Exposure to carcinogenic metals, such as trivalent arsenic [As(III)] and hexavalent chromium [Cr(VI)], through drinking water is a major global public health problem and is associated with various cancers. However, the mechanism of their carcinogenicity remains unclear. In this study, we used azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse colitis-associated colorectal cancer model to investigate their tumorigenesis. Our results demonstrate that exposure to As(III) or Cr(VI), alone or in combination, together with AOM/DSS pretreatment has a promotion effect, increasing the colorectal tumor incidence, multiplicity, size, and grade, as well as cell inflammatory response. Two-dimensional differential gel electrophoresis coupled with mass spectrometry revealed that As(III) or Cr(VI) treatment alone significantly changed the density of proteins. The expression of β-catenin and phospho-GSK was increased by treatment of carcinogenic metals alone. Concomitantly, the expression of NADPH oxidase1 (NOX1) and the level of 8-OHdG were also increased by treatment of carcinogenic metals alone. Antioxidant enzymes, such as superoxide dismutase (SOD) and catalase, were decreased. Similarly, in an in vitro system, exposure of CRL-1807 to carcinogenic metals increased reactive oxygen species (ROS) generation, the expression of β-catenin, phospho-GSK, and NOX1. Inhibition of ROS generation by addition of SOD or catalase inhibited β-catenin expression and activity. Our study provides a new animal model to study the carcinogenicity of As(III) and Cr(VI) and suggests that As(III) and Cr(VI) promote colorectal cancer tumorigenesis, at least partly, through ROS-mediated Wnt/β-catenin signaling pathway.
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http://dx.doi.org/10.1016/j.taap.2012.04.014 | DOI Listing |
Mikrochim Acta
December 2024
Department of Chemistry, Yazd University, Yazd, 89195-741, Iran.
An electrochemical aptasensor has been developed specifically for the sensitive and selective determination of ochratoxin A (OTA), one of the most important mycotoxins. The aptasensor utilizes a glassy carbon electrode that has been modified with toluidine blue (TB) encapsulated in a Zn-based metal-organic framework (TB@Zn-MOF). The results demonstrate that in the presence of OTA, the peak current of the differential pulse voltammogram (DPV) related to TB oxidation is notably decreased.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Wise Laboratory for Environmental and Genetic Toxicology, Department of Pharmacology and Toxicology, University of Louisville, 500 S Preston Street, Building 55A, Room 1422, Louisville, KY 40292, United States. Electronic address:
Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread exposure. How Cr(VI) causes cancer is poorly understood, but chromosome instability plays a central role. Inhibition of DNA repair pathways leads to chromosome instability; however, despite the importance of these pathways in the mechanism of Cr(VI)-induced lung carcinogenesis, there are no data considering in-depth analysis on the transcriptional changes of genes involved in them.
View Article and Find Full Text PDFJ Contam Hydrol
December 2024
School of Biosciences, The University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S10 2TN, United Kingdom.
This study analyzed surface water from the River Swat, Pakistan, using inductively coupled plasma mass spectrometry, multivariate statistical techniques, and US-EPA risk assessment models to evaluate the concentrations, distribution, pathways, and potential risks of arsenic (As) and heavy metals, including chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg), and lead (Pb). The results revealed significant correlations (p ≤ 0.01) among metals that indicated common pollution sources, likely influenced by anthropogenic point and non-point activities.
View Article and Find Full Text PDFMar Pollut Bull
December 2024
BCSIR Laboratories Dhaka, Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka 1205, Bangladesh; Cental Analytical Research Facilities (CARF), Bangladesh Council of Scientific and Industrial, Dr Qudrat-i-Khuda Road, Dhanmondi, Dhaka 1205, Bangladesh. Electronic address:
The Payra River, cicual for fish breeding, feeding and nursery in coastal Bangladesh, faces heavy contamination from industrial activities, agricultural runoff and poor waste management. This study used ICP-MS to assess metal contamination levels, risk status and potential sources in river sediment. The findings showed that the mean concentrations (mg/kg) of metals followed the decreasing order: Mn (434.
View Article and Find Full Text PDFEnviron Health Insights
December 2024
Faculty of Health and Life Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK.
The growing use of artificial turf in place of natural turf in residential, recreational and commercial settings has raised concerns regarding its potential impact on human health. A systematic review of databases revealed 5673 articles of which, 30 were deemed eligible. Those performing total concentration analyses, bioaccessibility analyses or human health risk assessments (HHRAs) of artificial turf fibres or crumb rubber infill were of interest.
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