RESUMO
Background: Gastric cancer is one of the most common malignancies worldwide. Epirubicin (EPI) is used extensively in the treatment of multiple cancers despite its tendency to induce multidrug resistance though overexpression of the ABCB1 efflux pump. However, this overexpression can be disrupted using short interfering RNAs (siRNAs). Objective and Methods: The aim of this study was to explore approaches to reverse EPI resistance and thus increase the success of chemotherapy treatment in an EPI-resistant gastric cancer cell subline (AGS/EPI). Methods: The study focused on effects of ABCB1 knockdown by siRNA technology using TaqMan gene expression assays with quantitative real-time reverse-transcription PCR (qRT-PCR). MTT assays were performed to evaluate viability and prolifer in subline. ABCB1 protein localization and EPI intracellular fluorescence intensity in AGS/EPI cells were detected by confocal microscopy. Results: The siRNA efficiently downregulated ABCB1 mRNA in AGS/EPI cells. Thus MDR reversal was clearly demonstrated in the AGS/EPI cells, offering the possibility of future in vitro chemoresistance assays for the GC field. Conclusions: ABCB1 knockdown decreased EPI efflux and increased EPI sensitivity in AGS/EPI cells. This result provides a novel strategy for targeted gene therapy to reverse EPI resistance in gastric cancer.
Assuntos
Adenocarcinoma/tratamento farmacológico , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Epirubicina/farmacologia , RNA Interferente Pequeno/genética , Neoplasias Gástricas/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adenocarcinoma/genética , Adenocarcinoma/patologia , Antibióticos Antineoplásicos/farmacologia , Apoptose , Sobrevivência Celular , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Células Tumorais CultivadasRESUMO
PURPOSE: To propose an experimental burn model in NIH-3T3 cell line. METHODS: Induction of thermal injury in cultures of mouse fibroblast - NIH-3T3- cell line and determination of cell viability by MTT and immunofluorescence. RESULTS: The heating of the Petri dish increased proportionally to the temperature of the base and the time of exposure to microwave. In this in vitro burn model, using the cell line NIH-3T3 was observed drastic cellular injury with significant changes in cell viability and activity. It showed drastically modified cell morphology with altered membrane, cytoskeleton and nucleus, and low cellularity compared to the control group. CONCLUSION: The burn model in vitro using the cell line NIH-3T3 was reproductive and efficient. This burn model was possible to determine significant changes in cell activity and decreased viability, with drastic change in morphology, cell lysis and death.
Assuntos
Queimaduras/patologia , Técnicas de Cultura de Células/métodos , Modelos Animais de Doenças , Células NIH 3T3 , Animais , Sobrevivência Celular , Imunofluorescência , Formazans , Temperatura Alta , Técnicas In Vitro/métodos , Camundongos , Microscopia Confocal , Reprodutibilidade dos Testes , Sais de Tetrazólio , Fatores de TempoRESUMO
PURPOSE: To characterize the anatomy of the fruit and leaf and the presence of phytocompounds. To evaluate the antitumor and antimicrobial activity of ethanolic extract of Garcinia mangostana L. (mangosteen) cultivated in southeastern Brazil. METHODS: Anatomical characterization and histochemical reactions were performed for structural identification and the presence of phytocompounds. Preparation of ethanolic extract of the fruit, leaf and resin of mangosteen. Culture B16-F10 melanoma cells for treatment with mangosteen ethanolic extract to determine cell viability by MTT and genotoxic effect by comet assay. Evaluation by antimicrobial activity against Staphylococcus aureus and Escherichia coli by agar diffusion test and by determination of Minimum Inhibitory Concentration (MIC). RESULTS: Our results showed many secretory canals in resin fruit and leaf; identifying lipids, starch, lignin and phenolic compounds. The leaf extract induced genotoxicity and apoptosis in B16-F10 cells, since the fragmentation of DNA in the comet assay. The ethanolic extract of mangosteen obtained in the resin, leaf and fruit showed antimicrobial activity against Staphylococcus aureus and Escherichia coli with a MIC at 0.1 mg/mL. CONCLUSION: In conclusion, we have demonstrated both antimicrobial and antitumor activity of ethanol extract of mangosteen emphasizing its therapeutic potential in infectious diseases and in cancer, such as melanoma.
Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Garcinia mangostana/química , Extratos Vegetais/farmacologia , Animais , Antineoplásicos Fitogênicos/isolamento & purificação , Brasil , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Ensaio de Imunoadsorção Enzimática , Frutas/química , Melanoma/tratamento farmacológico , Camundongos , Testes de Sensibilidade Microbiana , Reprodutibilidade dos Testes , Staphylococcus aureus/efeitos dos fármacos , Fatores de TempoRESUMO
Gastric cancer (GC) remains a virtually incurable disease when metastatic and requires early screening tools for detection of early tumor stages. Therefore, finding effective strategies for prevention or recurrence of GC has become a major overall initiative. RNA-interference (RNAi) is an innovative technique that can significantly regulate the expression of oncogenes involved in gastric carcinogenesis, thus constituting a promising epigenetic approach to GC therapy. This review presents recent advances concerning the promising biomolecular mechanism of RNAi for GC treatment.
Assuntos
Recidiva Local de Neoplasia/prevenção & controle , RNA Interferente Pequeno/uso terapêutico , Neoplasias Gástricas/genética , Neoplasias Gástricas/terapia , Transformação Celular Neoplásica/genética , Citocinas/biossíntese , Citocinas/genética , Humanos , Recidiva Local de Neoplasia/genética , Proteínas Oncogênicas/biossíntese , Proteínas Oncogênicas/genética , Interferência de RNA , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genéticaRESUMO
Multidrug resistance (MDR) is a major impediment to successful chemotherapy of gastric cancer. Our aim was to establish an epirubicin-resistant cell subline (AGS/EPI) and to elucidate the mechanisms involved in acquired EPI resistance. The AGS/EPI cell subline developed by exposing parental AGS cells to stepwise increasing concentrations of EPI demonstrated 2.52-fold resistance relative to the AGS cell line, and mRNA expression of the ATP-dependent drug-efflux pump P-glycoprotein (Pgp), more recently known as ABCB1 protein, was similarly upregulated. An AGS/EPI cell subline could thus be effectively established, and MDR mechanism of these cells was shown to be related to the overexpression of mRNA of the ABCB1 gene.
Assuntos
Antibióticos Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Epirubicina/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP/biossíntese , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Apoptose/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/genética , Humanos , RNA Mensageiro/biossíntese , Neoplasias Gástricas/genéticaRESUMO
PURPOSE: To characterize the anatomy of the fruit and leaf and the presence of phytocompounds. To evaluate the antitumor and antimicrobial activity of ethanolic extract of Garcinia mangostana L. (mangosteen) cultivated in southeastern Brazil. METHODS: Anatomical characterization and histochemical reactions were performed for structural identification and the presence of phytocompounds. Preparation of ethanolic extract of the fruit, leaf and resin of mangosteen. Culture B16-F10 melanoma cells for treatment with mangosteen ethanolic extract to determine cell viability by MTT and genotoxic effect by comet assay. Evaluation by antimicrobial activity against Staphylococcus aureus and Escherichia coli by agar diffusion test and by determination of Minimum Inhibitory Concentration (MIC). RESULTS: Our results showed many secretory canals in resin fruit and leaf; identifying lipids, starch, lignin and phenolic compounds. The leaf extract induced genotoxicity and apoptosis in B16-F10 cells, since the fragmentation of DNA in the comet assay. The ethanolic extract of mangosteen obtained in the resin, leaf and fruit showed antimicrobial activity against Staphylococcus aureus and Escherichia coli with a MIC at 0.1 mg/mL. CONCLUSION: In conclusion, we have demonstrated both antimicrobial and antitumor activity of ethanol extract of mangosteen emphasizing its therapeutic potential in infectious diseases and in cancer, such as melanoma. .
Assuntos
Animais , Camundongos , Anti-Infecciosos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Garcinia mangostana/química , Extratos Vegetais/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Brasil , Linhagem Celular Tumoral , Ensaio Cometa , Sobrevivência Celular/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Frutas/química , Testes de Sensibilidade Microbiana , Melanoma/tratamento farmacológico , Reprodutibilidade dos Testes , Staphylococcus aureus/efeitos dos fármacos , Fatores de TempoRESUMO
PURPOSE: To propose an experimental burn model in NIH-3T3 cell line. METHODS: Induction of thermal injury in cultures of mouse fibroblast - NIH-3T3- cell line and determination of cell viability by MTT and imunofluorescence. RESULTS: The heating of the Petri dish increased proportionally to the temperature of the base and the time of exposure to microwave. In this in vitro burn model, using the cell line NIH-3T3 was observed drastic cellular injury with significant changes in cell viability and activity. It showed drastically modified cell morphology with altered membrane, cytoskeleton and nucleus, and low cellularity compared to the control group. CONCLUSION: The burn model in vitro using the cell line NIH-3T3 was reproductive and efficient. This burn model was possible to determine significant changes in cell activity and decreased viability, with drastic change in morphology, cell lysis and death. .
Assuntos
Animais , Camundongos , Queimaduras/patologia , Técnicas de Cultura de Células/métodos , Modelos Animais de Doenças , Sobrevivência Celular , Imunofluorescência , Formazans , Temperatura Alta , Técnicas In Vitro/métodos , Microscopia Confocal , Reprodutibilidade dos Testes , Sais de Tetrazólio , Fatores de TempoRESUMO
Tocopherols promote or inhibit growth in different cell types. In the hematopoietic system, the radioprotective property of tocopherols is thought to act through the expansion of primitive hematopoietic cells. However, the mechanisms activated by tocopherols and which HPs are affected remain poorly understood. To better address these questions, mice were treated with α-tocopherol, and its effects were investigated in the BM microenvironment. α-Tocopherol induced increased proliferation in HSC/HP cells, leading to BM hyperplasia. In addition, differentiation to the granulocytic/monocytic lineage was enhanced by α-tocopherol treatment. α-Tocopherol treatment resulted in decreased basal phosphorylation of ERK1/2, PKC, and STAT-5 in HSC/HP cells. In contrast, α-tocopherol enhanced ERK1/2 activation in response to IL-3 stimulation in HSC/HP cells without altering the expression of IL-3Rs. Moreover, α-tocopherol-induced differentiation and ERK1/2 activation were abolished in mice pretreated with a MEK inhibitor (PD98059); however, pretreatment with PD98059 did not reduce the α-tocopherol-mediated increase in HSC/HP cells but instead, further enhanced their proliferation. Therefore, α-tocopherol induces expansion of HSC/HP cells by a nonidentified intracellular pathway and granulocytic/monocytic differentiation through ERK1/2 activation.
