Project description:In this study, we assess potential differences in mechanism of action for two PAHs, benzo[a]pyrene (BAP) and dibenzo-[def,p]chrysene (DBC), in a primary human 3D bronchial epithelial culture (HBEC) model based on short-term biosignatures identified from global transcriptional profiling.
Project description:In this study, we assess potential differences in mechanism of action for two PAHs, benzo[a]pyrene (BAP) and dibenzo-[def,p]chrysene (DBC), in a primary human 3D bronchial epithelial culture (HBEC) model based on short-term biosignatures identified from global transcriptional profiling.
Project description:Sub-chronic transcriptional response in adult male MutaTMMouse following oral exposure to chrysene in lung, liver, and forestomach tissues [Chr]
Project description:Despite advances in treatment modalities, 5-year survival of OSCC has remained at ~50% for the past decades, mostly due to the high risk of developing secondary primary tumors. Early detection of OSCC represents one of the most promising approaches to improving survival. In this study, we examined the alterations of DNA methylation in early stage of oral carcinogenesis in mice induced by carcinogen dibenzo[def,p]chrysene. We identified 30 differentially methylated sites and canonical pathways that may be served as potential biomarkers for early detection of OSCC.
Project description:Polycyclic aromatic hydrocarbons (PAHs) are a class of hundreds of structurally similar chemicals ubiquitously present in our environment. They are created during the incomplete combustion of organic materials, such as oil, wood, tobacco, and charbroiled meat. As such, human exposure to mixtures of PAHs can occur through consumption of PAH-containing foods and water, inhalation of polluted air, or dermal contact. Several PAHs have been classified as carcinogenic to humans or probably carcinogenic to humans by the International Agency for Research on Cancer. Chrysene is one such compound. In the present study, we sought to determine the dose-dependent changes in gene expression upon oral exposure to benz(a)anthracene in the lung, liver, and forestomach tissues. Adult male MutaTMMouse were exposed to three doses of chrysene or vehicle control (olive oil) for 28 days and sacrificed three days after the final exposure.
Project description:Dibenzo[def,p]chrysene (DBC) is the most carcinogenic polycyclic aromatic hydrocarbon (PAH) examined to date. We investigated the immunotoxicity of DBC, manifested as spleen atrophy following acute exposure of adult Muta™Mouse males by oral gavage. Mice were exposed to 0, 2.0, 6.2, or 20.0 mg DBC /kg-bw per day, for three days. Genotoxic endpoints (DBC-DNA adducts and lacZ mutant frequency in spleen and bone marrow, and red blood cell micronucleus frequency) and global gene expression changes were measured. All of the genotoxicity measures increased in a dose-dependent manner in both tissues. Gene expression analysis showed that DBC activates p53 signalling pathways related to cellular growth and proliferation, which was evident even at the low dose. Strikingly, the expression profiles of DBC exposed mouse spleens were highly inversely correlated with the expression profiles of the only published toxicogenomics dataset of enlarged mouse spleen. This analysis suggested a central role for Bnip3l, a pro-apoptotic protein involved in negative regulation of erythroid maturation. RT-PCR confirmed expression changes in several genes related to apoptosis, iron metabolism, and aryl hydrocarbon receptor signalling that are regulated in the opposite direction during spleen atrophy versus benzo[a]pyrene-mediated splenomegaly. In addition, benchmark dose modeling of toxicogenomics data yielded toxicity estimates that are very close to traditional toxicity endpoints. This work illustrates the power of toxicogenomics to reveal rich mechanistic information of immunotoxic compounds and its ability to provide information that is quantitatively similar to that derived from standard toxicity methods in health risk assessment.