RESUMO
Diphenyl ditelluride (DPDT) is an organotellurium (OT) compound with pharmacological properties, including antioxidant, antigenotoxic and antimutagenic activities when applied at low concentrations. However, DPDT as well as other OT compounds also show cytotoxicity against mammalian cells when treatments occur at higher drug concentrations. Considering that the underlying mechanisms of toxicity of DPDT against tumor cells have been poorly explored, the objective of our study was to investigate the effects of DPDT against both human cancer and non-tumorigenic cells. As a model, we used the colonic HCT116 cancer cells and the MRC5 fibroblasts. Our results showed that DPDT preferentially targets HCT116 cancer cells when compared to MRC5 cells with IC50 values of 2.4 and 10.1 µM, respectively. This effect was accompanied by the induction of apoptosis and a pronounced G2/M cell cycle arrest in HCT116 cells. Furthermore, DPDT induces DNA strand breaks at concentrations below 5 µM in HCT116 cells and promotes the occurrence of DNA double strand breaks mostly during S-phase as measured by γ-H2AX/EdU double staining. Finally, DPDT forms covalent complexes with DNA topoisomerase I, as observed by the TARDIS assay, with a more prominent effect observed in HCT116 than in MRC5 cells. Taken together, our results show that DPDT preferentially targets HCT116 colon cancer cells likely through DNA topoisomerase I poisoning. This makes DPDT an interesting molecule for further development as an anti-proliferative compound in the context of cancer.
Assuntos
Neoplasias do Colo , DNA Topoisomerases Tipo I , Animais , Humanos , Células HCT116 , DNA Topoisomerases Tipo I/metabolismo , Apoptose , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/metabolismo , DNA , Mamíferos/metabolismoRESUMO
In this study, we aimed to evaluate two sets of sesquiterpene-aryl derivatives linked by an ester bond, their cytotoxic activities, and their capacity to activate caspases 3/7 and inhibit human topoisomerase I (TOP1). A total of 13 compounds were synthesized from the natural sesquiterpene (-)-drimenol and their cytotoxic activity was evaluated in vitro against three cancer cell lines: PC-3 (prostate cancer), HT-29 (colon cancer), MCF-7 (breast cancer), and an immortalized non-tumoral cell line (MCF-10). From the results, it was observed that 6a was the most promising compound due to its cytotoxic effect on three cancer cell lines and its selectivity, 6a was 100-fold more selective than 5-FU in MCF-7 and 20-fold in PC-3. It was observed that 6a also induced apoptosis by caspases 3/7 activity using a Capsase-Glo-3/7 assay kit and inhibited TOP1. A possible binding mode of 6a in a complex with TOP1-DNA was proposed by docking and molecular dynamics studies. In addition, 6a was predicted to have a good pharmacokinetic profile for oral administration. Therefore, through this study, it was demonstrated that the drimane scaffold should be considered in the search of new antitumoral agents.
Assuntos
Antineoplásicos , Sesquiterpenos , Humanos , Linhagem Celular Tumoral , DNA Topoisomerases Tipo I/metabolismo , Ésteres/farmacologia , Antineoplásicos/química , Sesquiterpenos/farmacologia , Apoptose , Caspases/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Simulação de Acoplamento Molecular , Proliferação de Células , Relação Estrutura-Atividade , Estrutura MolecularRESUMO
Topoisomerase inhibitors are extensively used in cancer chemotherapy. In the process of identifying novel anticancer compounds, biological evaluations are crucial and include, among others, the use of in silico and in vitro approaches. This work aimed to present recent research involving the obtainment and in silico and in vitro evaluation of topoisomerase I, II, and double inhibitors, of synthetic and natural origin, as potential compounds against tumor cells, in addition to proposing the construction of a desirable enzyme catalytic site. Therefore, it was observed that most Topoisomerase I inhibitors presented medium to large structures, with a rigid portion and a flexible region. In contrast, Topoisomerase IIα inhibitors showed medium and large structural characteristics, in addition to the planarity of the aromatic rings, which are mitigated due to flexible rings but may also present elements that restrict conformation. Most compounds that exhibit dual inhibitory activity had relatively long chains, in addition to a flat and rigid portion suggestive of affinity for Topo I and a flexible region characteristic of selective drugs for Topo II. Besides, it is noticed that most compounds that exhibit dual inhibitory showed similarities in the types of interactions and amino acids when compared to the selective compounds of Topo I and II. For instance, selective Topoisomerase I inhibitors interact with Arginine364 residues, and selective Topoisomerase II inhibitors interact with Arginine487 residues, as both residues are targets for dual compounds.
Assuntos
Antineoplásicos , Neoplasias , Humanos , Antineoplásicos/química , Proliferação de Células , DNA Topoisomerases Tipo II/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Neoplasias/tratamento farmacológico , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/farmacologia , Inibidores da Topoisomerase I/uso terapêutico , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase II/farmacologia , Inibidores da Topoisomerase II/química , Inibidores da Topoisomerase II/metabolismoRESUMO
Chromenes are compounds that may be useful for inhibiting topoisomerase and cytochrome, enzymes involved in the growth of cancer and fungal cells, respectively. The aim of this study was to synthesize a series of some novel 2-amino-3-cyano-4-aryl-6,7-methylendioxy-4H-chromenes 4a-o and 2-amino-3-cyano-5,7-dimethoxy-4-aryl-4H-chromenes 6a-h by a three-component reaction, and test these derivatives for anticancer and antifungal activity. Compounds 4a and 4b were more active than cisplatin (9) and topotecan (7) in SK-LU-1 cells, and more active than 9 in PC-3 cells. An evaluation was also made of the series of compounds 4 and 6 as potential antifungal agents against six Candida strains, finding their MIC50 to be less than or equal to that of fluconazole (8). Molecular docking studies are herein reported, for the interaction of 4 and 6 with topoisomerase IB and the active site of CYP51 of Candida spp. Compounds 4a-o and 6a-h interacted in a similar way as 7 with key amino acids of the active site of topoisomerase IB and showed better binding energy than 8 at the active site of CYP51. Hence, 4a-o and 6a-h are good candidates for further research, having demonstrated their dual inhibition of enzymes that participate in the growth of cancer and fungal cells.
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Introdução: a esclerose sistêmica (ES) é uma enfermidade do tecido conjuntivo de caráter autoimune caracterizada pela tríade de injúria vascular, autoimunidade (celular e humoral) e fibrose tecidual. Os autoanticorpos não parecem ser simplesmente epifenômenos, mas sim estarem envolvidos na patogênese da doença. Acredita-se que os autoanticorpos específicos da ES são responsáveis tanto pela amplificação da resposta imune quanto por alvejar os tipos celulares que são relevantes na fisiopatologia da ES. Objetivos: correlacionar o perfil de autoanticorpos específicos (anti-SCL70, ACA, anti-POL3) com as manifestações clínicas e laboratoriais observadas em 46 pacientes com ES da região Centro-Oeste do Brasil. Métodos: pesquisou-se a ocorrência de autoanticorpos específicos em 46 pacientes com diagnóstico de ES e correlacionou-se o tipo de autoanticorpo com as manifestações clínicas e laboratoriais encontradas. Resultados: dentre todos os pacientes avaliados, encontrou-se predomínio feminino (97,8%), idade média de 50,21 anos, cor branca (50%), forma limitada da doença (47,8%), tempo de diagnóstico entre cinco e 10 anos (50%) e tempo de evolução da doença de 9,38 anos. De acordo com o autoanticorpo específico, 24 pacientes apresentavam ACA positivo (52,2%), 15 apresentavam positividade para anti-SCL70 (32,6%) e sete apresentavam anti-POL3 positivo (15,2%). O autoanticorpo anti-SCL70 se correlacionou com a forma difusa da doença, com maior gravidade e atividade da doença, com pior qualidade de vida medida pelo índice HAQ, com maior prevalência de fenômeno de Raynaud objetivo e microcicatrizes de polpas digitais. O ACA se correlacionou com a forma limitada da doença, com o início mais precoce da enfermidade, bem como com maior prevalência de telangiectasias nos pacientes. Já o anti-POL3 se correlacionou com a forma difusa da doença, com maior ocorrência de fenômeno de Raynaud subjetivo e de atrofia muscular. Para as demais variáveis relacionadas ...
Introduction: Systemic sclerosis (SSc) is a connective tissue disease of autoimmune nature characterized by the triad of vascular injury, autoimmunity (cellular and humoral) and tissue fibrosis. Autoantibodies do not seem to be simply epiphenomena, but are involved in disease pathogenesis. It is believed that the SSc-specific autoantibodies are responsible both for amplifying immune response and targeting cell types that are relevant in the pathophysiology of SSc. Objectives: To correlate the profile of the following specific autoantibodies: anti-centromere (ACA), anti-topoisomerase I (topo I) and anti-RNA polymerase III (RNAP III) with clinical and laboratory manifestations were observed in 46 patients with SSc in the Midwest region of Brazil. Methods: The occurrence of specific autoantibodies in 46 patients with SSc was investigated, correlating the type of autoantibody with clinical and laboratory manifestations found. Results: Among all patients evaluated, we found a predominance of females (97.8%), mean age 50.21 years old, Caucasian (50%), limited cutaneous SSc (47.8%), time of diagnosis between 5 and 10 years (50%), and disease duration of 9.38 years. According to the specific autoantibody profile, 24 patients were ACA-positive (52.2%), 15 were positive for anti-topo I (32.6%), and 7 showed positive anti-RNAP III (15.2%). The anti-topo I autoantibody correlated with diffuse scleroderma, with greater disease severity and activity, with worse quality of life measured by the SHAQ index, with a higher prevalence of objective Raynaud's phenomenon and digital pitting scars of fingertips. The ACA correlated with limited scleroderma, with earlier onset of disease, as well as higher prevalence of telangiectasias. The anti-RNAP III correlated with diffuse scleroderma, with a higher occurrence of subjective Raynaud's phenomenon and muscle atrophy. There was no association between the positivity for anti-topo I, ACA and anti-RNAP III antibodies ...
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Autoanticorpos/sangue , Escleroderma Sistêmico/sangue , Escleroderma Sistêmico/imunologia , Brasil , Estudos Transversais , Estudos ProspectivosRESUMO
INTRODUCTION: Systemic sclerosis (SSc) is a connective tissue disease of autoimmune nature characterized by the triad of vascular injury, autoimmunity (cellular and humoral) and tissue fibrosis. Autoantibodies do not seem to be simply epiphenomena, but are involved in disease pathogenesis. It is believed that the SSc-specific autoantibodies are responsible both for amplifying immune response and targeting cell types that are relevant in the pathophysiology of SSc. OBJECTIVES: To correlate the profile of the following specific autoantibodies: anti-centromere (ACA), anti-topoisomerase I (topo I) and anti-RNA polymerase III (RNAP III) with clinical and laboratory manifestations observed in 46 patients with SSc in the Midwest region of Brazil. METHODS: The occurrence of specific autoantibodies in 46 patients with SSc was investigated, correlating the type of autoantibody with clinical and laboratory manifestations found. RESULTS: Among all patients evaluated, we found a predominance of females (97.8%), mean age 50.21 years old, Caucasian (50%), limited cutaneous SSc (47.8%), time of diagnosis between 5-10 years (50%), and disease duration of 9.38 years. According to the specific autoantibody profile, 24 patients were ACA-positive (52.2%), 15 were positive for anti-topo I (32.6%), and 7 showed positive anti-RNAP III (15.2%). The anti-topo I autoantibody correlated with diffuse scleroderma, with greater disease severity and activity, with worse quality of life measured by the SHAQ index, with a higher prevalence of objective Raynaud's phenomenon and digital pitting scars of fingertips. The ACA correlated with limited scleroderma, with earlier onset of disease, as well as higher prevalence of telangiectasias. The anti- RNAP III correlated with diffuse scleroderma, with a higher occurrence of subjective Raynaud's phenomenon and muscle atrophy. There was no association between the positivity for anti-topo I, ACA and anti-RNAP III antibodies and other variables related to laboratory abnormalities, as well as Rodnan skin score and skin, vascular, musculoskeletal, gastrointestinal, cardiopulmonary and renal manifestations. CONCLUSIONS: The clinical subtype of the disease and some clinical manifestations in SSc may correlate positively with the presence of specific autoantibodies.
Assuntos
Autoanticorpos/sangue , Escleroderma Sistêmico/sangue , Escleroderma Sistêmico/imunologia , Brasil , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
In this review, epidemiological, physiological, pathophysiological and pharmacological themes of cancer are dealt. So far, there are over 200types of cancers, which are linked to six key events that collectively lead to the formation of a malignance: self-sufficiency in growth signals, insensitivity to growth inhibitory signals, evasion of apoptosis, unlimited replication potential, sustained angiogenesis and invasion and metastasis. These six capabilities are possibly shared by most human tumors. In2000, there were 10 million new cancer cases and 6 million cancer deaths worldwide. According to estimates by the American Cancer Society, the disease produced approximately 556,000 deaths in 2003, corresponding to 1,500 deaths from cancer every day in America. Annually, in Chile, cancer is responsible for 23 percent of all deaths, constituting the second leading cause of death after cardiovascular diseases. They have identified several risk factors for cancer such as smoking, chronic infections, alcohol consumption, reproductive factors, hormone replacement therapy, dietary habits, sunlight, among others. These factors may cause multiple genetic alterations that involve activation of several oncogenes and the loss of two or more suppressor genes, but not a single change will lead to the formation of a neoplasm. The Knowledge of the molecular differences between normal and malignant cells could be used to target specific pathways and receptors of the latter, thus preventing normal cell death.