Limonene was also effective against Leishmania major, Leishmania braziliensis and Leishmania chagasi promastigotes. The treatment of L. amazonensis-infected macrophages with 300 microM limonene resulted in 78% reduction in infection rates. L. amazonensis-infected mice treated topically or intrarectally with limonene had significant reduction of lesion sizes. A significant decrease in the parasite load was shown in the lesions treated topically with limonene by histopathological examination. The intrarectal treatment was highly effective in decreasing the parasite burden, healing established lesions and suppressing the dissemination of ulcers. Limonene presents low toxicity in humans and has been shown to be effective as an agent for enhancing the percutaneous permeation of drugs. Our results suggest that limonene should be tested in different experimental models of infection by Leishmania.
Assuntos
Antiprotozoários/farmacologia , Cicloexenos/farmacologia , Leishmania/efeitos dos fármacos , Terpenos/farmacologia , Animais , Feminino , Limoneno , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Óxido Nítrico/biossíntese , Testes de Sensibilidade ParasitáriaRESUMO
OBJECTIVE: Available chemotherapy presents poor control over the development of metastatic melanoma. FTY720 is a compound already approved by the Food and Drug Administration for the treatment of patients with multiple sclerosis. It has also been observed that FTY720 inhibits tumor growth in vivo (experimental models) and in vitro (animal and human tumor cells). The aim of this study was to evaluate the effects of FTY720 on a metastatic melanoma model and in tumor cell lines. METHODS: We analyzed FTY720 efficacy in vivo in a syngeneic murine metastatic melanoma model, in which we injected tumor cells intravenously into C57BL/6 mice and then treated the mice orally with the compound for 7 days. We also treated mice and human tumor cell lines with FTY720 in vitro, and cell viability and death pathways were analyzed. RESULTS: FTY720 treatment limited metastatic melanoma growth in vivo and promoted a dose-dependent decrease in the viability of murine and human tumor cells in vitro. Melanoma cells treated with FTY720 exhibited characteristics of programmed cell death, reactive oxygen species generation, and increased β-catenin expression. In addition, FTY720 treatment resulted in an immunomodulatory effect in vivo by decreasing the percentage of Foxp3+ cells, without interfering with CD8+ T cells or lymphocyte-producing interferon-gamma. CONCLUSION: Further studies are needed using FTY720 as a monotherapy or in combined therapy, as different types of cancer cells would require a variety of signaling pathways to be extinguished. .