RESUMO
PURPOSE: The importance of the DNA damage response in mediating effects of radiotherapy (RT) has galvanized efforts to target this pathway with radiosensitizers. Yet early clinical trials of this approach have failed to yield a benefit in unselected populations. We hypothesized that ataxia-telangiectasia mutated (Atm)-null tumors would demonstrate genotype-specific synergy between RT and an inhibitor of the DNA damage response protein ataxia-telangiectasia and Rad3-related (ATR) kinase. EXPERIMENTAL DESIGN: We investigated the synergistic potential of the ATR inhibitor (ATRi) RP-3500 and RT in two Atm-null and isogenic murine models, both in vitro and in vivo. Staining of γ-H2AX foci, characterization of the immune response via flow cytometry, and tumor rechallenge experiments were performed to elucidate the mechanism of interaction. To examine genotype specificity, we tested the interaction of ATRi and RT in a Brca1-null model. Finally, patients with advanced cancer with ATM alterations were enrolled in a phase I/II clinical trial to validate preclinical findings. RESULTS: Synergy between RP-3500 and RT was confirmed in Atm-null lines in vitro, characterized by an accumulation of DNA double-strand breaks. In vivo, Atm-null tumor models had higher rates of durable control with RT and ATRi than controls. In contrast, there was no synergy in tumors lacking Brca1. Analysis of the immunologic response indicated that efficacy is largely mediated by cell-intrinsic mechanisms. Lastly, early results from our clinical trial showed complete responses in patients. CONCLUSIONS: Genotype-directed radiosensitization with ATRi and RT can unleash significant therapeutic benefit and could represent a novel approach to develop more effective combinatorial synthetic cytotoxic RT-based treatments.
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Arabidopsis microRNA165a (miR165a) targets Class III Homeodomain Leucine-Zipper (HD-ZIPIII) transcription factors to regulate various aspects of plant development and stress response. Over-expression of miR165a mimics the loss-of-function phenotype of HD-ZIPIII genes and leading to ectopic organ formation, shoot apical meristem (SAM) termination, loss of leaf polarity, and defective vasculature development. However, the molecular mechanisms underlying these phenotypes remain unresolved. Here, we over-expressed miR165a in a dexamethasone inducible manner and identified differentially expressed genes in the SAM through RNA-Seq. Simultaneously, using multi-channel FACS combined with RNA-Seq approach, we characterized global transcriptome patterns in miR165a expressing cell-types compared to HD-ZIPIII expressing cell-types and other cell-types in SAM. By integrating our results we identified sets of genes which are up-regulated by miR165a as well have enriched expression in miR165a cell-types, and vice-versa. Known plant development related genes such as HD-ZIPIII and their targets LITTLE ZIPPERs, Like AUXIN RESISTANT 2, BEL1-like homeodomain 6, ROTUNDIFOLIA like 16 were found to be down-regulated. Among the up-regulated genes, GIBBERELLIN 2-OXIDASEs, various elemental transporters (YSL3, ZIFL1, SULTR), and other transporter genes were prominent. Thus, the genes identified in this study help to unravel the molecular mechanism of miR165a and HD-ZIPIII regulated plant development and stress response.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Meristema , Transcriptoma , MicroRNAs/genéticaRESUMO
SETD2 is a histone H3 lysine 36 (H3K36) trimethyltransferase that is mutated with high prevalence (13%) in clear cell renal cell carcinoma (ccRCC). Genomic profiling of primary ccRCC tumors reveals a positive correlation between SETD2 mutations and metastasis. However, whether and how SETD2 loss promotes metastasis remains unclear. In this study, we used a SETD2-mutant (SETD2MT) metastatic ccRCC human-derived cell line and xenograft models and showed that H3K36me3 restoration greatly reduced distant metastases of ccRCC in mice in a matrix metalloproteinase 1 (MMP1)-dependent manner. An integrated multiomics analysis using assay for transposase-accessible chromatin using sequencing (ATAC-seq), chromatin immunoprecipitation-sequencing (ChIP-seq) and RNA sequencing (RNA-seq) established a tumor suppressor model in which loss of SETD2-mediated H3K36me3 activates enhancers to drive oncogenic transcriptional output through regulation of chromatin accessibility. Furthermore, we uncovered mechanism-based therapeutic strategies for SETD2-deficient cancer through the targeting of specific histone chaperone complexes, including ASF1A/ASF1B and SPT16. Overall, SETD2 loss creates a permissive epigenetic landscape for cooperating oncogenic drivers to amplify transcriptional output, providing unique therapeutic opportunities.
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Carcinoma de Células Renais , Histona-Lisina N-Metiltransferase/metabolismo , Neoplasias Renais , Animais , Carcinogênese/genética , Carcinoma de Células Renais/genética , Proteínas de Ciclo Celular/genética , Epigênese Genética , Feminino , Chaperonas de Histonas/genética , Histona-Lisina N-Metiltransferase/genética , Histonas/genética , Humanos , Neoplasias Renais/genética , Masculino , Camundongos , Chaperonas Moleculares/genéticaRESUMO
The clinical success of EGFR inhibitors in EGFR-mutant lung cancer is limited by the eventual development of acquired resistance. We hypothesize that enhancing apoptosis through combination therapies can eradicate cancer cells and reduce the emergence of drug-tolerant persisters. Through high-throughput screening of a custom library of â¼1,000 compounds, we discover Aurora B kinase inhibitors as potent enhancers of osimertinib-induced apoptosis. Mechanistically, Aurora B inhibition stabilizes BIM through reduced Ser87 phosphorylation, and transactivates PUMA through FOXO1/3. Importantly, osimertinib resistance caused by epithelial-mesenchymal transition (EMT) activates the ATR-CHK1-Aurora B signaling cascade and thereby engenders hypersensitivity to respective kinase inhibitors by activating BIM-mediated mitotic catastrophe. Combined inhibition of EGFR and Aurora B not only efficiently eliminates cancer cells but also overcomes resistance beyond EMT.
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Acrilamidas/farmacologia , Compostos de Anilina/farmacologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Pulmonares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Aurora Quinase B/antagonistas & inibidores , Proteína 11 Semelhante a Bcl-2/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ensaios de Triagem em Larga Escala , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Proteínas Proto-Oncogênicas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologiaRESUMO
Lineage plasticity is implicated in treatment resistance in multiple cancers. In lung adenocarcinomas (LUAD) amenable to targeted therapy, transformation to small cell lung cancer (SCLC) is a recognized resistance mechanism. Defining molecular mechanisms of neuroendocrine (NE) transformation in lung cancer has been limited by a paucity of pre/posttransformation clinical samples. Detailed genomic, epigenomic, transcriptomic, and protein characterization of combined LUAD/SCLC tumors, as well as pre/posttransformation samples, supports that NE transformation is primarily driven by transcriptional reprogramming rather than mutational events. We identify genomic contexts in which NE transformation is favored, including frequent loss of the 3p chromosome arm. We observed enhanced expression of genes involved in the PRC2 complex and PI3K/AKT and NOTCH pathways. Pharmacologic inhibition of the PI3K/AKT pathway delayed tumor growth and NE transformation in an EGFR-mutant patient-derived xenograft model. Our findings define a novel landscape of potential drivers and therapeutic vulnerabilities of NE transformation in lung cancer. SIGNIFICANCE: The difficulty in collection of transformation samples has precluded the performance of molecular analyses, and thus little is known about the lineage plasticity mechanisms leading to LUAD-to-SCLC transformation. Here, we describe biological pathways dysregulated upon transformation and identify potential predictors and potential therapeutic vulnerabilities of NE transformation in the lung. See related commentary by Meador and Lovly, p. 2962. This article is highlighted in the In This Issue feature, p. 2945.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Tumores Neuroendócrinos , Carcinoma de Pequenas Células do Pulmão , Adenocarcinoma de Pulmão/tratamento farmacológico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Mutação , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/patologia , Fosfatidilinositol 3-Quinases/genética , Carcinoma de Pequenas Células do Pulmão/patologiaRESUMO
Adolescents, pregnant women and mothers of children under 2 years of age are in stages of life characterized by higher nutritional demands. The study measured the dietary diversity of 17,680 adolescent girls, pregnant women and mothers of children under age 2 years in the eastern Indian states of Bihar, Chhattisgarh and Odisha using data from the Swabhimaan baseline survey conducted in 2016. The association of women's mean Dietary Diversity Scores with socioeconomic, health and nutrition service indicators was assessed. The sampled population was socioeconomically more vulnerable than the average Indian population. There was not much variation in the types of foods consumed daily across target groups, with diet being predominantly cereal (98%) and vegetable (83%) based. Nearly 30% of the mothers had low Dietary Diversity Scores, compared with 25% of pregnant women and 24% of adolescent girls. In each target group, more than half of the respondents were unable to meet the Minimum Dietary Diversity score of at least five of ten food groups consumed daily. Irrespective of their background characteristics, mean Dietary Diversity Scores were significantly lower in Bihar than in Chhattisgarh and Odisha for all target groups. Having at least 6 years of education, belonging to a relatively rich household and possessing a ration card predicted mean dietary diversity. Project interventions of participatory women's group meetings improved mean Dietary Diversity Scores for mothers and adolescent girls. Considering the association between poverty and dietary diversity, the linkage between girls and women and nutrition-focused livelihoods and supplementary nutrition programmes needs to be tested.
Assuntos
Mães , Gestantes , Adolescente , Criança , Pré-Escolar , Dieta , Feminino , Humanos , Índia , Lactente , Estado Nutricional , Gravidez , População RuralRESUMO
Acute kidney injury (AKI) is characterized by injury to the tubular epithelium that leads to the sudden loss of renal function. Proper tubular regeneration is essential to prevent progression to chronic kidney disease. In this study, we examined the role of FoxM1, a forkhead box family member transcription factor in tubular repair after AKI. Renal FoxM1 expression increased after renal ischemia/reperfusion (I/R)-induced AKI in mouse kidneys. Treatment with thiostrepton, a FoxM1 inhibitor, reduced FoxM1 regulated pro-proliferative factors and cell proliferation in vitro, and tubular regeneration in mouse kidneys after AKI. Glycogen synthase kinase-3 (GSK3) was found to be an upstream regulator of FoxM1 because GSK3 inhibition or renal tubular GSK3ß gene deletion significantly increased FoxM1 expression, and improved tubular repair and renal function. GSK3 inactivation increased ß-catenin, Cyclin D1, and c-Myc, and reduced cell cycle inhibitors p21 and p27. Importantly, thiostrepton treatment abolished the improved tubular repair in GSK3ß knockout mice following AKI. These results demonstrate that FoxM1 is important for renal tubular regeneration following AKI and that GSK3ß suppresses tubular repair by inhibiting FoxM1.
Assuntos
Injúria Renal Aguda/metabolismo , Proteína Forkhead Box M1/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Linhagem Celular , Proliferação de Células , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Túbulos Renais/patologia , Túbulos Renais/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RegeneraçãoRESUMO
BACKGROUND: Fibrosis is a major cause of loss of renal function in autosomal dominant polycystic kidney disease (ADPKD). In this study, we examined whether vasopressin type-2 receptor (V2R) activity in cystic epithelial cells can stimulate interstitial myofibroblasts and fibrosis in ADPKD kidneys. METHODS: We treated Pkd1 gene knockout (Pkd1KO) mice with dDAVP, a V2R agonist, for 3 days and evaluated the effect on myofibroblast deposition of extracellular matrix (ECM). We also analyzed the effects of conditioned media from primary cultures of human ADPKD cystic epithelial cells on myofibroblast activation. Because secretion of the profibrotic connective tissue growth factor (CCN2) increased significantly in dDAVP-treated Pkd1KO mouse kidneys, we examined its role in V2R-dependent fibrosis in ADPKD as well as that of yes-associated protein (YAP). RESULTS: V2R stimulation using dDAVP increased the renal interstitial myofibroblast population and ECM deposition. Similarly, conditioned media from human ADPKD cystic epithelial cells increased myofibroblast activation in vitro, suggesting a paracrine mechanism. Renal collecting duct-specific gene deletion of CCN2 significantly reduced cyst growth and myofibroblasts in Pkd1KO mouse kidneys. We found that YAP regulates CCN2, and YAP inhibition or gene deletion reduces renal fibrosis in Pkd1KO mouse kidneys. Importantly, YAP inactivation blocks the dDAVP-induced increase in myofibroblasts in Pkd1KO kidneys. Further in vitro studies showed that V2R regulates YAP by an ERK1/2-dependent mechanism in human ADPKD cystic epithelial cells. CONCLUSIONS: Our results demonstrate a novel mechanism by which cystic epithelial cells stimulate myofibroblasts in the pericystic microenvironment, leading to fibrosis in ADPKD. The V2R-YAP-CCN2 cell signaling pathway may present a potential therapeutic target for fibrosis in ADPKD.
Assuntos
Proteínas de Ciclo Celular/fisiologia , Fator de Crescimento do Tecido Conjuntivo/fisiologia , Rim/patologia , Miofibroblastos/fisiologia , Rim Policístico Autossômico Dominante/patologia , Receptores de Vasopressinas/fisiologia , Fatores de Transcrição/fisiologia , Animais , Desamino Arginina Vasopressina/farmacologia , Matriz Extracelular/metabolismo , Fibrose , Humanos , Camundongos , Canais de Cátion TRPP/fisiologiaRESUMO
Arginine vasopressin (AVP) and its type-2 receptor (V2R) play an essential role in the regulation of salt and water homeostasis by the kidneys. V2R activation also stimulates proliferation of renal cell carcinoma (RCC) cell lines in vitro. The current studies investigated V2R expression and activity in human RCC tumors, and its role in RCC tumor growth. Examination of the cancer genome atlas (TCGA) database, and analysis of human RCC tumor tissue microarrays, cDNA arrays and tumor biopsy samples demonstrated V2R expression and activity in clear cell RCC (ccRCC). In vitro, V2R antagonists OPC31260 and Tolvaptan, or V2R gene silencing reduced wound closure and cell viability of 786-O and Caki-1 human ccRCC cell lines. Similarly in mouse xenograft models, Tolvaptan and OPC31260 decreased RCC tumor growth by reducing cell proliferation and angiogenesis, while increasing apoptosis. In contrast, the V2R agonist dDAVP significantly increased tumor growth. High intracellular cAMP levels and ERK1/2 activation were observed in human ccRCC tumors. In mouse tumors and Caki-1 cells, V2R agonists reduced cAMP and ERK1/2 activation, while dDAVP treatment had the reverse effect. V2R gene silencing in Caki-1 cells also reduced cAMP and ERK1/2 activation. These results provide novel evidence for a pathogenic role of V2R signaling in ccRCC, and suggest that inhibitors of the AVP-V2R pathway, including the FDA-approved drug Tolvaptan, could be utilized as novel ccRCC therapeutics.
Assuntos
Carcinoma de Células Renais/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Renais/tratamento farmacológico , Receptores de Vasopressinas/química , Tolvaptan/farmacologia , Animais , Antagonistas dos Receptores de Hormônios Antidiuréticos/farmacologia , Apoptose , Biomarcadores Tumorais , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Estudos de Casos e Controles , Ciclo Celular , Proliferação de Células , Feminino , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Camundongos , Camundongos Nus , Prognóstico , Receptores de Vasopressinas/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
INTRODUCTION: Swabhimaan is a community-based programme to improve adolescent girls' and women's nutrition in the rural areas of three Indian states-Bihar, Chhattisgarh and Odisha with high prevalence of undernutrition. METHODS AND ANALYSIS: Swabhimaan has a nested prospective, non-randomised controlled evaluation. Since 2017, five intervention sites receive community-led interventions through national government's livelihood mission supported women's self-help group federations and five control sites will initiate these activities 36 months later, in 2020. Community-led activities aim to improve coverage of 18 interventions including adequacy of food consumed, prevention of micronutrient deficiencies, access to basic health services and special care of nutritionally 'at risk' girls and women, improving hygiene and access to water and sanitation services and access to family planning services. The evaluation includes baseline (2016-2017), midline (2018-2019) and endline (2020-2021) surveys covering 6638 adolescent girls, 2992 pregnant women and 8755 mothers of children under 2. The final impact analysis will be by intention to treat, comparing primary and secondary outcomes in five intervention areas and five control areas. The primary outcomes are: (1) a 15% reduction in the proportion of adolescent girls with a body mass index (BMI) <18.5 kg/m2; (2) a 15% reduction in the proportion of mothers of children under two with a BMI <18.5 kg/m2 and (3) and a 0.4 cm improvement in mean mid-upper arm circumference among pregnant women. ETHICS AND DISSEMINATION: All procedures involving human subjects were approved by the Institutional Ethics Committee of the All India Institute of Medical Sciences, Bihar, Chhattisgarh and Odisha and in compliance with guidelines laid down in the Declaration of Helsinki. Evidence will inform maternal and preconception nutrition policy at national and state level. TRIAL REGISTRATION NUMBER: 58261b2f46876 and CTRI/2016/11/007482; Pre-results.
Assuntos
Desnutrição/prevenção & controle , Ensaios Clínicos Controlados não Aleatórios como Assunto , Estado Nutricional , Cuidado Pós-Natal/métodos , Cuidado Pré-Concepcional/métodos , Complicações na Gravidez/prevenção & controle , Cuidado Pré-Natal/métodos , Adolescente , Adulto , Feminino , Humanos , Índia , Lactente , Recém-Nascido , Gravidez , Estudos Prospectivos , Saúde da População Rural , Adulto JovemRESUMO
Fly ash (FA) being a heterogeneous mixture of heavy metal affects plant system in various ways. Previous studies have shown bioaccumulation of toxic metals in the plants and disturbance in cellular activities. Here, we have studied the impacts of FA treatment through the life cycle of economically important, annual crop plant mustard (Brassica juncea and Brassica alba). Result revealed that FA did not alter germination rate and photosynthetic pigment levels. Tolerance index of B. juncea was higher compared to B. alba. Seed setting was significantly affected by FA in B. alba. Significant increase in DNA damage was observed in both B. alba and B. juncea. Proline accumulation was significantly higher in B. alba. In B. juncea catalase activity and reduced glutathione content declined in initial days which were restored at the end of experimental period. Significant decrease in non-enzymatic antioxidants was noted in B. alba. Higher accumulation of Pb and As was noted in shoot of B. juncea and in B. alba Cu, Pb, Cr and As accumulated in shoots. As observed from these results, both plants could translocate certain toxic heavy metals from roots to the shoot which affected the physiological and biochemical balance and induced genotoxic response.
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Cinza de Carvão/toxicidade , Mostardeira/fisiologia , Estresse Oxidativo/fisiologia , Sinapis/fisiologia , Poluentes do Solo/toxicidade , Antioxidantes , Dano ao DNA , Germinação , Glutationa/metabolismo , Metais Pesados , Mostardeira/efeitos dos fármacos , Mostardeira/metabolismo , Fotossíntese , Raízes de Plantas/metabolismo , Sementes/metabolismo , Sinapis/metabolismoRESUMO
ZnO-np has immense potential and application in cosmetic and health care sectors. Hence it was imperative to assess the toxicity/safety of these nanoparticles. In this study, we have evaluated the effects of ZnO-np in human peripheral blood mononuclear cells (PBMCs) in vitro and in Swiss albino male mice in vivo for cyto-genotoxicity and oxidative damage. In vitro results showed that ZnO-nps were weakly genotoxic, induced significant decrease in mitochondrial membrane potential and was capable of ROS generation, leading to apoptosis. In bone marrow cells in vivo, reduction of mitochondrial membrane potential (MMP), increased oxidative stress and G0/G1 cell cycle arrest was observed along with chromosome aberrations and micronuclei formation. In liver cells DNA damage and induction of oxidative stress with concurrent decrease in inhibition of antioxidant enzymes were noted. These in vitro and in vivo results demonstrated that ZnO-np induced genotoxic response and ROS production leading to apoptotic cell death and established a good co-relation between the two biological systems. More importantly, the results stress on the need of multiple endpoint assay-approaches, with an in vitro-in vivo study design to assess nanoparticle toxicology.
Assuntos
Apoptose/efeitos dos fármacos , Medula Óssea/patologia , Dano ao DNA/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Nanopartículas Metálicas/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Óxido de Zinco/toxicidade , Animais , Antioxidantes/metabolismo , Medula Óssea/efeitos dos fármacos , Aberrações Cromossômicas/efeitos dos fármacos , Dano ao DNA/genética , Fármacos Dermatológicos/administração & dosagem , Fármacos Dermatológicos/toxicidade , Humanos , Técnicas In Vitro , Linfócitos/metabolismo , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Óxido de Zinco/administração & dosagemRESUMO
Cytotoxicity, genotoxicity, and biochemical effects were evaluated in the plants Allium cepa, Nicotiana tabacum, and Vicia faba following exposure to ZnO nanoparticles (np; diameter, â¼85nm). In the root meristems of Allium cepa cells, we observed loss of membrane integrity, increased chromosome aberrations, micronucleus formation, DNA strand breaks, and cell-cycle arrest at the G2/M checkpoint. In Vicia faba and Nicotiana tabacum, we observed increased intracellular ROS production, lipid peroxidation, and activities of some antioxidant enzymes. TEM images revealed gross morphological alterations and internalization of the np. Our findings provide evidence of ZnO np toxicity, characterized by deregulation of components of ROS-antioxidant machinery, leading to DNA damage, cell-cycle arrest, and cell death. These plants, especially Allium cepa, are reliable systems for assessment of np toxicology.
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Dano ao DNA , Pontos de Checagem da Fase G2 do Ciclo Celular , Peroxidação de Lipídeos , Meristema/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Óxido de Zinco/toxicidade , Allium , Meristema/metabolismo , Nanopartículas Metálicas/química , Nicotiana , Vicia fabaRESUMO
Clinical efficacy of the widely used anticancer drug cisplatin is limited due to its adverse side effects in normal tissues mediated by oxidative stress. This study was aimed to investigate the protective effects of vetiver acetate oil, Java (VO) against cisplatin-induced toxicity in Swiss albino mice. The ameliorating potential was evaluated by orally priming the animals with VO at doses 5, 10 or 20 mg/kg bw for 7 days prior to cisplatin treatment. Acute toxicity in mice was induced by injecting cisplatin (3 mg/kg bw) intraperitoneally for 5 consecutive days. Significant attenuation of renal toxicity was confirmed by histopathological examination, lowered levels of serum blood urea nitrogen, creatinine and reduced DNA damage. VO also compensated deficits in the renal antioxidant system. VO intervention significantly inhibited DNA damage, clastogenic effects, and cell cycle arrest in the bone marrow cells of mice. Hematological parameters indicated attenuation of cisplatin-induced myelosuppression. Overall, this study provides for the first time that VO has a protective role in the abatement of cisplatin-induced toxicity in mice which may be attributed to its antioxidant activity.
Assuntos
Células da Medula Óssea/efeitos dos fármacos , Cisplatino/efeitos adversos , Rim/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Óleos de Plantas/farmacologia , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antioxidantes/farmacologia , Nitrogênio da Ureia Sanguínea , Células da Medula Óssea/metabolismo , Cisplatino/administração & dosagem , Creatinina/sangue , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glutationa/sangue , Rim/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Testes para Micronúcleos , Testes de Toxicidade AgudaRESUMO
Fluoride generated the attention of toxicologists due to its deleterious effects at high concentrations in human populations suffering from fluorosis and with in vivo experimental models. Interest in its undesirable effects has resurfaced due to the awareness that this element interacts with cellular systems even at low doses. This study focused on examining the adverse effects of inorganic fluoride (NaF) on human lymphocyte cells in vitro. Mitochondrial function, oxidative stress, cell cycle progression, and mode of cell death were combined with genotoxic endpoints. Data demonstrated that NaF at lower concentrations, although not significantly cytotoxic and genotoxic, induced oxidative stress leading to apoptotic cell death. The results also suggested that at low concentrations (<1 µg/ml), NaF may affect cell cycle progression. Taken together, our findings confirm earlier reports on mechanisms involved in NaF-induced apoptosis.
Assuntos
Apoptose/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Fluoreto de Sódio/efeitos adversos , Divisão Celular/efeitos dos fármacos , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Humanos , Linfócitos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Testes para Micronúcleos , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacosRESUMO
The present investigation was undertaken to study the cytotoxic and genotoxic potential of the essential oils (palmarosa, citronella, lemongrass and vetiver) and monoterpenoids (citral and geraniol) in human lymphocytes. Trypan blue dye exclusion and MTT test was used to evaluate cytotoxicity. The genotoxicity studies were carried out by comet and DNA diffusion assays. Apoptosis was confirmed by Annexin/PI double staining. In addition, generation of reactive oxygen species was evaluated by DCFH-DA staining using flow cytometry. The results demonstrated that the four essential oils and citral induced cytotoxicity and genotoxicity at higher concentrations. The essential oils were found to induce oxidative stress evidenced by the generation of reactive oxygen species. With the exception of geraniol, induction of apoptosis was confirmed at higher concentrations of the test substances. Based on the results, the four essential oils are considered safe for human consumption at low concentrations.
Assuntos
Cymbopogon/química , Linfócitos/efeitos dos fármacos , Óleos Voláteis/toxicidade , Monoterpenos Acíclicos , Adulto , Apoptose/efeitos dos fármacos , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Fluoresceínas/química , Humanos , Monoterpenos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Terpenos/toxicidade , Adulto JovemRESUMO
A short-term in vivo genotoxicity evaluation of 4-carboxyl-2,6-dinitrophenylazohydronaphthalenes (AZ-01 to AZ-04) has been carried out in mice. Aqueous colloidal solutions of the dyes were administered to mice on each day for 5 successive days using gastric gavages. Two end point assessments of the genotoxicity potentials of the dyes were assessed using comet assay and chromosomal aberration studies using the mice bone marrow cells. The dyes were well tolerated at the doses investigated, as there were no deaths or any adverse pharmacotoxic events. Dose-dependent DNA damage (in terms of percentage of tail DNA and Olive tail moment) occurred with AZ-01 and AZ-02, although the effects were significant only with the highest doses. AZ-03 gave similar patterns with those of AZ-01 and AZ-02, while replacement with butanone in AZ-04 altered the observed pattern. Minimal chromosomal damages were obtained for the four dyes, with AZ-01 and AZ-02 giving nonsignificant damages, while the highest dose of AZ-03 produced significant aberrations in terms of breaks. Some minor isochromatid breaks and gaps were also noticed in the dye-treated mice. Mitotic indices in all cases were not significantly different from concomitantly administered vehicle control showing lack of cytotoxicity of the monoazo dyes at these doses. The monoazo dyes show the potential of being utilized as colorants, pending further required tests.
Assuntos
Compostos Azo/toxicidade , Corantes/toxicidade , Naftalenos/toxicidade , Animais , Aberrações Cromossômicas/induzido quimicamente , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Masculino , Camundongos , Testes de MutagenicidadeRESUMO
Fluoride compounds are naturally present in soil, water and food. The objective of this study was to investigate the genotoxic and oxidative damage induced by chronic fluoride exposure on mammalian cells in vivo. For this purpose, the genotoxic potential was investigated in bone marrow cells by the micronucleus test, chromosome aberration assay and comet assay (DNA strand breaks). In addition, DNA damage was evaluated in soft tissues and organs like spleen, liver and kidney cells. The oxidative damage was assessed by selective biochemical parameters by the measurement of lipid peroxidation, reduced glutathione (GSH), glutathione S-transferase (GST) and catalase (CAT) activity in liver. Adult Swiss albino male mice were exposed to sodium fluoride in drinking water at the concentrations of 4, 12 and 20mg/L for 30 consecutive days. Control groups (vehicle and positive) were also included. Animals were sacrificed; bone marrow and soft tissue samples were collected and subjected to series of assays respectively. We observed that NaF exposure, at the various concentrations tested caused a significant increase in the frequency of micronucleus (MN) in polychromatic erythrocytes (PCEs), structural chromosome aberrations in bone marrow cells. With the exception of the spleen cells, DNA damage was observed in bone marrow cells as well as in kidney and liver cells. We found an increase in lipid peroxidation, and catalase activity as well as decrease in glutathione activity (GSH and GST) in liver of mice respectively which were exposed to sodium fluoride. In conclusion, the data obtained clearly documents that NaF exhibits genotoxic activity and enhanced oxidative damage in mouse model.
Assuntos
Dano ao DNA , Determinação de Ponto Final , Estresse Oxidativo , Fluoreto de Sódio/toxicidade , Animais , Aberrações Cromossômicas , Ensaio Cometa , Quebras de DNA , Fígado/metabolismo , Camundongos , Testes para MicronúcleosRESUMO
The biocidal effect of silver nanoparticles (Ag-np) has resulted in their incorporation into consumer products. While the population exposed to Ag-np continues to increase with ever new applications, Ag-np remains a controversial research area with regard to their toxicity in biological systems. Here a genotoxic and cytotoxic approach was employed to elucidate the activity of Ag-np in vitro and in vivo. Characterization of Ag-np using scanning electron microscopy revealed a size range of 90-180nm. Cytotoxic potential of Ag-np was evaluated in human lymphocytes via cell viability assay (Trypan blue dye exclusion method, MTT and WST assay). The uptake and incorporation of Ag-np into the lymphocytes was confirmed by flow cytometry. Additionally apoptosis (AnnexinV-FITC-PI staining) and DNA strand breaks (comet assay) in human lymphocytes revealed that Ag-np at concentration 25µg/ml can cause genotoxicity. In vivo experiments on plants (Allium cepa and Nicotiana tabacum) and animal (Swiss albino male mice) showed impairment of nuclear DNA. Induction of oxidative stress was also studied. The DNA damage and chromosomal aberrations raise the concern about the safety associated with applications of the Ag-np. A single ip administration of Ag-np gave a significant (P≤0.05) increase in the frequency of aberrant cells and Tail DNA percent at concentrations 10mg/kg body weight and above. Results of comet assay in A. cepa and N. tabacum demonstrated that the genotoxic effect of Ag-np was more pronounced in root than shoot/leaf of the plants. The present study indicated a good correlation between the in vitro and in vivo experiments. Therefore the biological applications employing Ag-np should be given special attention besides adapting the antimicrobial potential.
Assuntos
Dano ao DNA , Mutagênicos/toxicidade , Nanopartículas/toxicidade , Prata/toxicidade , Animais , Apoptose , Células da Medula Óssea , Ensaio Cometa , Humanos , Linfócitos/efeitos dos fármacos , Camundongos , Cebolas , Espécies Reativas de Oxigênio , NicotianaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Essential oils of palmarosa and citronella have been extensively used in ancient Indian and South-east Asian traditional medicines. AIM OF THE STUDY: These essential oils have been reported to exhibit antimicrobial, anti parasitic effects against bacteria, yeasts, filamentous fungi, and viruses. In the present study the oils were tested for their potential antigenotoxic and antioxidant properties in human lymphocyte cells. MATERIALS AND METHODS: The antigenotoxic effect on human lymphocyte cells (measurement of cell viability, DNA damage) was studied using trypan blue dye exclusion test, plasmid pBR322 DNA strand scission, and comet assay. Anti-oxidant activity was evaluated by DPPH(+) free radical scavenging and lipid peroxidation assay. RESULTS: The essential oils showed a good antigenotoxic activity against methyl methanesulphonate (MMS) and hydrogen peroxide. In addition, a significant dose dependent antioxidant activity was observed. CONCLUSION: Our data provide evidence that support the usage of palmarosa and citronella essential oils in traditional herbal preparations. They can constitute a natural source of a new and safe antioxidant.