RESUMO
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
Microtubules are important drug targets in tumor cells, owing to their role in supporting and determining the cell shape, organelle movement and cell division. The complementarity-determining regions (CDRs) of immunoglobulins have been reported to be a source of anti-tumor peptide sequences, independently of the original antibody specificity for a given antigen. We found that, the anti-Lewis B mAb light-chain CDR1 synthetic peptide Rb44, interacted with microtubules and induced depolymerization, with subsequent degradation of actin filaments, leading to depolarization of mitochondrial membrane-potential, increase of ROS, cell cycle arrest at G2/M, cleavage of caspase-9, caspase-3 and PARP, upregulation of Bax and downregulation of Bcl-2, altogether resulting in intrinsic apoptosis of melanoma cells. The in vitro inhibition of angiogenesis was also an Rb44 effect. Peritumoral injection of Rb44L1 delayed growth of subcutaneously grafted melanoma cells in a syngeneic mouse model. L1-CDRs from immunoglobulins and their interactions with tubulin-dimers were explored to interpret effects on microtubule stability. The opening motion of tubulin monomers allowed for efficient L1-CDR docking, impairment of dimer formation and microtubule dissociation. We conclude that Rb44 VL-CDR1 is a novel peptide that acts on melanoma microtubule network causing cell apoptosis in vitro and melanoma growth inhibition in vivo.
RESUMO
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
Short peptide sequences from complementarity-determining regions (CDRs) of different immunoglobulins may exert anti-infective, immunomodulatory and antitumor activities regardless of the specificity of the original monoclonal antibody (mAb). In this sense, they resemble early molecules of innate immunity. C36L1 was identified as a bioactive light-chain CDR1 peptide by screening 19 conserved CDR sequences targeting murine B16F10-Nex2 melanoma. The 17-amino acid peptide is readily taken up by melanoma cells and acts on microtubules causing depolymerization, stress of the endoplasmic reticulum and intrinsic apoptosis. At low concentrations, C36L1 inhibited migration, invasion and proliferation of B16F10-Nex2 cells with cell cycle arrest at G2/M phase, by regulating the PI3K/Akt signaling axis involving Rho-GTPase and PTEN mediation. Peritumor injection of the peptide delayed growth of subcutaneously grafted melanoma cells. Intraperitoneal administration of C36L1 induced a significant immune-response dependent anti-tumor protection in a syngeneic metastatic melanoma model. Dendritic cells stimulated ex-vivo by the peptide and transferred to animals challenged with tumor cells were equally effective. The C36 VL CDR1 peptide is a promising microtubule-interacting drug that induces tumor cell death by apoptosis and inhibits metastases of highly aggressive melanoma cells.
Assuntos
Antineoplásicos/farmacologia , Regiões Determinantes de Complementaridade/química , Melanoma/metabolismo , Melanoma/patologia , Microtúbulos/metabolismo , Peptídeos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Melanoma/tratamento farmacológico , Melanoma/imunologia , Melanoma Experimental , Camundongos , Microtúbulos/química , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Metástase Neoplásica , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Multimerização Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Proteínas rho de Ligação ao GTP/metabolismoRESUMO
Short synthetic peptides corresponding to sequences of complementarity-determining regions (CDRs) from different immunoglobulin families have been shown to induce antimicrobial, antiviral and antitumor activities regardless of the specificity of the original monoclonal antibody (mAb). Presently, we studied the in vitro and in vivo antitumor activity of synthetic peptides derived from conserved CDR sequences of different immunoglobulins against human tumor cell lines and murine B16F10-Nex2 melanoma aiming at the discovery of candidate molecules for cancer therapy. Four light- and heavy-chain CDR peptide sequences from different antibodies (C36-L1, HA9-H2, 1-H2 and Mg16-H2) showed cytotoxic activity against murine melanoma and a panel of human tumor cell lineages in vitro. Importantly, they also exerted anti-metastatic activity using a syngeneic melanoma model in mice. Other peptides (D07-H3, MN20v1, MS2-H3) were also protective against metastatic melanoma, without showing significant cytotoxicity against tumor cells in vitro. In this case, we suggest that these peptides may act as immune adjuvants in vivo. As observed, peptides induced nitric oxide production in bone-marrow macrophages showing that innate immune cells can also be modulated by these CDR peptides. The present screening supports the search in immunoglobulins of rather frequent CDR sequences that are endowed with specific antitumor properties and may be candidates to be developed as anti-cancer drugs.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/farmacologia , Imunoglobulinas/química , Melanoma/tratamento farmacológico , Peptídeos/farmacologia , Animais , Antineoplásicos/síntese química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Regiões Determinantes de Complementaridade/imunologia , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Imunoglobulinas/imunologia , Imunomodulação , Células MCF-7 , Melanoma/imunologia , Melanoma/patologia , Camundongos , Peptídeos/síntese química , Peptídeos/química , Relação Estrutura-AtividadeRESUMO
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
OBJECTIVES: To evaluate whether an engineered synthetic decapeptide (KP) derived from the sequence of a recombinant anti-idiotypic antibody, that represents the internal image of a Pichia anomala killer toxin, could be fungicidal in vitro and therapeutic in vivo against Paracoccidioides brasiliensis and paracoccidioidomycosis (PCM). METHODS: Fungicidal activity of KP was assessed in vitro and in vivo by inhibition of colony forming units and by histological examination, 8 days after infection, of organs from mice intravenously injected with a virulent strain of P. brasiliensis (3 x 10(6) yeast cells) and intraperitoneally treated with KP (3.3 microg/g body weight, three doses), in comparison with control animals equally administered with a scrambled decapeptide (SP). RESULTS: KP but not SP was fungicidal in vitro at 39 ng/multiply-budding yeast cell and less efficiently in its D-isomeric form (0.31 microg/multiply-budding yeast cell). It was also able to markedly reduce the fungal load in organs (liver, lung, spleen) of infected animals. CONCLUSIONS: The therapeutic effect observed opens the way for using the antifungal peptide as an alternative control of PCM in association with conventional antifungal drugs.