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THP-1 monocytes but not macrophages as a potential alternative for CD34+ dendritic cells to identify chemical skin sensitizers
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Abstracts / Toxicology Letters 189S (2009) S57–S273
Conclusions: Our results suggest to use Fpg modified comet test on A549 cells to assess genotoxic effects of complex mixtures of air pollutants on target organ. doi:10.1016/j.toxlet.2009.06.214
V24 Cyto-genotoxic effect of styrene and acrylonitrile combination Elisabetta Strafella ∗ , Marco Tomasetti ∗ , Massimo Bracci, Monica Amati, Lory Santarelli Polytechnic University of Marche, Molecular Pathology & Innovative Therapies, Ancona, Italy Styrene (STY) and acrylonitrile (ACN) are monomers used in the production of acrylonitrile–butadiene–styrene resins and copolymers. These monomers were nominated by the U.S. Environmental Protection Agency for toxicologic evaluation and genotoxicity studies based on their high production and limited information available on their toxicity. In this study, the cyto-genotoxic effect of STY and ACN has been evaluate in pleural and lung target cells, mesothelial cells (Met-5A) and epithelial alveolar cells (A549). Met5A and A549 cells were exposed to increased concentration of STY and ACN alone and in combination and cell viability, cell proliferation, DNA damage and its repair and the carcinogenic effect were evaluated over the time. STY itself inhibits cell proliferation and induces low cytotoxicity in Met-5A cells. Conversely, it induces cell proliferation in A549 cells at low concentration. Low doses of ACN increased cell proliferation both in Met-5A cells and A549 cells, whereas high dose induces cell death. The STY–ACN combination showed an indifferent effect on cell viability. ACN induces DNA damage in a dose-dependent manner after 1 h of incubation. The ACN-induced DNA damage was slightly repaired. STY exposure did not induce DNA damage in both cell types, but it was shown to inhibit DNA repair in Met-5A cells. STY and ACN at low doses induce cell colony formation in soft-agar when combined together. The STY–ACN combination is genotoxic, ACN acts as DNA damage promoter and STY as inhibitor of DNA repair. Un-repaired DNA damage could accumulate in the cells leading to cell transformation. doi:10.1016/j.toxlet.2009.06.215
V25 THP-1 monocytes but not macrophages as a potential alternative 夽 for CD34+ dendritic cells to identify chemical skin sensitizers Nathalie Lambrechts 1,∗ , Sandra Verstraelen 1 , Jef Hooyberghs 1 , Hilda Witters 1 , Viggo Van Tendeloo 2 , Paul Van Cauwenberge 3 , Inge Nelissen 1 , Rosette Van Den Heuvel 1 , Greet Schoeters 1,4 1
VITO-CARDAM, Environmental Risk and Health, Mol, Belgium, University of Antwerp, Laboratory of Experimental Hematology, Antwerp, Belgium, 3 University of Ghent, Department of Otolaryngology, Gent, Belgium, 4 University of Antwerp, Department of Biomedical Sciences, Antwerp, Belgium 2
Early detection of the sensitizing potential of chemicals is an emerging issue for chemical, pharmaceutical and cosmetic industries. In our institute, an in vitro classification model for prediction of chemical-induced skin sensitization based on gene expression signatures in human CD34+ progenitor-derived dendritic cells (DC) has been developed. This primary cell model is able to closely mimic
the induction phase of sensitization by Langerhans cells in the skin, but it has drawbacks, such as the availability of cord blood. The aim of this study was to investigate whether human in vitro cultured THP-1 monocytes or macrophages display a similar expression profile for 13 predictive gene markers previously identified in DC and whether they also possess a discriminating capacity towards skin sensitizers and non-sensitizers based on these marker genes. To this end, the cell models were exposed to 5 skin sensitizers (ammonium hexachloroplatinate IV, 1-chloro-2,4-dinitrobenzene, eugenol, para-phenylenediamine, and tetramethylthiuram disulfide) and 5 non-sensitizers (l-glutamic acid, methyl salicylate, sodium dodecyl sulfate, tributyltin chloride, and zinc sulfate) for 6, 10, and 24 h, and mRNA expression of the 13 genes was analyzed using real-time RT-PCR. The transcriptional response of 7 out of 13 genes in THP-1 monocytes was significantly correlated with DC, whereas only 2 out of 13 genes in THP-1 macrophages. After cross-validation of a discriminant analysis of the gene expression profiles in THP-1 monocytes, this cell model demonstrated also to have capacity to distinguish skin sensitizers from non-sensitizers. However, the DC model was superior to the monocyte model for discrimination of (non-)sensitizing chemicals. 夽 Selected for Oral Presentation. doi:10.1016/j.toxlet.2009.06.216
V26 Cytotoxicity of the mycotoxin enniatin B in tumour and nontumour cells Claudia Behm ∗ , Alena Rasche, Gisela H. Degen, Wolfram Föllmann Leibniz Research Centre for Working Environment and Human Factors at the TU Dortmund (IfADo), Chemical Risks, Dortmund, Germany Enniatins, fungal metabolites produced by several Fusarium species, are now recognized as mycotoxin contaminants in grains from various countries. Ingestion of contaminated products may adversely affect animal and/or human health since enniatins can exert potent cytotoxic effects in vitro. On the other hand, enniatins show interesting biological activities, and are considered also as compounds for potential uses as anticancer drugs. Therefore, it is interesting to study whether their cytotoxicity is more pronounced in cancer cells than in non-tumour cells. In the present study we focused on enniatin B (ENNB) and compared its cytotoxic potency in cultures of non-tumour cells (V79 hamster fibroblasts; NHDF normal human dermal fibroblasts) and in two human tumour cell lines (MCF-7 breast cancer cells; 5637 urothelial carcinoma cells). Using the neutral red uptake assay, IC50 values were determined for 48 h treatment with ENNB in these cell cultures. Under these experimental conditions, the IC50 -values for V79 and NHDF cells range from 2.1 to 3.1 M ENNB. For the tumour cell lines MCF-7 and 5637, IC50 -values range between 2.3 and 4.8 M ENNB. These data and IC50 values for 24 and 72 h treatment showed no significant difference between the cytotoxic potency of ENNB in normal versus tumour cells. We therefore conclude that tumour cells are not more susceptible to ENNB compared to non-tumour cells, also since apoptosis is induced in vitro in both cell types. As cytotoxicity of ENNB is not well understood at present, further investigations are needed to study its mode of action. doi:10.1016/j.toxlet.2009.06.217
Abstracts / Toxicology Letters 189S (2009) S57–S273
Conclusions: Our results suggest to use Fpg modified comet test on A549 cells to assess genotoxic effects of complex mixtures of air pollutants on target organ. doi:10.1016/j.toxlet.2009.06.214
V24 Cyto-genotoxic effect of styrene and acrylonitrile combination Elisabetta Strafella ∗ , Marco Tomasetti ∗ , Massimo Bracci, Monica Amati, Lory Santarelli Polytechnic University of Marche, Molecular Pathology & Innovative Therapies, Ancona, Italy Styrene (STY) and acrylonitrile (ACN) are monomers used in the production of acrylonitrile–butadiene–styrene resins and copolymers. These monomers were nominated by the U.S. Environmental Protection Agency for toxicologic evaluation and genotoxicity studies based on their high production and limited information available on their toxicity. In this study, the cyto-genotoxic effect of STY and ACN has been evaluate in pleural and lung target cells, mesothelial cells (Met-5A) and epithelial alveolar cells (A549). Met5A and A549 cells were exposed to increased concentration of STY and ACN alone and in combination and cell viability, cell proliferation, DNA damage and its repair and the carcinogenic effect were evaluated over the time. STY itself inhibits cell proliferation and induces low cytotoxicity in Met-5A cells. Conversely, it induces cell proliferation in A549 cells at low concentration. Low doses of ACN increased cell proliferation both in Met-5A cells and A549 cells, whereas high dose induces cell death. The STY–ACN combination showed an indifferent effect on cell viability. ACN induces DNA damage in a dose-dependent manner after 1 h of incubation. The ACN-induced DNA damage was slightly repaired. STY exposure did not induce DNA damage in both cell types, but it was shown to inhibit DNA repair in Met-5A cells. STY and ACN at low doses induce cell colony formation in soft-agar when combined together. The STY–ACN combination is genotoxic, ACN acts as DNA damage promoter and STY as inhibitor of DNA repair. Un-repaired DNA damage could accumulate in the cells leading to cell transformation. doi:10.1016/j.toxlet.2009.06.215
V25 THP-1 monocytes but not macrophages as a potential alternative 夽 for CD34+ dendritic cells to identify chemical skin sensitizers Nathalie Lambrechts 1,∗ , Sandra Verstraelen 1 , Jef Hooyberghs 1 , Hilda Witters 1 , Viggo Van Tendeloo 2 , Paul Van Cauwenberge 3 , Inge Nelissen 1 , Rosette Van Den Heuvel 1 , Greet Schoeters 1,4 1
VITO-CARDAM, Environmental Risk and Health, Mol, Belgium, University of Antwerp, Laboratory of Experimental Hematology, Antwerp, Belgium, 3 University of Ghent, Department of Otolaryngology, Gent, Belgium, 4 University of Antwerp, Department of Biomedical Sciences, Antwerp, Belgium 2
Early detection of the sensitizing potential of chemicals is an emerging issue for chemical, pharmaceutical and cosmetic industries. In our institute, an in vitro classification model for prediction of chemical-induced skin sensitization based on gene expression signatures in human CD34+ progenitor-derived dendritic cells (DC) has been developed. This primary cell model is able to closely mimic
the induction phase of sensitization by Langerhans cells in the skin, but it has drawbacks, such as the availability of cord blood. The aim of this study was to investigate whether human in vitro cultured THP-1 monocytes or macrophages display a similar expression profile for 13 predictive gene markers previously identified in DC and whether they also possess a discriminating capacity towards skin sensitizers and non-sensitizers based on these marker genes. To this end, the cell models were exposed to 5 skin sensitizers (ammonium hexachloroplatinate IV, 1-chloro-2,4-dinitrobenzene, eugenol, para-phenylenediamine, and tetramethylthiuram disulfide) and 5 non-sensitizers (l-glutamic acid, methyl salicylate, sodium dodecyl sulfate, tributyltin chloride, and zinc sulfate) for 6, 10, and 24 h, and mRNA expression of the 13 genes was analyzed using real-time RT-PCR. The transcriptional response of 7 out of 13 genes in THP-1 monocytes was significantly correlated with DC, whereas only 2 out of 13 genes in THP-1 macrophages. After cross-validation of a discriminant analysis of the gene expression profiles in THP-1 monocytes, this cell model demonstrated also to have capacity to distinguish skin sensitizers from non-sensitizers. However, the DC model was superior to the monocyte model for discrimination of (non-)sensitizing chemicals. 夽 Selected for Oral Presentation. doi:10.1016/j.toxlet.2009.06.216
V26 Cytotoxicity of the mycotoxin enniatin B in tumour and nontumour cells Claudia Behm ∗ , Alena Rasche, Gisela H. Degen, Wolfram Föllmann Leibniz Research Centre for Working Environment and Human Factors at the TU Dortmund (IfADo), Chemical Risks, Dortmund, Germany Enniatins, fungal metabolites produced by several Fusarium species, are now recognized as mycotoxin contaminants in grains from various countries. Ingestion of contaminated products may adversely affect animal and/or human health since enniatins can exert potent cytotoxic effects in vitro. On the other hand, enniatins show interesting biological activities, and are considered also as compounds for potential uses as anticancer drugs. Therefore, it is interesting to study whether their cytotoxicity is more pronounced in cancer cells than in non-tumour cells. In the present study we focused on enniatin B (ENNB) and compared its cytotoxic potency in cultures of non-tumour cells (V79 hamster fibroblasts; NHDF normal human dermal fibroblasts) and in two human tumour cell lines (MCF-7 breast cancer cells; 5637 urothelial carcinoma cells). Using the neutral red uptake assay, IC50 values were determined for 48 h treatment with ENNB in these cell cultures. Under these experimental conditions, the IC50 -values for V79 and NHDF cells range from 2.1 to 3.1 M ENNB. For the tumour cell lines MCF-7 and 5637, IC50 -values range between 2.3 and 4.8 M ENNB. These data and IC50 values for 24 and 72 h treatment showed no significant difference between the cytotoxic potency of ENNB in normal versus tumour cells. We therefore conclude that tumour cells are not more susceptible to ENNB compared to non-tumour cells, also since apoptosis is induced in vitro in both cell types. As cytotoxicity of ENNB is not well understood at present, further investigations are needed to study its mode of action. doi:10.1016/j.toxlet.2009.06.217