RESUMEN
A significant amount of research toward commercial development of cellulose based nanomaterials (CNM) is now in progress with some potential applications. Using human A549 and THP-1 cells, we evaluated the biological responses of various CNMs, made out of similar material but with functional and morphological variations. While A549 cells displayed minimal or no cytotoxic responses following exposure to CNMs, THP-1 cells were more susceptible to cytotoxicity, cellular damage and inflammatory responses. Further analysis of these biological responses evaluated using hierarchical clustering approaches was effective in discriminating (dis)-similarities of various CNMs studied and identified potential inflammatory factors contributing to cytotoxicity. No correlation between cytotoxicity and surface properties of CNMs was found. This study clearly highlights that, in addition to the source and characteristics of CNMs, cell type-specific differences in the recognition/uptake of CNMs along with their inherent capability to respond to external stimuli are crucial for assessing the toxicity of CNMs.
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Celulosa/química , Lignina/química , Nanoestructuras/química , Células A549 , Celulosa/efectos adversos , Celulosa/farmacología , Humanos , Lignina/efectos adversos , Lignina/farmacología , Nanoestructuras/efectos adversosRESUMEN
Waterproofing sprays can cause acute respiratory symptoms after inhalation, including coughing and dyspnoea shortly after use. Here, we describe two cases where persons used the same brand of waterproofing spray product. In both cases the persons followed the instructions on the product and maximized the ventilation by opening windows and doors; however, they still became affected during the application of the product. Products with the same batch number as that used in one case were tested for their effect on respiration patterns of mice in whole-body plethysmographs and lung surfactant function inhibition in vitro. The product was used in spraying experiments to determine the particle size distribution of the aerosol, both using a can from one case and a can with an identical batch number. In addition, the aerosols in the mouse exposure chamber were measured. Aerosol data from a small-scale exposure chamber and data on the physical and temporal dimensions of the spraying during one case were used to estimate the deposited dose during the spraying events. All collected data point to the spraying of the waterproofing product being the reason that two people became ill, and that the inhibition of lung surfactant function was a key component of this illness.
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BACKGROUND: Widespread occupational exposure to carbon black nanoparticles (CBNPs) raises concerns over their safety. CBNPs are genotoxic in vitro but less is known about their genotoxicity in various organs in vivo. METHODS: We investigated inflammatory and acute phase responses, DNA strand breaks (SB) and oxidatively damaged DNA in C57BL/6 mice 1, 3 and 28 days after a single instillation of 0.018, 0.054 or 0.162 mg Printex 90 CBNPs, alongside sham controls. Bronchoalveolar lavage (BAL) fluid was analyzed for cellular composition. SB in BAL cells, whole lung and liver were assessed using the alkaline comet assay. Formamidopyrimidine DNA glycosylase (FPG) sensitive sites were assessed as an indicator of oxidatively damaged DNA. Pulmonary and hepatic acute phase response was evaluated by Saa3 mRNA real-time quantitative PCR. RESULTS: Inflammation was strongest 1 and 3 days post-exposure, and remained elevated for the two highest doses (i.e., 0.054 and 0.162 mg) 28 days post-exposure (P < 0.001). SB were detected in lung at all doses on post-exposure day 1 (P < 0.001) and remained elevated at the two highest doses until day 28 (P < 0.05). BAL cell DNA SB were elevated relative to controls at least at the highest dose on all post-exposure days (P < 0.05). The level of FPG sensitive sites in lung was increased throughout with significant increases occurring on post-exposure days 1 and 3, in comparison to controls (P < 0.001-0.05). SB in liver were detected on post-exposure days 1 (P < 0.001) and 28 (P < 0.001). Polymorphonuclear (PMN) cell counts in BAL correlated strongly with FPG sensitive sites in lung (r = 0.88, P < 0.001), whereas no such correlation was observed with SB (r = 0.52, P = 0.08). CBNP increased the expression of Saa3 mRNA in lung tissue on day 1 (all doses), 3 (all doses) and 28 (0.054 and 0.162 mg), but not in liver. CONCLUSIONS: Deposition of CBNPs in lung induces inflammatory and genotoxic effects in mouse lung that persist considerably after the initial exposure. Our results demonstrate that CBNPs may cause genotoxicity both in the primary exposed tissue, lung and BAL cells, and in a secondary tissue, the liver.
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Daño del ADN/efectos de los fármacos , Hígado/patología , Hígado/fisiopatología , Pulmón/patología , Pulmón/fisiología , Nanopartículas/química , Hollín/farmacología , Animales , Líquido del Lavado Bronquioalveolar/citología , Ensayo Cometa , Femenino , Inflamación , Hígado/inmunología , Pulmón/inmunología , Ratones , Ratones Endogámicos C57BL , Exposición ProfesionalRESUMEN
BACKGROUND: PPP1R13L gene has been found to be over-expressed in variety of cancers and its expression in p53 wild-type background is sufficient to promote tumor growth in vivo. However, in the non-transformed cells it acts as a tumor suppressor which suggests that the role of PPP1R13L is multifaceted. METHODS: We have used siRNA optimized for inhibition of p53, PPP1R13L, BAX and GADD45 alpha expression and investigated the role of those gene products for PPP1R13L expression and induction in a variety of mouse and human cells with different p53 status. In addition we have applied Western Blot, Q-PCR and proteasome inhibition analysis to further ascertain the link between PPP1R13L induction and p53 status. RESULTS: We show that the pattern and extent of the PPP1R13L expression depend on the presence of active p53. Downregulation of p53 target genes BAX and/or GADD45 alpha led to decreased in PPP1R13L activation after adriamycin and/or etoposide treatments. Treatment of the cells with the proteasome inhibitor MG-132 resulted in the accumulation of both p53 and PPP1R13L proteins. CONCLUSIONS: We have provided evidence that endogenous PPP1R13L acts as a negative regulator of p53 function, presumably by direct binding. p53 accumulation and activity after DNA damage is compromised by PPP1R13L expression. We suggest that PPP1R13L and p53 form a negative feedback loop which regulates their amount and activity. GENERAL SIGNIFICANCE: The profound modulatory effect of the PPP1R13L protein on the ability of p53 to cause cellular apoptosis has important implications in cancer and presents new therapeutic possibilities.
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Daño del ADN , Retroalimentación Fisiológica/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Represoras/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Antineoplásicos/farmacología , Sitios de Unión/genética , Western Blotting , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Células Cultivadas , Doxorrubicina/farmacología , Etopósido/farmacología , Retroalimentación Fisiológica/efectos de los fármacos , Células HEK293 , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Leupeptinas/farmacología , Ratones , Mutación , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma , Unión Proteica , Interferencia de ARN , Proteínas Represoras/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Activación Transcripcional/efectos de los fármacos , Proteína p53 Supresora de Tumor/genética , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Nanocellulose (NC) is emerging as a highly promising nanomaterial for a wide range of applications. Moreover, many types of NC are produced, each exhibiting a slightly different shape, size, and chemistry. The main objective of this study was to compare cytotoxic effects of cellulose nanocrystals (CNC) and nanofibrillated cellulose (NCF). The human lung epithelial cells (A549) were exposed for 24 h and 72 h to five different NC particles to determine how variations in properties contribute to cellular outcomes, including cytotoxicity, oxidative stress, and cytokine secretion. Our results showed that NCF were more toxic compared to CNC particles with respect to cytotoxicity and oxidative stress responses. However, exposure to CNC caused an inflammatory response with significantly elevated inflammatory cytokines/chemokines compared to NCF. Interestingly, cellulose staining indicated that CNC particles, but not NCF, were taken up by the cells. Furthermore, clustering analysis of the inflammatory cytokines revealed a similarity of NCF to the carbon nanofibers response and CNC to the chitin, a known immune modulator and innate cell activator. Taken together, the present study has revealed distinct differences between fibrillar and crystalline nanocellulose and demonstrated that physicochemical properties of NC are critical in determining their toxicity.
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Celulosa/toxicidad , Células Epiteliales/efectos de los fármacos , Nanofibras/toxicidad , Nanopartículas/toxicidad , Células A549 , Supervivencia Celular/efectos de los fármacos , Citocinas/metabolismo , Células Epiteliales/metabolismo , Humanos , Inflamación/metabolismo , Pulmón/citologíaRESUMEN
Multiple myeloma (MM) is a severe, incurable neoplasm of the plasma cells. In this study we have used genetic epidemiology to associate the risk of MM with endogenous retroviral loci in humans. We used SNP analysis on a Sequenom platform and statistical analysis in SPSS. Markers near two endogenous retroviral loci, HERV-Fc1 on chromosome X and HERV-K on chromosome 1, were associated with MM. Moreover, there was strong gene-gene interaction in relation to risk of MM. We take this as indirect confirmation of the association.
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Retrovirus Endógenos/genética , Mieloma Múltiple/genética , Mieloma Múltiple/virología , Epistasis Genética , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Polimorfismo de Nucleótido SimpleRESUMEN
17 alpha-Ethinylestradiol (EE) can induce oxidative DNA damage in terms of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in rat testicular cells by an apparent estrogen receptor-mediated mechanism. We investigated differential susceptibility to EE in cell sub-populations from rat testes and the role of rat 8-oxo-guanine DNA glycosylase (rOGG1). Isolated rat testicular cells were incubated with EE concentrations ranging from 0.1 to 1000 nM. Single strand DNA breaks and oxidised purines as fapyguanine glycosylase (FPG) sensitive sites were assessed by the comet assay. In the total cell population and in round haploid cells, oxidised purines showed a bell-shaped concentration-response relationship with a maximally increased levels at 10 nM EE, whereas, no significant effects were seen in diploid, S-phase or tetraploid cells. The mRNA level of rOGG1 in testes cells was unaffected by EE, whereas, baseline levels were higher than in liver tissue and similar to colon tissue.
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Daño del ADN , Etinilestradiol/toxicidad , Estrés Oxidativo/efectos de los fármacos , Ploidias , Testículo/efectos de los fármacos , Animales , Células Cultivadas , Ensayo Cometa , ADN Glicosilasas/genética , ADN-Formamidopirimidina Glicosilasa/farmacología , Masculino , ARN Mensajero/genética , ARN Ribosómico 18S/genética , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Testículo/citología , Testículo/metabolismoRESUMEN
The idea that shiftwork may be carcinogenic in humans has gained widespread attention since the pioneering work linking shiftwork to breast cancer over two decades ago. However, the biomolecular consequences of long-term shiftwork exposure have not been fully explored. In this study, we performed a genome-wide CpG island methylation assay of microRNA (miRNA) promoters in long-term night shiftworkers and day workers. This analysis indicated that 50 CpG loci corresponding to 31 miRNAs were differentially methylated in night shiftworkers compared to day workers, including the circadian-relevant miR-219, the expression of which has been implicated in several cancers. A genome-wide expression microarray assay was carried out in a miR-219-overexpressed MCF-7 breast cancer cell line, which identified 319 differentially expressed transcripts. The identified transcriptional targets were analyzed for network and functional interrelatedness using the Ingenuity Pathway Analysis (IPA) software. Overexpression of miR-219 in MCF-7 breast cancer cells resulted in accentuated expression of apoptosis- and proliferation-related anti-viral immunodulators of the Jak-STAT and NF-κß pathways. These findings suggest that long-term night shiftwork exposure may lead to the methylation-dependent downregulation of miR-219, which may in turn lead to the downregulation of immunomediated antitumor activity and increased breast cancer risk.
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Neoplasias de la Mama/genética , Metilación de ADN , MicroARNs/genética , Enfermedades Profesionales/genética , Regiones Promotoras Genéticas , Tolerancia al Trabajo Programado , Apoptosis/genética , Línea Celular Tumoral , Islas de CpG/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , FN-kappa B/metabolismo , RiesgoRESUMEN
Exposure to light at night through shiftwork has been linked to alterations in DNA methylation and increased risk of cancer development. Using an Illumina Infinium Methylation Assay, we analyzed methylation levels of 397 CpG sites in the promoter regions of 56 normally imprinted genes to investigate whether shiftwork is associated with alteration of methylation patterns. Methylation was significantly higher at 20 CpG sites and significantly lower at 30 CpG sites (P < 0.05) in 10 female long-term shiftworkers as compared to 10 female age- and folate intake-matched day workers. The strongest evidence for altered methylation patterns in shiftworkers was observed for DLX5, IGF2AS, and TP73 based on the magnitude of methylation change and consistency in the direction of change across multiple CpG sites, and consistent results were observed using quantitative DNA methylation analysis. We conclude that long-term shiftwork may alter methylation patterns at imprinted genes, which may be an important mechanism by which shiftwork has carcinogenic potential and warrants further investigation.
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Metilación de ADN , Proteínas de Unión al ADN/genética , Impresión Genómica , Proteínas de Homeodominio/genética , Proteínas Nucleares/genética , Proteínas/genética , Factores de Transcripción/genética , Proteínas Supresoras de Tumor/genética , Tolerancia al Trabajo Programado , Islas de CpG/genética , Femenino , Humanos , Luz/efectos adversos , Persona de Mediana Edad , Neoplasias/etiología , Neoplasias/genética , Regiones Promotoras Genéticas , Riesgo , Encuestas y Cuestionarios , Factores de Tiempo , Transcriptoma , Proteína Tumoral p73RESUMEN
Epigenetic association studies have demonstrated differential promoter methylation in the core circadian genes in breast cancer cases relative to cancer-free controls. The current pilot study aims to investigate whether epigenetic changes affecting breast cancer risk could be caused by circadian disruption through exposure to light at night. Archived DNA samples extracted from whole blood of 117 female subjects from a prospective cohort conducted in Denmark were included in this study. A polymerase chain reaction (PCR)-based method was used for detection of gene-promoter methylation, whereas genome-wide methylation analysis was performed using the Illumina Infinium Methylation Chip. Long-term shiftwork resulted in the same promoter hypomethylation of CLOCK and hypermethylation of CRY2, as was previously observed in breast cancer case-control studies. Genome-wide methylation analysis further discovered widespread methylation alterations in shiftworkers, including changes in many methylation- and cancer-relevant genes. Pathway analysis of the genes with altered methylation patterns revealed several cancer-related pathways. One of the top three networks generated was designated as "DNA replication, recombination, and repair, gene expression, behavior" with ESR1 (estrogen receptor α) featured most prominently in the network, underscoring the potential breast cancer relevance of the genes differentially methylated in long-term shiftworkers. These results, although exploratory, demonstrate the first evidence of the cancer-relevant epigenetic effects of night shiftwork, which warrant further investigation. Considering there are millions of shiftworkers worldwide, understanding the effects of this exposure may lead to novel strategies for cancer prevention and new policies regulating shiftwork.
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Péptidos y Proteínas de Señalización del Ritmo Circadiano/metabolismo , Epigenómica , Genoma Humano/fisiología , Tolerancia al Trabajo Programado/fisiología , Péptidos y Proteínas de Señalización del Ritmo Circadiano/genética , Femenino , Perfilación de la Expresión Génica , Humanos , Metilación , Persona de Mediana Edad , Regiones Promotoras Genéticas , Factores de TiempoRESUMEN
PURPOSE: The purpose of this study was to investigate whether specific combinations of polymorphisms in genes encoding proteins involved in 5-fluorouracil (5-FU) pharmacokinetics and pharmacodynamics are associated with increased risk of treatment-induced toxicity. EXPERIMENTAL DESIGN: We analyzed two cohorts of 161 and 340 patients, the exploration and validation cohort, respectively. All patients were treated similarly with 5-FU-based adjuvant chemotherapy. We analyzed 13 functional polymorphisms and applied a four-fold analysis strategy using individual polymorphisms, haplotypes, and phenotypic enzyme activity or expression classifications based on combinations of functional polymorphisms in specific genes. Furthermore, multifactor dimensionality reduction analysis was used to identify a genetic interaction profile indicating an increased risk of toxicity. RESULTS: Alleles associated with low activity of methylene tetrahydrofolate reductase (MTHFR) were associated with decreased risk of toxicity [OR(Exploration) 0.39 (95% CI: 0.21-0.71, P = 0.003), OR(Validation) 0.63 (95% CI: 0.41-0.95, P = 0.03)]. A specific combination of the MTHFR 1298A>C and thymidylate synthase (TYMS) 3'-UTR (untranslated region) ins/del polymorphisms was significantly associated with increased toxicity in both cohorts [OR(Exploration) 2.40 (95% CI: 1.33-4.29, P = 0.003), OR(Validation) 1.81 (95% CI: 1.18-2.79, P = 0.007)]. The specific combination was also associated with increased cumulative incidence and earlier occurrence of severe toxicity during treatment. CONCLUSIONS: Our results indicate that MTHFR activity and a specific combination of the MTHFR 1298A>C and TYMS 3'-UTR ins/del polymorphisms are possible predictors of 5-FU treatment-related toxicity.
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Antimetabolitos Antineoplásicos/metabolismo , Antimetabolitos Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Fluorouracilo/metabolismo , Fluorouracilo/uso terapéutico , Tracto Gastrointestinal/efectos de los fármacos , Polimorfismo Genético , Adulto , Anciano , Anciano de 80 o más Años , Antimetabolitos Antineoplásicos/efectos adversos , Neoplasias Colorrectales/enzimología , Neoplasias Colorrectales/genética , Femenino , Fluorouracilo/efectos adversos , Tracto Gastrointestinal/metabolismo , Genotipo , Haplotipos , Humanos , Masculino , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Persona de Mediana Edad , Timidilato Sintasa/genéticaRESUMEN
A strong and persistent effect of plant-derived foods on the prevention of lifestyle diseases has emerged from observational studies. Several groups of constituents in plants have been identified as potentially health promoting in animal studies, including cholesterol-lowering factors, antioxidants, enzyme inducers, apoptosis inducers etc. In human intervention studies the dose levels achieved tend to be lower than the levels found to be effective in animals and sampling from target organs is often not possible. A controlled dietary human intervention study was performed with forty-three volunteers, providing 600 g fruit and vegetables/d or in the controls a carbohydrate-rich drink to balance energy intake. Surrogate markers of oxidative damage to DNA, protein and lipids, enzymic defence and lipid metabolism were determined in blood and urine. It was found that a high intake of fruit and vegetables tends to increase the stability of lipids towards oxidative damage. Markers of oxidative enzymes indicate a steady increase in glutathione peroxidase (GPX1) activity in erythrocytes during intervention with fruit and vegetables but there is no effect on GPX1 transcription levels in leucocytes. No change occurs in glutathione-conjugating or -reducing enzyme activities in erythrocytes or plasma, and there are no effects on the transcription of genes involved in phase 2 enzyme induction or DNA repair in leucocytes. Fruit and vegetable intake decreases the level of total cholesterol and LDL-cholesterol, but does not affect sex hormones. In conclusion, it has been shown that total cholesterol and LDL-cholesterol, markers of peripheral lipid oxidation, and erythrocyte GPX1 activity are affected by high intakes of fruit and vegetables. This finding provides support for a protective role of dietary fruit and vegetables against CVD.