Effects of low concentrations of benzene on human lung cells in vitro.

Exposure to benzene causes health hazards to humans. The airway epithelium is a physical barrier to inhaled toxicants and particulates. This is an in vitro basic science study to evaluate the effects of benzene on lung cells without the inflammatory responses triggered by inhalation. Dose-response cytotoxicity was assessed using two cell lines: alveolar derived (A549) human epithelial adenocarcinoma and human lung (LL24) fibroblast. A549 cells were more resistant than LL24 fibroblast lung cells to benzene. LL24 cells demonstrated enhanced proliferation with diluted benzene solutions. Moreover, low concentrations of benzene enhanced telomerase activity in LL24 cells while no effects were observed in the adenocarcinoma cells. Proteolysis of lung matrix by matrix metalloproteinases (MMPs) is an early event observed in lung pathologies. Benzene increased MMP-2 and MMP-3 mRNA. Using the ratio (MMP-1+MMP-2+MMP-3)/(TIMP-1+TIMP-2), as an index of prodestructive activity, we observed a dose-dependent increase. The overall higher expression levels of MMPs in benzene treated cells did not appear to be controlled by TIMPs, which are negatively correlated. Comparing different cell lines, we demonstrated how crucial is the target's susceptibility. Our observations may represent early functional alterations that occur in the airways of exposed people.

[1]  J. Huff.  Chemicals Studied and Evaluated in Long‐Term Carcinogenesis Bioassays by Both the Ramazzini Foundation and the National Toxicology Program , 2002, Annals of the New York Academy of Sciences.

[2]  T. Standiford,et al.  Matrix metalloproteinases and matrix metalloproteinase inhibitors in acute lung injury. , 2006, Human pathology.

[3]  M. Georgieff,et al.  A novel apparatus for the exposure of cultured cells to volatile agents. , 1998, Journal of pharmacological and toxicological methods.

[4]  M. Lamberti,et al.  Matrix metalloproteinases and their inhibitors as biomarkers for metal toxicity in vitro. , 2006, Toxicology in vitro : an international journal published in association with BIBRA.

[5]  D. E. Pritchard,et al.  Apoptosis and P53 induction in human lung fibroblasts exposed to chromium (VI): effect of ascorbate and tocopherol. , 2000, Toxicological sciences : an official journal of the Society of Toxicology.

[6]  M. Sacco,et al.  An optimized method for in vitro exposure of human derived lung cells to volatile chemicals. , 2009, Experimental and toxicologic pathology : official journal of the Gesellschaft fur Toxikologische Pathologie.

[7]  L. Soleo,et al.  Application of the standard addition approach for the quantification of urinary benzene. , 2005, Journal of chromatography. B, Analytical technologies in the biomedical and life sciences.

[8]  T. Mosmann.  Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. , 1983, Journal of immunological methods.

[9]  D. Thomas,et al.  Reproductive history, occupational exposures, and thyroid cancer risk among women textile workers in Shanghai, China , 2006, International archives of occupational and environmental health.

[10]  J. Varani,et al.  Matrix metalloproteinases in acute inflammation: induction of MMP-3 and MMP-9 in fibroblasts and epithelial cells following exposure to pro-inflammatory mediators in vitro. , 2004, Experimental and molecular pathology.

[11]  S. Shapiro,et al.  Matrix metalloproteinases in lung biology , 2000, Respiratory research.

[12]  M. Selman,et al.  Molecular mechanisms of pulmonary fibrosis. , 2002, Frontiers in bioscience : a journal and virtual library.

[13]  R. Lea,et al.  Identification of a novel co-transcription of P450/1A1 with telomerase in A549. , 2007, Gene.

[14]  J. Varani,et al.  Role of matrix metalloproteinases in models of macrophage-dependent acute lung injury. Evidence for alveolar macrophage as source of proteinases. , 1999, American journal of respiratory cell and molecular biology.

[15]  P. Sime,et al.  The aryl hydrocarbon receptor is a regulator of cigarette smoke induction of the cyclooxygenase and prostaglandin pathways in human lung fibroblasts. , 2005, American journal of physiology. Lung cellular and molecular physiology.

[16]  D. Veeramachaneni,et al.  Impact of environmental pollutants on the male: effects on germ cell differentiation. , 2008, Animal reproduction science.

[17]  G. Metzner,et al.  T(H1)-directed modulation of in vitro cytokine production in human peripheral blood mononuclear cells by styrene-7.8-oxide. , 2006, Toxicology letters.

[18]  C B Harley,et al.  Specific association of human telomerase activity with immortal cells and cancer. , 1994, Science.

[19]  R. C. Vignesh,et al.  Effect of ethanol on human osteosarcoma cell proliferation, differentiation and mineralization. , 2006, Toxicology.

[20]  M. Lamberti,et al.  In vitro evaluation of matrix metalloproteinases as predictive testing for nickel, a model sensitizing agent. , 2004, Toxicology and applied pharmacology.

[21]  S. Bakand,et al.  A novel in vitro exposure technique for toxicity testing of selected volatile organic compounds. , 2006, Journal of environmental monitoring : JEM.

[22]  B J Blaauboer,et al.  Toxicodynamic modelling and the interpretation of in vitro toxicity data. , 2001, Toxicology letters.

[23]  R. Fridman,et al.  TIMP-1 regulation of cell cycle in human breast epithelial cells via stabilization of p27KIP1 protein , 2006, Oncogene.

[24]  P. Henson,et al.  The matrix degrades, neutrophils invade , 2006, Nature Medicine.

[25]  S. Keith,et al.  Toxicological profile for benzene , 2007 .

[26]  D. Albertson,et al.  Rac1b and reactive oxygen species mediate MMP-3-induced EMT and genomic instability , 2005, Nature.

[27]  Barry H. Smith,et al.  A continuous tumor‐cell line from a human lung carcinoma with properties of type II alveolar epithelial cells , 1976, International journal of cancer.

[28]  G. Wichmann,et al.  Release of MCP-1 and IL-8 from lung epithelial cells exposed to volatile organic compounds. , 2008, Toxicology in vitro : an international journal published in association with BIBRA.

[29]  R. Shohet,et al.  Gasoline exhaust emissions induce vascular remodeling pathways involved in atherosclerosis. , 2006, Toxicological sciences : an official journal of the Society of Toxicology.

[30]  C. C. Lombardi,et al.  Measurement and characterization of micronuclei in cultured primary lung cells of mice following inhalation exposure to benzene. , 1998, Mutagenesis.

[31]  M. Mehlman.  Carcinogenic Effects of Benzene: Cesare Maltoni's Contributions , 2002, Annals of the New York Academy of Sciences.

[32]  K. Wetterhahn,et al.  Effects of Cr(VI) on the expression of the oxidative stress genes in human lung cells. , 1998, Carcinogenesis.

[33]  M. Seo,et al.  Activation of telomerase by silica in rat lung. , 2000, Toxicology letters.

[34]  K. Willecke,et al.  Exacerbation of benzene pneumotoxicity in connexin 32 knockout mice: enhanced proliferation of CYP2E1-immunoreactive alveolar epithelial cells. , 2004, Toxicology.

[35]  F. Drago,et al.  Long-lasting neurotoxicity of prenatal benzene acute exposure in rats. , 2006, Toxicology.

[36]  N. Krug,et al.  Expression of Xenobiotic Metabolizing Enzymes in Different Lung Compartments of Smokers and Nonsmokers , 2006, Environmental health perspectives.

[37]  O. Herbarth,et al.  An experimental model for the determination of immunomodulating effects by volatile compounds. , 2005, Toxicology in vitro : an international journal published in association with BIBRA.

[38]  N. Philips,et al.  Identification of Benzene Metabolites in Dermal Fibroblasts as Nonphenolic: Regulation of Cell Viability, Apoptosis, Lipid Peroxidation and Expression of Matrix Metalloproteinase 1 and Elastin by Benzene Metabolites , 2004, Skin Pharmacology and Physiology.

[39]  S. Nomura,et al.  In situ detection of TGF betas, TGF beta receptor II mRNA and telomerase activity in rat cholangiocarcinogenesis. , 2003, World journal of gastroenterology.

[40]  S. Ceccatelli,et al.  Analysis of oxidative stress in SK-N-MC neurons exposed to styrene-7,8-oxide. , 2005, Toxicology in vitro : an international journal published in association with BIBRA.

[41]  N. Rothman,et al.  Benzene increases aneuploidy in the lymphocytes of exposed workers: A comparison of data obtained by fluorescence in situ hybridization in interphase and metaphase cells , 1999, Environmental and molecular mutagenesis.

[42]  G. Carlson,et al.  Benzene metabolism in human lung cell lines BEAS‐2B and A549 and cells overexpressing CYP2F1 , 2004, Journal of biochemical and molecular toxicology.

[43]  Wenyuan Gao,et al.  Cyclophosphamide promotes pulmonary metastasis on mouse lung adenocarcinoma , 2008, Clinical & Experimental Metastasis.

[44]  J. Hodgson,et al.  TIMP-1 Alters Susceptibility to Carcinogenesis , 2004, Cancer Research.

[45]  D. Hockenbery.  MMPs in unusual places. , 2006, The American journal of pathology.

[46]  Hui Lin,et al.  Effect of benzene, toluene, xylene on the semen quality and the function of accessory gonad of exposed workers. , 2001, Industrial health.

[47]  M. Denison,et al.  Recombinant cell bioassays for endocrine disruptors: development of a stably transfected human ovarian cell line for the detection of estrogenic and anti-estrogenic chemicals. , 2000, In vitro & molecular toxicology.